Department of Chemistry, Dr. B R Ambedkar National Institute of Technology, Jalandhar Punjab, India.
Department of Chemistry, Dr. B R Ambedkar National Institute of Technology, Jalandhar Punjab, India.
J Environ Manage. 2019 Mar 15;234:345-356. doi: 10.1016/j.jenvman.2018.12.117. Epub 2019 Jan 9.
The research work proposes the synthesis of a nanocomposite hydrogel which is a dual combination of binary interpenetrating network (BIPN) and bismuth ferrite nanoparticles. BIPN synthesized from binary graft copolymer (BGC) used as starting material. The cross-linked network of BGC is interpenetrating the newly synthesized cross-linked network of poly(acrylic acid) and the product is named as BIPN. Binary graft copolymer had been synthesized from grafting of guggul aqueous extract with copolymeric chains of acrylamide (primary monomer) and acrylic acid (secondary monomer) crosslinked by N,N'-methylene bisacrylamide (MBA). The maximum percentage swelling was evaluated for BGC through optimization of various reaction parameters: amount of water, binary ratio of acrylamide to acrylic acid, concentrations of MBA, ammonium persulphate, pH, temperature and time. Considering pre-optimized parameters for BGC synthesis, BIPN formation required optimization of only acrylic acid. Maximum percentage swelling obtained was 1497.79% and 308.15% for BGC and BIPN, respectively. Maximum percentage biodegradation of 90.64% and 82.38% were calculated for BGC and BIPN, respectively using composting method. Degradation efficiency of brilliant blue (BB) and fuchsin basic (FB) dyes was in the order: Nanocomposite ≫ BIPN > BGC. Maximum percentage degradation observed in case of nanocomposite was 94.1% and 99.3% in sunlight for BB and FB, respectively. The interaction of dyes with the nanocomposite involved mainly ionic interactions. The adsorption models Freundlich and Langmuir were applicable to overall adsorption and degradation process of BB and FB, respectively. Maximum adsorption capacities corresponding to minimum concentration i.e. 10 mg L for BB and FB were calculated as 0.409 mg g and 0.439 mg g, respectively. Second order and first order kinetics were found to be suitable for BB and FB adsorption-degradation pathways, respectively. Intraparticle diffusion mechanism was favorable to both dyes and adsorption followed three steps. Gas chromatography coupled with mass spectrometric analysis could give the degraded products which was helpful in drawing degradation pathway. The degradation process involved active radical species (O, OH) and they carry out oxidation-reduction reactions on dyes to give decolorized solution containing mineral ions.
该研究工作提出了一种纳米复合水凝胶的合成方法，该水凝胶是二元互穿网络（BIPN）和铋铁氧体纳米粒子的双重组合。BIPN 是由二元接枝共聚物（BGC）合成的，BGC 用作起始材料。Guggul 水提取物与丙烯酰胺（初级单体）和丙烯酸（次级单体）的共聚链接枝合成了 BGC，其交联网络贯穿于新合成的聚丙烯酸交联网络中，产物命名为 BIPN。通过优化各种反应参数：水的量、丙烯酰胺与丙烯酸的二元比、MBA 的浓度、过硫酸铵、pH 值、温度和时间，对 BGC 进行了最大百分比溶胀的评估。考虑到 BGC 合成的预优化参数，仅需优化 BIPN 形成中的丙烯酸。BGC 和 BIPN 的最大百分比溶胀分别为 1497.79%和 308.15%。使用堆肥法分别计算出 BGC 和 BIPN 的最大生物降解百分比为 90.64%和 82.38%。使用复合方法，亮蓝（BB）和碱性品红（FB）染料的降解效率顺序为：纳米复合材料＞BIPN＞BGC。纳米复合材料在阳光照射下对 BB 和 FB 的最大降解百分比分别为 94.1%和 99.3%。染料与纳米复合材料的相互作用主要涉及离子相互作用。Freundlich 和 Langmuir 吸附模型分别适用于 BB 和 FB 的整体吸附和降解过程。在最低浓度 10 mg/L 下，相应的最大吸附容量分别计算为 0.409 mg/g 和 0.439 mg/g。发现二级和一级动力学分别适用于 BB 和 FB 的吸附-降解途径。内扩散机制对两种染料都有利，吸附分为三个步骤。气相色谱-质谱联用分析可以提供降解产物，有助于绘制降解途径。降解过程涉及活性自由基（O、OH），它们对染料进行氧化还原反应，得到含有矿物质离子的褪色溶液。
