Minju N, Jobin G, Savithri S, Ananthakumar S
Academy of Scientific and Innovative Research , Ghaziabad , Uttar Pradesh 201002 , India.
Department of Geology, School of Earth Sciences , Central University of Karnataka , Gulbarga 585367 , India.
Langmuir. 2019 Jul 23;35(29):9382-9395. doi: 10.1021/acs.langmuir.9b00898. Epub 2019 Jul 10.
In this work, a lightweight inorganic-organic hybrid foam adsorbent is processed out of economically cheap "double-silicate" precursors employing natural bentonite and water glass through a facile cross-linking and polymerization technique. Poly(vinyl alcohol) was used to provide structural strength to the three-dimensional framework. The foam adsorbent possessed an apparent density of 0.083 g cm, indicating its internetworks and exposed surface area for the uptake of dyes. The foam was systematically studied for the treatment of textile dye effluent. Multivariate optimization process was carried out using response surface methodology. The Box-Behnken model was used for the design of experiments and to study the interplay between the variables. Batch adsorption and continuous column adsorption studies were carried out at respective levels of initial concentration (200-1000 μM), adsorbent dose (1-10 g L), and contact time (0-120 min). The results revealed that the hybrid silicate foam exhibits adsorption capacity as high as 99.9, 98.9, and 98.2% for 200, 600, and 1000 μM concentrations of methylene blue in 120 min, respectively, and 100% adsorption for 200, 600, and 1000 μM concentrations of crystal violet in 120 min for 10 g L of adsorbent. Adsorption equilibrium data fitted well to Langmuir isotherm, and the kinetics followed second-order kinetic model. Synthetic industrial effluent with 1000 μM dye concentration was also prepared and studied with continuous column for determining the working capacity of the adsorbent, and the results are presented. The silicate hybrid foam is a cheap adsorbent that does not produce any secondary waste and can be repeatedly used making it attractive for dye industries.
在本研究中，通过简便的交联和聚合技术，利用经济廉价的天然膨润土和水玻璃制成的“双硅酸盐”前驱体，制备出一种轻质无机-有机杂化泡沫吸附剂。使用聚乙烯醇为三维骨架提供结构强度。该泡沫吸附剂的表观密度为0.083 g/cm³，表明其具有相互连通的网络结构以及用于染料吸附的暴露表面积。对该泡沫用于处理纺织印染废水进行了系统研究。采用响应面法进行多变量优化过程。使用Box-Behnken模型进行实验设计并研究变量之间的相互作用。在初始浓度（200 - 1000 μM）、吸附剂剂量（1 - 10 g/L）和接触时间（0 - 120 min）的各自水平下进行了间歇吸附和连续柱吸附研究。结果表明，对于120 min内浓度为200、600和1000 μM的亚甲基蓝，杂化硅酸盐泡沫的吸附容量分别高达99.9%、98.9%和98.2%；对于10 g/L的吸附剂，在120 min内对浓度为200、600和1000 μM的结晶紫的吸附率为100%。吸附平衡数据很好地符合朗缪尔等温线，动力学遵循二级动力学模型。还制备了染料浓度为1000 μM的合成工业废水，并使用连续柱进行研究以确定吸附剂的工作容量，并给出了结果。该硅酸盐杂化泡沫是一种廉价的吸附剂，不会产生任何二次废物，并且可以重复使用，这使其对印染行业具有吸引力。
