硫化镍异相结晶法处理含镍废水

针对含络合剂的重金属废水，以含镍废水为例，探索了以气体硫化氢为结晶药剂的硫化镍异相结晶技术。废水以薄层液膜方式铺展于结晶载体表面，硫化氢气体穿过气液界面进入液相，硫离子与金属离子在载体表面异相结晶析出，重金属得以去除。以含酒石酸的模拟化学镀镍废水为对象，静态实验与动态实验均表明该技术具有可行性，硫化镍沉淀在结晶载体表面异相结晶析出，且附着稳定；络合剂对反应影响小；进水流速为4 mL/min，硫化钠流速为0.65 g/min，氮气流速为0.16 L/min时，出水镍浓度为49~53 mg/L，单位面积滤布表面结晶平均去除镍量为0.98 g/(m2·h)。

Nickel wastewater treatment by heterogeneous crystallization of nickel sulfide

Nickel sulfide heterogeneous crystallization with hydrogen sulfide as precipitant was proposed for treatment of nickel wastewater containing complexing agent.Wastewater was spread on the surface of crystallization carrier to form a thin liquid film.Hydrogen sulfide,transferring from the gas phase into the liquid phase,dissociated into sulfide ion,which was then heterogeneously crystallized with metal ions on the carrier surface.Exploratory experiment was carried out using model solution containing Ni2+ and tartaric acid.Both static and dynamic experiment results showed that nickel sulfide precipitate was stably attached to the surface of the carrier through heterogeneous crystalline precipitation.There was little effect of complexing agent on crystalline reaction.Effluent nickel concentration was between 49~53 mg/L when flow rate of influent,sodium sulfide loading and nitrogen flow were controlled at 4 mL/min,0.65 g/min and 0.16 L/min,respectively.Average nickel removal rate through crystallizing was 0.98 g/(m2·h) per unit surface of filter cloth.