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Chen T, Wang Y, Zhang Y. Thermal Decomposition Mechanism of P(DAC-AM) with Serial Cationicity and Intrinsic Viscosity. Polymers (Basel) 2024; 16:1522. [PMID: 38891468 PMCID: PMC11174957 DOI: 10.3390/polym16111522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 05/13/2024] [Accepted: 05/20/2024] [Indexed: 06/21/2024] Open
Abstract
The thermal decomposition of the thermodynamic, kinetic and mechanisms of copolymer P(DAC-AM) samples with serial cationicity and intrinsic viscosity ([η]), and the control samples of homopolymer PAM and PDAC, were studied and analyzed using TG, DSC, FTIR. The results of the thermal decomposition thermodynamics confirmed that the thermal decomposition processes of the serial P(DAC-AM) samples and the two control samples could be divided into two stages. It was found that the processes of the copolymer P(DAC-AM) samples were not a simple superposition of those of homopolymers, whose monomers had composed the unit structures of the copolymer, but there were interactions between the two suspension groups. The results of thermal decomposition kinetics showed that the apparent activation energy (E) of the thermal decomposition process of all polymer samples had different varying trends in the terms of weight-loss rate (α). The reaction order (n) of the thermal decomposition of P(DAC-AM) in Stage I and II was close to 1, but in the former and the latter it tended to be 2 and 0.5, respectively. Finally, the thermal decomposition mechanism of copolymer P(DAC-AM) samples was discussed. The above research could not only fill in the knowledge vacancy of the thermal decomposition of the thermodynamic, kinetic and mechanisms of P(DAC-AM), but could also lay a foundation for the study of thermal decomposition mechanisms of the other types of polymers, including cationic polymers.
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Affiliation(s)
- Tingting Chen
- School of Chemistry and Chemical Engineering, Nanjing University of Science & Technology, Nanjing 210094, China; (T.C.); (Y.W.)
- Shaanxi Coal Chemical Industry Technology Research Institute Co., Ltd., Xi’an 710100, China
| | - Yongji Wang
- School of Chemistry and Chemical Engineering, Nanjing University of Science & Technology, Nanjing 210094, China; (T.C.); (Y.W.)
- School of Chemistry and Material Engineering, Chaohu University, Chaohu 238024, China
| | - Yuejun Zhang
- School of Chemistry and Chemical Engineering, Nanjing University of Science & Technology, Nanjing 210094, China; (T.C.); (Y.W.)
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2
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Li Y, Yao S, Dong X, Fan Y, Ma X, Zhu B, Chang M. Preparation of a Lignin-Based Cationic Flocculant and Its Application in Kaolin Suspension Treatment. Polymers (Basel) 2024; 16:1131. [PMID: 38675049 PMCID: PMC11054052 DOI: 10.3390/polym16081131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 04/11/2024] [Accepted: 04/12/2024] [Indexed: 04/28/2024] Open
Abstract
The preparation of an environmentally friendly and efficient flocculant for solid-liquid separation in industrial wastewater is highly important. In this study, a novel cationic flocculant (AL-g-PAMA) was synthesized by a thermal initiation method using alkali lignin (AL) as the main chain and acrylamide (AM) and methacrylamido propyl trimethyl ammonium chloride (MAPTAC) as the grafted side chains. The structure, thermal stability, and surface morphology of the copolymers were investigated by various characterization methods. The results indicated the successful synthesis of AL-g-PAMA. AL-g-PAMA was applied to improve solid-liquid separation in kaolin suspensions. The results showed that AL-g-PAMA had excellent flocculation-sedimentation and dewatering efficiency. When the dosage of AL-g-PAMA #5 was 600.0 g/t(s), the thickness of the compressed layer was 2.2 cm, the floc settling velocity was 24.1 cm/min, and the transmittance of the supernatant was 84.0%. The moisture content of the filter cake decreased from 55.0% to 43.4% after treatment with AL-g-PAMA #5. The results of zeta potential and focused beam reflectance measurement (FBRM) analysis indicated that bridging and electroneutralization were the main flocculation mechanisms. Therefore, this study extends the potential for using lignin as a bioflocculant and provides a feasible approach to efficiently purify high-turbidity wastewater.
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Affiliation(s)
- Yan Li
- College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Suling Yao
- College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Xianshu Dong
- College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Yuping Fan
- College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Xiaomin Ma
- College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China
- State Key Laboratory of Mineral Processing, Beijing 100160, China
| | - Benkang Zhu
- College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Ming Chang
- College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China
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Phonlakan K, Pornsuwan S, Nijpanich S, Budsombat S. Co 2+-adsorbed chitosan-grafted-poly(acrylic acid) hydrogel as peroxymonosulfate activator for effective dye degradation. Int J Biol Macromol 2024; 265:130922. [PMID: 38518932 DOI: 10.1016/j.ijbiomac.2024.130922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 03/13/2024] [Accepted: 03/14/2024] [Indexed: 03/24/2024]
Abstract
In this work, chitosan-grafted-poly(acrylic acid) (CS-g-PAA) was synthesized for use as a Co2+ adsorbent and circularly utilized as a peroxymonosulfate (PMS) activator in the degradation of rhodamine B (RhB) dye. CS-g-PAA demonstrated 3.7 times higher adsorption capacity toward Co2+ than pristine chitosan. The impact of the adsorption conditions was evaluated. The pseudo-second-order kinetic model and the Langmuir isotherm model best described the adsorption process. Under optimum conditions, the adsorption capacity of CS-g-PAA for Co2+ was 212 mg/g. The Co2+-adsorbed CS-g-PAA hydrogel was further utilized in the RhB degradation process. The effects of catalyst dosage, initial RhB concentration, pH, and the coexistence of anions on the degradation of RhB were studied. The hydrogel catalyst could remove 98 % of RhB within 5 min, at a degradation rate of 0.624 per min. Electron paramagnetic resonance (EPR) analysis and the radical scavenger experiment suggested that SO4•-, HO•, 1O2, and O2•- were involved in the degradation. Furthermore, when tested in various water systems, high degradation efficiencies of 98 % were attained after 20 min. The hydrogel catalyst performed excellent degradation over ten cycles without any chemical recovery processes. Moreover, high degradation efficiencies were observed between 95 % and 98 % when tested with other dyes.
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Affiliation(s)
- Kunlarat Phonlakan
- Department of Chemistry and Center of Excellence for Innovation in Chemistry, Materials Chemistry Research Center, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Soraya Pornsuwan
- Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Mahidol University, 272 Rama VI Rd., Ratchathewi, Bangkok 10400, Thailand
| | - Supinya Nijpanich
- Synchrotron Light Research Institute (Public organization), Nakhonratchasima 30000, Thailand
| | - Surangkhana Budsombat
- Department of Chemistry and Center of Excellence for Innovation in Chemistry, Materials Chemistry Research Center, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand.
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4
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Wu H, Shen W, Zhao Q, Zhang W. Synthesis of chitosan-based flocculant by dielectric barrier discharge modification and its flocculation performance in wastewater treatment. RSC Adv 2024; 14:2410-2421. [PMID: 38223699 PMCID: PMC10785050 DOI: 10.1039/d3ra06265a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 01/04/2024] [Indexed: 01/16/2024] Open
Abstract
As a typical type of organic flocculant, chitosan is limited by its poor water solubility and narrow pH range application. Grafting modification can improve chitosan's solubility and availability through linking macromolecular chains with other types of water-soluble groups or functional side groups. In this study, dielectric barrier discharge (DBD) was used to active the surface of chitosan, then activated chitosan was polymerized with acrylamide to synthesize a chitosan-based flocculant, chitosan-acrylamide (CS-AM). During the synthesis of CS-AM, the optimal conditions were determined as follows: discharge time of 5 min, discharge power of 60 W, total monomer mass concentration of 80 g L-1, polymerization time of 3 h, polymerization temperature of 70 °C, and m(CS) : m(AM) ratio of 1 : 3. The structure and morphological characteristics of CS-AM were investigated and analyzed by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), thermogravimetric (TG) analysis, scanning electron microscopy (SEM), X-ray diffraction (XRD) and N2 physical adsorption, respectively. The removal efficiency of kaolin suspension and CNTs suspension can reach up to 95.9% and 90.2% after flocculation of CS-AM. Furthermore, the zeta potential of the supernatant from the CS-AM treated kaolin suspension at different pH values was examined, and the flocculation mechanism of CS-AM was analyzed. This study provides new ideas for the preparation and development of modified chitosan and broadens its application in water treatment.
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Affiliation(s)
- Haixia Wu
- College of Urban Construction, Nanjing Tech University Nanjing 211816 China
| | - Wang Shen
- College of Urban Construction, Nanjing Tech University Nanjing 211816 China
| | - Quanfa Zhao
- College of Urban Construction, Nanjing Tech University Nanjing 211816 China
| | - Weiwei Zhang
- College of Urban Construction, Nanjing Tech University Nanjing 211816 China
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5
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Zhou X, Jiao J, Jiao W, Wang R. Oxidative desulfurization of model oil over the bowl-shaped N-doped carbon material loaded by the defective silicotungstic acid. Sep Purif Technol 2023. [DOI: 10.1016/j.seppur.2023.123180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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6
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Li L, Peng C, Zhan Z, Ma F, Zhang J. A novel treatment for amelioration of sludge dewaterability using green starch-grafted flocculant and realized mechanism. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.122060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Choi S, Park A, Seo D, Lee WB, Nam KM, Kim Y, Chang J. Redox-Transition from Irreversible to Reversible Vitamin C by Pore Confinement in Microporous Carbon Network. ACS APPLIED MATERIALS & INTERFACES 2022; 14:36557-36569. [PMID: 35917313 DOI: 10.1021/acsami.2c07719] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Enhancement of redox-reversibility in electroactive species has been studied because of fundamental interest and their importance for energy storage systems. Various electroactive molecules suffer from redox-irreversible behavior, and this is a critical reason for their exclusion as redox electrolytes in energy storage systems. In this article, we fully demonstrated that ascorbic acid (ASC), which is an abundant but redox-irreversible molecule, can become redox-reversible when it is confined in microporous carbon regimes. From a theoretical perspective, redox-reversibility in an electrochemical reaction coupled with an irreversible chemical process can be greatly enhanced due to kinetic acceleration toward the inverse direction of the chemical reaction by accumulation of products in the nanoconfined regime. However, the kinetic acceleration in a nanoconfined domain shows limitations for enhancing the redox-reversibility, which indicates that stabilization of the species undergoing an irreversible chemical process is another important factor for redox-reversibility enhancement. The origin of nanoporous confinement of ASC and its enhanced redox-reversibility was rationalized by molecular dynamics simulations. We found that ASC-clusters of a fully protonated ASC and its conjugated base formed inside carbon pores, which would be a main driving force for its confinement in microporous carbon networks. Lastly, we demonstrated a prototype energy storage device using redox-reversible ASC in microporous carbon as the half electrode, which shows the feasibility of ASC as a possible redox electrolyte in an aqueous energy storage system.
