中文摘要：

研究了Fe°处理冷轧含铬废水的适宜条件，并对Fe°去除废水中Cr（Ⅵ）的反应机制及动力学规律进行了探讨。结果表明，在30℃，Fe°和酸液的投加量分别为2．2g／L和1．2％（体积分数），振荡转速为200r／min，反应时间20min，沉淀pH值为8～9，沉淀1h时，总cr和cr（Ⅵ）去除率高达99．99％和100％。Cr（Ⅵ）去除的反应机制主要是Fe°对cr（Ⅵ）的还原作用及金属氢氧化物在Fe°表面的沉积和共沉积作用，其中Cr（Ⅵ）的还原反应符合拟一级反应动力学规律，表观速率常数随反应温度的升高而增大。

英文摘要：

This paper studies the optimum conditions of treatment for cold rolling wastewater containing chromium by zero - valent iron, and discusses the reaction mechanism and kinetics roles for Cr（ Ⅵ） removal in the wastewater. When the reac- tion temperature, dosage of Fe° and acid solution, oscillator speed, reaction time, pH value range of precipitation and pre- cipitation time shows 30 ℃, 2.2 g/L, 1.2%, 200 r/min, 20 rain, 8 ～ 9 and lh respectively, the removal e/ilciencies of total Cr and Cr（ Ⅵ ） could achieve 99.99% and 100%. The Cr（ Ⅵ ）removal is mainly attributed to reduction effect of Fe°, moreover the precipitation and co- precipitation effect of metal hydroxides on the Fe° surface. The reduction process of Cr （Ⅵ ） follows to pseudo first order reaction law and the apparent rate constant increases with the increase of reaction temperature.