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The gel was produced by condensing and grafting glutathione as a grafting monomer onto the main polyacrylamide chain, based on the Mannich reaction mechanism with formaldehyde. FTIR, SEM, TG-DSC, and zeta potentials were used to characterize the gel. The results demonstrated that the gel was morphologically folded and porous, with a net-like structure, which enhanced its net trapping and sweeping abilities, and that glutathione was used to provide sulfhydryl groups to boost the metal trapping ability of polyacrylamide. Coagulation experiments showed that the highest efficiency of the removal of Cd ions from water samples was achieved when the concentration of polyacrylamide\u2013glutathione was 84.48 mgL\u22121, the concentration of Cd was 10.0 mgL\u22121, the initial turbidity was 10.40 NTU, and the initial pH was 9.0. Furthermore, the presence of two cations, Cu and Zn, had an inhibitory effect on the removal of Cd ions. In addition, analysis of the zeta potential revealed the flocculation of polyacrylamide\u2013glutathione. The flocculation mechanism of glutathione is mainly chelation, adsorption bridging, and netting sweeping.<\/jats:p>","DOI":"10.3390\/polym15030500","type":"journal-article","created":{"date-parts":[[2023,1,19]],"date-time":"2023-01-19T04:19:40Z","timestamp":1674101980000},"page":"500","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":16,"title":["Preparation of Heavy Metal Trapping Flocculant Polyacrylamide\u2013Glutathione and Its Application for Cadmium Removal from Water"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8209-8950","authenticated-orcid":false,"given":"Wenjie","family":"Ding","sequence":"first","affiliation":[{"name":"School of Metallurgy and Environment, Central South University, Changsha 410083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yunyan","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Metallurgy and Environment, Central South University, Changsha 410083, China"},{"name":"Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha 410083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Weizhi","family":"Zeng","sequence":"additional","affiliation":[{"name":"School of Metallurgy and Environment, Central South University, Changsha 410083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hui","family":"Xu","sequence":"additional","affiliation":[{"name":"School of Metallurgy and Environment, Central South University, Changsha 410083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bingxin","family":"Chen","sequence":"additional","affiliation":[{"name":"School of Metallurgy and Environment, Central South University, Changsha 410083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,1,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"167","DOI":"10.1093\/bmb\/ldg032","article-title":"Hazards of Heavy Metal Contamination","volume":"68","year":"2003","journal-title":"Br. Med. Bull."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"869","DOI":"10.1016\/j.chemosphere.2013.01.075","article-title":"Phytoremediation of Heavy Metals\u2014Concepts and Applications","volume":"91","author":"Ali","year":"2013","journal-title":"Chemosphere"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"407","DOI":"10.1016\/j.jenvman.2010.11.011","article-title":"Removal of Heavy Metal Ions from Wastewaters: A Review","volume":"92","author":"Wang","year":"2011","journal-title":"J. Environ. Manag."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1337","DOI":"10.1016\/j.eurpolymj.2008.12.027","article-title":"Chitosan for Coagulation\/Flocculation Processes\u2014An Eco-Friendly Approach","volume":"45","author":"Renault","year":"2009","journal-title":"Eur. Polym. J."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"608","DOI":"10.1016\/j.watres.2018.07.029","article-title":"Coagulation\/Flocculation in Dewatering of Sludge: A Review","volume":"143","author":"Wei","year":"2018","journal-title":"Water Res."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"142795","DOI":"10.1016\/j.scitotenv.2020.142795","article-title":"Application of Coagulation\/Flocculation in Oily Wastewater Treatment: A Review","volume":"765","author":"Zhao","year":"2021","journal-title":"Sci. Total Environ."