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Affiliation(s)
- Sarah Choi
- Department of Chemistry and Research Institute for Convergence of Basic Science, Hanyang University, Seoul 04763, Republic of Korea
| | - Anseong Park
- Department of Chemical and Biological Engineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Dongho Seo
- Department of Chemistry and Chemistry Institute of Functional Materials, Pusan National University, Busan 46241, Republic of Korea
| | - Won Bo Lee
- Department of Chemical and Biological Engineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Ki Min Nam
- Department of Chemistry and Chemistry Institute of Functional Materials, Pusan National University, Busan 46241, Republic of Korea
| | - YongJoo Kim
- School of Advanced Materials Engineering, Kookmin University, Seoul 02707, Republic of Korea
| | - Jinho Chang
- Department of Chemistry and Research Institute for Convergence of Basic Science, Hanyang University, Seoul 04763, Republic of Korea
- Department of HY-KIST Bio-convergence, Hanyang University, Seoul 04763, Republic of Korea
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Xia J, Rao T, Ji J, He B, Liu A, Sun Y. Enhanced Dewatering of Activated Sludge by Skeleton-Assisted Flocculation Process. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19116540. [PMID: 35682124 PMCID: PMC9180161 DOI: 10.3390/ijerph19116540] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 05/20/2022] [Accepted: 05/24/2022] [Indexed: 02/06/2023]
Abstract
Sludge dewatering is the fundamental process of sludge treatment. Environmentally friendly and efficient sludge conditioning methods are the premises of sludge to achieve dehydration reduction and resource utilization. In response to sewage plant sludge dehydration, fly ash (FA), polymerized aluminum chloride (PAC), and polymer sulfate (PFS) were studied separately to determine their sludge dehydration performance, and the effects of these three conditioner composite regulations on sludge dehydration properties were studied. Compared to the sludge treated only with conditioner, the average particle size of floc increased and the organic matter content in the filtrate decreased. The sludge dewatering efficiency after the conditioning effect is better than that after conditioning a single conditioner. After PFS conditioning with fly ash, the water content and specific resistance (SRF) of the sludge cake can be reduced to 76.39% and 6.63 × 1010 m/kg, respectively. The moisture content and specific resistance (SRF) of the sludge cake can be reduced to 76.10% and 6.91 × 1010 m/kg, respectively. The pH of the sludge and filtrate changed slightly after PAC conditioning with fly ash coupling. These results indicate that fly-ash coupled with PAC and fly-ash coupled with PFS are expected to become a novel and effective environmental protection combined conditioning method for sludge dewatering.
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Affiliation(s)
- Jiahua Xia
- Nanjing Jiangbei New Area Public Utilities Holding Group Co., Ltd., Nanjing 210044, China; (J.X.); (T.R.); (J.J.); (B.H.)
| | - Ting Rao
- Nanjing Jiangbei New Area Public Utilities Holding Group Co., Ltd., Nanjing 210044, China; (J.X.); (T.R.); (J.J.); (B.H.)
| | - Juan Ji
- Nanjing Jiangbei New Area Public Utilities Holding Group Co., Ltd., Nanjing 210044, China; (J.X.); (T.R.); (J.J.); (B.H.)
| | - Bijuan He
- Nanjing Jiangbei New Area Public Utilities Holding Group Co., Ltd., Nanjing 210044, China; (J.X.); (T.R.); (J.J.); (B.H.)
| | - Ankang Liu
- Nanjing Water Purification Environmental Research Institute Co., Ltd., Nanjing 211100, China;
| | - Yongjun Sun
- College of Urban Construction, Nanjing Tech University, Nanjing 211800, China
- Correspondence:
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9
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Chunming Wang, Huang Z, Lee X, Tang Y, Zeng L, Chen Y. Screening of Composite Flocculants for Food Wastewater Treatment. J WATER CHEM TECHNO+ 2022. [DOI: 10.3103/s1063455x22020102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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10
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Sun Y, Yu Y, Zhou S, Shah KJ, Sun W, Zhai J, Zheng H. Functionalized chitosan-magnetic flocculants for heavy metal and dye removal modeled by an artificial neural network. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2021.120002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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11
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Maćczak P, Kaczmarek H, Ziegler-Borowska M, Węgrzynowska-Drzymalska K, Burkowska-But A. The Use of Chitosan and Starch-Based Flocculants for Filter Backwash Water Treatment. MATERIALS 2022; 15:ma15031056. [PMID: 35161001 PMCID: PMC8838026 DOI: 10.3390/ma15031056] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/18/2022] [Accepted: 01/25/2022] [Indexed: 11/16/2022]
Abstract
Inorganic aluminum or iron salts supported with synthetic polymers are commonly used to eradicate colloidal particles from water in coagulation and flocculation processes. Nevertheless, these agents have several disadvantages, such as large volumes of sludge produced or environmental toxicity. Recently biodegradable polymers have been suggested as eco-friendly flocculants for water treatment. This study aimed to investigate the possibilities of using starch and chitosan and their oxidized derivatives as flocculants for filter backwash water treatment. Dialdehyde starch (DST) and dialdehyde chitosan (DCT) were synthesized by periodate oxidization of natural starch from corn and low molecular weight chitosan. The obtained materials have been characterized with scanning electron microscopy (SEM), ATR-FTIR spectroscopy, and thermogravimetric analysis (TGA). Furthermore, we studied the flocculation properties of polysaccharide flocculants in a series of jar tests. The effectiveness of chitosan and starched-based flocculants was compared to synthetic polymers commonly used to treat iron ions-rich filter backwash water. The environmental aspects of these chemicals, particularly the biodegradability of post-flocculation residues, were also addressed. It was found that oxidized starch and chitosan derivatives can be used as ecological flocculating materials to treat potable water or sludge.
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Affiliation(s)
- Piotr Maćczak
- Faculty of Chemistry, Nicolaus Copernicus University in Toruń, Gagarina 7, 87-100 Torun, Poland; (M.Z.-B.); (K.W.-D.)
- Water Supply and Sewage Enterprise LLC, Przemysłowa 4, 99-300 Kutno, Poland
- Correspondence: (P.M.); (H.K.)
| | - Halina Kaczmarek
- Faculty of Chemistry, Nicolaus Copernicus University in Toruń, Gagarina 7, 87-100 Torun, Poland; (M.Z.-B.); (K.W.-D.)
- Correspondence: (P.M.); (H.K.)
| | - Marta Ziegler-Borowska
- Faculty of Chemistry, Nicolaus Copernicus University in Toruń, Gagarina 7, 87-100 Torun, Poland; (M.Z.-B.); (K.W.-D.)
| | | | - Aleksandra Burkowska-But
- Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Torun, Poland;
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12
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Advanced Treatment of Phosphorus Pesticide Wastewater Using an Integrated Process of Coagulation and Ozone Catalytic Oxidation. Catalysts 2022. [DOI: 10.3390/catal12010103] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Conventional pretreatment and secondary biochemical treatment are ineffective methods for removing phosphorus from phosphorus-containing pesticide wastewater. In this study, coagulation-coupled ozone catalytic oxidation was used to treat secondary biochemical tailwater of phosphorus-containing pesticide wastewater thoroughly. The effects of the coagulant type, coagulant dosage, coagulant concentration, wastewater pH, stirring rate, and stirring time on the removal efficiency of chemical oxygen demand (COD), total phosphorus (TP), and chromaticity were investigated during coagulation. When the dosage of the coagulant PAFS was equal to 100 mg/L, the concentration of the coagulant, pH, stirring rate, and stirring time were 5 wt%, 8, 100 rpm, and 5 min, respectively, and the removal rates of COD, TP, and chroma in wastewater reached the maximum value of 17.6%, 86.8%, and 50.0%, respectively. Effluent after coagulation was treated via ozone catalytic oxidation. When the respective ozone dosage, H2O2 dosage, catalyst dosage, and reaction time were 120 mg/L, 0.1 vt‰, 10 wt%, and 90 min, residual COD and chromaticity of the final effluent were 10.3 mg/L and 8, respectively. The coagulation-coupled ozone catalytic oxidation process has good application prospects in the treatment of secondary biochemical tailwater from phosphorus-containing pesticide wastewater.
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Sun Y, Li D, Lu X, Sheng J, Zheng X, Xiao X. Flocculation of combined contaminants of dye and heavy metal by nano-chitosan flocculants. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 299:113589. [PMID: 34467861 DOI: 10.1016/j.jenvman.2021.113589] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 08/15/2021] [Accepted: 08/20/2021] [Indexed: 06/13/2023]
Abstract
In this study, two multifunctional nano-chitosan flocculants (CPAM-NCS1 and CPAM-NCS2) were made through the graft modification of cationic monomer and carboxymethylchitosan (CMCTS) to remove combined contaminants. The effects of various factors (pH, flocculant dosage and hydraulic mixing conditions) on the flocculation performance under single and composite pollution conditions were systematically investigated, the optimal chemical oxygen demand (COD) and the chromaticity removal rates in the dye wastewater were 79.9% and 83.9% at wastewater pH 7, the fast stirring rate 300 rpm, the fast stirring time 8 min, and the dosage of CPAM-NCS1 80 mg/L, respectively. The optimal removal rates of Cu (II) obtained by CPAM-NCS1 and CPAM-NCS2 at were 80.3% and 75.2% at 60 mg/L and the wastewater pH 7, respectively. The optimal removal rates of Cu (II) and disperse orange were 85.3% and 89.4%, respectively, in a composite pollutant system in which Cu (II) and disperse orange coexisted when the pH of the composite system was 9 and the dosage of CPAM -NCS1 was 60 mg/L. This study proved that nanoflocculants made by modifying CMCTS with different structures can demonstrate ideal flocculation removal performance for dye and heavy metal wastewaters.
