人工湿地组合工艺处理对含油含污水净化效果研究

摘要

In order to elaborate the advantages of constructed wetland and membrane technology and overcomes both shortcomings, the study investigated the feasibility of treatment of oil wastewater by the constructed wetland combined process. Experiment of the process of horizontal subsurface flow constructed wetland with ultra filtration membrane for oil wastewater was carried out. The results showed that the average removal rates of TN, COD, petroleum, BOD and NH4+-N in the constructed wetland system were 66.07%, 82.98%, 73.18%, 58.99% and 55.36% respectively. When influent flow was 1.2 m3·d-1 and the operating pressures of ultrafiltration membrane(PVDF) was 0.2 MPa, the constructed wetland combined process can achieve better effect of treatment. As influent TN, COD, petroleum, BOD and NH4+-N were 9.59, 270.80, 1.99, 14.59 and 4.40 mg·L-1, respectively, the effluent were 3.23, 46.02, 0.53, 5.97 and 1.96 mg·L-1, respectively. According to China Standard for Surface Water Resources (GB3838-2002), mean effluent TN and COD and petroleum can nearly reach Grade V, Grade V and Grade IV, and BOD and NH4+-N can reach Grade IV, respectively. In addition, seasonal variation analysis showed that purification efficiency of the constructed wetland combined process was the best in summer. The purification efficiency is better in spring than in autumn. Moreover, wetland plant plays an important role in treatment process.%　　为了发挥人工湿地与膜工艺两种水处理技术的优点，克服彼此的缺点，拟把两种技术组合，考察人工湿地组合工艺处理含油污水的可行性.本研究采用水平潜流人工湿地与超滤组合工艺对含油污水进行处理实验。试验结果表明：在进水流量1.2 m3·d-1，PVDF超滤膜操作压力0.2 MPa，人工湿地组合工艺对含油污水具有较好的处理效果。人工湿地组合工艺系统对含油污水中的TN、COD、石油类、BOD、NH4+-N平均去除率分别为66.07%，82.98%，73.18%，58.99%和55.36%，进水的TN、COD、石油类、BOD、NH4+-N平均质量浓度分别为9.59，270.80，1.99，14.59和4.40 mg·L-1，出水的TN、COD、石油类、BOD、NH4+-N平均质量浓度分别为3.23，46.02，0.53，5.97和1.96 mg·L-1，按照地表水环境质量标准(GB 3838-2002)，出水中TN含量接近V类，COD含量接近V类，石油类含量接近IV类，BOD含量为IV类。NH4+-N含量为V类。另外，通过对人工湿地组合工艺处理效果季节性变化分析表明：夏季优于春季，春季优于秋季，夏季人工湿地系统对污染物的去除效果最佳，而且湿地植物在处理过程中起着重要的作用。