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Pan H, Sun C, Shen T, Sun J, He S, Li T, Lu X. Coal gasification crude slag based complex flocculants by two-step acid leaching process: synthesis, flocculation and mechanisms. RSC Adv 2024; 14:2705-2719. [PMID: 38229713 PMCID: PMC10790280 DOI: 10.1039/d3ra07232k] [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: 10/24/2023] [Accepted: 12/25/2023] [Indexed: 01/18/2024] Open
Abstract
Coal gasification crude slag (CGCS) is the side-product of the coal gasification process, and its effective utilization has attracted great attention. A novel flocculant of poly-aluminum-ferric-acetate-chloride (PAFAC) was synthesized based on the recovery of CGCS by a two-step acid leaching process, namely HCl-acid leaching and HAc-acid leaching, which was optimized by an acid leaching liquor volume ratio of HCl to HAc of 3 : 2, polymerization pH of 3.5, and reaction temperature and time of 70 °C and 3.0 h, respectively. The performance of PAFAC was further evaluated by kaolin simulated wastewater, domestic sewage, river water, and aquaculture wastewater. The results revealed that PAFAC was feasible for the removal of turbidity, chemical oxygen demand (COD) and total phosphorus (TP). Moreover, PAFAC was characterized by X-ray Diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray fluorescence spectrometry (XRF) and scanning electron microscopy (SEM), which proved that PAFAC was a kind of amorphous polyionic composite. Additionally, the acid leaching kinetics and flocculation mechanisms were further investigated. It was found that the acid leaching process was followed by the unreacted shrinkage core model, and the flocculation process was dominated by charge neutralization, adsorption bridging and precipitation net trapping. The work is expected to develop a new method for the safe disposal of CGCS and provide a novel way for the preparation of Fe-Al composite flocculants, especially, offering a potential strategy for the promotion of the additional value of the coal chemical industry.
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Affiliation(s)
- Haoqi Pan
- School of Environmental Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences) Jinan 250353 P. R. China
| | - Chenxu Sun
- School of Environmental Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences) Jinan 250353 P. R. China
| | - Tingting Shen
- School of Environmental Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences) Jinan 250353 P. R. China
| | - Jing Sun
- School of Environmental Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences) Jinan 250353 P. R. China
| | - Shaocang He
- School of Environmental Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences) Jinan 250353 P. R. China
| | - Tianpeng Li
- School of Environmental Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences) Jinan 250353 P. R. China
| | - Xuqian Lu
- School of Environmental Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences) Jinan 250353 P. R. China
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Panahi R, Ravi M, Abdollahi K. The concentrated polyaluminum chloride with tailor-made distribution of Al species: synthesis, distribution and transformation of Al species, and coagulation performance. ENVIRONMENTAL TECHNOLOGY 2023; 44:3215-3228. [PMID: 35298360 DOI: 10.1080/09593330.2022.2055497] [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: 03/26/2021] [Accepted: 03/10/2022] [Indexed: 06/14/2023]
Abstract
Production of concentrated polyaluminum chloride (PACl) with the proper distribution of Al species (Ala, Alb, and Alc) is still a challenging issue on both industrial and laboratory scale. Hence, the effects of total aluminum concentration (AlT) at high levels, regular basicity values, and low base injection rates on the distribution of Al species in PACl solutions were investigated using quadratic models. The results confirmed the possibility to synthesize tailor-made PACl solutions with a specified value of either Ala, Alb, or Alc within the range of 22-51%, 4-51%, or 0.5-74%, respectively. For instance, in agreement with the predicted value, a PACl sample rich in both Alb (42,200 ppm) and AlT was produced by applying the basicity of 1.7, AlT of 9.07% as Al2O3, and basification rate of 0.48 ml/h. In addition, the maximum Alc could be acquired by exploiting the highest C, B, and Q values. This condition also minimized both Ala and Alb. The trends of Ala and Alc changes by the increment of basicity were concave and convex, respectively, while Alb showed either a decreasing trend or a concave pattern based on the values of injection rate and AlT. The Alb-rich PACl sample was effectively applied for turbidity removal from synthetic wastewater at various pHs and initial turbidities. At best, residual turbidity of about 1% was observed after the coagulation process. These findings can be constructive for the production and application of tailor-made PACl.
