摘要
土壤重金属Cr具有难降解、强迁移性、易在生物体内积累等特点,会对人体健康及自然环境造成极大危害。文章主要研究水厂失效生物活性炭(S-BAC),通过分析S-BAC表面官能团丰度、亚甲基蓝值和碘值、表面形貌,以及对重铬酸钾溶液的分批吸附试验效果,来探讨S-BAC对Cr的吸附效能。同时,以土壤理化性质和Cr形态分布情况为指标,评价和验证了S-BAC对Cr污染土壤的稳定效果,确定了最佳添加量。结果表明,S-BAC对溶液中Cr的吸附性能良好,吸附过程符合Langmuir模型以及准二级动力学方程;经S-BAC处理后,Cr污染土壤中可交换态Cr浓度显著降低,可氧化态和残渣态Cr含量大幅增加,土壤阳离子交换量(CEC)、pH均明显升高;在S-BAC掺入量为5%的条件下,经过35 d的修复,土壤中Cr固定效果良好。S-BAC固定土壤中Cr的机制主要包括离子交换、表面络合、沉淀作用等,但土壤修复过程对Cr价态的影响还有待进一步研究。
The heavy metal Cr has the characteristics of hard degradation,strong mobility and easy accumulation in organisms,which can cause great harm to human health and the natural environment.The spent biological activated carbon(S-BAC)in WTPs was studied in this paper.Through analyzing the surface functional group abundance,methylene blue value,iodine value,surface morphology of S-BAC,and the batch adsorption experiment effect on potassium dichromate solution,the adsorption efficiency of S-BAC on chromium was discussed.Based on the physical and chemical properties of soil and the change of Cr form distribution,the stabilization effect of S-BAC on Cr polluted soil was evaluated,and the optimal amount of S-BAC was determined.The results showed that the adsorption effect of S-BAC on Cr in solution was good,and the adsorption process conformed to Langmuir model and quasi second order kinetic equation;After S-BAC treatment,the exchangeable chromium content decreased,the oxidizable and residual chromium content increased,and the cation exchange capacity(CEC),pH value and respiratory enzyme activity increased significantly;Under the condition of adding 5%S-BAC,after 35 d of remediation,the fixation effect of chromium in soil was good.The mechanism of Cr fixation in soil by S-BAC includes ion exchange,precipitation,complexation,etc.However,the change of Cr valence in the process of remediation needs further study.
作者
许展鹏
陈卫
李聪聪
冯昌龙
兰童
刘成
XU Zhanpeng;CHEN Wei;LI Congcong;FENG Changlong;LAN Tong;LIU Cheng(Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes,Ministry of Education,Hohai University,Nanjing 210098,China;College of Environment,Hohai University,Nanjing 210098,China)
出处
《净水技术》
CAS
2023年第6期66-73,共8页
Water Purification Technology
基金
国家水体污染控制与治理科技重大专项(2012ZX07403-001)。
关键词
失效生物活性炭
土壤修复
铬(Cr)
吸附模型
吸附机制
spent biological activated carbon(S-BAC)
soil remediation
chromium(Cr)
adsorption model
adsorption mechanism
