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Ahmaruzzaman M, Roy P, Bonilla-Petriciolet A, Badawi M, Ganachari SV, Shetti NP, Aminabhavi TM. Polymeric hydrogels-based materials for wastewater treatment. CHEMOSPHERE 2023; 331:138743. [PMID: 37105310 DOI: 10.1016/j.chemosphere.2023.138743] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 04/18/2023] [Accepted: 04/19/2023] [Indexed: 05/19/2023]
Abstract
Low-cost and reliable wastewater treatment is a relevant issue worldwide to reduce the concentration of environmental pollutants. Industrial effluents containing dyes, heavy metals, and other inorganic and organic compounds can pollute water resources; therefore, novel technologies are required to mitigate and control their release into the environment. Adsorption is one of the simplest methods for treating contaminated water in which a wide spectrum of adsorbents can be used to remove emerging compounds. Hydrogels are interesting materials with high adsorption capacities that can be synthesized via green routes. These adsorbents are promising for large-scale industrial wastewater treatment applications; however, gaps still exist in achieving sustainable commercial implementation. This review focuses on the discussion and analysis of preparation, characterization, and adsorption properties of hydrogels for water purification. The advantages of these polymeric materials for water treatment were analyzed, including their performance in the removal of different organic and inorganic contaminants. Recent advances in the functionalization of hydrogels and the synthesis of novel composites have also been described. The adsorption capacities of hydrogel-based adsorbents are higher than 500 mg/g for different organic and inorganic pollutants, and can reach values of up to >2000 mg/g for organic compounds, significantly outperforming other materials reported for water cleaning. The main interactions involved in the adsorption of water pollutants using hydrogel-based adsorbents were described and explained to allow the interpretation of their removal mechanisms. The current challenges in the implementation of hydrogels for water purification in real-life operations are also highlighted. This review provides an updated picture of hydrogels as interesting materials to address water depollution worldwide.
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Affiliation(s)
- Md Ahmaruzzaman
- Department of Chemistry, National Institute of Technology Silchar, 788010, Assam, India.
| | - Prerona Roy
- Department of Chemistry, National Institute of Technology Silchar, 788010, Assam, India
| | | | - Michael Badawi
- Laboratoire de Physique et Chimie Théoriques UMR CNRS 7019, Université de Lorraine, Nancy, France
| | - Sharanabasava V Ganachari
- Center for Energy and Environment, School of Advanced Sciences, KLE Technological University, Hubballi, 580 031, India
| | - Nagaraj P Shetti
- Center for Energy and Environment, School of Advanced Sciences, KLE Technological University, Hubballi, 580 031, India
| | - Tejraj M Aminabhavi
- Center for Energy and Environment, School of Advanced Sciences, KLE Technological University, Hubballi, 580 031, India.
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Du B, Tang Q, Chen W, Rong X, Zhang K, Ma D, Wei Z, Chen W. Insight into the purification of algael water by a novel flocculant with enhanced branched nanochitosan structure. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 331:117283. [PMID: 36701886 DOI: 10.1016/j.jenvman.2023.117283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 01/04/2023] [Accepted: 01/09/2023] [Indexed: 06/17/2023]
Abstract
For improving inadequate nanostructural stability and promote algal removal efficiency, a novel nanochitosan-grafted flocculant (PAD-g-MNC) with an enhanced branched nanostructure and high molecular weight (MW) was fabricated via maleic anhydride acylation polymerization. Characterization results verified the successful synthesis of the flocculant and the formation of an irregular particle nanostructure. PAD-g-MNC exhibited superior algal and extracellular organic matter (EOM) removal and obtained the turbidity and chlorophyll-a removal rates of 93.46%-95.39% and 95.10%-97.31%, respectively, at the dosage of 4-5 mg L-1. The growth rate, strength factor, and recovery factor of algal flocs flocculated by PAD-g-MNC were 90.36, 0.63, and 0.27 (100 rpm), respectively, and were higher than other flocculants prepared through conventional methods. Results indicated that the high intrinsic viscosity and stability branched nanostructure promoted the formation of stable flocs and regeneration ability of flocs. MW distribution and three-dimensional fluorescence analyses revealed that the special structure of PAD-g-MNC was beneficial to the removal of tryptophan-like proteins in EOM. Strong adsorption-adhesion and bridging-netting effects of the nanostructure chain were the dominated mechanisms in the improvement of flocculation efficiency. This study provided theoretical and experimental guidance for the design of flocculants with superior performance and efficient algal water purification performance.
