潜流人工湿地污水处理系统长期运行中pH及酸度和碱度的变化

Variation in pH,Acidity and Alkalinity in Long-Term Operation of the Subsurface Flow Constructed Wetland as a Domestic Wastewater Treatment System

研究了潜流人工湿地污水处理系统长期运行中pH值、酸度及碱度的变化.结果表明,在运行期间,各湿地单元出水的pH值均在中性范围内变化;运行初期,出水的pH值偏高,而且以煤渣为填料的湿地出水的pH值高于以砾石为填料的湿地出水的pH值;人工湿地出水回流使以煤渣为填料的湿地单元的pH值下降,且同时引起P的去除率增高;人工湿地出水酸度低于进水酸度,碱度大于进水碱度,而且出水中的碱度值明显高于酸度值,表明人工湿地内部呈厌氧状态;湿地进水有机负荷和温度对碱度有显著性影响.

The variation in pH, alkalinity and acidity in the subsurface flow constructed wetland as a do- mestic sewage treatment was studied. The experimental results demonstrated that pH of the effluents of various wetland units fluctuated around 7. The pH of the effluents of all wetland units stood at relatively high levels at the beginning run of the system. Furthermore, the pH value of the effluent with cinder as the substrate was higher than that of the effluent with gravel as the substrate. The recycling of the efflu- ent decreased the effluent pH in the cinder-based wetland, and enhanced phosphorus removal. The acidity of the effluent was lower than that of the influent; however, the alkalinity of the effluent was higher than that of the influent. The alkalinity of the effluent was markedly higher than its acidity, suggesting an an- aerobic condition in the wetland system. The organic loading rate （OLR） and temperature showed signifi- cant effects on alkalinity of the effluent.