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Affiliation(s)
- Yongjun Sun
- College of Urban Construction, Nanjing Tech University, Nanjing, 211800, China.
| | - Deng Li
- College of Urban Construction, Nanjing Tech University, Nanjing, 211800, China
| | - Xi Lu
- Jiangsu Key Laboratory of Industrial Water-Conservation & Emission Reduction, College of Environment, Nanjing Tech University, Nanjing, 211800, China
| | - Jinwei Sheng
- College of Urban Construction, Nanjing Tech University, Nanjing, 211800, China
| | - Xing Zheng
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Xuefeng Xiao
- College of Urban Construction, Nanjing Tech University, Nanjing, 211800, China
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15
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Chen Y, Li X, Zizeng W, Feng L, Xie J, Lin Z, Xu Z, Liu B, Li X, Zheng H. Research on a new cationic polyacrylamide (CPAM) with a cationic microblock structure and its enhanced effect on sludge condition and dewatering. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:51865-51878. [PMID: 33990923 DOI: 10.1007/s11356-021-14325-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 05/03/2021] [Indexed: 06/12/2023]
Abstract
Flocculation is one of the commonly used sludge conditioning methods in water supply plants, which can improve the sludge dewatering performance by reducing the specific resistance of sludge (SRF), decreasing the amount of sludge, and finally lowering the transportation cost and subsequent disposal cost of sludge. Therefore, it is particularly important to develop new and efficient flocculants. In this paper, the template copolymer of acryloxy trimethylammonium chloride (DAC) and acrylamide (AM) was successfully synthesized by microwave-template copolymerization (MV-TP) using sodium polyacrylate (NaPAA) as template. The template copolymer was analyzed by infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance hydrogen spectroscopy (1H NMR), and scanning electron microscopy (SEM). It was found that this template copolymer had obvious cationic microblock structure. In addition, the test results of association constant (KM) and polymerization kinetics showed that the MW-TP was assigned to free radical initiated polymerization and the polymerization mechanism was I Zip-up (ZIP). It confirmed the formation of cation fragment structure again. Due to its dense positive charges in this new cationic microblock structure, it greatly improved the functions of electric neutralization, electrical patching, and adsorption bridging. The cationic fragment structure in the template copolymer could help to generate large and dense floc structure and form stable drainage channels. Under external pressure, these large and compact floc structures had greater compressive resistance, which avoided deformation and blockage of drainage channels and voids. It was beneficial to reduce SRF and evidently enhanced sludge dewatering performance.
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Affiliation(s)
- Yuning Chen
- School of Civil and Transportation Engineering, Guangdong University of Technology, No 100, Waihuan Xi Road, Higher Education Mega Center, Panyu District, Guangzhou, 510006, Guangdong, People's Republic of China
| | - Xuhao Li
- School of Civil and Transportation Engineering, Guangdong University of Technology, No 100, Waihuan Xi Road, Higher Education Mega Center, Panyu District, Guangzhou, 510006, Guangdong, People's Republic of China
| | - Wang Zizeng
- School of Civil and Transportation Engineering, Guangdong University of Technology, No 100, Waihuan Xi Road, Higher Education Mega Center, Panyu District, Guangzhou, 510006, Guangdong, People's Republic of China
| | - Li Feng
- School of Civil and Transportation Engineering, Guangdong University of Technology, No 100, Waihuan Xi Road, Higher Education Mega Center, Panyu District, Guangzhou, 510006, Guangdong, People's Republic of China.
| | - Jiehong Xie
- School of Civil and Transportation Engineering, Guangdong University of Technology, No 100, Waihuan Xi Road, Higher Education Mega Center, Panyu District, Guangzhou, 510006, Guangdong, People's Republic of China
| | - Zeluan Lin
- School of Civil and Transportation Engineering, Guangdong University of Technology, No 100, Waihuan Xi Road, Higher Education Mega Center, Panyu District, Guangzhou, 510006, Guangdong, People's Republic of China
| | - Zhihong Xu
- School of Civil and Transportation Engineering, Guangdong University of Technology, No 100, Waihuan Xi Road, Higher Education Mega Center, Panyu District, Guangzhou, 510006, Guangdong, People's Republic of China
| | - Bingzhi Liu
- School of Civil and Transportation Engineering, Guangdong University of Technology, No 100, Waihuan Xi Road, Higher Education Mega Center, Panyu District, Guangzhou, 510006, Guangdong, People's Republic of China
| | - Xiang Li
- School of Civil Engineering and Architecture, Chongqing University of Science and Technology, Chongqing, 401331, China
- Chongqing Key Laboratory of Energy Engineering Mechanics & Disaster Prevention and Mitigation, Chongqing, 401331, China
| | - Huaili Zheng
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China
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Xiao X, Yu Y, Sun Y, Zheng X, Chen A. Heavy metal removal from aqueous solutions by chitosan-based magnetic composite flocculants. J Environ Sci (China) 2021; 108:22-32. [PMID: 34465434 DOI: 10.1016/j.jes.2021.02.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 02/07/2021] [Accepted: 02/09/2021] [Indexed: 06/13/2023]
Abstract
In this study, three magnetic flocculants with different chelating groups, namely, carboxymethyl chitosan-modified Fe3O4 flocculant (MC), acrylamide-grafted magnetic carboxymethyl chitosan flocculant (MCM), and 2-acrylamide-2-methylpropanesulfonic acid copolyacrylamide-grafted magnetic carboxymethyl chitosan flocculant (MCAA) were prepared, synthesized, and characterized by photopolymerization technology. They were applied to the flocculation removal of Cr(III), Co(II), and Pb(II). The effect of flocculation condition on the removal performance of Cr(III), Co(II), and Pb(II) was studied. Characterization results show that the three magnetic carboxymethyl chitosan-based flocculants have been successfully prepared with good magnetic induction properties. Flocculation results show that the removal rates of MC, MCM, and MCAA on Cr(III) are 51.79%, 82.33%, and 91.42%, respectively, under the conditions of 80 mg/L flocculant, pH value of 6, reaction time of 1.5 hr, G value of 200 s-1, and precipitation magnetic field strength of 120 mT. The removal rates of Co(II) by MC, MCM, and MCAA are 54.33%, 84.99%, and 90.49%, respectively. The removal rates of Pb(II) by MC, MCM, and MCAA are 61.54%, 91.32%, and 95.74%, respectively. MCAA shows good flocculation performance in composite heavy metal-simulated wastewater. The magnetic carboxymethyl chitosan-based flocculant shows excellent flocculation performance in removing soluble heavy metals. This research provides guidance and ideas for the development of efficient and low-cost flocculation technology to remove heavy metals in wastewater.
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Affiliation(s)
- Xuefeng Xiao
- College of Urban Construction, Nanjing Tech University, Nanjing 211800, China
| | - Yuanyuan Yu
- College of Urban Construction, Nanjing Tech University, Nanjing 211800, China
| | - Yongjun Sun
- College of Urban Construction, Nanjing Tech University, Nanjing 211800, China.
| | - Xing Zheng
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong 999077, China
| | - Aowen Chen
- College of Urban Construction, Nanjing Tech University, Nanjing 211800, China
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17
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Zhang Y, Zhao M, Cheng Q, Wang C, Li H, Han X, Fan Z, Su G, Pan D, Li Z. Research progress of adsorption and removal of heavy metals by chitosan and its derivatives: A review. CHEMOSPHERE 2021; 279:130927. [PMID: 34134444 DOI: 10.1016/j.chemosphere.2021.130927] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 05/12/2021] [Accepted: 05/12/2021] [Indexed: 06/12/2023]
Abstract
Chitosan has received widespread attention as an adsorbent for pollutants because of its low cost and great adsorption potentials. Chitosan has abundant hydroxyl and amino groups that can bind heavy metal ions. However, it has defects such as sensitivity to pH, low thermal stability, and low mechanical strength, which limit the application of chitosan in wastewater treatment. The functional groups of chitosan can be modified to improve its performance via crosslinking and graft modification. The porosity and specific surface area of chitosan in powder form are not ideal, therefore, physical modification has been attempted to generate chitosan nanoparticles and hydrogel. Chitosan has also been integrated with other materials (e.g. graphene, zeolite) resulting in composite materials with improved adsorption performance. This review mainly focuses on reports about the application of chitosan and its derivatives to remove different heavy metals. The preparation strategy, adsorption mechanism, and factors affecting the adsorption performance of adsorbents for each type of heavy metal are discussed in detail. Recent reports on important organic pollutants (dyes and phenol) removal by chitosan and its derivatives are also briefly discussed.
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Affiliation(s)
- Yuzhe Zhang
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, China
| | - Meiwen Zhao
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, China
| | - Qian Cheng
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, China
| | - Chao Wang
- Jiangsu Longhuan Environmental Science Co. LTD, Changzhou, 213164, China
| | - Hongjian Li
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, China
| | - Xiaogang Han
- Changzhou Qingliu Environmental Protection Technology Co. LTD, Changzhou, 213000, China
| | - Zhenhao Fan
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, China
| | - Gaoyuan Su
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, China
| | - Deng Pan
- School of Global Affairs, King's College London, WC2R 2LS, London, United Kingdom.
| | - Zhongyu Li
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, China; Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, 213164, China; Advanced Catalysis and Green Manufacturing Collaborative Innovation Center, Changzhou University, Changzhou, 213164, China.
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Khairul Zaman N, Rohani R, Izni Yusoff I, Kamsol MA, Basiron SA, Abd. Rashid AI. Eco-Friendly Coagulant versus Industrially Used Coagulants: Identification of Their Coagulation Performance, Mechanism and Optimization in Water Treatment Process. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:9164. [PMID: 34501755 PMCID: PMC8430898 DOI: 10.3390/ijerph18179164] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/21/2021] [Accepted: 08/23/2021] [Indexed: 02/02/2023]
Abstract
The evaluation of complex organic and inorganic coagulant's performances and their relationships could compromise the surface water treatment process time and its efficiency. In this work, process optimization was investigated by comparing an eco-friendly chitosan with the industrially used coagulants namely aluminum sulfate (alum), polyaluminum chloride (PAC), and aluminum chlorohydrate (ACH) in compliance with national drinking water standards. To treat various water samples from different treatment plants with turbidity and pH ranges from 20-826.3 NTU and 5.21-6.80, respectively, 5-20 mg/L coagulant dosages were varied in the presence of aluminum, ferum, and manganese. Among all, 10 mg/L of the respective ACH and chitosan demonstrated 97% and 99% turbidity removal in addition to the removal of the metals that complies with the referred standard. However, chitosan owes fewer sensitive responses (turbidity and residual metal) with the change in its input factors (dosage and pH), especially in acidic conditions. This finding suggested its beneficial role to be used under the non-critical dosage monitoring. Meanwhile, ACH was found to perform better than chitosan only at pH > 7.4 with half dosage required. In summary, chitosan and ACH could perform equally at a different set of optimum conditions. This optimization study offers precise selections of coagulants for a practical water treatment operation.
