粉煤灰基沸石对亚甲基蓝和Cr(Ⅲ)的共吸附行为——Ⅱ.竞争吸附机制

Co-adsorption behavior of methylene blue(MB) and Cr(Ⅲ) on synthesized zeolite from fly ash: Ⅱ.Competitive adsorption mechanism

以粉煤灰基合成沸石为吸附剂,亚甲基蓝(MB)和Cr(Ⅲ)为去除对象,通过静态批次实验研究溶液pH值、反应时间对废水净化效果的影响,借助FT-IR、SEM初步揭示MB和Cr(Ⅲ)的竞争吸附机制。研究发现,溶液pH值为6和5时,沸石对MB和Cr(Ⅲ)的最大吸附量分别为8.14 mg/g和6.46 mg/g;反应10 min后,沸石对MB和Cr(Ⅲ)的吸附量超过60 min总吸附量的80%和55%。FT-IR和SEM结果表明,—OH、硅铝酸盐类官能团对MB和Cr(Ⅲ)的共吸附有重要作用,反应后沸石表面出现连续的、蓬松状态的絮状结构。推测MB分子被吸附于沸石表面或层间,形成较为复杂的网状络合物,这种结构又促进吸附过程的离子交换和配位络合等化学效应,强化了污染物的共吸附效果。

Zeolite synthesized from fly ash was used to remove methylene blue（ MB） and Cr（ Ⅲ） at different initial pH values and reaction times,FT-IR and SEM were applied into the investigation of competitive adsorption mechanism. At initial pH values of 6 and 5,the maximum adsorption capacity for MB and Cr（ Ⅲ） were 8. 14 mg/g and 6. 46 mg/g,and the 80% and 55% of total adsorption capacity（ 60 min） attained at 10 min,respectively. The results of FT-IR and SEM revealed that —OH and functional groups of aluminosilicate were important for wastewater purification,and the floc structures appeared on zeolite surface. It was believed that MB moleculars distributed on surface and inner room of zeolite,formed to be complex floc compounds,benefit to chemical effect of ion exchange and complexation,and removal efficiency for MB and Cr（ Ⅲ）.