中文摘要：

改良型循环比可调式氧化沟在廊道内设置缓流板，以此调节循环比(氧化沟廊道断面通过的循环流量与进水流量的比值)，同时改变好氧区混合液回流向缺氧区的量．利用质量平衡的方法，研究了设置缓流板前后系统内氮污染物的转化途径及有机物、氮和磷去除效果的变化．结果表明：不设缓流板，循环比为241 时，COD、TP、TN、4NH+ 的平均去除率分别为91.2%,、86.4%,、67.2%,和82.7%,，进水总氮中有23.6%,通过传统硝化反硝化去除，12.3%,通过反硝化除磷去除；而增设缓流板，循环比为27 时，COD、TP、TN、4NH+ 的平均去除率分别为93.3%,、96.0%,、78.1%,和87.1%,，进水总氮中有12.0%,通过传统硝化反硝化去除，41.1%,通过反硝化除磷去除．综上可知：增设缓流板控制循环比，有助于提高氧化沟工艺的同步脱氮除磷效果，更有利于增强反硝化除磷脱氮能力．

英文摘要：

The recirculation ratio (namely the ratio of circulation flow to influent flow in compartment section) is changed byadding flashboard in compartment section to regulate mixed liquor refluxing from aerobic zone to anoxic zone in modifiedoxidation ditch. This study has been done by comparing the changes of the organics,simultaneous nitrogen and phosphorusremoval before and after adding flashboard in oxidation ditch compartment,and with mass balance to the differences of theconversion pathways of nitrogen. The results show that,when the recirculation ratio is 241without the flashboard,the averageefficiencies of COD,TP,TN,NH4+ removal are 91.2%,86.4%,67.2% and,82.7% respectively.The ratios are23.6% and 12.3% which influence total nitrogen conversation to N2 by traditional denitrification and denitrifying phosphorusremoval respectively.When the recirculation ratio is 27 with the flashboard,the average efficiencies of COD,TP,TN,NH4+,removal are 93.3%,96.0%,78.1% and 87.1%,respectively. The ratios are 12.0% and 41.1% which influence totalnitrogen conversation to N2 by traditional denitrification and denitrifying phosphorus removal respectively.To sum up,regulating recirculation ratio by adding flashboard is helpful for improving the simultaneous nitrogen and phosphorus removalof oxidation ditch process,and is also helpful for increasing the capability of denitrifying phosphorus and nitrogenremoval.