复合型人工湿地及其在小城镇污水处理中的应用

The Compound Artificial Wetland and Its Application in Treating Wastewater in Small Cities and Towns

针对中国小城镇的水污染特点，开发了1种复合型人工湿地污水处理技术，该工艺由处于厌氧环境的竖向折流湿地滤池和处于兼氧环境的侧向潜流湿地床组成，通过设置内回流系统、自然复氧区以及粒径为叩8～30mm的碎石填料，实现了系统内溶解氧的合理分区，并优化了污水流态，显著提高了处理效率。低温和常温条件下的运行结果表明：该工艺在进水流量300～450m^3／a，COD、NHg—N及TP分别为60～250mg／L、4．5～23mg／L、1．5～8mg／L条件下，低温出水中COD、NH4＋N及TP的浓度分别为20～30mg／L、2～4mg／L、0．3～0．5mg／L，常温出水中的浓度分别在30mg／L、4mg／L、0．43mg／L以下。

A technology of wastewater treatment-compound artificial wetland was developed in connection with the characteristics of water pollution in small cities and towns in China. That compound system was composed of vertical baffled wetland filter under anaerobic conditions and lateral subsurface flow wetland bed under facultative conditions. By setting up the inner back-flow system, the nature reoxygenation area and the gravel filler with a particle size of 8-30 mm, the dissolved oxygen（DO） division in the system was achieved with the optimization of the flow pattern and the increase of treatment efficiency. The application results indicated that, under the conditions that the water flow rate was 300-450 m3/d, COD, NH4＋-N and TP concentration of the inffluent were 60-250 mg/L, 4.5-23 mg/L and 1.5-8 mg/L respectively. And these values of the effluent were 20-30 mg/L, 2-4 mg/L and 0.3-0.5 mg/L respectively at low temperature and could fall below 30 mg/L, 4 mg/L and 0.43 mg/L at normal temperature.