摘要
通过摸拟试验研究了砷在土壤中的有效性及其价态变化的动态规律。结果表明:As^(3+)和As^(5+)进入土壤后,均能被土壤很快固定,且50—500μg/g的As^(5+)进入土壤1天后,有4.63％—10.70％被还原成As^(3+),但3天后又测不到As^(3+)的存留;As^(3+)进入土壤后,在65％最大田间持水量的条件下,会被很快氧化,其氧化速率与As^(3+)浓度成正比,50—500μg/g的As^(3+)进入土壤后完全被氧化为As^(5+)所需的时间为1—7d。在500μg/gAs^(3+)的处理水平时,剩余As^(3+)浓度的对数值与处理后的培养时间呈显著线性负相关(r=-0.9851 α=0.02),其相关方程为:lnX(μg/g)=12.58-1.98Y(d)。
Laboratory tests were conducted to study the extractability and chemical valence changes of arsenic in soil. The results showed: both As^(3+) and As^(5+) could be fixed in soil. When soil was treated with 50—500μgAs^(5+)/g soi 1, about 4.63％—10.1％ of added As^(5+) could be reduced into As^(3+), but three days later, no As^(3+) could be detected in lmol/L HCl extracted solution. Under the condition of 65％ capacity of field holded water,As^(3+) added to soil could be oxided quickly after entering soil, the rate of As^(3+) oxidation varied directly with concentration of added As^(3+). The time of complete oxidation of 50—500μgAs^(3+)/g·soil was 1-7 days respectively. When soil was treated with 500μgAs^(3+)/g·soil, the time of incubation was negatively corrected with logarithm of remained As^(3+) concentration.
出处
《农业环境保护》
CSCD
1992年第5期206-208,共3页
Agro-Environmental Protection