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Affiliation(s)
- Reza Panahi
- Chemistry & Chemical Engineering Research Center of Iran (CCERCI), Tehran, Iran
| | - Mehdi Ravi
- Chemistry & Chemical Engineering Research Center of Iran (CCERCI), Tehran, Iran
| | - Kourosh Abdollahi
- School of Science, RMIT University, Bundoora West Campus, Melbourne, Australia
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Baria DM, Patel NY, Yagnik SM, Panchal RR, Rajput KN, Raval VH. Exopolysaccharides from marine microbes with prowess for environment cleanup. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:76611-76625. [PMID: 36166130 DOI: 10.1007/s11356-022-23198-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 09/19/2022] [Indexed: 06/16/2023]
Abstract
A variety of both small and large biologically intriguing compounds can be found abundantly in the marine environment. Researchers are particularly interested in marine bacteria because they can produce classes of bioactive secondary metabolites that are structurally diverse. The main secondary metabolites produced by marine bacteria are regarded as steroids, alkaloids, peptides, terpenoids, biopolymers, and polyketides. The global urbanization leads to the increased use of organic pollutants that are both persistent and toxic for humans, other life forms and tend to biomagnified in environment. The issue can be addressed, by using marine microbial biopolymers with ability for increased bioremediation. Amongst biopolymers, the exopolysaccharides (EPS) are the most prominent under adverse environmental stress conditions. The present review emphasizes the use of EPS as a bio-flocculent for wastewater treatment, as an adsorbent for the removal of textile dye and heavy metals from industrial effluents. The biofilm-forming ability of EPS helps with soil reclamation and reduces soil erosion. EPS are an obvious choice being environmentally friendly and cost-effective in processes for developing sustainable technology. However, a better understanding of EPS biosynthetic pathways and further developing novel sustainable technologies is desirable and certainly will pave the way for efficient usage of EPS for environment cleanup.
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Affiliation(s)
- Dhritiksha Mansukhlal Baria
- Department of Microbiology and Biotechnology, University School of Sciences, Gujarat University, 380 009, Ahmedabad, Gujarat, India
| | - Nidhi Yogeshbhai Patel
- Department of Microbiology and Biotechnology, University School of Sciences, Gujarat University, 380 009, Ahmedabad, Gujarat, India
| | | | - Rakeshkumar Ramanlal Panchal
- Department of Microbiology and Biotechnology, University School of Sciences, Gujarat University, 380 009, Ahmedabad, Gujarat, India
| | - Kiransinh Narendrasinh Rajput
- Department of Microbiology and Biotechnology, University School of Sciences, Gujarat University, 380 009, Ahmedabad, Gujarat, India
| | - Vikram Hiren Raval
- Department of Microbiology and Biotechnology, University School of Sciences, Gujarat University, 380 009, Ahmedabad, Gujarat, India.
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Synthesis and characterization of polyamine-based polyelectrolytes for wastewater treatment in the sugar industry. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2022.134573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Interface adsorption mechanism of the improved flotation of fine pyrite by hydrophobic flocculation. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2021.119245] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Jahedi E, Panahi R. Conversion of lignocellulosic waste into effective flocculants: synthesis, characterization, and performance. BIORESOUR BIOPROCESS 2021; 8:69. [PMID: 38656091 PMCID: PMC11341801 DOI: 10.1186/s40643-021-00422-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/26/2021] [Indexed: 11/10/2022] Open
Abstract
Development of cationic flocculants from lignocellulosic wastes not only eliminates the health and environmental concerns associated with the use of conventional chemicals, but also is the way of waste valorization. In the present study, cellulose fibers extracted from rice husk were cationized through an optimization method based on response surface methodology. The fibers cationized at the optimal conditions had a zeta-potential of 15.2 ± 1.0 mV, while the highest potential was + 8.76 mV, for the samples developed before optimization. FTIR analysis proved the presence of the corresponding functional groups. The functionalized fibers were biodegradable and had absolutely positive surface charges at a broad pH range. The cationized fibers were employed as a flocculant to remove turbidity from the synthetic wastewaters at various pHs and initial turbidities. The cationic fibers showed the excellent turbidity removals up to 98.5% from the synthetic wastewater without the need for conventional coagulants. In contrast to traditionally cationized fibers, the synthesized flocculants did not affect the effluent color during coagulation-flocculation. The charge neutralization and bridging through adsorption were the governing mechanisms of flocculation. The procedure can be applied on lignocellulosic wastes to develop cationic fibers with the excellent flocculation ability and suitable operational characteristics.
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Affiliation(s)
- Elham Jahedi
- Chemistry & Chemical Engineering Research Center of Iran (CCERCI), Tehran, Iran
| | - Reza Panahi
- Chemistry & Chemical Engineering Research Center of Iran (CCERCI), Tehran, Iran.
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Applications of Biocatalysts for Sustainable Oxidation of Phenolic Pollutants: A Review. SUSTAINABILITY 2021. [DOI: 10.3390/su13158620] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Phenol and its derivatives are hazardous, teratogenic and mutagenic, and have gained significant attention in recent years due to their high toxicity even at low concentrations. Phenolic compounds appear in petroleum refinery wastewater from several sources, such as the neutralized spent caustic waste streams, the tank water drain, the desalter effluent and the production unit. Therefore, effective treatments of such wastewaters are crucial. Conventional techniques used to treat these wastewaters pose several drawbacks, such as incomplete or low efficient removal of phenols. Recently, biocatalysts have attracted much attention for the sustainable and effective removal of toxic chemicals like phenols from wastewaters. The advantages of biocatalytic processes over the conventional treatment methods are their ability to operate over a wide range of operating conditions, low consumption of oxidants, simpler process control, and no delays or shock loading effects associated with the start-up/shutdown of the plant. Among different biocatalysts, oxidoreductases (i.e., tyrosinase, laccase and horseradish peroxidase) are known as green catalysts with massive potentialities to sustainably tackle phenolic contaminants of high concerns. Such enzymes mainly catalyze the o-hydroxylation of a broad spectrum of environmentally related contaminants into their corresponding o-diphenols. This review covers the latest advancement regarding the exploitation of these enzymes for sustainable oxidation of phenolic compounds in wastewater, and suggests a way forward.
