低温下潮汐流人工湿地系统对污水净化效果

Wastewater Purification Efficiency by Tidal-flow Constructed Wetland System in Low Temperature Seasons

潮汐流人工湿地是将湿地按时间序列周期性地充水和排干,使得湿地内部形成好氧-厌氧交替过程,从而实现并强化污染物去除的新型人工湿地形式.该研究主要考察了低温条件下(9～13℃)潮汐流人工湿地与传统连续流人工湿地对污染物处理的效能差异,以及运行工况对处理效果的影响;同时对各人工湿地系统中微生物活性进行研究.结果表明:在水力负荷为0.2 m3/(m2.d)条件下,采用3个周期/d的潮汐流人工湿地,出水ρ(DO)为0.61 mg/L,高于连续流人工湿地的0.22 mg/L;NH4+-N,CODCr及PO43--P的去除率达到48.57%,68.96%及29.02%,分别比连续流人工湿地提高了约30%,20%和20%.同时,通过对各反应器内微生物呼吸作用和脱氢酶活性等的对比研究发现,3个周期/d的潮汐流人工湿地中微生物具有更高的活性.

The tidal-flow constructed wetland is a new type of constructed wetland which takes advantage of the rhythmic input and output of wastewater and air,creating aerobic and anaerobic circumstances to realize and enhance pollutant removal.This study mainly focused on the difference of purification capacities of tidal-flow constructed wetlands and traditional continuous-flow constructed wetlands at low temperatures（9-13 ℃）,as well as treatment performances under different operation conditions.At the same time,the microbial activities were investigated in different reactors.The results showed that,under a hydraulic load of 0.2 m3 /（m2.d）,the effluent DO value in the three-cycles /d tidal-flow constructed wetland was 0.61 mg /L,which was higher than that in the continuous-flow constructed wetland（0.22 mg /L）.The removal rates for NH 4＋-N,CODCr and PO43--P in the three-cycles /d tidal-flow constructed wetland reached 48.57%,68.96% and 29.02% respectively,which were about 30%,20% and 20% higher than those in the continuous-flow wetland,respectively.Meanwhile,the microbial respiration and dehydrogenase activity results suggested that the microbial activity in the three-cycles /d tidal-flow constructed wetland was higher than others.