氢氧化镁处理含镍废水条件探索及机理研究

Study on Conditions and Mechanisms of the Removal of Nickel in Wastewater With Magnesium Hydroxide

考察了氢氧化镁用量、搅拌时间、温度及pH值对含镍废水处理效果的影响,进一步探讨氢氧化镁吸附作用机理。结果表明,常温下,废水pH值在4.8～8.6之间时,以1.5 g/L的投加量加入氢氧化镁并搅拌4 min,废水中镍离子去除率可达90%以上。吸附机理研究表明,镍离子在氢氧化镁上的饱和吸附容量为19.25 mg/g。轻烧吸附过镍离子的氢氧化镁,用得到的氧化镁替代氢氧化镁乳液重复上述实验,出水仍可以达到国家排放标准,说明氢氧化镁水处理剂可以轻烧回收多次利用。最后X射线衍射分析显示,氢氧化镁吸附含镍废水为典型的化学吸附。

This paper studies the effects of magnesium hydroxide dose,stirring time,temperature and pH value on nickle removing rate and the mechanism for the adsorption of magnesium. The results illustrate that the removal rate of Ni2＋ in wastewater can reach as high as 90% under conditions： normal temperature, pH value 4.8 - 8.6, magnesium hydroxide dose 1.5 g/L and 4 minutes. The saturated extent of adsorption is 19.25 mg/g .The magnism hydroxide can be recycled by burning llghtly,the product MgO could be used as a absorbent and the westewater can meet the national discharge standards.Finally, X- ray diffraction analysis shows that adsorption of nickel containing westewater by Mg（ OH）2 is a typical chemical adsorption.