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Affiliation(s)
- Nadiah Khairul Zaman
- Department of Chemical & Process Engineering, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia, UKM, Bangi 43600, Malaysia; (N.K.Z.); (I.I.Y.); (M.A.K.); (S.A.B.)
| | - Rosiah Rohani
- Department of Chemical & Process Engineering, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia, UKM, Bangi 43600, Malaysia; (N.K.Z.); (I.I.Y.); (M.A.K.); (S.A.B.)
- Research Centre for Sustainable Process Technology, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia, UKM, Bangi 43600, Malaysia
| | - Izzati Izni Yusoff
- Department of Chemical & Process Engineering, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia, UKM, Bangi 43600, Malaysia; (N.K.Z.); (I.I.Y.); (M.A.K.); (S.A.B.)
| | - Muhammad Azraei Kamsol
- Department of Chemical & Process Engineering, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia, UKM, Bangi 43600, Malaysia; (N.K.Z.); (I.I.Y.); (M.A.K.); (S.A.B.)
| | - Siti Aishah Basiron
- Department of Chemical & Process Engineering, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia, UKM, Bangi 43600, Malaysia; (N.K.Z.); (I.I.Y.); (M.A.K.); (S.A.B.)
- Makmal Pusat, Syarikat Air Melaka Berhad, Jalan Padang Keladi, Durian Tunggal, Melaka 76100, Malaysia
| | - Aina Izzati Abd. Rashid
- Department of Civil Engineering, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia, UKM, Bangi 43600, Malaysia;
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19
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Xiao X, Sun Y, Liu J, Zheng H. Flocculation of heavy metal by functionalized starch-based bioflocculants: Characterization and process evaluation. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2021.118628] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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20
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Preparation and Characterization of High-Efficiency Magnetic Heavy Metal Capture Flocculants. WATER 2021. [DOI: 10.3390/w13131732] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
In this study, a high-efficiency magnetic heavy metal flocculant MF@AA was prepared based on carboxymethyl chitosan and magnetic Fe3O4. It was characterized by SEM, FTIR, XPS, XRD and VSM, and the Cu(II) removal rate was used as the evaluation basis for the preparation process. The effects of AMPS content, total monomer concentration, photoinitiator concentration and reaction time on the performance of MF@AA flocculation to remove Cu(II) were studied. The characterization results show that MF@AA has been successfully prepared and exhibits good magnetic induction characteristics. The synthesis results show that under the conditions of 10% AMPS content, 35% total monomer concentration, 0.04% photoinitiator concentration, and 1.5 h reaction time, the best yield of MF@AA is 77.69%. The best removal rate is 87.65%. In addition, the response surface optimization of the synthesis process of MF@AA was performed. The optimal synthesis ratio was finally determined as iron content 6.5%, CMFS: 29.5%, AM: 53.9%, AMPS: 10.1%. High-efficiency magnetic heavy metal flocculant MF@AA shows excellent flocculation performance in removing Cu(II). This research provides guidance and ideas for the development of efficient and low-cost flocculation technology to remove Cu(II) in wastewater.
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21
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Sun Y, Yu Y, Zheng X, Chen A, Zheng H. Magnetic flocculation of Cu(II) wastewater by chitosan-based magnetic composite flocculants with recyclable properties. Carbohydr Polym 2021; 261:117891. [PMID: 33766376 DOI: 10.1016/j.carbpol.2021.117891] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 02/07/2021] [Accepted: 03/01/2021] [Indexed: 12/17/2022]
Abstract
In this study, three magnetic flocculants, namely, MC, MC-g-PAM, and MC-g-PAA, were prepared. The structure characteristics, flocculation performance, and floc characteristics of the three magnetic flocculants were systematically studied and compared. SEM, FT-IR, XPS, XRD, TG-DSC, and VSM characterization results show that MC, MC-g-PAM, and MC-g-PAA are successfully prepared and exhibit good magnetic induction. The removal rates of copper ions by MC, MC-g-PAM, and MC-g-PAA under the optimal coagulation conditions are 93.39 %, 88.64 %, and 61.41 %, respectively. Kinetic fitting shows that the flocculation reaction process of MC and MC-g-PAM conforms to pseudo first-order kinetics, while the flocculation reaction process of MC-g-PAA conforms to pseudo second-order kinetics. The flocs produced by MC-g-PAA have larger particle size and fractal dimension than those by MC and MC-g-PAM. At 80 mg/L dosage and pH 6, the floc size and floc fractal dimension obtained by MC-g-PAA reach the maximum values of 48.28 um and 1.468, respectively. Zeta potential studies show that the flocculation functions of the three flocculants are mainly adsorption bridging, adsorption electric neutralization, and chelating precipitation. Recycling experiments show that MC-g-PAA has good recyclability, and the recovery rate after the fifth use is 77.24 % with the Cu(II) removal rate of 67.53 %.
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Affiliation(s)
- Yongjun Sun
- College of Urban Construction, Nanjing Tech University, Nanjing, 211800, China.
| | - Yuanyuan Yu
- College of Urban Construction, Nanjing Tech University, Nanjing, 211800, China
| | - Xing Zheng
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Aowen Chen
- College of Urban Construction, Nanjing Tech University, Nanjing, 211800, China
| | - Huaili Zheng
- College of Environemnt and Ecology, Chongqing University, Chongqing, 400045, China
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22
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Yu P, Li X, Zhang X, Zhou H, Xu Y, Sun Y, Zheng H. Insights into the glyphosate removal efficiency by using magnetic powder activated carbon composite. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2020.117662] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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23
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Sun W, Zhou S, Sun Y, Xu Y. Synthesis and evaluation of cationic flocculant P(DAC-PAPTAC-AM) for flocculation of coal chemical wastewater. J Environ Sci (China) 2021; 99:239-248. [PMID: 33183701 DOI: 10.1016/j.jes.2020.07.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 06/28/2020] [Accepted: 07/01/2020] [Indexed: 06/11/2023]
Abstract
In this study, a high-efficiency cationic flocculant, P(DAC-MAPTAC-AM), was successfully prepared using UV-induced polymerization technology. The monomer Acrylamide (AM): Acryloxyethyl Trimethyl ammonium chloride (DAC): methacrylamido propyl trimethyl ammonium chloride (MAPTAC) ratio, monomer concentration, photoinitiator concentration, urea content, and cationic monomer DAC:MAPTAC ratio, light time, and power of high-pressure mercury lamp were studied. The characteristic groups, characteristic diffraction peaks, and characteristic proton peaks of P(DAC-MAPTAC-AM) were confirmed by fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), 1H nuclear magnetic resonance spectrometer (1H NMR), and scanning electron microscopy (SEM). The effects of dosage, pH value, and velocity gradient (G) value on the removal efficiencies of turbidity, COD, ammonia nitrogen, and total phenol by poly aluminum ferric chloride (PAFC), P(DAC-MAPTAC-AM), and PAFC/P(DAC-MAPTAC-AM) in the flocculation treatment of coal chemical wastewater were investigated. Results showed that the optimal conditions for the flocculation of coal chemical wastewater using P(DAC-MAPTAC-AM) alone are as follows: dosage of 8-12 mg/L, G value of 100-250 s - 1, and pH value of 4-8. The optimal dosage of PAFC is 90-150 mg/L with a pH of 2-12. The optimal dosage for PAFC/P(DAC-MAPTAC-AM) is as follows: PAFC dosage of 90-150 mg/L, P(DAC-MAPTAC-AM) dosage of 8-12 mg/L, and pH range of 2-6. When P(DAC-MAPTAC-AM) was used alone, the optimal removal efficiencies of turbidity, COD, ammonia nitrogen, and total phenol were 81.0%, 35.0%, 75.0%, and 80.3%, respectively. PAFC has good tolerance to wastewater pH and good pH buffering. Thus, the flocculation treatment of coal chemical wastewater using the PAFC/P(DAC-MAPTAC-AM) compound also exhibits excellent resistance and buffering capacity.
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Affiliation(s)
- Wenquan Sun
- College of Urban Construction, Nanjing Tech University, Nanjing 211800, China
| | - Shengbao Zhou
- College of Urban Construction, Nanjing Tech University, Nanjing 211800, China
| | - Yongjun Sun
- College of Urban Construction, Nanjing Tech University, Nanjing 211800, China.
| | - Yanhua Xu
- School of Environmental Sciences and Engineering, Nanjing Tech University, Nanjing 211816, China
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Chen J, Xu X, Nie R, Feng L, Li X, Liu B. Chitosan Modified Cationic Polyacrylamide Initiated by UV-H 2O 2 for Sludge Flocculation and New Insight on the Floc Characteristics Study. Polymers (Basel) 2020; 12:E2738. [PMID: 33218149 PMCID: PMC7698928 DOI: 10.3390/polym12112738] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/13/2020] [Accepted: 11/16/2020] [Indexed: 11/16/2022] Open
Abstract
In the present study, a novel graft modified flocculant CTS-g-PAMD was synthesized and applied to conduct sludge conditioning and dewatering. CTS-g-PAMD was copolymerized with AM, DMC and chitosan (CTS) under UV-H2O2 initiation. In addition, the effects of single factor experiments on the molecular weight (MW) CTS grafting efficiency (GE) of CTS-g-PAMD were determined and the optimal copolymerization conditions were achieved. The GE of CTS-g-PAMD reached 91.1% and the MW was 4.82 × 106 Da. As revealed from the characterized results of Fourier-transform infrared spectra (FT-IR), 1H/ NMR, X-ray diffraction (XRD), scanning electron microscopic (SEM) and X-ray photoelectron spectroscopy (XPS), the successful synthesis of CTS-g-PAMD was confirmed, which is considered to be conducive to explaining sludge dewatering performance. Under the optimal conditions (pH = 7.0, flocculant dosage = 35 mg/L), the best flocculating performance (FCMC: 73.7%; SRF: 4.7 × 1012 m·kg-1, turbidity: 9.4 NTU) and large and dense sludge flocs (floc size d50 = 379.142 µm, floc fractal dimension Df = 1.58) were formed. The DMC and CTS chain segments exhibiting cationic properties significantly improved the positive charge density and enhanced the electrical patching effect of CTS-g-PAMD. The long molecular chain of CTS-g-PAMD exhibited superior extensibility, which enhanced bridging effect on adsorption. Moreover, the sludge floc after undergoing CTS-g-PAMD conditioning exhibited robust shear resistance and regeneration ability. After the sludge floc was crushed and broken, a large and dense sludge floc was formed, helping significantly reduce the sludge specific resistance (SRF), turbidity and cake moisture content (FCMC) and enhance the sludge dewatering effect. The novel CTS-g-PAMD flocculant shows promising practical applications and high market value.