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Affiliation(s)
- Bin Du
- Students Innovation and Entrepreneurship Center, Enrollment and Employment Department, Sichuan Agricultural University, Chengdu, 611130, China; College of Civil Engineering, Sichuan Agricultural University, Chengdu, 611830, China
| | - Qian Tang
- College of Civil Engineering, Sichuan Agricultural University, Chengdu, 611830, China
| | - 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, Sichuan Agricultural University, Chengdu, 611830, China.
| | - Xiang Rong
- College of Civil Engineering, Sichuan Agricultural University, Chengdu, 611830, China
| | - Ke Zhang
- College of Civil Engineering, Sichuan Agricultural University, Chengdu, 611830, China; Sichuan Higher Education Engineering Research Center for Disaster Prevention and Mitigation of Village Construction, Sichuan Agricultural University, Chengdu, 611830, China
| | - Dandan Ma
- College of Civil Engineering, Sichuan Agricultural University, Chengdu, 611830, China; Sichuan Higher Education Engineering Research Center for Disaster Prevention and Mitigation of Village Construction, Sichuan Agricultural University, Chengdu, 611830, China
| | - Zhaolan Wei
- College of Civil Engineering, Sichuan Agricultural University, Chengdu, 611830, China; Sichuan Higher Education Engineering Research Center for Disaster Prevention and Mitigation of Village Construction, Sichuan Agricultural University, Chengdu, 611830, China
| | - Wei Chen
- Sichuan Higher Education Engineering Research Center for Disaster Prevention and Mitigation of Village Construction, Sichuan Agricultural University, Chengdu, 611830, China
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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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Chen W, Zhang F, Tang Q, Du B, Ma D, Zhao Z, Fan L, Luo H, Zhao Z, Huang X, Zheng H. Evaluating the performance of bridging-assembly chelating flocculant for heavy metals removal: Role of branched architectures. CHEMOSPHERE 2022; 289:133260. [PMID: 34906524 DOI: 10.1016/j.chemosphere.2021.133260] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 10/06/2021] [Accepted: 12/09/2021] [Indexed: 06/14/2023]
Abstract
A novel chelating flocculant with branched architectures, polyacrylamide grafted maleoyl chitosan-mercaptoacetic acid (PAM-g-M(CS-MA)), was successfully fabricated using maleic anhydride as the "bridge" between chitosan and polyacrylamide. The functional groups and structural characteristic information of copolymers were obtained via characterization analysis. Flocculation performance was systematically investigated via purifying a series of simulated wastewater containing Cu or Cd. The properties of the flocs were studied to give in-depth evidences for the role of chelation groups and branched architectures in flocculation. Results indicated that PAM-g-M(CS-MA) showed excellent flocculation capacity for heavy metals in high concentrations and was superior to other chelating flocculants. The maximum flocculation efficiency of Cu (93.90%) and Cd (92.47%) was achieved by PAM-g-M(CS-MA) at pH 7, dosage of 100 mg L-1 and stirring speed of 90 rpm. The flocculation mechanisms of PAM-g-M(CS-MA) were deeply explored through the analyses of floc properties. The strong synergistic chelation of mercapto, carboxyl, amide and hydroxyl groups predominated for the capturing of heavy metals; and the branched architectures facilitated the formation of large and stable flocs via adsorption and bridging-furl effect. This study provided a solid foundation for the fabrication of flocculants for heavy metal wastewater treatment.
