含钛高炉渣制备复合吸附剂及其铬吸附性能

Study on the preparation of composite adsorbent with titaniumcontaining blast furnace slag and chromium adsorption performance

Cr(Ⅵ)是一种有害污染物,既污染水环境,也会对人体造成伤害。本文以工业固废含钛高炉渣为原料,通过酸浸得到浸出渣基体,经壳聚糖改性,制备一种新型GLZ-jcz/CS复合吸附剂,用来去除废水中的Cr(Ⅵ)。研究了吸附温度、废水pH、吸附剂量、Cr(Ⅵ)初始浓度、吸附时间对Cr(Ⅵ)吸附性能的影响。以Cr(Ⅵ)吸附率为评价指标,确定最优实验条件,并研究了GLZ-jcz/CS复合吸附剂的再生性能。采用扫描电子显微镜、傅里叶红外变换光谱仪、X射线光电子能谱仪、BET比表面积测试仪对GLZ-jcz/CS复合吸附剂进行表征,结合吸附动力学模型和吸附等温线模型分析,确定吸附机理。实验结果表明:当吸附温度为70℃、废水pH=4、吸附剂用量为0.13g、Cr(Ⅵ)初始浓度为50mg/L、吸附时间为2h时,吸附率达到99.8%,吸附容量可以达到67mg/g,GLZ-jcz/CS复合吸附剂经过6次洗脱,吸附率仍可达到96%以上,吸附模型符合拟二级动力学模型和Langmuir吸附等温模型。

Cr(Ⅵ)is a harmful pollutant that not only pollutes the water environment but also causes harm to humans.In this paper,a new composite adsorbent(GLZ-jcz/CS)was prepared for the removal of Cr(Ⅵ)from wastewater,using industrial solid waste containing titanium blast furnace slag as raw material,and the leached slag matrix was obtained by acid leaching and modified by chitosan.The effects of adsorption temperature,pH of wastewater,adsorbent dosage,initial concentration of Cr(Ⅵ)and adsorption time on the adsorption performance of Cr(Ⅵ)were studied.The optimal experimental conditions were determined using the Cr(Ⅵ)adsorption rate as the evaluation index,and the regeneration performance of GLZ-jcz/CS composite adsorbent was investigated.The GLZ-jcz/CS composite adsorbent was characterized by SEM,FTIR,XPS and BET,combined with adsorption kinetic model and adsorption isotherm model analysis to determine the adsorption mechanism.The experimental results showed that the adsorption rate reached 99.8%and the adsorption capacity could reach 67mg/g when the adsorption temperature was 70℃,the pH of wastewater was 4,the amount of adsorbent was 0.13g,the initial concentration of Cr(Ⅵ)was 50mg/L and the adsorption time was 2h.The GLZ-jcz/CS composite adsorbent can still reach over 96%adsorption after six elutions,and the adsorption model was compounded with the proposed secondary kinetic modeland the Langmuir adsorption isotherm model.