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Affiliation(s)
- Jie Chen
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China; (J.C.); (X.X.); (R.N.)
| | - Xiaojun Xu
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China; (J.C.); (X.X.); (R.N.)
| | - Rui Nie
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China; (J.C.); (X.X.); (R.N.)
| | - Li Feng
- School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, China; (X.L.); (B.L.)
| | - Xuhao Li
- School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, China; (X.L.); (B.L.)
| | - Bingzhi Liu
- School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, China; (X.L.); (B.L.)
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Maćczak P, Kaczmarek H, Ziegler-Borowska M. Recent Achievements in Polymer Bio-Based Flocculants for Water Treatment. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E3951. [PMID: 32906667 PMCID: PMC7559979 DOI: 10.3390/ma13183951] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 08/30/2020] [Accepted: 09/04/2020] [Indexed: 01/04/2023]
Abstract
Polymer flocculants are used to promote solid-liquid separation processes in potable water and wastewater treatment. Recently, bio-based flocculants have received a lot of attention due to their superior advantages over conventional synthetic polymers or inorganic agents. Among natural polymers, polysaccharides show many benefits such as biodegradability, non-toxicity, ability to undergo different chemical modifications, and wide accessibility from renewable sources. The following article provides an overview of bio-based flocculants and their potential application in water treatment, which may be an indication to look for safer alternatives compared to synthetic polymers. Based on the recent literature, a new approach in searching for biopolymer flocculants sources, flocculation mechanisms, test methods, and factors affecting this process are presented. Particular attention is paid to flocculants based on starch, cellulose, chitosan, and their derivatives because they are low-cost and ecological materials, accepted in industrial practice. New trends in water treatment technology, including biosynthetic polymers, nanobioflocculants, and stimulant-responsive flocculants are also considered.
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Affiliation(s)
- Piotr Maćczak
- Faculty of Chemistry, Nicolaus Copernicus University in Toruń, Gagarina 7, 87-100 Toruń, Poland; (P.M.); (M.Z.-B.)
- Water Supply and Sewage Enterprise LLC, Przemysłowa 4, 99-300 Kutno, Poland
| | - Halina Kaczmarek
- Faculty of Chemistry, Nicolaus Copernicus University in Toruń, Gagarina 7, 87-100 Toruń, Poland; (P.M.); (M.Z.-B.)
| | - Marta Ziegler-Borowska
- Faculty of Chemistry, Nicolaus Copernicus University in Toruń, Gagarina 7, 87-100 Toruń, Poland; (P.M.); (M.Z.-B.)
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Flocculation activity and evaluation of chitosan-based flocculant CMCTS-g-P(AM-CA) for heavy metal removal. Sep Purif Technol 2020. [DOI: 10.1016/j.seppur.2020.116737] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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27
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Wu P, Yi J, Feng L, Li X, Chen Y, Liu Z, Tian S, Li S, Khan S, Sun Y. Microwave assisted preparation and characterization of a chitosan based flocculant for the application and evaluation of sludge flocculation and dewatering. Int J Biol Macromol 2020; 155:708-720. [PMID: 32259538 DOI: 10.1016/j.ijbiomac.2020.04.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 03/31/2020] [Accepted: 04/02/2020] [Indexed: 10/24/2022]
Abstract
In this study, a new type of graft modified flocculant (CS-g-PAD) was copolymerized of AM, DAC and chitosan (CS) by microwave assisted initiation and used for sludge conditioning and dewatering. The effect of reaction conditions on microwave assisted copolymerization was investigated and their optimal values were obtained by orthogonal experiments. The structure and chemical properties of CS-g-PAD were characterized and the results indicated that microwave assisted polymerization can cause the generated side polymer chain of PAD to react with the -NH2 active group in CS. Thus, the graft copolymerization occurred at amino group connected with C2 site. Compared with CCPAM, PAD and CS, the synthesized CS-g-PAD exhibits superior sludge dewatering performance (FCMC: 72.1%, SRF: 4.5 × 1012 m/kg, d50: 679.556 μm, Df: 1.72, floc sedimentation rate: 5.72 cm/min) in a wide pH range (pH = 3.5-9.5). Because CS-g-PAD contains a large amount of cationic DAC and positively charged CS as well as many functional groups on CS, it increases the charge neutralization, electrical patching and adsorption capability. Additionally, the grafting PAD on CS has a good extension in solution to increase its adsorption bridging effect. The new grafted CS-g-PAD is promising and has great practical application value in sludge dewatering and condition.
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Affiliation(s)
- Pei Wu
- School of Civil Engineering and Architecture, Chongqing University of Science and Technology, Chongqing 401331, China; Chongqing Xin Yun Chuang Institute of Environmental Protection Research Co. Ltd, Chongqing 402566, China
| | - Jiaxiang Yi
- School of Civil Engineering and Architecture, Chongqing University of Science and Technology, Chongqing 401331, China; Chongqing Xin Yun Chuang Institute of Environmental Protection Research Co. Ltd, Chongqing 402566, China
| | - Li Feng
- Chongqing Xin Yun Chuang Institute of Environmental Protection Research Co. Ltd, Chongqing 402566, China; School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, Guangdong, China.
| | - Xuhao Li
- School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, Guangdong, China
| | - Yao Chen
- School of River and Ocean Engineering, Chongqing Jiaotong University, Chongqing 400074, China
| | - Zhen Liu
- School of River and Ocean Engineering, Chongqing Jiaotong University, Chongqing 400074, China
| | - Shenghai Tian
- Chongqing Water Supply Co., Ltd, Chongqing 400013, China
| | - Shiyao Li
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045,China
| | - Sarfaraz Khan
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045,China
| | - Yongjun Sun
- College of Urban Construction, Nanjing Tech University, Nanjing, 211800, China.
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Chen T, Fu X, Ning S, Zhang Y. The apparent viscosity of poly(acryloyloxyethyltrimethyl ammonium chloride-acrylamide) with serial molecular weights in the aqueous salt solutions. JOURNAL OF MACROMOLECULAR SCIENCE PART A-PURE AND APPLIED CHEMISTRY 2020. [DOI: 10.1080/10601325.2019.1691446] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Tingting Chen
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, P.R. China
| | - Xingqin Fu
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, P.R. China
| | - Siyun Ning
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, P.R. China
| | - Yuejun Zhang
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, P.R. China
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29
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An Y, Zheng H, Sun Q, Zheng X, Liu W, Tang X, Xiong Z. Two-step synthesis of a single-layer grafting self-floating adsorbent for anionic dyes adsorption, surface separation and concentration. JOURNAL OF HAZARDOUS MATERIALS 2020; 384:121262. [PMID: 31586922 DOI: 10.1016/j.jhazmat.2019.121262] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Revised: 09/09/2019] [Accepted: 09/19/2019] [Indexed: 05/26/2023]
Abstract
In the case of a sharp increase in the price of dyes, the dyes concentration of in wastewater is important for environmental protection and industrial costs reduction. In this study, we grafted single-layer amino groups onto the surface of the hollow glass microspheres by a two-step simple synthesis, and the anionic dyes adsorption process reaches equilibrium within 10 min. The as-synthesized adsorbent has self-floating ability to achieve high-efficiency surface solid-liquid separation with water. SEM, EDS, SBET, FT-IR, XPS, TGA characterizations results demonstrated the successful grafting of amino groups and the important role of the pretreatment process in the two-step synthesis. The results of adsorption isotherms and kinetics show the adsorption process belongs to single-layer adsorption with equal adsorption sites, and the adsorption capacities for acid orange 7 and amaranth reach 428.99 mg g-1 and 145.62 mg g-1, respectively. Regeneration of the adsorbent and concentration of the dye solutions can be achieved by dispersing the separated adsorbent in alkaline solution, the maximum concentrated concentration of acid orange 7 and amaranth was 6321.57 mg L-1 and 2431.84 mg L-1, respectively. This study provides new insights for the solid-liquid separation of water treatment agents and the resource regenerating of dyeing wastewater.
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Affiliation(s)
- Yanyan An
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, State Ministry of Education, Chongqing University, Chongqing 400045, PR China; State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, PR China
| | - Huaili Zheng
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, State Ministry of Education, Chongqing University, Chongqing 400045, PR China; State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, PR China.
| | - Qiang Sun
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, State Ministry of Education, Chongqing University, Chongqing 400045, PR China
| | - Xinyu Zheng
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, State Ministry of Education, Chongqing University, Chongqing 400045, PR China
| | - Wangqing Liu
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, State Ministry of Education, Chongqing University, Chongqing 400045, PR China
| | - Xiaomin Tang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, State Ministry of Education, Chongqing University, Chongqing 400045, PR China
| | - Zikang Xiong
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, State Ministry of Education, Chongqing University, Chongqing 400045, PR China
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Chen W, Rong X, Peng J, Tang Q, Luo H, Fan L, Feng K, Zheng H. Assessment of a novel nanostructured flocculant with elevated flocculation and antimicrobial activity. CHEMOSPHERE 2020; 239:124736. [PMID: 31494326 DOI: 10.1016/j.chemosphere.2019.124736] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 08/22/2019] [Accepted: 08/30/2019] [Indexed: 06/10/2023]
Abstract
In this work, a novel process involving the preparation of nanochitosan-grafted flocculants (CPAM-g-NCS) to treat low turbid and salmonella suspensions simultaneously was introduced. Nanotechnology was employed to enhance the adsorption-adhesion and sterilization abilities of dual-functional flocculants. The monomers of chitosan, acrylamide, methacryloyl ethyl trimethyl ammonium chloride, and sodium tripolyphosphate were utilized for flocculants copolymerization. Then, using fourier-transform infrared spectroscopy, nuclear magnetic resonance hydrogen spectrum, and thermogravimetric and differential scanning calorimetry analysis, the successful synthesis of CPAM-g-NCS was verified. Scanning electron microscopy and size analysis suggested that nanostructured flocculants with irregular morphology and nanocolloids of 60.44 nm were formed. CPAM-g-NCS was applied to treat a series of simulated low turbid and salmonella suspensions. The simulation results showed that the minimum residual turbidity of 1.97 NTU and optical density of 0.16 (initial 0.89) can be achieved at dosages of 2.5 and 8.75 mg L-1, respectively, which were superior to conventional organics flocculants. Mechanistic studies suggested that the excellent adsorption property, and large numbers of quaternary ammonium and amino groups of nanoflocculants contributed to the superior flocculation and antibacterial performance of CPAM-g-NCS.
