摘要
针对农村污水流量小浓度高、排放不均匀及降雨冲击等特点,设计多级跌水充氧式沟渠连通生态塘组合工艺,进行水力负荷、运行方式、水量波动、降雨冲击等影响因素及参数优化试验。结果表明:随着水力负荷的增大,污染物的去除率逐渐降低;间歇运行的处理效果优于连续运行;水量的波动导致污染物的去除率也随之变化,其中化学需氧量和氨氮的去除率最大降幅接近20%;总氮去除率的降幅最大,约25%;总磷的去除率最大降幅最小,约15%左右;当降雨规模变大时,组合工艺对各污染物去除率分别从53.95%、52.44%、49.92%、71.64%下降到40.94%、43.75%、34.93%、53.84%。采取地表径流截流措施后,组合工艺对各污染物的去除效果有所改善,去除率的上升与截流倍数的增加近似呈现线性关系,当降雨为暴雨,采取截流倍数为5时,出水水质仍能达到城镇污水处理厂污染物排放标准(GB18918-2002)一级排放标准,对降雨期间农村污水的污染去除具有重要意义。
According to the characteristics of sewage dispersion with small flow and high concentration, fluctuation and rainfall impact, the process combining multi-level drop aeration-type ditch and ecological pond was designed to dispose the distributed wastewater of the rural areas in China. The combination process contains five parts： water inlet tank, constant flow pump, multi-level drop aeration-type ditch, ecological pond and water storage tank. Among them, multi-level drop aeration-type ditch includes five sections： advection I, drop I, advection II, drop II and advection III. Each section consists of water inlet area（A）, sewage disposal area with gravel and vermiculite laid at the bottom（B） and water outlet area（C）. Ditch based on drop aeration is conducive to the growth and metabolism of biofilm in vermiculite. Most of the pollutants can be removed into easily biodegradable organism or small molecular substances, achieving the purpose of purifying water quality. The 50 mm soil rich in microorganisms was laid in the bottom of the ecological pond, and the biozone, which was 50 mm wide and 400 mm long, was fixed on the surface of the pond with the iron shelf for 4 lines and each line has 5 colomns. And they were immersed in the sewage water. One hand, the treatment effect of ecological pond could strengthen the ditch system, and solve the problem of poor treatment of nitrogen and phosphorus; on the other hand, it would take in nitrogen and phosphorus of surface runoff in rainy days, increase the residential time of the rain and strengthen the treatment effect. Meanwhile, the hanging biozone would improve the ecological pond load and purify pollutants efficiently. At last, the hydraulic load, operation mode, water fluctuation, rainfall impact factors and parameters were studied. The results showed that： 1） The average removal rate of pollutant decreased when the hydraulic loading was increasing from 35 to 55 cm/d. The removal rates of chemical oxygen demand（COD）, NH＋4-N, total nitrogen（TN） and total phosphorous（TP） of the combined process were 62.18%-98.84%, 69.49%-92.46%, 63.37%-88.29% and 63.93%-91.58%, respectively. 2） The treatment effect of intermittent operation was better than the continuous operation. When the combination process was operated intermittently, the average removal rate of COD and NH＋4-N was 95.02% and 77.04%, respectively, which was better than constantly running. The average removal rate of TN was 49.10% with a slight decrease, and the average removal rate of TP was 82.61% which remained unchanged. 3） The removal rate of pollutants varied with water fluctuation. The maximum removal rate of COD and NH＋4-N was decreased nearly by 20%, and TN was the largest, about 25%, while TP was the least, about 15%. 4） When rainfall was in large-scale, the removal rate of each pollutant in the combined process was declined from 53.95%, 52.44%, 49.92% and 71.64% to 40.94%, 43.75%, 34.93% and 53.84%, respectively. 5） Adopting intercepting measure and controlling first flush pollution was the key of controlling pollution in the combined process. The relationship between removal rate and interception ratio was linear. Taking the interception ratio of 5 in torrential rain, the water quality still reached Class I according to the standard of Discharge Standards of Pollutants for Municipal Wastewater Treatment Plants（GB 18918-2002）. It is of great significance to remove rural wastewater during the rainfall.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2015年第3期242-248,共7页
Transactions of the Chinese Society of Agricultural Engineering
基金
"十二五"国家科技支撑计划课题"中部水网区连片村镇控源与水体强化净化技术集成与示范"(2012BAJ21B06)
关键词
污水处理
农村地区
参数优化
多级跌水
生态塘
影响因素
wastewater treatment
rural areas
optimization
multi-level drop aeration
ecological pond
influence factors
作者简介
胡将军，男，教授，博士生导师，主要从事污废水处理和大气污染控制研究与教学工作。武汉武汉大学资源与环境科学学院，430079。Emaihjjhu@163．com
通信作者：李海彩，女，河南驻马店人，主要从事水污染控制工程的研究。武汉武汉大学资源与环境科学学院，430079。Emaihwhlihc@163．com，Tbl：18207143398。
