采用Tessier连续提取ICP-AES法对湖南某厂铬渣堆场土壤中重金属铬的存在形态(水溶性铬、交换态铬、碳酸盐结合态铬、有机结合态铬、铁锰结合态铬和残渣态铬)进行分析。研究结果表明,铬渣堆场土壤铬污染严重;铬渣堆场下土壤中大部分铬以铁锰结合态形式存在,在铬渣堆场周围和离铬渣堆场5km处未污染土壤中铬大部分以残渣态的形式存在;交换态铬和碳酸盐结合态铬在土壤各剖面层次的含量相差不是很大,而可溶性铬和残渣态铬在0-40cm土层富集,有机结合态铬和铁锰结合态铬在40~60cm土层富集。
The selective sequential extraction procedure developed by Tessier was used to investigate the contents of various chromium fractions including water soluble chromium, exchangeable chromium, carbonate bonded chromium, organics bonded chromium, Fe-Mn bonded chromium and residual chromium, and their distribution in soils contaminated by chromium-containing slag in a chromate manufactory in Hunan Province. The contents of chromium in the suspensions were determined with ICP-AES. Results show that chromium-containing slag results in a serious soil contamination. And in the contaminated soils underneath the chromium slag Fe-Mn-bound chromium is the predominant fraction, while in the soils in the vicinity of slag and the uncontaminated soils, residual chromium is the main fraction. There is no obvious difference of exchangeable chromium and carbonate-bound chromium in soil profiles, but relatively high amounts of soluble chromium and residual chromium are found in 0-40 cm of soil depth and relatively high amounts of organics bonded chromium and Fe-Mn bonded chromium in 40-60 cm of profile layer.