1.National Engineering Laboratory for Clean Technology of Leather Manufacture, Sichuan University;2.Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University
Supported by the National Key Research and Development Program of China (No. 2018YFC1802201)
In recent years, the issue of chromium pollution in tannery sites has attracted widespread attention. Through analyzing their tanning process, properties of the wastewater and solid waste discharged from tanning and history and status quo of their disposal, this paper points out that irrational disposal of these chromium-containing wastes and inadvertent dripping and leaking of chromium-containing liquor are the main sources of chromium pollution in tannery sites, and characterizes the chromium pollution in their soils and groundwater. The soils are mainly polluted by trivalent chromium rather than hexavalent chromium. However, the contents of total chromium and hexavalent chromium in some tannery sites far exceed the limit set in the national standards for soil environmental safety. Soil chromium content is characterized by site regional distribution, vertical distribution, and fractionation. Chromium polluted soil is mainly located in sludge disposal sites, workshops, and waste water discharge sites. The content of total chromium is high in the surface soil, and decreases gradually with soil depth. In the soils short in exposure to pollution, the content of available chromium (e.g., water soluble and exchangeable) is higher, while in the soils long in exposure to pollution, stable fractions, such as residue, dominate in content. Total chromium and hexavalent chromium are detected in groundwater, and the content of chromium is affected by factors, such as soil chromium content, time of exposure to pollution, and hydrogeology. As tannery sites are also exposed to organic pollution and acid-base pollution, this paper further elaborates effects of organic pollutants and soil pH on chromium behaviors, such as redox, fractionation, and transport in the soil. This paper points out that researches should be focused on contents and formation mechanism of available chromium and hexavalent chromium. In the end, the paper discusses the main challenges faced and countermeasures to be adopted in preventing the environmental risk of chromium pollution in tannery sites.
徐 腾,南 丰,蒋晓锋,唐余玲,张文华,石 碧.制革场地土壤和地下水中铬污染来源及污染特征研究进展[J].土壤学报,2020,57(6):1341-1352. DOI:10.11766/trxb201911120506 XU Teng, NAN Feng, JIANG Xiaofeng, TANG Yuling, ZHANG Wenhua, SHI Bi. Progresses in Research on Sources and Characteristics of Chromium Pollution in Soils and Groundwater of Tannery Sites[J]. Acta Pedologica Sinica,2020,57(6):1341-1352.复制