Yoon Seong-Hoon, Kim Hyung-Soo, Yeom Ik-Tae
Global Research Center, Nalco Company, Naperville, IL 60563-1198, USA.
Water Res. 2004 Jan;38(1):37-46. doi: 10.1016/j.watres.2003.09.001.
A methodology to obtain the most economical operational condition of membrane bioreactor (MBR) is developed. In order to achieve the optimum design parameters of MBR with which operational costs are minimized, aeration and sludge treatment costs were estimated for various operational conditions. Generally sludge treatment cost and aeration cost were inversely proportional to each other, which means sludge treatment cost is minimized when aeration cost is maximized and vice versa. Therefore, there might exist an optimum point between the two extreme cases. However, sludge treatment cost turned out to overwhelm the aeration cost over the reasonable operational conditions. Therefore, sludge minimization was considered to be a key for the economical operation of MBR. In the case of typical municipal wastewater of which COD was 400mgL(-1), steady-state MLSS was expected to increase from 11,000 to 15,000mg/L without sludge removal when HRT was decreasing from 16 to 12h. For the range of operational conditions considered in this study, economically optimum HRT and target MLSS were turned out to be 16h and 11,000mg/L, respectively. Under this condition, aeration for the biodegradation of organic matters would be 13.3m(3) air/min when influent was 1000m(3)/day.
开发了一种获取膜生物反应器（MBR）最经济运行条件的方法。为了实现使运行成本最小化的MBR最佳设计参数，对各种运行条件下的曝气和污泥处理成本进行了估算。一般来说，污泥处理成本和曝气成本相互成反比，这意味着当曝气成本最大化时污泥处理成本最小化，反之亦然。因此，在这两种极端情况之间可能存在一个最佳点。然而，在合理的运行条件下，污泥处理成本超过了曝气成本。因此，污泥最小化被认为是MBR经济运行的关键。对于典型的化学需氧量为400mg/L的城市污水，当水力停留时间（HRT）从16小时降至12小时且不进行污泥去除时，稳态混合液悬浮固体（MLSS）预计将从11000mg/L增加到15000mg/L。对于本研究中考虑的运行条件范围，经济上最佳的HRT和目标MLSS分别为16小时和11000mg/L。在此条件下，当进水流量为1000m³/天时，用于有机物生物降解的曝气流量为13.3m³空气/分钟。
