人工湿地污泥处理技术研究进展

人工湿地污泥处理技术是利用植物、污泥微生物和自然力对活性污泥法处理城市污水的剩余污泥进行脱水与稳定。该技术具有运行费用低、不需要添加化学药剂、终产物可以安全处置或农用等优点。文中介绍了人工湿地污泥处理技术的概念、工作原理、脱水和稳定效果、温室气体排放以及设计和运行中常见的问题。在人工湿地处理污泥过程中,污泥脱水是由植物蒸发蒸腾、污泥渗滤和矿化作用协同完成的;污泥中有机质和氮磷等物质的转化和去除受进泥性质、运行参数和气象条件等因素影响较大。湿地植物芦苇能够保持足够的渗透系数并通过蒸腾作用去除污泥中的毛细水,在污泥脱水和污泥稳定中发挥着显著作用。由于人工湿地技术处理污泥工程实践时间相对较短,运行时通常出现一些问题,常见问题包括芦苇的长势不良、湿地中的液态厌氧污泥含水率过高、最后的稳定期污泥含水率过低等,需要在实践中予以解决。

Review of Constructed Wetland Sludge Treatment Technology

Constructed wetland sludge treatment technology is a kind of dewatering and stabilization technology of surplus sludge from activated sludge process waste water treatment plant by using com bined role of wetland plant,microorganism in sludge and natural power.This technology has such advantages as low operation fee,no chemical dosage requirement,and stabilized sludge for land ap plication in safety.The paper presents constructed wetland sludge treatment technology concept,working principle,effect of dewatering and stabilization,greenhouse gases discharge and normal problems in design and operation.In the process of sludge treatment by constructed wetland,sludge dewatering is completed by plant evapotranspiration,sludge infiltration and mineralization;transfor mation and removal of organic matter and nitrogen and phosphorus in sludge are affected by the nature of sludge,operating parameters and meteorological conditions.The wetland plant reed can maintain sufficient permeability coefficient and remove capillary water from sludge by evapotranspiration,which plays a significant role in sludge dewatering and sludge stabilization.Due to relatively short engineering practice time of the constructed wetland sludge treatment technology,some problems may be found during the operation.Common problems include poor bulrush,high water content of liquid anaerobic sludge in the wetland,low sludge water content in the final stable stage,etc,which should be solved in the future practice.