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Mao S, Xu X, Zhang L, Bai B, Hu N, Wang H. Methylated mud snail protein as a bio-flocculant for high turbidity wastewater treatment. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2021; 84:737-751. [PMID: 34388131 DOI: 10.2166/wst.2021.262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The authors reported a potential candidate methylated mud snail protein (MeMsp) as an effective and eco-friendly flocculant to treat the high turbidity wastewater. MeMsp was obtained by extraction of mud snail protein (Msp) through isoelectric precipitation (PSC-IP) and then methylated via the esterification with side-chain carboxyl. Structural characterization of FT-IR, zeta potential and elemental analysis were carried out and further confirmed the successful of the methylation. Flocculation experiments with kaolin suspension simulated wastewater indicated that MeMsp-24 displayed more excellent flocculation efficiency at a low dosage. At the optimum dosage 27 mg/L, the maximum clarification efficiency of MeMsp-24 was 97.46% under pH 7.0. Furthermore, MeMsp-24 exhibited a wide flocculation window in the pH range 1.0-9.0, and faster sedimentation velocity and larger flocs size. In addition, MeMsp-24 exhibited 92.12% clarification efficiency in treating railway tunnel construction effluent. The flocculation kinetic and mechanism analysis revealed that the most effective particle collision occurred at the optimal dosage, with charge neutralization and adhesion playing irreplaceable roles in different environments, respectively. Therefore, through extraction and methylation modification, MeMsp could be a promising eco-friendly flocculant for high turbidity wastewater treatment.
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Affiliation(s)
- Shaohui Mao
- Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region of the Ministry of Education, School of Water and Environment, Chang'an University, No. 126, Yanta Road, Xi'an 710054, Shaanxi, China
| | - Xiaohui Xu
- Department of Chemical and Biological Engineering Princeton University, Princeton, New Jersey 08544, USA
| | - Linjiang Zhang
- Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region of the Ministry of Education, School of Water and Environment, Chang'an University, No. 126, Yanta Road, Xi'an 710054, Shaanxi, China
| | - Bo Bai
- Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region of the Ministry of Education, School of Water and Environment, Chang'an University, No. 126, Yanta Road, Xi'an 710054, Shaanxi, China; Department of Chemical and Biological Engineering Princeton University, Princeton, New Jersey 08544, USA; CAS Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Xining 810001, China
| | - Na Hu
- CAS Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Xining 810001, China
| | - Honglun Wang
- CAS Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Xining 810001, China
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Das N, Ojha N, Mandal SK. Wastewater treatment using plant-derived bioflocculants: green chemistry approach for safe environment. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2021; 83:1797-1812. [PMID: 33905353 DOI: 10.2166/wst.2021.100] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The rapid expansion of global trade and human activities has resulted in a massive increase in wastewater pollution into the atmosphere. Suspended solids, organic and inorganic particles, dissolved solids, heavy metals, dyes, and other impurities contained in wastewater from various sources are toxic to the atmosphere and pose serious health risks to humans and animals. Coagulation-flocculation technology is commonly used in wastewater treatment to remove cell debris, colloids, and contaminants in a comfortable and effective manner. Flocculants, both organic and inorganic, have long been used in wastewater treatment. However, because of their low performance, non-biodegradability, and associated health risks, their use has been limited. The use of eco-friendly bioflocculants in wastewater treatment has become essential due to the health implications of chemical flocculants. Because of their availability, biodegradability, and protection, plant-derived coagulants/flocculants and plant-based grafted bioflocculants have recently made significant progress in wastewater treatment. This study will undoubtedly provide a clearer understanding of the current state, challenges, and solutions for bioflocculation in wastewater remediation using green materials for the sake of a cleaner climate.
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Affiliation(s)
- Nilanjana Das
- Bioremediation Laboratory, Department of Biomedical Sciences, School of Bio Sciences and Technology, VIT, (Vellore Institute of Technology), Vellore, Tamil Nadu 632014, India E-mail:
| | - Nupur Ojha
- Bioremediation Laboratory, Department of Biomedical Sciences, School of Bio Sciences and Technology, VIT, (Vellore Institute of Technology), Vellore, Tamil Nadu 632014, India E-mail:
| | - Sanjeeb Kumar Mandal
- Department of Biotechnology, Sri Shakthi Institute of Engineering and Technology, Coimbatore, Tamil Nadu 641062, India
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