污泥减量工艺:HA-A/A-MCO的好氧脱氮机制分析

针对污泥减量技术存在对氮、磷去除能力低的问题,开发了一种具有强化脱氮除磷功能并可实现污泥减量化的HA-A/A-MCO工艺。在该工艺取得同步脱氮除磷和污泥减量优异效果的条件下,采用其处理校园生活污水,当进水TN平均为47 mg/L时,出水TN为10.9 mg/L,系统的总脱氮率为76.8%,其中好氧脱氮量占总脱氮量的50%,缺氧脱氮量占26%;HA-A/A-MCO系统存在着在好氧条件下具有反硝化能力的菌属,对好氧脱氮有一定贡献,且DO浓度对其反硝化能力没有抑制作用;好氧池中的DO浓度梯度有利于在污泥絮体内形成缺氧环境,从而促进同步硝化反硝化(SND)的发生,但减小污泥絮体尺寸会削弱絮体内部缺氧区域比例、降低SND的脱氮效率。

Mechanism of Aerobic Nitrogen Removal in Advanced Sludge Reduction Process-HA-A/A-MCO

In order to improve phosphorus and nitrogen removal in sludge reduction technologies, an advanced process combining excess sludge reduction and phosphorus and nitrogen removal was devel-oped.It is the hydrolysis acidification-anaerobic/anoxic-multistep continuous oxic (HA-A/A-MCO) process.With a favorable effect of phosphorus and nitrogen removal and sludge reduction, the process was used to treat campus wastewater.When the average influent TN is 47 mg/L, the effluent TN is 10.9 mg/L, and the total removal rate of TN is 76.8%, of which, the rate of aerobic nitrogen removal is 50%, and the rate of anoxic nitrogen removal is 26%.There are a certain amount of bacteria having denitrification ability under aerobic condition in HA-A/A-MCO system.They contribute to aerobic nitro-gen removal, and DO can not affect their denitrification ability.DO concentration gradient in aerobic tank contributes to creating an anoxic environment in sludge floc, which can promote simultaneous nitrification and denitrification (SND).Besides, reducing the size of sludge floc can decrease of anoxic area propor-tion of sludge floc, accordingly reduce nitrogen removal efficiency by SND.