海泡石对污染土壤镉、锌有效态的影响及其机制  

Effects of Sepiolite on the Immobilization of Cadmium and Zinc in Soil

作　　者：林大松[1,2] 刘尧[1] 徐应明[2] 周启星[1] 孙国红[3] 

机构地区：[1]南开大学环境科学与工程学院、教育部环境污染过程与基准重点实验室,天津300071 [2]农业部环境保护科研监测所、农业部农业环境与农产品安全重点开放实验室,天津300191 [3]天津农学院基础科学系,天津300384

出　　处：《北京大学学报（自然科学版）》2010年第3期346-350,共5页Acta Scientiarum Naturalium Universitatis Pekinensis

基　　金：国家高技术研究发展计划专项经费(2008AA06Z334);天津市自然科学基金(08JCYBJC02200);中央级公益性科研院所基本科研业务费专项(2006-aepi-03)资助

摘　　要：通过土壤原位钝化与等温吸附试验,研究了海泡石黏土矿物对污染土壤中镉、锌有效态及pH对海泡石吸附镉、锌的影响。结果表明:海泡石黏土矿物加入土壤后,显著降低了土壤中水溶态镉、锌和可提取态镉、锌含量。在海泡石最大施用量(土重的4%)时,水溶态镉、锌含量分别比对照下降了57.3%和41.4%;而可提取态镉、锌含量分别比对照下降42.8%和24.7%。海泡石对Cd和Zn的吸附过程符合Langmuir和Freundich等温吸附方程所描述的规律。随着体系pH升高,海泡石对镉、锌的吸附能力增强,在pH为6,海泡石对Cd2+和Zn2+的最大吸附量分别为12.3mg/g和6.80mg/g,海泡石对2种金属离子的吸附能力为Cd2+>Zn2+。海泡石作为土壤重金属钝化剂,施入土壤后能有效地降低土壤中Cd2+和Zn2+的活性;而pH是控制海泡石的钝化能力强弱的关键因素。Effects of natural sepiolite amendment on a heavy metals polluted soil and the sorption behaviour of sepiolite with respect to cadmium and zinc were studied by means of batch extractions. Using sepiolite as stabilizing agent, the soluble amount of both metals as well as their readily-extractable fractions are substantially decreased, when a sepiolite dose of 4% is applied, sepiolite has significant stabilizing efect on soluble amount of Cd and Zn as evidenced by a decline of 57.3% and 41.4% respectively, while the readily-extractable fractions of Cd and Zn as evidenced by a decline of 42.8% and 24. 7% for Cd and Zn. The sorption processes of Cd and Pb by sepiolite can be described by Langmuir and Freundlich model. The sorption capacities are pH dependent undergoing a decrease with H^＊ concentration increase. The maximum sorption capacities shown at pH 6 are 12.3 mg/g and 6. 80 mg/g for cadmium and zinc, respectively.

关 键 词：海泡石 镉 锌 土壤污染 原位修复 

分 类 号：X53[环境科学与工程—环境工程]