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Affiliation(s)
- Wei Chen
- College of Civil Engineering, Sichuan Agricultural University, Chengdu, 611830, China; Sichuan Higher Education Engineering Research Center for Disaster Prevention and Mitigation of Village Construction, Department of Municipal Engineering, Chengdu, 611830, China.
| | - Xiang Rong
- College of Civil Engineering, Sichuan Agricultural University, Chengdu, 611830, China
| | - Jiujing Peng
- College of Civil Engineering, Sichuan Agricultural University, Chengdu, 611830, China
| | - Qian Tang
- College of Civil Engineering, Sichuan Agricultural University, Chengdu, 611830, China
| | - Hongbing Luo
- College of Civil Engineering, Sichuan Agricultural University, Chengdu, 611830, China; Sichuan Higher Education Engineering Research Center for Disaster Prevention and Mitigation of Village Construction, Department of Municipal Engineering, Chengdu, 611830, China
| | - Liangqian Fan
- College of Civil Engineering, Sichuan Agricultural University, Chengdu, 611830, China; Sichuan Higher Education Engineering Research Center for Disaster Prevention and Mitigation of Village Construction, Department of Municipal Engineering, Chengdu, 611830, China
| | - Keqin Feng
- College of Civil Engineering, Sichuan Agricultural University, Chengdu, 611830, China
| | - Huaili Zheng
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, State Ministry of Education, Chongqing University, Chongqing, 400045, China
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Feng L, Liu J, Xu C, Lu W, Li D, Zhao C, Liu B, Li X, Khan S, Zheng H, Sun Y. Better understanding the polymerization kinetics of ultrasonic-template method and new insight on sludge floc characteristics research. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 689:546-556. [PMID: 31279201 DOI: 10.1016/j.scitotenv.2019.06.475] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 06/27/2019] [Accepted: 06/27/2019] [Indexed: 06/09/2023]
Abstract
As one of the core technologies employed in the field of sludge conditioning, flocculation has the ability to improve the sludge dewatering performance and reduce its volume and amount, which can accordingly result in lower costs in sludge transportation as well as subsequent disposal. Therefore, the development of new and high-efficiency flocculants is a hot topic in this field. The template copolymer (TPAD) of acryloyloxyethyl trimethyl ammonium chloride (DAC) and acrylamide (AM) was successfully synthesized through ultrasonic-template copolymerization using sodium-polyacrylate (NaPAA) as a template. The analysis of FTIR, 1H (13C) NMR, TG/DSC and SEM revealed that TPAD had a conspicuously significant cationic segmental structure. In addition, the results obtained from the analysis on the association constant (KM) and the kinetics of the template reaction indicated that the ultrasonic-template was a free radical initiated polymerization and the polymerization mechanism was I Zip-up (ZIP), and which once again confirmed the formation of the cationic fragment structure. This novel cationic fragment structure in TPAD greatly enhanced the ability of charge neutralization, electric patching, adsorption and bridging, thus improving the active sludge conditioning and dewatering performance (FCMC: 72.9%, SRF: 4.0 × 1012 m·kg-1, d50: 228.604 μm, Df: 2.02 at 400 r/min). The floc breakage and regeneration experiments showed that the cationic fragment structure in TPAD could make great contribution to the formation of large and dense floc structures, and these flocs were able to regenerate rapidly after breakage. Finally, it was also known that these large and compact floc structures were beneficial to the creation of more channels and voids, thereby decreasing sludge resistance (SRF) and improving sludge dewatering performance.
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Affiliation(s)
- Li Feng
- School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, Guangdong, China.
| | - Junyang Liu
- School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, Guangdong, China
| | - Chuang Xu
- School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, Guangdong, China; State Key Laboratory of Geodesy and Earth's Dynamics, Institute of Geodesy and Geophysics, Chinese Academy of Sciences, Wuhan 430077, China
| | - Wencong Lu
- School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, Guangdong, China
| | - Dongmei Li
- School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, Guangdong, China
| | - Chuanliang Zhao
- School of Civil Engineering, Chang'an University, Xi'an 710061, China
| | - Bingzhi Liu
- College of Civil Engineering, Hunan University of Technology, Zhuzhou 412007, China
| | - Xiang Li
- School of Civil Engineering and Architecture, Chongqing University of Science and Technology, Chongqing 401331, China
| | - Sarfaraz Khan
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045,China
| | - Huaili Zheng
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045,China
| | - Yongjun Sun
- College of Urban Construction, Nanjing Tech University, Nanjing 211800, China
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Sun Y, Chen A, Pan SY, Sun W, Zhu C, Shah KJ, Zheng H. Novel chitosan-based flocculants for chromium and nickle removal in wastewater via integrated chelation and flocculation. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 248:109241. [PMID: 31306928 DOI: 10.1016/j.jenvman.2019.07.012] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 06/30/2019] [Accepted: 07/05/2019] [Indexed: 06/10/2023]
Abstract
Carboxylated chitosan (CPCTS) is used as substrates in the design and synthesis of CPCTS-based flocculants through UV-initiated polymerization techniques. The synthesized flocculants are applied to remove Cr and Ni ions from chromic acid lotion and electroplating wastewater through two-stage flocculation. This study investigates the effect of flocculant dosage, pH, reaction time, and stirring speed on the removal efficiency of Cr and Ni ions. Results indicated that the total Cr removal ratios by CPCTS-graft-polyacrylamide-co-sodium xanthate (CAC) and CPCTS-graft-poly [acrylamide-2-Acrylamido-2-methylpropane sulfonic acid] (CPCTS-g-P(AM-AMPS)) are 94.7% and 94.6%, respectively. The total Ni removal efficiencies by CAC and CPCTS-g-P(AM-AMPS) are 99.3% and 99.4%, respectively. The two-stage flocculation with CPCTS-based flocculants could reduce the total concentrations of Cr and Ni to 1.0 mg/L and 0.5 mg/L, respectively. The relationship of removal capacity and structural properties between the flocculants with different functional groups is established through Fourier transform infrared spectroscopy, nuclear magnetic resonance, scanning electron microscopy, and X-ray diffraction. The micro-interfacial behavior between the colloidal particles and the solution during the integrated chelation-flocculation are elucidated. Thus, CPCTS-based flocculants could be a potential material for the removal of high amounts of Cr and Ni ions in industrial wastewater.
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Affiliation(s)
- Yongjun Sun
- College of Urban Construction, Nanjing Tech University, Nanjing, 211800, China.
| | - Aowen Chen
- College of Urban Construction, Nanjing Tech University, Nanjing, 211800, China
| | - Shu-Yuan Pan
- Department of Bioenvironmental System Engineering, National Taiwan University, Taipei City, 10617, Taiwan; Carbon Cycle Research Center, Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chou-Shan Road, Taipei City, 10673, Taiwan
| | - Wenquan Sun
- College of Urban Construction, Nanjing Tech University, Nanjing, 211800, China
| | - Chengyu Zhu
- College of Urban Construction, Nanjing Tech University, Nanjing, 211800, China
| | - Kinjal J Shah
- College of Urban Construction, Nanjing Tech University, Nanjing, 211800, China; Carbon Cycle Research Center, Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chou-Shan Road, Taipei City, 10673, Taiwan
| | - Huaili Zheng
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, State Ministry of Education, Chongqing University, Chongqing, 400045, China
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You Z, Zhuang C, Sun Y, Zhang S, Zheng H. Efficient Removal of TiO2 Nanoparticles by Enhanced Flocculation–Coagulation. Ind Eng Chem Res 2019. [DOI: 10.1021/acs.iecr.9b01504] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Zhaoyang You
- College of Urban Construction, Nanjing Tech University, Nanjing, 211800, China
| | - Chang Zhuang
- College of Urban Construction, Nanjing Tech University, Nanjing, 211800, China
| | - Yongjun Sun
- College of Urban Construction, Nanjing Tech University, Nanjing, 211800, China
| | - Shujuan Zhang
- College of Urban Construction, Nanjing Tech University, Nanjing, 211800, China
| | - Huaili Zheng
- Key Laboratory of the Three Gorges Reservoir Region’s Eco-Environment, State Ministry of Education, Chongqing University, Chongqing 400045, China
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Combination of Coagulation and Ozone Catalytic Oxidation for Pretreating Coking Wastewater. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16101705. [PMID: 31096662 PMCID: PMC6572503 DOI: 10.3390/ijerph16101705] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 05/02/2019] [Accepted: 05/07/2019] [Indexed: 11/30/2022]
Abstract
In this study, coagulation, ozone (O3) catalytic oxidation, and their combined process were used to pretreat actual coking wastewater. The effects on the removal of chemical oxygen demand (COD) and phenol in coking wastewater were investigated. Results showed that the optimum reaction conditions were an O3 mass flow rate of 4.1 mg min−1, a reaction temperature of 35 °C, a catalyst dosage ratio of 5:1, and a O3 dosage of 500 mg·L−1. The phenol removal ratio was 36.8% for the coagulation and sedimentation of coking wastewater under optimal conditions of 25 °C of reaction temperature, 7.5 reaction pH, 150 reaction gradient (G) value, and 500 mg·L−1 coagulant dosage. The removal ratios of COD and phenol reached 24.06% and 2.18%, respectively. After the O3-catalyzed oxidation treatment, the phenols, polycyclic aromatic hydrocarbons, and heterocyclic compounds were degraded to varying degrees. Coagulation and O3 catalytic oxidation contributed to the removal of phenol and COD. The optimum reaction conditions for the combined process were as follows: O3 dosage of 500 mg·L−1, O3 mass flow of 4.1 mg·min−1, catalyst dosage ratio of 5:1, and reaction temperature of 35 °C. The removal ratios of phenol and COD reached 47.3% and 30.7%, respectively.