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1800526","DOI":"10.1002\/mame.201800526","article-title":"Water Soluble Polymer Flocculants: Synthesis, Characterization, and Performance Assessment","volume":"304","author":"Vajihinejad","year":"2018","journal-title":"Macromol. Mater. 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Res."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1016\/j.jcis.2010.04.063","article-title":"Solid\u2013Liquid Separations with a Temperature-Responsive Polymeric Flocculant: Effect of Temperature and Molecular Weight on Polymer Adsorption and Deposition","volume":"348","author":"Qiao","year":"2010","journal-title":"J. Colloid Interface Sci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2301","DOI":"10.1016\/j.watres.2007.03.012","article-title":"Organic Polyelectrolytes in Water Treatment","volume":"41","author":"BOLTO","year":"2007","journal-title":"Water Res."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"489","DOI":"10.1016\/j.psep.2014.04.010","article-title":"A Review on Application of Flocculants in Wastewater Treatment","volume":"92","author":"Lee","year":"2014","journal-title":"Process Saf. Environ. Prot."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"495","DOI":"10.1016\/j.cej.2015.08.003","article-title":"Removal of Cu(II) and Tetracycline Using an Aromatic Rings-Functionalized Chitosan-Based Flocculant: Enhanced Interaction between the Flocculant and the Antibiotic","volume":"283","author":"Jia","year":"2016","journal-title":"Chem. Eng. J."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"3130","DOI":"10.1021\/bm400752k","article-title":"Polymer-Grafted Cellulose Nanocrystals as PH-Responsive Reversible Flocculants","volume":"14","author":"Kan","year":"2013","journal-title":"Biomacromolecules"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"160","DOI":"10.1016\/j.watres.2017.04.032","article-title":"Evaluation of Structural Effects on the Flocculation Performance of a Co-Graft Starch-Based Flocculant","volume":"118","author":"Liu","year":"2017","journal-title":"Water Res."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"361","DOI":"10.1016\/j.watres.2016.01.031","article-title":"Combination of Forward Osmosis (FO) Process with Coagulation\/Flocculation (CF) for Potential Treatment of Textile Wastewater","volume":"91","author":"Han","year":"2016","journal-title":"Water Res."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1016\/j.scitotenv.2018.05.309","article-title":"A Novel Carboxyl-Rich Chitosan-Based Polymer and Its Application for Clay Flocculation and Cationic Dye Removal","volume":"640\u2013641","author":"Liu","year":"2018","journal-title":"Sci. Total Environ."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"115735","DOI":"10.1016\/j.seppur.2019.115735","article-title":"Ultrasound-Assisted Synthesis of the \u03b2-Cyclodextrin Based Cationic Polymeric Flocculants and Evaluation of Flocculation Performance: Role of \u03b2-Cyclodextrin","volume":"228","author":"Liu","year":"2019","journal-title":"Sep. Purif. Technol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"243","DOI":"10.1016\/j.scitotenv.2018.05.286","article-title":"Evaluation of a Novel Dextran-Based Flocculant on Treatment of Dye Wastewater: Effect of Kaolin Particles","volume":"640\u2013641","author":"Zhao","year":"2018","journal-title":"Sci. Total Environ."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"124866","DOI":"10.1016\/j.chemosphere.2019.124866","article-title":"Evaluation of the Structural Factors for the Flocculation Performance of a Co-Graft Cationic Starch-Based Flocculant","volume":"240","author":"Hu","year":"2020","journal-title":"Chemosphere"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"208","DOI":"10.1016\/j.seppur.2019.01.017","article-title":"Performance Evaluation of Chitosan-Based Flocculants with Good PH Resistance and High Heavy Metals Removal Capacity","volume":"215","author":"Sun","year":"2019","journal-title":"Sep. Purif. Technol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"379","DOI":"10.1016\/j.carbpol.2004.04.020","article-title":"Characterisation of Carboxymethyl Cellulose and Polyacrylamide Graft Copolymer","volume":"57","author":"Biswal","year":"2004","journal-title":"Carbohydr. Polym."