零价铁对水中六价铬还原性能及沉淀污泥中铬的固定化

采用零价铁还原水中六价铬,考察了溶液初始pH、铁粉投量、反应温度及水体中常见阴阳离子对还原效率的影响,得出其工艺参数为:初始pH=3.0,反应时间t=30 min,反应温度为室温,Fe0与Cr(VI)质量比为1 000: 1。将还原后产生的三价铬以沉淀形式从水中彻底分离出来,并对其进行了碱激发矿渣固定化处理,考察了固定化样品中Cr在不同环境条件下的浸出水平,结果表明,固定化处理能有效控制沉淀污泥中Cr的浸出。

Reduction of aqueous Cr(VI) by zero-valent iron (ZVI) and solidification of chromium-containing precipitation produced in reduction process

Zero-valent iron (ZVI) was used for the Cr(VI) reduction in the water. The effects of the initial pH, iron powder dosage, temperature, coexisting anions and cations on the removal rate of Cr(VI) by ZVI were investigated. The results indicated that the highest Cr(VI) reduction rate was obtained at 30 min, pHinitial=3.0, T=298 K, with ZVI and Cr(VI) mass ratio of 1 000. In the reduction process, the produced Cr(III) was removed from water by precipitation. The solidification of Cr from the precipitation was performed using lime-activated ground granulated blast furnace slag (GGBFS). The leaching level of Cr in the solidification samples in the different environments were evaluated, the results showed that the Cr release from the settling sludge can be controlled by solidification.