受硝基苯污染地下水的村镇分散应急处理技术

为保障村镇分散供水的安全性,采用稻壳灰吸附协同强化混凝沉淀-加热共沸的组合技术,研究其对地下水中微量硝基苯的去除效果.结果表明,稻壳灰对地下水中硝基苯的吸附平衡时间为30min,当硝基苯的剩余浓度为3.5μg/L时,稻壳灰对硝基苯的饱和吸附容量约为44μg/g;单独的混凝沉淀对硝基苯的去除作用不大,但在稻壳灰吸附后,混凝沉淀对硝基苯的去除率提高到35%～52%;加热共沸能够大幅度去除水中的硝基苯,去除率可以达到90%以上;试验最后出水可以达到硝基苯未检出的效果.稻壳灰吸附协同强化混凝沉淀-加热共沸是一种适合村镇分散供水经济有效的应急处理工艺.

Emergent treatment process of groundwater polluted by nitrobenzene in decentralized water supply

To ensure the safety of decentralized water supply in villages and small towns,the removal efficiency of nitrobenzene in groundwater was investigated using a combined process of rice husk ash adsorption and enhanced coagulation followed by heating and boiling. The experimental results indicate that the rice husk ash adsorption equilibrium time is about 30 min for nitrobenzene,and the adsorption of nitrobenzene by rice husk ash is about 44 μg/g with the equilibrium concentration of 3.5 μg/L. Coagulation/sedimentation has little effect on the nitrobenzene removal,but the removal rate of 35%-52% can be achieved with pre-adsorption using rice husk ash. The nitrobenzene removal rate of more than 90% can be obtained by heating and boiling. The nitrobenzene concentration is under the limit determination in the finished water treated by the combined process. The combined process is a cost-effective technology for emergent nitrobenzene removal in decentralized water supply.