山西省典型土壤对重金属Cu、Zn和Pb等温吸附特征及应用

Isothermal adsorption characteristics and applications of Cu , Zn , and Pb in typical soil of Shanxi

寻求高效廉价重金属吸附材料在污水重金属去除领域具有重要意义。本研究采用摇瓶试验,研究了山西省石灰性黏壤土、石灰性砂壤土及碱性膨润土对Cu、Zn和Pb的等温吸附效果,并利用土柱吸附试验进一步研究了3类吸附材料对污水处理厂入厂污水中重金属的实际吸附去除能力。研究结果表明,石灰性黏壤土、石灰性砂壤土及碱性膨润土对污水中Cu、Zn和Pb的等温吸附行为均可用Freundlich吸附等温线显著拟合。吸附材料对Cu、Zn和Pb的吸附作用力与吸附容量呈现石灰性黏壤土>碱性膨润土>石灰性砂壤土的变化趋势。石灰性黏壤土、石灰性砂壤土及碱性膨润土对3类重金属的吸附作用力表现为Zn>Cu>Pb、Cu>Zn>Pb与Cu>Zn>Pb,而吸附容量顺序却为Cu>Zn>Pb、Pb>Cu>Zn及Cu>Pb>Zn。石灰性黏壤土对污水处理厂接纳污水中Cu、Zn和Pb的吸附去除率为79.9%、97.7%和73.4%,碱性膨润土对相应污水重金属指标的去除率也高达70.3%、90.6%和90.6%。该研究结果可为湿地污水处理土壤的选择以及污水重金属吸附材料的选择提供一定的理论依据。

It was significant to find cheap and efficient adsorption materials to remove heavy metals from wastewater.In this study,the isothermal adsorption efficiencies of Cu,Zn,and Pb by calcareous clay soil,calcareous sandy soil,and alkaline bentonite were investigated through shake flask experiments.In addition,the removal efficiencies of Cu,Zn,and Pb from sewage treatment plant wastewater were studied by the above three adsorption material in the subsequent fixed bed adsorption process.Results showed that the isothermal adsorption characteristics of Cu,Zn,and Pb by calcareous clay soil,calcareous sandy soil,and alkaline bentonite was obviously correlated with Freundlich equation.The heavy metals adsorption forces of the calcareous clay soil,calcareous sandy soil,and alkaline bentonite were Zn〉Cu〉Pb,Cu〉Zn〉Pb,and Cu〉Zn〉Pb,respectively,while the heavy metals adsorption capacity of the calcareous clay soil,calcareous sandy soil,and alkaline bentonite were Cu〉Zn〉Pb,Pb〉Cu〉Zn,and Cu〉Pb〉Zn.Meanwhile,further fixed bed adsorption experiments revealed that the removal efficiency of Cu,Zn,and Pb from wastewater by calcareous clay soil adsorption were 79.9%,97.7%,and 73.4%,and the removal efficiency of Cu,Zn,and Pb by the alkaline bentonite adsorption were also reached to 70.3%,90.6%,and 90.6%,respectively.The results obtained from this study were helpful in choose of adsorbent to remove the heavy metals from wastewater.