Different factors on nitrogen and phosphorus self-purification ability from an urban Guandu-Huayuan river

Abstract

以典型城市河道(苏州官渎花园内河)为研究对象,通过室内和室外模拟实验,研究不同污染物浓度、流速、曝气复氧、渗滤作用和温度对氮、磷自净能力的影响,结果表明:水体中氮、磷的自净作用受污染物浓度、流速、溶解氧浓度、温度和微生物等多种因素的影响.随着污染物浓度的增加,氨氮和硝态氮降解速率增加,而底泥中磷的总体吸附速率却增大.与静止水体相比,模拟河道通过增加流速、曝气复氧、渗滤作用能增强水体氮磷的自净能力,提高氮、磷降解速率.其中,改变流速后自净参数氨氮和总磷增量分别为17.05%和34.85%;曝气复氧后自净参数氨氮和总磷增量分别为8.35%和59.33%;增加微生物量(渗滤作用)后自净参数氨氮和总磷增量分别为50.00%和23.01%.自然条件下,随着温度的上升,氨氮和总氮的降解系数逐渐增大,总磷的降解系数逐渐减小.;An urban Guandu-Huayuan river in Suzhou was selected to study the impacts of different factors(contaminant concentration, flow velocity, aeration, filtration, microorganisms and temperature)on nitrogen and phosphorus self-purification ability by indoor and outdoor simulation experiment. The results showed that, with the increase of pollutants concentration, ammonia nitrogen and nitrate nitrogen degradation coefficient increased, and the overall sediment phosphorus adsorption rate increased. Compared with static water, the nitrogen and phosphorus self-purification ability can be enhanced by increased velocity, aeration and filtration. The increment of self-purification parameter was 17.05% for ammonia nitrogen and 34.85% for total phosphorus(TP) in the velocity change experiment; 8.35% for ammonia nitrogen and 59.33% for TP in the aeration experiment; and 50.00% for ammonia nitrogen and 23.01% for TP in the filtration experiment. With the increase of temperature in natural conditions, the ammonia nitrogen and total nitrogen degradation coefficient increased gradually, while TP degradation coefficient reduced.