不同基质垂直流人工湿地对猪场污水季节性处理效果的研究

研究了3套不同基质垂直流人工湿地小试装置在不同季节处理猪场污水的运行效果.结果表明,垂直流人工湿地对有机污染物的去除效果随季节变化差异不明显,对有机物降解情况可用一级降解模型模拟;传统型湿地系统NH4 -N去除率在各季节稳定在52%,而沸石和沸石-煤渣型系统冬季NH4 -N去除效率分别从秋季的89.8%和93.4%下降至冬季的64.2%和73.5%,春、夏季回升至80%左右.冬季湿地系统中生物硝化与反硝化作用的减弱影响了垂直流人工湿地系统TN的去除;3套不同基质系统中,沸石-煤渣型系统各高度层硝化强度均为最高,沸石型和沸石-煤渣型系统的反硝化强度明显高于传统型系统,与实际运行过程TN去除率变化相吻合.采用沸石作为基质有利于系统的反硝化进程和TN的去除.垂直流系统对TP去除率随季节性变化波动不显著,但随着垂直流人工湿地系统的运行,基质层对TP的吸附逐渐饱和,去除效率明显下降.

Seasonal performances of three vertical-flow constructed wetlands filled with different packing materials for piggery wastewater treatment

Seasonal performances of three vertical-flow constructed wetlands (VFCWs) filled with different packing materials for piggery wastewater treatment was investigated. Results showed that there were no some significant seasonal differences in the COD_ Cr removal efficiency among three types of VFCWs. Biodegradation of organic matter in all three VFCWs were found following the first order rate model. The NH~ _ 4 -N removal efficiencies in conventional VFCWs in different seasons constantly maintained at 52%. However, NH~ _ 4 -N removal efficiencies were found fluctuating over seasons in VFCWs filled with either zeolite or zeolite-cinder, i.e., 89.8% and 93.4% in autumn, 64.2% and 73.5% in winter, and around 80% in spring and summer, respectively. Total nitrogen (TN) removal efficiencies of all VFCWs in winter were considerably lower than those in the other seasons due to relatively weaker processes of nitrification-denitrification. The nitrification activity in VFCWs filled with zeolite-cinder was the highest among all of VFCWs, while the denitrification activity in VFCWs filled with zeolite or zeolite-cinder was more intensive than that in the conventional VFCWs, agreeing with the TN removal efficiencies in three VFCWs. As packing material, zeolite is able to accelerate the process of denitrification as well as TN removal efficiencies of VFCWs. Nevertheless, there was no apparent difference over seasons in total phosphorus (TP) removal efficiency. With saturation of phosphorus adsorption in packing material, TP removal efficiency was declined obviously in all VFCWs.