【摘要】 以低ρCOD/ρTN生活污水为处理对象,在连续和分段2种进水方式下分析了交替缺氧/好氧循环式活性污泥法工艺的脱氮性能及曝气需求量,并研究了分段进水方式下pH、ρDO和氧化还原电位(oxidation reduction potential,ORP)的变化规律.结果表明,连续进水方式下,系统TN平均去除率75.1%,系统因长期低负荷运行而发生污泥膨胀,污泥容积指数(sludge volume index,SVI)平均值为229 mL/g,同时,曝气量升至0.56 m3/h时,才能使NH4+-N去除率大于99%;采用分段进水方式时,系统TN平均去除率可提高至81.5%,污泥沉降性能良好,并且曝气量降至0.24 m3/h时,系统NH 4+-N去除率仍大于99%,节省了运行费用.此外,当采用分段进水时,反应区内的pH值、ρDO和ORP值曲线有较明显的变化规律,并与反应区内污染物浓度的变化有着较好的相关性.更多还原

【Abstract】 This study investigates the effects of continuous-feeding and step-feeding patterns on the nitrogen removal performance and the aeration rate under the anoxic/aerobic(A/O) condition of cyclic activated sludge technology(CAST) process treating low ρCOD/ρTN wastewater,and analyzes the profiles of pH,DO and ORP under the step-feed mode.Results show that the average removal rate of ρTN is 75.1% and SVI is 229 mL/g when the system runs under the continuous feeding mode,and activated sludge bulking occurs because of the operation under long-term condition of a low influent load.However,the average removal rate of ρTN increases to 81.5% and the average SVI decreases when the system runs under the step-feeding mode.Meanwhile,the aeration rate of the continuous-feeding mode is 0.56 m3/h but 0.24 m3/h under the step-feeding mode when the removal rate of ρ(NH+4-N) is above 99%.Consequently,the operation cost can be significantly reduced by using the step-feeding mode.Furthermore,pH,DO,ORP curves have an observe variation during a cycle under the step-feed,which also have a better correlation with the variation of contamination in the system.更多还原