Kishida N, Tsuneda S, Sakakibara Y, Kim J H, Sudo R
Department of Civil and Environmental Engineering, Waseda University, 3-4-1 Ohkubo, Tokyo 169-8555, Japan.
Water Sci Technol. 2008;58(2):445-50. doi: 10.2166/wst.2008.410.
To achieve stable and simultaneous removal of nitrogen and phosphorus using aerobic granular sludge in a sequencing batch reactor, a real-time control strategy was established, where time derivatives of electric conductivity (EC) and pH were monitored to facilitate the determinations of ends of phosphate release, nitrification and denitrification as well as corresponding optimum time-lengths of anaerobic, oxic, and anoxic phases in treatment cycles. Although biomass concentration in a reactor drastically fluctuated at the startup period because of very short sludge settling time for the formation of aerobic granular sludge, cycle length for proper treatment was automatically adjusted in this control system. Even when characteristics of influent wastewater markedly fluctuated, stable nitrogen and phosphorus removal was successfully attained both before and at pseudo-steady-state. Effluent concentrations of NH4-N, NOx-N and PO4-P were always lower than 0.3 mg/L. On the other hand, when time lengths of the anaerobic/oxic/anoxic phases were fixed, stable nitrogen and phosphorus removal was not accomplished. Therefore, it is clear that the designed control system is very effective to obtain stable treatment performance in simultaneous nitrogen and phosphorus removal by aerobic granular sludge.
为了在序批式反应器中利用好氧颗粒污泥实现氮和磷的稳定同步去除，建立了一种实时控制策略，通过监测电导率（EC）和pH的时间导数，以确定磷酸盐释放、硝化和反硝化的终点，以及处理周期中厌氧、好氧和缺氧阶段的相应最佳时长。尽管在启动阶段，由于形成好氧颗粒污泥的污泥沉降时间非常短，反应器中的生物量浓度剧烈波动，但在该控制系统中，适当处理的周期长度会自动调整。即使进水废水的特性显著波动，在伪稳态之前和期间都成功实现了稳定的氮和磷去除。NH4-N、NOx-N和PO4-P的出水浓度始终低于0.3 mg/L。另一方面，当厌氧/好氧/缺氧阶段的时长固定时，无法实现稳定的氮和磷去除。因此，很明显，所设计的控制系统对于通过好氧颗粒污泥同时去除氮和磷以获得稳定的处理性能非常有效。
