Chowdhury Noman, Roy Chanchal Kumar, Firoz Shakhawat H, Foyez Tahmina, Imran Abu Bin
Department of Chemistry, Faculty of Engineering, Bangladesh University of Engineering and Technology, Dhaka 1000, Bangladesh.
Department of Pharmaceutical Sciences, School of Health and Life Sciences, North South University, Dhaka 1229, Bangladesh.
ACS Omega. 2020 Dec 31;6(1):836-844. doi: 10.1021/acsomega.0c05411. eCollection 2021 Jan 12.
A variety of methods for removing heavy metal ions from wastewater have been developed but because of their low efficiency, further production of toxic sludge or other waste materials, high expense, and lengthy procedures, limited progress has been achieved to date. Polymeric hydrogel has been attracting particular attention for the effective removal of heavy metal ions from wastewater. Here, ionogenic polymeric hydrogels were prepared by free-radical copolymerization of a neutral acrylamide (AAm) monomer with an ionic comonomer in the presence of a suitable initiator and a cross-linker. Different types of ionic comonomers such as strongly acidic: 2-acrylamido-2-methylpropane sulfonic acid, weakly acidic: acrylic acid (AAc), and zwitterionic: 2-methacryloyloxy ethyl dimethyl-3-sulfopropyl ammonium hydroxide with varying amounts were incorporated into the poly(AAm) networks to fabricate the hydrogels. The heavy metal ions (Fe, Cr, and Hg) removal capacity of the fabricated hydrogels from an aqueous solution via electrostatic interactions, coordination bond formation, and a diffusion process was compared and contrasted. The poly(AAm) hydrogel containing weakly acidic AAc groups shows excellent removal capacity of heavy metal ions. The release and recovery of heavy metal ions from the hydrogel samples are also impressive. The compressive strength of hydrogels was found to be significantly high after incorporating heavy metal ions that will increase their potential applications in different sectors.
人们已经开发出多种从废水中去除重金属离子的方法，但由于这些方法效率低下、会进一步产生有毒污泥或其他废料、成本高昂且程序冗长，到目前为止进展有限。聚合物水凝胶因能有效去除废水中的重金属离子而备受关注。在此，通过中性丙烯酰胺（AAm）单体与离子共聚单体在合适的引发剂和交联剂存在下进行自由基共聚制备了离子型聚合物水凝胶。将不同类型的离子共聚单体，如强酸性的2-丙烯酰胺基-2-甲基丙烷磺酸、弱酸性的丙烯酸（AAc）以及两性离子型的2-甲基丙烯酰氧基乙基二甲基-3-磺丙基氢氧化铵，以不同含量引入聚（AAm）网络中来制备水凝胶。通过静电相互作用、配位键形成和扩散过程，比较并对比了所制备水凝胶从水溶液中去除重金属离子（铁、铬和汞）的能力。含有弱酸性AAc基团的聚（AAm）水凝胶对重金属离子显示出优异的去除能力。重金属离子从水凝胶样品中的释放和回收也令人印象深刻。在掺入重金属离子后，发现水凝胶的抗压强度显著提高，这将增加它们在不同领域的潜在应用。
