烟厂污泥热解制备载铁生物炭吸附水中Cr(Ⅵ)的研究

Preparation of Fe-BC by Pyrolysis of Tobacco Wastewater Sludge and Its Adsorption of Cr(Ⅵ)from Aqueous Solution

文章以造纸法烟草薄片生产废水处理所得的压滤污泥(简称烟厂污泥)为原料制备载铁生物炭(Fe-BC)并用于去除水中Cr(Ⅵ)。结果表明,Fe-BC的最佳制备条件为热解温度700℃、热解时间1.5 h,污泥含水率10%。在Cr(Ⅵ)初始浓度为100 mg/L,FeBC投加量为6 g/L时可使溶液中Cr(Ⅵ)去除率达到99.8%。Fe-BC对Cr(Ⅵ)的吸附行为属于非均质表面吸附,满足Sips等温吸附模型及拟二级动力学方程,最大饱和吸附容量为75.23 mg/g。SEM及XRD分析表明,Fe-BC对Cr(Ⅵ)的去除是物理吸附与化学吸附综合作用的结果,涉及到静电吸附、氧化还原、原电池反应、共沉淀等过程。烟厂污泥热解制备的Fe-BC是一种良好的Cr(Ⅵ)吸附剂,可用于含Cr(Ⅵ)工业废水的处理,实现废弃物的资源化利用。

Iron loaded biochar(Fe-BC)was prepared from dewatered sludge of tobacco factory and used to remove Cr(Ⅵ)from water.Results showed that the optimal preparation conditions of Fe-BC were pyrolysis temperature 700℃,pyrolysis time 1.5 h,and moisture content of raw sludge 10%.When the initial concentration of Cr(Ⅵ)was 100 mg/L and the dosage of biochar was 6 g/L,the removal rate of Cr(Ⅵ)could reach 99.8%.The adsorption behavior of Fe-BC for Cr(Ⅵ)was heterogeneous,which could be well fitted by sips isothermal adsorption model and pseudo second order kinetic equation.The maximum saturated adsorption capacity was 75.23 mg/g.SEM and XRD analysis indicated that the removal of Cr(Ⅵ)by iron loaded biochar was the result of physical adsorption and chemical adsorption,involving electrostatic adsorption,redox,galvanic cell reaction,coprecipitation.Therefore,Fe-BC prepared by pyrolysis of sludge from tobacco factory will be a good adsorbent for heavy metals and can be used in the treatment of tannery wastewater and other industrial wastewater,and thus realizes the comprehensive utilization of waste treatment.