Study on Municipal Wastewater Treatment by Immobilized Microbes

为了处理生活污水中主要含有的溶解性基质，近年来研究者开发了一种新型的生物处理工艺--自固定化微生物系统（AIMS），并在不同进水基质浓度的人工污水中进行了300多天的小试试验。从结果来看，AIMS可以降低流出物总的和溶解的COD浓度低至约16和9毫克/升，分别对进水COD约220毫克/升，没有应用的污泥循环和最终的固液分离过程。从AIMS排放的颗粒物主要是轮虫的身体，预计将被鱼类摄食。因此，该工艺对污水处理过程中产生的污泥的处理和处置要求不像活性污泥法那样高，并已应用于实际生活污水的小型试验中。一般来说，从节能的观点来看，在小型生物处理厂中，从节能的观点来看，不推荐颗粒有机物的完全分解。本研究采用化学混凝沉淀工艺对原水进行处理，以达到控制颗粒物和磷的高效去除。将上清液引入AIMS。对实际生活污水的实验结果表明，在10 ℃下，进水总COD和溶解COD分别被去除约30 - 50 mg/l至出水20和15 mg/l的水平。日本的水温相对较低。

In order to treat mainly dissolved substrate contained in domestic sewage, a new biological treatment process named Auto-Immobilized Microbial System (AIMS) has been developing for these few years by the suthors.The bench-scale experiments have been conducted for more than 300 days with varying the influent substrate concentration of artificial wastewater. From the results, AIMS could reduce effluent total and dissolved COD concentrations to as low as around 16 and 9 mg/l, respectively, against influent COD around 220 mg/l with no application of sludge recycle and final solids-liquid separation processes. The particulate matter discharged from AIMS was mostly rotifer's bodies which were expected to be fed upon by fish. Thus, there will not be such an intensive requirement for treatment and disposal of sludge produced in wastewater treatment process as that for activated sludge process.This process has been also applied to the bench-scale experiments by using practical domestic sewage. Generally speaking from the view point of energy saving, on a small scale biological treatment plant, full decomposition of particulate organic matter has not been recommended from the view point of energy saving. In this research, particulate pollutants and phosphorus were controlled and removed in high efficiency by applying chemical coagulation-sedimentation operation to raw sewage. The supernatant was introduced to the AIMS. The results of this experiments against practical domestic sewage showed that influent total and dissolved COD were removed by around 30 - 50 mg/l to the level of 20 and 15 mg/l in the effluent, respectively, at 10 deg.C. which was comparatively lower water temperature in Japan.