五级跌水复氧式沟渠处理污水性能改进研究

Performance Improvement of Sewage Treatment Based on FiveStage Water-dropping Aeration Ditch

采用五级跌水复氧式沟渠工艺,并通过沟渠填料选择、跌水坡度和高度优化等试验,以期提高系统的高效性和稳定性。结果表明:蛭石对NH_4^+-N和TP的吸附量随时间先快速增大至变缓直至平衡,平衡时蛭石对NH_4^+-N和TP的吸附量分别为3.269、1.635mg/g。通过蛭石吸附动力学模型拟合得出蛭石对NH_4^+-N和TP的吸附以表面吸附为主;跌水是改善沟渠系统溶解氧状况的有效措施之一,跌水高度为35 cm时能达到较为理想的复氧效果;同时坡度=0.10时有利于污染物的去除;处理装置的监测表明,COD、NH_4^+-N、TN和TP的最大去除率分别为94.38%、81.26%、77.28%和85.99%,出水水质可达《城镇污水处理厂污染物排放标准》(GB18918-2002)一级排放标准。

A technology of 5-stage water-dropping aeration ditch was studied highlighting the improvement of its sewage treatment efficiency and stability by the measures such as laying proper media,optimizing waterfall slope and waterfall height in the ditch. The study indicated that adsorption of NH_4~＋-N and TP from the sewage by vermiculite,the adsorbing media,increased very rapidly in the first stage until into a state of balance,with the adsorption amounts of NH_4~＋-N and TP in balance were 3.269 mg/g and 1.635 mg/g,respectively. The dynamic modeling of the adsorption of NH_4~＋-N and TP showed that surface adsorption of vermiculite dominated the mechanism.Waterfall re-oxygenation was one of the effective operations increasing DO levels of the sewage;in addition,waterfall height in 35 cm is an adequate height for good re-oxygenation.Meanwhile,the slope of 0.10 was conducive to removal of the pollutants. Monitoring for the operation of the aeration ditch showed that the maximum removal rate of COD,NH_4~＋-N,TN and TP could attain 94.38%,81.26%,77.28% and 85.99%,respectively;and the effluent quality reached Class I specified in Discharge Standards of Pollutants for Municipal Wastewater Treatment Plants（GB 18918-2002）.