壳聚糖改性沸石吸附废水中的苯酚

Adsorption of phenol in wastewater with modified zeolite-chitosan adsorbent

开发新型低成本苯酚吸附剂是含酚废水处理技术的重点。采用90%脱乙酰度壳聚糖制备改性沸石,在与天然沸石对比的基础上,研究了改性沸石去除废水中的效果。并对影响去除率的主要因素,包括壳聚糖与斜发沸石质量比、废水pH值,吸附时间,改性沸石用量,苯酚的质量浓度等进行研究。通过正交试验确定吸附废水中苯酚最佳工艺条件是:壳聚糖与沸石质量比为1∶20,沸石-壳聚糖颗粒吸附剂用量为12g·L-1,废水中苯酚质量浓度不大于40mg·L-1,pH值为4～6,吸附平衡时间为35min,苯酚去除率为90%;吸附适合用Langmuir吸附等温方程来模拟。

Although non- metallic mines have been used widely as water amender, there are few reports for remedy contaminated waste water by modified chitosan-zeolite especially for phenol contaminated waste water. For the purpose of providing a new way to control and remedy phenol contaminated waste water, the equilibrium adsorption isotherm experiments were conducted to investigate the effect of the adsorption behaviors toward phenol in solution on the compound adsorbent. The compound adsorbent was prepared with the combination of chitosan and zeolite. Interchangeability is characteristic of natural zeolite ions,and chitosan has positive charge in the acid solution. Based on the two properties mentioned above,zeolite was added in chitosan slurry of 90% the degree of deacetylation to prepare adsorbent which mass ratio is 1 ： 20. Chitosan loading rate on zeolite was 32.6% at 700 ℃. Its adsorptivity toward phenol was studied and results show： the dosage of the adsorbent is 12 g/L, the mass concentration of phenol in wastewater does not exceed 40 mg/L, the pH value 4 - 6, the adsorption equilibrium time is about 35 min and phenol removal efficiency is 90%. The adsorption isotherm followed Langmuir isotherm equation.