中国科学技术大学学报 ›› 2015, Vol. 45 ›› Issue (5): 388-396.DOI: 10.3969/j.issn.0253-2778.2015.05.007

• 原创论文 • 上一篇    下一篇

淮南顾桥采煤沉陷区土壤中镉的赋存特征 及其生物有效性

陈 辉   

  1. 1.安徽大学资源与环境工程学院,矿山环境修复与湿地生态安全协同创新中心,安徽合肥 230601; 2.煤矿生态环境保护国家工程实验室,安徽淮南 232001
  • 收稿日期:2015-01-15 修回日期:2015-03-03 出版日期:2015-05-31 发布日期:2015-05-31
  • 通讯作者: 郑刘根
  • 作者简介:陈辉,男,1989年生,硕士生. 研究方向:环境地球化学. E-mail: chenhui0001@yeah.net
  • 基金资助:
    国家自然科学基金(41373108),“十二五”国家科技支撑计划(2012BAC10B02),煤矿生态环境保护国家工程实验室科技攻关项目(HKKY-JT-JS2012),安徽省自然科学基金(1208085ME66),安徽省教育厅重点基金(KJ2012A022)资助.

Occurrences and bioavailability of cadmium in soils of Guqiao Mine subsidence area, Huainan

CHEN Hui   

  1. 1.School of Resource and Environment Engineering, Collaborative Innovation Center for Mines Environmental Remediation and Wetland Ecological Security, Anhui University, Hefei 230601, China; 2.National Engineering Laboratory of Coal Mine Ecological Environment Protection, Huainan 232001, China
  • Received:2015-01-15 Revised:2015-03-03 Online:2015-05-31 Published:2015-05-31

摘要: 为了解淮南采煤沉陷区土壤中镉的赋存特征和潜在危害,以淮南顾桥采煤沉陷区为例,采用DTPA提取法和Tessier逐级连续提取法,对其土壤中Cd的形态分布及生物有效性进行了研究.结果表明,研究区土壤中总Cd和有效态Cd 均在表层农田土壤0~20 cm富集,两者呈显著正相关.总Cd是淮南土壤背景值的367倍,且Cd的平均活化率为3786%,有较强活性.土壤中Cd的不同形态含量关系为残渣态(5059%)> 可交换态(2324%)> 铁锰氧化物结合态(1577%)> 碳酸盐结合态(618%)> 有机物结合态(422%).土壤中Cd的生物可利用态(可交换态)和生物潜在可利用态(铁锰氧化物结合态、碳酸盐结合态、有机物结合态)比例分别为2324%和2617%,其在矿区土壤环境影响下易于转化为有效态.土壤中有机质、总氮、总磷是影响Cd各形态分布的重要因素,同时pH的改变也是其他形态转化为有效态的关键因素.

关键词: 采煤沉陷区, 土壤, 镉, 赋存特征, 生物有效性

Abstract: Cadmium in soils of coal-mining subsidence poses potential ecological risks. DTPA extraction and Tessier sequential extraction methods were used to investigate the speciation and bioavailability of Cd in subsidence soils of Guqiao Coal Mine. The results show that total Cd and availability Cd are highly correlated, and are both enriched in topsoil (0~20 cm). Cadmium in studied soils is 367 times of that in the Huainan background soil, with a high activation rate of 3786%. The proportions of different Cd species in studied soils are: residual fraction (5059%)>exchangeable fraction (2324%)> Fe-Mn oxides bound fraction (1577%)>carbonate bound fraction (618%)>organic bound fraction (422%). Bioavailable (exchangeable) and potentially bioavailable Cd (carbonate bound, Fe-Mn oxide bound, organic bound) account for 2324% and 2617%, respectively, which could be activated under the soil environment of mines. The organic matter, total nitrogen and total phosphor of soil are the main factors controlling Cd species. In addition, the variation of pH values in soil could promote the conversion of Cd in other forms to bioavailable forms.

Key words: coal-mining subsidence, soil, cadmium, occurrence, bioavailability