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.cis.2011.06.004","article-title":"Adsorption and Flocculation by Polymers and Polymer Mixtures","volume":"169","author":"Gregory","year":"2011","journal-title":"Adv. Colloid Interface Sci."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"711","DOI":"10.1146\/annurev.bi.52.070183.003431","article-title":"Glutathione","volume":"52","author":"Meister","year":"1983","journal-title":"Annu. Rev. Biochem."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"4552","DOI":"10.1074\/jbc.M111.315705","article-title":"Glutathione Degradation Is a Key Determinant of Glutathione Homeostasis","volume":"287","author":"Lagniel","year":"2012","journal-title":"J. Biol. Chem."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"623","DOI":"10.1016\/j.ijbiomac.2010.08.009","article-title":"Microwave Assisted Synthesis of Polyacrylamide Grafted Dextrin (Dxt-g-PAM): Development and Application of a Novel Polymeric Flocculant","volume":"47","author":"Pal","year":"2010","journal-title":"Int. J. Bio. Macro."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"2621","DOI":"10.1002\/app.33471","article-title":"Synthesis and Characterization of Grafted Carboxymethyl Guar Gum","volume":"120","author":"Adhikary","year":"2010","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"698","DOI":"10.1080\/10601325.2022.2112516","article-title":"One-Pot Production of a Graft Copolymer of Cationic Starch and Cationic Polyacrylamide Applicable as Flocculant for Wastewater Treatment","volume":"59","author":"Tajbakhsh","year":"2022","journal-title":"J. Macromol. Sci. Part A"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"5390","DOI":"10.1080\/19443994.2013.807476","article-title":"Optimization of Flocculation Process by Response Surface Methodology for Diethyl Phthalate Removal Using Anionic Polyacrylamide","volume":"52","author":"Zheng","year":"2013","journal-title":"Desalination Water Treat."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"342","DOI":"10.3390\/w5020342","article-title":"Modeling and Optimization of New Flocculant Dosage and PH for Flocculation: Removal of Pollutants from Wastewater","volume":"5","author":"Dawood","year":"2013","journal-title":"Water"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"965","DOI":"10.1016\/j.talanta.2008.05.019","article-title":"Response Surface Methodology (RSM) as a Tool for Optimization in Analytical Chemistry","volume":"76","author":"Bezerra","year":"2008","journal-title":"Talanta"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1080\/00224065.2004.11980252","article-title":"Response Surface Methodology: A Retrospective and Literature Survey","volume":"36","author":"Myers","year":"2004","journal-title":"J. Qual. Technol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"629","DOI":"10.14233\/ajchem.2014.16055","article-title":"Cationic Polyacrylamide: Synthesis and Application in Sludge Dewatering Treatment","volume":"26","author":"Jiang","year":"2014","journal-title":"Asian J. Chem."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"7071","DOI":"10.14233\/ajchem.2013.15144","article-title":"Synthesis and Application of Anionic Polyacrylamide in Water Treatment","volume":"25","author":"Zheng","year":"2013","journal-title":"Asian J. Chem."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"5923","DOI":"10.14233\/ajchem.2014.16860","article-title":"Hydrophobically Modified Polyacrylamide Synthesis and Application in Water Treatment","volume":"26","author":"Liao","year":"2014","journal-title":"Asian J. Chem."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"109","DOI":"10.2174\/1570193X13999160405112331","article-title":"Advances in the Initiation System and Synthesis Methods of Cationic Poly-Acrylamide: A Review","volume":"13","author":"Zhao","year":"2016","journal-title":"Mini-Rev. Org. Chem."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1517","DOI":"10.1007\/s42247-021-00338-8","article-title":"Enhanced Sequestration of Heavy Metals from Aqueous Solution on Polyacrylamide Grafted with Cell@Fe3O4 Nanocomposite","volume":"5","author":"Ahmad","year":"2022","journal-title":"Emergent Mater."