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Sun Y, Shah KJ, Sun W, Zheng H. Performance evaluation of chitosan-based flocculants with good pH resistance and high heavy metals removal capacity. Sep Purif Technol 2019. [DOI: 10.1016/j.seppur.2019.01.017] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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36
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Sun Y, Sun W, Shah KJ, Chiang PC, Zheng H. Characterization and flocculation evaluation of a novel carboxylated chitosan modified flocculant by UV initiated polymerization. Carbohydr Polym 2019; 208:213-220. [DOI: 10.1016/j.carbpol.2018.12.064] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 12/05/2018] [Accepted: 12/20/2018] [Indexed: 01/20/2023]
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Sun Y, Ren M, Sun W, Xiao X, Xu Y, Zheng H, Wu H, Liu Z, Zhu H. Plasma-induced synthesis of chitosan-g-polyacrylamide and its flocculation performance for algae removal. ENVIRONMENTAL TECHNOLOGY 2019; 40:954-968. [PMID: 29210322 DOI: 10.1080/09593330.2017.1414312] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Accepted: 12/03/2017] [Indexed: 06/07/2023]
Abstract
Chitosan (CS)-g-polyacrylamide (PAM) is a highly efficient and environmentally friendly flocculant, which was synthesized through plasma-induced graft copolymerization of CS and acrylamide (AM). The effects of monomer concentration, AM:CS ratio, discharge power, discharge time, post-polymerization temperature, and post-polymerization time on the intrinsic viscosity, grafting ratio, and grafting efficiency of CS-g-PAM were investigated. The optimum conditions of graft copolymerization were as follows: 20% monomer concentration, 7:3 AM:CS ratio, 40 W discharge power, 90 s discharge time, 50°C post-polymerization temperature, and 24 h post-polymerization time. The structural characteristics of CS-g-PAM were characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. CS-g-PAM exhibited better flocculation efficiency than the commercially available PAM in both diatomite-simulated wastewater and low-turbidity algal water. The optimal turbidity removal efficiency for the diatomite-simulated wastewater was 99.9%, which was obtained with 6 mg L-1 of CS-g-PAM at pH 11.0 and 250 s-1 of velocity gradient. In low-turbidity algal water, the optimal removal efficiencies for chlorophyll-a, turbidity, and COD were 93.6%, 94.5%, and 98.2%, respectively.
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Affiliation(s)
- Yongjun Sun
- a College of Urban Construction, Nanjing Tech University , Nanjing , People's Republic of China
- b Jiangsu Key Laboratory of Industrial Water-Conservation & Emission Reduction , College of Environment, Nanjing Tech University , Nanjing , People's Republic of China
| | - Mengjiao Ren
- a College of Urban Construction, Nanjing Tech University , Nanjing , People's Republic of China
| | - Wenquan Sun
- a College of Urban Construction, Nanjing Tech University , Nanjing , People's Republic of China
- b Jiangsu Key Laboratory of Industrial Water-Conservation & Emission Reduction , College of Environment, Nanjing Tech University , Nanjing , People's Republic of China
| | - Xuefeng Xiao
- a College of Urban Construction, Nanjing Tech University , Nanjing , People's Republic of China
| | - Yanhua Xu
- b Jiangsu Key Laboratory of Industrial Water-Conservation & Emission Reduction , College of Environment, Nanjing Tech University , Nanjing , People's Republic of China
| | - Huaili Zheng
- c Key laboratory of the Three Gorges Reservoir Region's Eco-Environment, State Ministry of Education , Chongqing University , Chongqing , People's Republic of China
| | - Huifang Wu
- a College of Urban Construction, Nanjing Tech University , Nanjing , People's Republic of China
| | - Zhiying Liu
- b Jiangsu Key Laboratory of Industrial Water-Conservation & Emission Reduction , College of Environment, Nanjing Tech University , Nanjing , People's Republic of China
| | - Hui Zhu
- a College of Urban Construction, Nanjing Tech University , Nanjing , People's Republic of China
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Chen L, Sun Y, Sun W, Shah KJ, Xu Y, Zheng H. Efficient cationic flocculant MHCS-g-P(AM-DAC) synthesized by UV-induced polymerization for algae removal. Sep Purif Technol 2019. [DOI: 10.1016/j.seppur.2018.07.090] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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39
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Evaluation a self-assembled anionic polyacrylamide flocculant for the treatment of hematite wastewater: Role of microblock structure. J Taiwan Inst Chem Eng 2019. [DOI: 10.1016/j.jtice.2018.09.030] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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40
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Shi C, Sun W, Sun Y, Chen L, Xu Y, Tang M. Synthesis, Characterization, and Sludge Dewaterability Evaluation of the Chitosan-Based Flocculant CCPAD. Polymers (Basel) 2019; 11:E95. [PMID: 30960079 PMCID: PMC6402025 DOI: 10.3390/polym11010095] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Revised: 12/27/2018] [Accepted: 12/30/2018] [Indexed: 11/16/2022] Open
Abstract
Carboxymethyl chitosan (CMCS), acrylamide, and methacryloxyethyltrimethyl ammonium chloride were used as co-monomers to produce a sludge dewatering agent carboxymethyl chitosan-graft-poly(acrylamide-methacryloxyethyltrimethyl ammonium chloride) (CCPAD) by UV-induced graft polymerization. Single-factor experiments and response surface methodology were employed to investigate and optimize the grafting rate, grafting efficiency, and intrinsic viscosity influenced by the total monomer concentration, CMCS concentration, cationic degree, pH value, and illumination time. The structure, surface morphology, and thermal stability of CCPAD were characterized by infrared spectroscopy, hydrogen nuclear magnetic resonance, X-ray diffraction, scanning electron microscopy, and differential thermal-thermogravimetry. The raw sludge with 97.9% water content was sourced from the concentrated tank of a sewage treatment plant and used in the sludge condition experiments. In addition, CCPAD was applied as the sludge conditioner to investigate the effects of cationic degree, intrinsic viscosity, and pH on the supernatant turbidity, moisture content, specific resistance to filtration, and sludge settling ratio. Moreover, the mechanism of sludge conditioning by CCPAD was discussed by examining the zeta potential and extracellular polymeric substance (EPS) content of the supernatant. The sludge dewatering results confirmed that CCPAD had excellent performance for improving sludge dewaterability.
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Affiliation(s)
- Chunhong Shi
- School of Energy and Environmental Engineering, University of Science and Technology Bejing, Bejing 100083, China.
| | - Wenquan Sun
- College of Urban Construction, Nanjing Tech University, Nanjing 211800, China.
| | - Yongjun Sun
- College of Urban Construction, Nanjing Tech University, Nanjing 211800, China.
| | - Lei Chen
- Jiangsu Key Laboratory of Industrial Water-Conservation & Emission Reduction, College of Environment, Nanjing Tech University, Nanjing 211800, China.
| | - Yanhua Xu
- Jiangsu Key Laboratory of Industrial Water-Conservation & Emission Reduction, College of Environment, Nanjing Tech University, Nanjing 211800, China.
| | - Mengdan Tang
- College of Urban Construction, Nanjing Tech University, Nanjing 211800, China.
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Carbon speciation and flocculation in Neochloris oleoabundans cultures using anaerobically digested stillage. World J Microbiol Biotechnol 2019; 35:14. [DOI: 10.1007/s11274-018-2582-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Accepted: 12/11/2018] [Indexed: 01/06/2023]
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Gumfekar SP, Vajihinejad V, Soares JBP. Advanced Polymer Flocculants for Solid-Liquid Separation in Oil Sands Tailings. Macromol Rapid Commun 2018; 40:e1800644. [PMID: 30417463 DOI: 10.1002/marc.201800644] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 10/04/2018] [Indexed: 01/09/2023]
Abstract
The generation of tailings as a by product of the bitumen extraction process is one of the largest environmental footprints of oil sands operations. Most of the tailings treatment technologies use polymer flocculants to induce solid-liquid separation. However, due to the complex composition of tailings, conventional flocculants cannot reach the same performance achieved in other wastewater treatments. Over the last couple of decades, the oil sands industry has used acrylamide-based flocculants to treat tailings, achieving major progress in process optimization and integration with mechanical operations, but they still could not reach the required land reclamation targets. Over the last 5 years, the group designed, synthesized, and tested several novel polymer flocculants tailored for oil sands tailings treatment. This feature article communicates recent developments in these innovative polymers. The article first provides a background on tailings generation and treatment, followed by the description of advanced polymer flocculants categorized according to their microstructures such as linear, branched, and graft. The other tailings remediation technologies and one of the initial works on modeling of tailings flocculation is discussed.
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Affiliation(s)
- Sarang P Gumfekar
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, T6G 2V4, Canada
| | - Vahid Vajihinejad
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, T6G 2V4, Canada
| | - João B P Soares
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, T6G 2V4, Canada
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Fabrication of Bifunctional Chitosan-Based Flocculants: Characterization, Assessment of Flocculation, and Sterilization Performance. MATERIALS 2018; 11:ma11102009. [PMID: 30336604 PMCID: PMC6213324 DOI: 10.3390/ma11102009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 10/08/2018] [Accepted: 10/15/2018] [Indexed: 11/17/2022]
Abstract
In this study, a series of chitosan-based quaternary ammonium graft flocculants, namely chitosan-graft-poly(acrylamide and methacryloyl ethyl trimethyl ammonium chloride) [CTS-g-P(AM-DMC)], was successfully synthesized by plasma initiation, and the as-prepared [CTS-g-P(AM-DMC)] had both flocculation and sterilization functions. Various characterization techniques were used to study the structure and physicochemical properties of the chitosan-based flocculants. ¹H nuclear magnetic resonance spectroscopy (¹H NMR), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), and thermogravimetric analysis/differential scanning calorimetry (TG/DSC) confirmed the successful synthesis of CTS-g-P(AM-DMC). Scanning electron microscopy (SEM) analysis exhibited that CTS-g-P(AM-DMC) contained a smooth convex and porous structure with an enormous surface area. CTS-g-P(AM-DMC) was then used to flocculate the simulated wastewater of the kaolin suspension and the Salmonella suspension. Besides external factors, such as the dosage of flocculant and pH, the effect of the internal factor graft ratio was also evaluated. The experimental results showed that CTS-g-P(AM-DMC) also revealed a strong sterilization effect, aside from the excellent flocculation effect. Moreover, the sterilization mechanism was investigated through a series of conductivity measurements and the analysis of fluorescence-based cell live/dead tests. The results indicated that CTS-g-P(AM-DMC) destroyed the cell membrane of Salmonella through its grafted quaternary ammonium salt, thereby exhibiting sterilization property.
