城市污水自养脱氮系统中有机物与磷的回收

Recovery of phosphorus and organic matter in an autotrophic nitrogen removal system

厌氧氨氧化的发现使开发低能耗城市污水处理技术成为可能,可通过生物吸附实现污水能源与资源的回收。强化除磷系统污泥龄(SRT)仅为2d,系统抗冲击性强,污泥沉降性良好,污泥体积指数(SVI)低于50,可为自养脱氮系统提供稳定的进水,但系统污泥碳含量仅为37%。将反应器内好氧水力停留时间(HRT)降至40min后,实现有机物去除序批式反应器(SBR)的稳定运行,厌氧段COD去除率占总COD去除率的93.8%,这表明系统对有机物的去除主要为生物吸附作用,同时污泥碳含量提升至48%。由于异养菌对有机物的消耗利用与除磷菌的吸磷过程同时进行,若试验废水C/P比较低,可降低系统水力停留时间、提升碳的回收率并辅助少量的化学除磷手段,对系统厌氧搅拌时间、曝气时间及污泥龄进行优化,从而实现C与P的高效回收。

The development of anaerobic ammonia oxidation（anammox） process,makes it possible to achieve domestic wastewater treatment with low energy consumptions.And the recovery of energy and resources from domestic wastewater can be realized through biological adsorption.The enhanced biological phosphorus removal（EBPR） system was successfully started under sludge retention time（SRT） of 2 d.The SVI of activity sludge was only 50 and the effluent of EBPR system was stable under fluctuant influent.While,the carbon content in EBPR system sludge was only 37%.Stable operation of organic matter removal SBR was achieved by decreasing the aerobic hydraulic residence time（HRT） to 40 min.The carbon content of sludge was then increased to 48%.93.8% of the removed COD was achieved during the anaerobic phase which meant the organic matter was mainly removed by the biological adsorption.Due to the consumption of organic matter by heterotrophic bacteria and the adsorption of phosphorus by PAO occurred simultaneously,when the C/P of domestic wastewater was relatively low,it was difficult to recover both organic matter and phosphorus at the same time.To enhance the recovery of organic matter,HRT of aerobic phase should be decreased and the chemical removal method should be applied to remove part of the phosphorus.The anaerobic mixing time,aeration time and sludge age should be optimized in order to achieve a higher efficient recovery of C and P.