通过盆栽试验研究添加2种含铁材料(Fe(OH)3、FeCl3)对污染水稻土壤中As、Pb、Cd、Cu、Zn生物有效性的影响。结果表明,添加Fe(OH)3对土壤As交换态含量没有显著的影响,添加FeCl3显著降低了土壤As交换态含量,添加量为0.50g/kg时,土壤As交换态含量比对照下降46%。添加Fe(OH)3使土壤Pb、Cu交换态含量显著降低,2.00g/kg的添加量使Pb、Cu交换态含量分别下降63%,74%。添加FeCl3使土壤Pb、Cd、Zn交换态含量显著升高,2.00g/kg的添加量使Pb、Cd、Zn交换态含量分别升高3 834%,247%,1 744%。添加Fe(OH)3对糙米中无机As和重金属Pb、Cd、Cu、Zn含量没有显著的影响,添加FeCl3显著降低了糙米中无机As含量,但显著提高了糙米中Pb、Cu含量,1.00g/kg的添加量使糙米中无机As含量降低33%,Pb、Cu含量分别升高147%,50%。表明添加FeCl3能有效降低土壤As的生物有效性,但提高了土壤重金属的生物有效性。添加Fe(OH)3对土壤pH无显著影响,而添加FeCl3能显著降低土壤pH值,这是FeCl3能有效固定土壤As,提高土壤重金属交换态含量的重要原因之一。
Pot experiments were conducted to study the influence of two kinds of iron-containing materials (Fe(OH)3, FeC13) on biological availability of arsenic and heavy metal in contaminated paddy soil. Results showed that the soil exchangeable arsenic content was not influenced by adding Fe(OH)3, while the addition of FeCl3 made soil exchangeable arsenic content decrease significantly, soil exchangeable arsenic content decrease 46% when adding 0.50 g/kg FeCl3. Furthermore, adding Fe(OH)3 made soil exchangeable lead and copper content decrease significantly, 2.00 g/kg Fe(OH)3 led a decrease of 63% and 74% in exchangeable lead and copper, respectively. Contrary to Fe(OH)3, adding FeCl3 made soil exchangeable lead, cadmium and zinc content increase significantly, and soil exchangeable lead, cadmium and zinc increase 3 834%, 247%0 and 1 744%, respectively, by adding 2.00 g/kg FeCl3. Results also showed that the addition of Fe(OH)a had limit effect on brown rice inorganic arsenic, lead, cadmium, copper and zinc content. The influence of adding FeCl3 on brown rice inorganic arsenic, lead, cadmium, copper and zinc content was in different manners, adding 1. 00 g/kg FeCl3 brown rice arsenic content decreased with the amount of 33%, while brown rice lead and copper content increased 147% and 50%, respectively. Results indicated that adding FeC13 could effectively reduce the soil arsenic biological availability, however, promote the biological availability of soil heavy metal. Adding Fe(OH)3 couldn't make soil pH significantly influence, while FeCla made soil pH decrease significantly, which should be the important reason that FeCl3 could effectively fix soil arsenic, increase soil heavy metal exchangeable content.