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"133553","DOI":"10.1016\/j.cej.2021.133553","article-title":"Incorporation of Aniline Tetramer into Alginate-Grafted-Polyacrylamide as Polymeric Binder for High-Capacity Silicon\/Graphite Anodes","volume":"433","author":"Gendensuren","year":"2022","journal-title":"Chem. Eng. J."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1175","DOI":"10.1016\/j.ijbiomac.2022.09.236","article-title":"3D Printing of Reduced Glutathione Grafted Gelatine Methacrylate Hydrogel Scaffold Promotes Diabetic Bone Regeneration by Activating PI3K\/Akt Signaling Pathway","volume":"222","author":"Wang","year":"2022","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"103162","DOI":"10.1016\/j.jece.2019.103162","article-title":"Synthesis of Cross-Linker Devoid Novel Hydrogels: Swelling Behaviour and Controlled Urea Release Studies","volume":"7","author":"Kiran","year":"2019","journal-title":"J. Environ. Chem. Eng."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"647","DOI":"10.1016\/j.reactfunctpolym.2010.05.014","article-title":"Covalent Grafting of Polyacrylamide-Based Hydrogels to a Polypropylene Surface Activated with Functional Polyperoxide","volume":"70","author":"Varvarenko","year":"2010","journal-title":"React. Funct. Polym."},{"key":"ref_43","first-page":"109489","article-title":"Simultaneous Removal of Nitrate and Nitrite Using Electrocoagulation\/Floatation (ECF): A New Multi-Response Optimization Approach","volume":"250","author":"Nazlabadi","year":"2019","journal-title":"J. Eviron. Manag."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"853","DOI":"10.32604\/jrm.2022.022901","article-title":"Synthesis and Properties of Rosin-Based Composite Acrylamide Hydrogels","volume":"11","author":"Zhang","year":"2023","journal-title":"J. Renew. Mater."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"130037","DOI":"10.1016\/j.colsurfa.2022.130037","article-title":"Design, Preparation and Properties of New Polyacrylamide Based Composite Nano-Microspheres with like \u201cBall in Ball\u201d Structure","volume":"654","author":"Ma","year":"2022","journal-title":"Colloids Surf. A Physicochem. Eng. Asp."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"122816","DOI":"10.1016\/j.jssc.2021.122816","article-title":"Two Stable Cadmium(II) Coordination Polymers for Fluorimetric Detection of Tetracycline and Fe3+ Ions","volume":"307","author":"Cao","year":"2022","journal-title":"J. Solid State Chem."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"109131","DOI":"10.1016\/j.jece.2022.109131","article-title":"An Overview of the Use of Water-Stable Metal-Organic Frameworks in the Removal of Cadmium Ion","volume":"11","author":"Nabipour","year":"2023","journal-title":"J. Environ. Chem. Eng."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"203","DOI":"10.1002\/elps.200305755","article-title":"Zeta Potential of Microfluidic Substrates: 2. Data for Polymers","volume":"25","author":"Kirby","year":"2004","journal-title":"Electrophoresis"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"136805","DOI":"10.1016\/j.chemosphere.2022.136805","article-title":"The Aggregation of Natural Inorganic Colloids in Aqueous Environment: A Review","volume":"310","author":"Guo","year":"2023","journal-title":"Chemosphere"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"121046","DOI":"10.1016\/j.memsci.2022.121046","article-title":"Tuneable Ion Transport by Electrically Responsive Membranes under Electrical Assistance","volume":"663","author":"Xu","year":"2022","journal-title":"J. Membr. Sci."}],"container-title":["Polymers"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4360\/15\/3\/500\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T18:09:15Z","timestamp":1760119755000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4360\/15\/3\/500"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,1,18]]},"references-count":50,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2023,2]]}},"alternative-id":["polym15030500"],"URL":"https:\/\/doi.org\/10.3390\/polym15030500","relation":{},"ISSN":["2073-4360"],"issn-type":[{"value":"2073-4360","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,1,18]]}}}