笋壳渣对阴阳离子染料的吸附特征及机制研究

Adsorption characteristics and mechanism of anion and cation dyes by bamboo shoot shell residue

为实现竹笋加工废弃笋壳(BSS)的综合利用,将笋壳逐级提取甾醇、木糖后产生的笋壳渣(BSSE)作为吸附材料,选用典型的阳离子染料亚甲基蓝(MB)和典型的阴离子染料酸性大红(AS)作为吸附质,研究BSSE对阳离子染料和阴离子染料的吸附特征及机制。结果表明:随着溶液初始pH的增大,BSSE对MB的去除率大体呈上升趋势,而对AS的去除率大体呈下降趋势;当MB溶液和AS溶液的初始质量浓度均为100 mg/L时,BSSE的最佳投加质量浓度为1.5 g/L,此时去除率分别可达99.5%和95.7%;BSSE吸附MB的过程较好地符合Freundlich和Elovich模型,吸附可自发进行,以化学吸附为主,物理吸附为辅;吸附AS的过程较好地符合Langmuir和Elovich模型,吸附可自发进行,以物理吸附为主,化学吸附为辅。

In order to realize the comprehensive utilization of bamboo shoots processing waste bamboo shoot shell(BSS),the bamboo shoot shell residue(BSSE)produced by extracting sterol and xylose step by step was used as the adsorption material.A typical cationic dye methylene blue(MB)and a typical anionic dyes acid scarlet(AS)were selected as adsorbents to study the adsorption characteristics and mechanism of BSSE for cationic and anionic dyes.The results showed that with the increase of the initial pH of the solution,the removal rate of MB generally showed a rising trend,while the removal rate of AS generally showed a downward trend.When the initial mass concentration of MB solution and AS solution was 100 mg/L,the optimal dosage of BSSE was 1.5 g/L,and the removal rate of MB and AS could reach 99.5%and 95.7%,respectively.The process of BSSE adsorption for MB better conformed to Freundlich and Elovich models,which was a spontaneous and mainly chemical adsorption process with complementary physical adsorption.The adsorption process of BSSE adsorption for AS better conformed to the Langmuir and Elovich models,which was a spontaneous and mainly physical adsorption process with complementary chemical adsorption.