铝灰是电解铝、铝加工和铝再生行业产生的危险废弃物，直接堆存易造成严重的环境污染和资源浪费。铝灰中氧化铝质量分数达70%以上，可用于制备聚合氯化铝净水剂。为实现铝灰废弃物利用和解决选煤废水的污染问题，以铝灰基聚合氯化铝（Aluminum dross-based poly aluminum chloride,AD-PAC）为原料处理选煤废水，系统考察了AD-PAC投加量、絮凝温度、pH、快搅速度、快搅时间、慢搅速度、慢搅时间、静沉时间等因素对选煤废水浊度去除率的影响；通过絮凝体粒径变化研究了AD-PAC与选煤废水颗粒物结合机制，初步明确了AD-PAC对选煤废水的絮凝机理。结果表明：在AD-PAC投加量100 mg/L、絮凝温度40 ℃、pH=10、快搅速度300 r/min、快搅时间30 s、慢搅速度100 r/min、慢搅时间45 min、静沉时间20 min的条件下，选煤废水浊度由54.63 NTU降至0.50 NTU，浊度去除率达99.08%。絮凝过程形成的絮凝体中位粒径由59.67 μm增至145.90μm；AD-PAC通过电中和/吸附、网捕作用使废水中的颗粒物脱稳，转变成大颗粒絮凝体，实现选煤废水净化,为AD-PAC在废水处理行业中的应用提供技术支撑。

Aluminum dross is a kind of hazardous wastes produced from aluminum electrolysis, processing and regeneration industry. Direct stacking is easy to cause serious environmental pollution and waste of resource. Nevertheless, aluminum dross containing alumina more than 70% can be used to produce poly aluminum chloride. In order to realize the utilization of aluminum dross and solve the pollution problem of coal washing waste water, the coal washing waste water was treated with aluminum dross based poly aluminum chloride (AD-PAC). And the effects of AD-PAC addition amount, temperature, pH, mixing speed for stirring, mixing time for stirring, reaction speed for stirring, reaction time and sedimentation time for stirring on removing the turbidity of coal washing waste water were systematically investigated. The binding mechanism between AD-PAC and particle in coal washing wastewater was discussed by the change of flocculating constituent particle size. And the flocculating mechanism of AD-PAC for coal washing waste water was expounded. The results show that the turbidity removal ratios reach maximum values 99.08%, and the turbidity of coal washing waste water decreases from 54.63 NTU to 0.50 NTU with the conditions of AD-PAC addition 100 mg/L, temperature 40 ℃, pH=10, mixing speed for stirring 300 r/min,mixing time for stirring 30 s, reaction speed for stirring 100 r/min, reaction time for stirring 45 min and sedimentation time 20 min. The average particle sizes of flocs increase from 59.67 μm to 145.90 μm. The AD-PAC make the particles unstable by electric neutralization/adsorption and net capture respectively, and make the particle transmit to large particle flocculates to purify coal washing waste water. The research in this paper will provide a strong support for the application of AD-PAC in wastewater treatment industry.

0 引言

1 试验

   1.1 试验原料

   1.2 试验仪器

   1.3 试验方法

2 结果与讨论

   2.1 铝灰基聚合氯化铝处理选煤废水工艺优化

   2.2 铝灰基聚合氯化铝处理选煤废水效果

3 结论