A novel cationic polyelectrolyte microsphere for ultrafast and ultra-efficient removal of heavy metal ions and dyes

An Overview on Composite Sorbents Based on Polyelectrolytes Used in Advanced Wastewater Treatment

“…Sorption processes in water treatment could require granular materials with certain size and, thus, the beads/microbeads composites based on polyelectrolytes could widen the possibilities of pollutants extraction in solid phases. Novel binary/ternary beads composites, where polyelectrolyte chain is the main component, could be mainly obtained by: (a) combination of CS with organic species (e.g., starches-g-polyacrylonitrile [53], carrageenan [31], PVAm [54], PEI [55], microcrystalline cellulose [56], carboxymethyl-βcyclodextrin [42], QCS [20,60], citrate [52]) and/or inorganic (e.g., Fe 3 O 4 [52], Fe [42]), (b) combination of SA with organic/inorganic entities, such as activated carbon [77], CMC [79], polyaniline [61], different types of clays (bentonite [63,78,80], ilite [76], kaolinite [76], montmorillonite [68,81,82], Fe 3 O 4 [59,64,67], SiO 2 [65], hydroxyapatite [66]), and (c) combination of other types of polyelectrolytes (PEI, PAA) [97] to form interpolyelectrolyte composite beads. The physico-chemical integrity of combined architectures inside the bead composite must be kept under different environmental conditions (pH, ionic strength, temperature, magnetic field, etc.…”

“…The cross-linking could be carried out in situ (emulsification method) during the bead formation or after the coagulation/precipitation or frozen of composite beads. The most important cross-links could be achieved by covalent or ionic crosslinking with bifunctional compounds (e.g., glutaraldehyde [53,62], ECH [20,31,54,55,96], poly(ethyleneglycol diglycidyl ether) [53], carbodiimide [42,52], 3-chloro-2-hydroxypropyl trimethyl ammonium chloride [60] etc.) and small ions (ionic gelation method), respectively, including Ca 2+ [56,61,[63][64][65][66]68,[76][77][78]80,82], Ce 3+ [67], Zr 4+ [59], Fe 3+ ), tripolyphoshate [54].…”

Analysis of Copper(II), Cobalt(II) and Iron(III) Sorption in Binary and Ternary Systems by Chitosan-Based Composite Sponges Obtained by Ice-Segregation Approach

“…Among these, adsorption is considered a simple and efficient technique to remove HMIs from wastewaters [8][9][10][11][12]. A large variety of sorbent materials, such as metal oxides/hydroxides [13,14], zeolites [15,16], commercial or synthetic activated carbon [17,18], biomass [19], synthetic organic supports [6,8,9], and unmodified or functionalized polysaccharides (chitosan, salecan, pullulan, alginate) [20][21][22][23][24][25][26][27][28][29] have been reported to remove HMIs from contaminated waters.…”

“…Lately, the employment of inexpensive and eco-friendly sorbents, such as renewable natural polymers, in the extraction and recovery of certain HMIs has drawn considerable interest [2,3,10,11,[20][21][22][23][24][25][26][27][28][29]. Amongst these low-cost sorbents, chitosan (CS) displayed promising abilities to bind different HMIs due to the presence of numerous amino and hydroxyl groups in its structure [2,20,27].…”

A salt-free, zero-discharge and dyebath-recyclable circular coloration technology based on cationic polyelectrolyte complex for cotton fabric dyeing

“…Examples include adsorption by adsorbents, oxidation, photocatalytic degradation, biological treatment, ozonation, electrochemical treatment, membrane ltration and chemical coagulation/ occulation, etc. (Cai et al 2021;Ahmad et al 2015;Vikrant et al 2018;Yagub et al 2014;Furlan et al 2010). Among them, chemical coagulation and occulation have been widely employed for pretreatment of dyeing wastewater by using cationic polyelectrolyte complex due to its low capital cost and the tailorability (Wilts et al 2018; Sun et al 2016).…”