芦苇和香蒲在人工湿地城市污泥处理系统中的应用

Application of reeds and cattails in constructed wetlands for treatment of municipal sludge

用有机玻璃材料做成模拟人工湿地,分别种植芦苇和香蒲考察2种模拟植物湿地对城市污泥干化和稳定化、污泥中营养元素和重金属去除效果,并和空白湿地对比。实验污泥取自当地污水厂二沉池,污水处理采用厌氧池加氧化沟工艺。模拟人工湿地进泥负荷为0.72 kg TS/(m2.d),进泥中TS平均含量为5.58 g/L,pH为6.80。实验期为1年,采用间歇式进泥,渗滤液月采集测样一次,湿地剩余污泥2月1次。实验结果受天气和气候影响较大,处理效果夏季好于冬季,出水水质和剩余污泥的干化及稳定效果芦苇湿地好于香蒲湿地。剩余污泥中各种重金属含量低于污泥农用标准中各重金属离子浓度要求。结果表明,人工湿地植物净化系统对城市污泥有较好的脱水和稳定化效果。

The constructed wetlands planted with reeds and cattails were constructed with plexiglass material to determine the sewage sludge drying and stabilization,the removal efficiency of nutrient elements and heavy metals.The experimental data were contrasted with those from the blank wetland.The sludge was from the secondary settling tank in the local wastewater treatment plant and oxidation ditch with anaerobic pond is used in that plant.The sludge input load was 0.72 kg TS/（m2·d） and the average content of TS was 5.58 g/L and the average pH was 6.80.The experiment lasted one year and intermittent sludge input was adopted.The leachate was collected and tested monthly and the remaining sludge was sampled every two months.According to the experimental results,the treatment effect was influenced by weather and climate;the treatment effect in summer was better than that in winter and the wetland planted with reeds was better than that with cattails.The content of metals in the remaining sludge are lower than the heavy metal ion concentrations in the sludge for agricultural use standards. The results show that constructed wetlands system has good effect for sludge drying and stabilization.