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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, Sichuan Agricultural University, Chengdu, 611830, China.
| | - Fengjiao Zhang
- College of Civil Engineering, Sichuan Agricultural University, Chengdu, 611830, China
| | - Qian Tang
- College of Civil Engineering, Sichuan Agricultural University, Chengdu, 611830, China
| | - Bin Du
- Admission and Employment Office, Sichuan Agricultural University, Chengdu, 611130, China
| | - Dandan Ma
- College of Civil Engineering, Sichuan Agricultural University, Chengdu, 611830, China
| | - Zhihan Zhao
- College of Civil Engineering, Sichuan Agricultural University, Chengdu, 611830, China
| | - Liangqian Fan
- Sichuan Higher Education Engineering Research Center for Disaster Prevention and Mitigation of Village Construction, Sichuan Agricultural University, Chengdu, 611830, China
| | - Hongbing Luo
- Sichuan Higher Education Engineering Research Center for Disaster Prevention and Mitigation of Village Construction, Sichuan Agricultural University, Chengdu, 611830, China
| | - Zhongguo Zhao
- College of Civil Engineering, Sichuan Agricultural University, Chengdu, 611830, China
| | - Xing Huang
- College of Architecture and Urban-Rural Planning, 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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Liu Y, Xiang Y, Xu H, Li H. The reuse of nano-TiO2 under different concentration of CO32– using coagulation process and its photocatalytic ability in treatment of methyl orange. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2021.120152] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Adsorption Characteristics of Chitosan-Modified Bamboo Biochar in Cd(II) Contaminated Water. J CHEM-NY 2022. [DOI: 10.1155/2022/6303252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The purpose of this study was to fabricate a low-cost and eco-friendly adsorbent using bamboo biochar (BB), a kind of charcoal composed of high Brunauer–Emmett–Teller surface area and variety of functional groups, and chitosan as substrates for remediation of Cd(II) in Cd(II) contaminated water and characterized the functional group characteristics, surface morphology, and Cd(II) adsorption effect using the Fourier transform infrared (FT-IR), scanning electron microscope (SEM), and energy-dispersive X-ray spectrometer (EDS). Results showed that chitosan-modified bamboo biochar (CBB) provided more active adsorption sites (such as –NH2, –COOH, –OH, and C=O) on the surface to enhance the Cd(II) removal efficiency in Cd(II) contaminated wastewater. Meanwhile, the optimal pH, contact time, and dose of CBB on the Cd(II) removal efficiency are 7, 120 min, and 600 mg, respectively. In addition, the adsorption isotherm results revealed that the possible adsorption mechanisms might include surface adsorption, electrostatic adsorption, and ion exchanges. Furthermore, the maximum adsorption capacity (Qm) values predicted from the Langmuir model were 37.74 and 93.46 mg/g for BB and CBB, respectively, also indicating a potential application of CBB in practical wastewater. Desorption and regeneration of CBB were attained simultaneously and the results showed that even after five cycles of adsorption-elution, the adsorption and desorption of CBB exhibited a slight decline and still reached at 71.70% and 65.92%. Results from this study would provide a reference to functionalized CBB for Cd(II) adsorption in contaminated water.
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7
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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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Gong Y, Bai Y, Zhao D, Wang Q. Aggregation of carboxyl-modified polystyrene nanoplastics in water with aluminum chloride: Structural characterization and theoretical calculation. WATER RESEARCH 2022; 208:117884. [PMID: 34837810 DOI: 10.1016/j.watres.2021.117884] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 11/05/2021] [Accepted: 11/17/2021] [Indexed: 06/13/2023]
Abstract
Nanoplastics (NPs) pollution of aquatic systems is becoming an emerging environmental issue due to their stable structure, high mobility, and easy interactions with ambient contaminants. Effective removal technologies are urgently needed to mitigate their toxic effects. In this study, we systematically investigated the removal effectiveness and mechanisms of a commonly detected nanoplastics, carboxyl-modified polystyrene (PS-COOH) via coagulation and sedimentation processes using aluminum chloride (AlCl3) as a coagulant. PS-COOH appeared as clearly defined and discrete spherical nanoparticles in water with a hydrodynamic diameter of 50 nm. The addition of 10 mg/L AlCl3 compressed and even destroyed the negatively charged PS-COOH surface layer, decreased the energy barrier, and efficiently removed 96.6% of 50 mg/L PS-COOH. The dominant removal mechanisms included electrostatic adsorption and intermolecular interactions. Increasing the pH from 3.5 to 8.5 sharply enhanced the PS-COOH removal, whereas significant loss was observed at pH 10.0. High temperature (23 °C) favored the removal of PS-COOH compared to lower temperature (4 °C). High PS-COOH removal efficiency was observed over the salinity range of 0 - 35‰. The presence of positively charged Al2O3 did not affect the PS-COOH removal, while negatively charged SiO2 reduced the PS-COOH removal from 96.6% to 93.2%. Moreover, the coagulation and sedimentation process efficiently removed 90.2% of 50 mg/L PS-COOH in real surface water even though it was rich in inorganic ions and total organic carbon. The fast and efficient capture of PS-COOH by AlCl3 via a simple coagulation and sedimentation process provides a new insight for the treatment of NPs from aqueous environment.
