改性纳米TiO2对砷污染土壤的稳定化试验

以黄壤、红壤、紫色土和黑土为供试土壤，研究改性纳米二氧化钛对土壤中砷的稳定化效果。采用溶胶-凝胶法制得活性炭负载纳米二氧化钛（ACT）和铁改性活性炭负载纳米二氧化钛（ACTI），并将粒径为100 nm的纳米二氧化钛（T-100）和活性炭（AC）作为对照材料。将改性纳米二氧化钛按照不同质量比添加到供试土壤中，稳定化14 d后，采用生物有效性简化提取法（simple bioavailability extraction test，SBET）研究改性纳米二氧化钛对不同类型土壤中砷的稳定化效果。结果表明:4种供试土壤的固砷能力顺序为红壤>黑土>黄壤>紫色土。ACTI和ACT在4种类型土壤中对砷的稳定效果均优于对照材料T-100和AC，在2%的添加量下，4种土壤对砷的稳定化率均高于60%。因此，ACTI和ACT可用作修复砷污染土壤的稳定剂。

STABILIZATION OF AS CONTAMINATED SOILS BY MODIFIED NANO-TITANIUM DIOXIDE

In this study, red soil, purple soil, black soil and yellow soil were used to study the stabilization effect of modified nano-titanium dioxide on arsenic in soil. The modified nano titanium dioxide was prepared by sol-gel process. The active carbon supported nano titanium dioxide (ACT) and iron modified activated carbon supported titanium dioxide (ACTI) were prepared by sol gel method. The nano size titanium dioxide (T-100) and activated carbon (AC) with a diameter of 100nm were used as the control materials. Modified nano-titanium dioxide was added to the tested soil according to different mass ratios. After 14 days of stabilization, the stabilization effect of modified nano-titanium dioxide on arsenic in different types of soil was studied by simple bioavailability extraction test SBET. The results showed that the arsenic fixation ability of the four types of tested soils was in the sequence of red soil>black soil>yellow soil>purple soil. ACTI and ACT were superior to the control materials T-100 and AC in arsenic stabilization in four types of soils. With 2% addition of ACTI and ACT, the stabilization rates of arsenic in four types of soils were higher than 60%. Therefore, ACTI and ACT can be used as stabilizers for arsenic-contaminated soil remediation.