EDTA、小分子有机酸对蛇纹岩发育土壤Ni、Co活性的影响

Effect of EDTA and LMWOA on Availability of Nickel and Cobalt in Serpentine Soil

研究了不同浓度的EDTA、柠檬酸以及丙二酸对蛇纹岩发育土壤中Ni、Co活性的影响。结果表明:在供试土壤中,Ni、Co的活化量随着EDTA、有机酸浓度的增大而增大,EDTA的活化效果大于其它两种小分子有机酸。同时也发现随着浓度的增大,EDTA与重金属的结合效率有下降的趋势,柠檬酸与丙二酸的结合率则呈现先上升后下降的趋势。EDTA对土壤的重金属萃取的最佳浓度约在1-10mmol/l之间。柠檬酸、丙二酸活化土壤中Ni、Co的最佳浓度浓度范围在10-30mmol/L之间。

Effects of chelator addition on the solubility of Ni and Co in serpentine soil were studied by adding EDTA, citric acid and malonate with various concentration. The experimental results indicated that available concentrations of Ni and Co increased with the increase of EDTA or organic acid concentration. EDTA was more effective on the solubility of Ni, Co than citric acid and malonate. The combining ratio, the ratio of molar concentration of heavy metal in solution and molar concentration of organic chelators, of EDTA decreased with its concentration, while the combining ratios of citric acid and malonate increased first and then dropped down. The optimal concentration of EDTA in extracting nickel and cobalt was 1-10 mmol/L, those of citric acid and malonate were 10-30 mmol/L.