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Affiliation(s)
- Yanyan Gong
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China.
| | - Yang Bai
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China
| | - Dongye Zhao
- Department of Civil and Environmental Engineering, Environmental Engineering Program, Auburn University, Auburn, AL 36849, United States
| | - Qilin Wang
- Center for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
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10
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Application of Spinel and Hexagonal Ferrites in Heterogeneous Photocatalysis. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app112110160] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Semiconducting materials display unique features that enable their use in a variety of applications, including self-cleaning surfaces, water purification systems, hydrogen generation, solar energy conversion, etc. However, one of the major issues is separation of the used materials from the process suspension. Therefore, chemical compounds with magnetic properties have been proposed as crucial components of photocatalytic composites, facilitating separation and recovery of photocatalysts under magnetic field conditions. This review paper presents the current state of knowledge on the application of spinel and hexagonal ferrites in heterogeneous photocatalysis. The first part focuses on the characterization of magnetic (nano)particles. The next section presents the literature findings on the single-phase magnetic photocatalyst. Finally, the current state of scientific knowledge on the wide variety of magnetic-photocatalytic composites is presented. A key aim of this review is to indicate that spinel and hexagonal ferrites are considered as an important element of heterogeneous photocatalytic systems and are responsible for the effective recycling of the photocatalytic materials.
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Khan R, Inam MA, Lee KH, Channa AS, Mallah MA, Wie YM, Abbasi MN. Synergetic Effect of Organic Flocculant and Montmorillonite Clay on the Removal of Nano-CuO by Coagulation-Flocculation-Sedimentation Process. NANOMATERIALS 2021; 11:nano11102753. [PMID: 34685190 PMCID: PMC8537118 DOI: 10.3390/nano11102753] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/14/2021] [Accepted: 10/14/2021] [Indexed: 12/18/2022]
Abstract
The widespread usage of nano-copper oxide particles (nano-CuO) in several industrial products and applications raises concerns about their release into water bodies. Thus, their elimination from drinking water is essential to reduce the risk to human health. This work investigated the removal of nano-CuO from pure water and montmorillonite clay (MC) suspensions using poly aluminum ferric chloride (PAFC) as well as cationic polyacrylamide (PAM) by the coagulation-flocculation-sedimentation (C/F/S) process. Moreover, the PAFC and PAFC/PAM flocculation performance for various nano-CuO particles concentrations, dosages, pH, settling times and stirring speeds were also investigated. The findings showed that the removal of nano-CuO and turbidity in MC suspension were higher as compared to pure water. Moreover, the combined effect of PAFC/PAM on the elimination of nano-CuO and turbidity was also substantially better than the individual use of PAFC or PAM. The efficient removal of CuO was observed in the solution containing higher mass concentration in the order (10 mg/L > 2.5 mg/L > 1 mg/L) with an increased coagulant dose. The improved removal performance of nano-CuO was observed in a pH range of 7-11 under various water matrices. The C/F/S conditions of nano-CuO were further optimized by the Box-Behnken statistical experiment design and response surface methodology. The PAFC/PAM dose resulted in the maximum removal of nano-CuO (10 mg/L) in both pure water (>97%) and MC suspension (>99%). The results of particle monitoring and Fourier transform infrared of composite flocs revealed that the main removal mechanism of nano-CuO may be the combined effect of neutralization, complexation as well as adsorption.
