摘要
采用人工柱对3个不同年代的铬渣进行为期5年不同pH值(4·0,5·0,6·0)下的模拟酸雨淋溶实验,结果表明:淋溶前铬渣具有很强的腐蚀性,pH值达到12以上,总铬和Cr6+分别占铬渣的4·68%—4·86%和1·19%—1·73%;Cr6+溶出浓度在淋溶初期大,随着淋溶时间的增加,溶出浓度急剧下降,淋溶接近第二年雨量时,溶出浓度减小且趋于稳定.5年模拟酸雨淋溶后,Cr6+累积溶出范围在2138—4490mg,浸出液浓度稳定范围50—127mg·l-1,仍然远高于排放标准.铬渣淋溶后,残渣态和结晶铁锰氧化物结合态铬含量保持不变,水溶态、酸溶态和稳定铁锰氧化物结合态铬有不同程度减小.
The diverse years of chromium slag were collected to study the release process of Cr and change of chromium forms under the condition of the simulated acid rain （adjusted to pH 4. 0, 5.0 and 6.0 ） with column models. The total amount of simulated acid rain was as much as the rainfall of five years. It indicated that causticity was serious in all chromium slag sample and pH exceed 12. Rates of total chromium and Cr^6＋ in chromium slag ranged from 4.68%---4.86% and 1.19%--1.73% respectively. Concentration of Cr^6＋ increased sharply in leaching incipient. With the time of leaching increased, concentration of Cr^6＋ decreased. Leaching concentration trend was steady about one year. After five years leaching, the total amount of chromium leaching ranged from 2138-4490mg. Concentration of steady leaching Cr^6＋ ranged from 50-127 mg·l^-1 and overtop the limited output standard. Concentration of residual and crystalline form changed little and concentration of water-soluble, acid-soluble and stable form decreased in chromium slag.
出处
《环境化学》
CAS
CSCD
北大核心
2007年第4期512-515,共4页
Environmental Chemistry
关键词
酸雨
淋溶
铬渣
铬
acid rain, leaching, chromium slag, chromium.