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44
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Synthesis and Characterization of Ampholytic Flocculant CPCTS-g-P (CTA-DMDAAC) and Its Flocculation Properties for Microcystis Aeruginosa Removal. Processes (Basel) 2018. [DOI: 10.3390/pr6050054] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
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Ma J, Shi J, Ding L, Zhang H, Zhou S, Wang Q, Fu X, Jiang L, Fu K. Removal of emulsified oil from water using hydrophobic modified cationic polyacrylamide flocculants synthesized from low-pressure UV initiation. Sep Purif Technol 2018. [DOI: 10.1016/j.seppur.2018.01.036] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Argüelles-Monal WM, Lizardi-Mendoza J, Fernández-Quiroz D, Recillas-Mota MT, Montiel-Herrera M. Chitosan Derivatives: Introducing New Functionalities with a Controlled Molecular Architecture for Innovative Materials. Polymers (Basel) 2018; 10:E342. [PMID: 30966377 PMCID: PMC6414943 DOI: 10.3390/polym10030342] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 03/16/2018] [Accepted: 03/17/2018] [Indexed: 11/20/2022] Open
Abstract
The functionalization of polymeric substances is of great interest for the development of innovative materials for advanced applications. For many decades, the functionalization of chitosan has been a convenient way to improve its properties with the aim of preparing new materials with specialized characteristics. In the present review, we summarize the latest methods for the modification and derivatization of chitin and chitosan under experimental conditions, which allow a control over the macromolecular architecture. This is because an understanding of the interdependence between chemical structure and properties is an important condition for proposing innovative materials. New advances in methods and strategies of functionalization such as the click chemistry approach, grafting onto copolymerization, coupling with cyclodextrins, and reactions in ionic liquids are discussed.
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Affiliation(s)
| | - Jaime Lizardi-Mendoza
- Centro de Investigación en Alimentación y Desarrollo, Hermosillo 83304, Sonora, Mexico.
| | - Daniel Fernández-Quiroz
- Departamento de Investigación en Física, Universidad de Sonora, Hermosillo 83000, Sonora, Mexico.
| | | | - Marcelino Montiel-Herrera
- Departamento de Medicina y Ciencias de la Salud, Universidad de Sonora, Hermosillo 83000, Sonora, Mexico.
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Synthesis of a Cationic Polyacrylamide under UV Initiation and Its Flocculation in Estrone Removal. INT J POLYM SCI 2018. [DOI: 10.1155/2018/8230965] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
A ternary cationic polyacrylamide (CPAM) with the hydrophobic characteristic was prepared through ultraviolet- (UV-) initiated polymerization technique for the estrone (E1) environmental estrogen separation and removal. The monomers of acrylamide (AM), acryloyloxyethyl-trimethyl ammonium chloride (DAC), and acryloyloxyethyl dimethylbenzyl ammonium chloride (AODBAC) were used to synthesize the ternary copolymer (PADA). Fourier transform infrared spectroscopy (FT-IR), 1H nuclear magnetic resonance spectroscopy (1H NMR), thermogravimetry/differential scanning calorimetry (TG/DSC), and scanning electron microscopy (SEM) were employed to characterize the structure, thermal decomposition property, and morphology of the polymers, respectively. FT-IR and 1H NMR results indicated the successful formation of the polymers. Besides, with the introduction of hydrophobic groups (phenyl group), an irregular and porous surface morphology and a favorable thermal stability of the PADA were observed by SEM and TG/DSC analyses, respectively. At the optimal condition (pH = 7, flocculant dosage = 4.0 mg/L and E1 concentration = 0.75 mg/L), an excellent E1 flocculation performance (E1 removal rate: 90.1%, floc size: 18.3 μm, and flocculation kinetics: 22.69×10-4 s−1) was acquired by using the efficient flocculant PADA-3 (cationic degree = 40%, and intrinsic viscosity = 6.30 dL·g−1). The zeta potential and floc size analyses were used to analyze the possible flocculation mechanism for the E1 removal. Results indicated that the charge neutralization, adsorption, and birding effects were dominant in the E1 removal progress.
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Lu X, Xu Y, Sun W, Sun Y, Zheng H. UV-initiated synthesis of a novel chitosan-based flocculant with high flocculation efficiency for algal removal. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 609:410-418. [PMID: 28755590 DOI: 10.1016/j.scitotenv.2017.07.192] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 07/15/2017] [Accepted: 07/21/2017] [Indexed: 05/03/2023]
Abstract
In this study, maleyl chitosan-graft-polyacrylamide (MHCS-g-PAM), a novel chitosan-based flocculant, was prepared through UV irradiation, and maleyl chitosan (MHCS) was designed and prepared with maleic anhydride and acrylamide (AM) through maleyl acylation reaction. The effects of monomer concentration, MHCS-to-AM ratio, illumination time, initiator concentration, pH on viscosity, and grafting efficiency were investigated to optimize the synthesis of these substances. MHCS-g-PAM was characterized through Fourier transform infrared spectroscopy, nuclear magnetic resonance hydrogen spectroscopy, scanning electron microscopy, and thermal gravimetric analysis. Flocculation mechanisms in alga-containing wastewater at various pH levels and dosages were examined in detail on the basis of zeta potential measurements. Zeta potential experiments indicated that the adsorption-bridging and charge neutralization mechanisms played an important role in algal removal. Flocculation tests on algal removal demonstrated that the flocculation performance of MHCS-g-PAM was more effective than that of cationic polyacrylamide, polyferric sulfate, and polymeric aluminium. The optimal Chl-a and COD removal rate obtained by MHCS-g-PAM was 98.6% and 94.9% at pH7 and 4mg·L-1, respectively.
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Affiliation(s)
- Xi Lu
- Jiangsu Key Laboratory of Industrial Water-Conservation & Emission Reduction, College of Environment, Nanjing Tech University, Nanjing 211800, China
| | - Yanhua Xu
- Jiangsu Key Laboratory of Industrial Water-Conservation & Emission Reduction, College of Environment, Nanjing Tech University, Nanjing 211800, China.
| | - Wenquan Sun
- Jiangsu Key Laboratory of Industrial Water-Conservation & Emission Reduction, College of Environment, Nanjing Tech University, Nanjing 211800, China; College of Urban Construction, Nanjing Tech University, Nanjing 211800, China
| | - Yongjun Sun
- Jiangsu Key Laboratory of Industrial Water-Conservation & Emission Reduction, College of Environment, Nanjing Tech University, Nanjing 211800, China; College of Urban Construction, Nanjing Tech University, Nanjing 211800, China.
| | - Huaili Zheng
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, State Ministry of Education, Chongqing University, Chongqing 400045, China
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Zheng H, Feng L, Gao B, Zhou Y, Zhang S, Xu B. Effect of the Cationic Block Structure on the Characteristics of Sludge Flocs Formed by Charge Neutralization and Patching. MATERIALS 2017; 10:ma10050487. [PMID: 28772848 PMCID: PMC5459051 DOI: 10.3390/ma10050487] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 04/23/2017] [Accepted: 04/27/2017] [Indexed: 11/30/2022]
Abstract
In this study, a template copolymer (TPAA) of (3-Acrylamidopropyl) trimethylammonium chloride (AATPAC) and acrylamide (AM) was successfully synthesized though ultrasonic-initiated template copolymerization (UTP), using sodium polyacrylate (PAAS) as a template. TPAA was characterized by an evident cationic microblock structure which was observed through the analyses of the reactivity ratio, Fourier transform infrared spectroscopy (FTIR), 1H (13C) nuclear magnetic resonance spectroscopy (1H (13C) NMR), and thermogravimetry/differential scanning calorimetry (TG/DSC). The introduction of the template could improve the monomer (AATPAC) reactivity ratio and increase the length and amount of AATPAC segments. This novel cationic microblock structure extremely enhanced the ability of charge neutralization, patching, and bridging, thus improving the activated sludge flocculation performance. The experiments of floc formation, breakage, and regrowth revealed that the cationic microblock structure in the copolymer resulted in large and compact flocs, and these flocs had a rapid regrowth when broken. Finally, the larger and more compact flocs contributed to the formation of more channels and voids, and therefore the specific resistance to filtration (SRF) reached a minimum.
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Affiliation(s)
- Huaili Zheng
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China.
- National Centre for International Research of Low-carbon and Green Buildings, Chongqing University, Chongqing 400045, China.
| | - Li Feng
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China.
- National Centre for International Research of Low-carbon and Green Buildings, Chongqing University, Chongqing 400045, China.
| | - Baoyu Gao
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China.
| | - Yuhao Zhou
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China.
- National Centre for International Research of Low-carbon and Green Buildings, Chongqing University, Chongqing 400045, China.
| | - Shixin Zhang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China.
- National Centre for International Research of Low-carbon and Green Buildings, Chongqing University, Chongqing 400045, China.
| | - Bingchen Xu
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China.
- National Centre for International Research of Low-carbon and Green Buildings, Chongqing University, Chongqing 400045, China.
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Sun Y, Zhu C, Sun W, Xu Y, Xiao X, Zheng H, Wu H, Liu C. Plasma-initiated polymerization of chitosan-based CS-g-P(AM-DMDAAC) flocculant for the enhanced flocculation of low-algal-turbidity water. Carbohydr Polym 2017; 164:222-232. [DOI: 10.1016/j.carbpol.2017.02.010] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Revised: 01/05/2017] [Accepted: 02/02/2017] [Indexed: 01/28/2023]
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