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Affiliation(s)
- Rizwan Khan
- Department of Chemical Engineering, Quaid-e-Awam University of Engineering, Science and Technology (QUEST), Nawabshah 67480, Pakistan; (R.K.); (A.S.C.); (M.A.M.); (M.N.A.)
| | - Muhammad Ali Inam
- Institute of Environmental Sciences and Engineering (IESE), School of Civil and Environmental Engineering (SCEE), H-12 Campus, National University of Sciences and Technology (NUST), Islamabad 44000, Pakistan;
| | - Kang-Hoon Lee
- Department of Civil and Environmental Engineering, Hanyang University, 222 Seongdong-gu, Seoul 04763, Korea
- Correspondence:
| | - Abdul Sami Channa
- Department of Chemical Engineering, Quaid-e-Awam University of Engineering, Science and Technology (QUEST), Nawabshah 67480, Pakistan; (R.K.); (A.S.C.); (M.A.M.); (M.N.A.)
| | - Mukhtiar Ali Mallah
- Department of Chemical Engineering, Quaid-e-Awam University of Engineering, Science and Technology (QUEST), Nawabshah 67480, Pakistan; (R.K.); (A.S.C.); (M.A.M.); (M.N.A.)
| | - Young-Min Wie
- Department of Materials Engineering, Kyonggi University, Suwon 16227, Korea;
| | - Mahmood Nabi Abbasi
- Department of Chemical Engineering, Quaid-e-Awam University of Engineering, Science and Technology (QUEST), Nawabshah 67480, Pakistan; (R.K.); (A.S.C.); (M.A.M.); (M.N.A.)
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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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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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14
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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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15
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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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16
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Wu Z, Zhang X, Pang J, Zhang X, Li J, Li J, Zhang P. Humic Acid Removal from Water with PAC-Al 30: Effect of Calcium and Kaolin and the Action Mechanisms. ACS OMEGA 2020; 5:16413-16420. [PMID: 32685804 PMCID: PMC7364432 DOI: 10.1021/acsomega.0c00532] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 06/19/2020] [Indexed: 06/11/2023]
Abstract
Polyaluminum chloride with a dominant species of Al30 (PAC-Al30) was prepared in laboratory and used for humic acid (HA) removal from water. The action properties and mechanisms of PAC-Al30, HA, calcium, and kaolin were tested and discussed. The results showed that the existence of calcium or kaolin contributed to the HA removal when the PAC-Al30 dosage was deficient and had no obvious effect when the amount of PAC-Al30 was sufficient. When the PAC-Al30 dosage was 0.01 and 0.02 mmol/L, the HA removal rate was increased by 66.59 and 42.20%, respectively, with a calcium concentration of 2.0 mmol/L, or increased by 53.31 and 40.92%, respectively, with the kaolin particle concentration of 150 mg/L. Calcium could compress the double electrical layers or complex with HA to neutralize a part of the surface negative charge of HA, but could not make the water system reach its isoelectric point. The mechanisms of calcium and kaolin's promoting coagulation effect were adsorption neutralization and collision aggregation respectively, but these actions were much weaker than that of PAC-Al30 with HA. The adsorption neutralization capacity of PAC-Al30 was calculated to be nearly 60 times than that of calcium, and the higher γ value of calcium modified by the Sips equation may indicate that the adsorption or neutralization sites of calcium on HA were pickier than PAC-Al30.
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Affiliation(s)
- Zhen Wu
- Department
of Chemical Engineering, Ordos Institute
of Technology, Ordos 017000, China
- Department
of Water Resources & Environmental Treatment, Redbud Innovation Institute, Ordos 017000, China
| | - Xian Zhang
- Department
of Chemical Engineering, Ordos Institute
of Technology, Ordos 017000, China
- Department
of Water Resources & Environmental Treatment, Redbud Innovation Institute, Ordos 017000, China
| | - Jinglin Pang
- Department
of Water Resources & Environmental Treatment, Redbud Innovation Institute, Ordos 017000, China
| | - Xianming Zhang
- Department
of Water Resources & Environmental Treatment, Redbud Innovation Institute, Ordos 017000, China
| | - Juan Li
- College
of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Jiding Li
- Department
of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Panyue Zhang
- College
of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
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