有机改性膨润土处理含铅废水

考查了影响有机改性膨润土吸附重金属离子铅的主要工艺参数,包括有机土种类、膨润土投加量、搅拌吸附时间,溶液初始pH等,通过试验确定的自制有机膨润土ZJ-4处理废水中铅的较优条件为:在室温条件下,废水初始pH为4～9,ZJ-4用量1.0g/L,吸附时间15min,另该工艺附加的固液分离时静置沉降时间不少于5h。同时得出有机改性膨润土铅吸附容量异常的主要原因是部分铅发生了自沉。膨润土深度除铅效果来自铅自沉与膨润土深度吸附两者之间的协同作用。自来水中的大部分铅离子在前5h与空气中CO2等结合,以沉淀形式在溶液中析出。除吸附外,有机土膨润还可充当絮凝剂,将先沉淀的含铅小颗粒卷扫沉降,协同达到深度处理目的。

Treatment of Lead-containing Wastewater Using Organic Modified Bentonite

The main parameters that have influences on the absorption of heavy metal ions of Pb2+ by the organic modified bentonite were investigated, which includes the types and dosage of the organic modified bentonite, the stirring adsorption time and the the initial pH value of solution. For the treatment of Pb2+ in the wastewater using ZJ-4 the optimal condition is that the initial pH value is 4-9, the dosage of ZJ-4 is 1.0g/L, the absorption time is 15min and the standing time is not less than 5h under the usual temperature. The main reason that there exists the anomaly of the Pb2+ absorption quantity is that the settling of Pb happens. The effect of removing Pb2+ by bentonite mainly depends on the cooperative roles of the settling of Pb and the deep adsorption of bentonite. The majority of Pb2+ in the tapwater was combined with CO2 in the first 5h and precipitated in the form of settling. Besides, the organic modified bentonite can work as flocculant to settle some little particles, reaching the aim of deep treatment collaboratively.