OPTIMUM OPERATION OF THE RURAL SEWAGE TREATMENT PLANT WHICH TREATMENT METHOD WAS CONVERTED INTO INTERMITTENT AERATION USING FLOATING SLUDGE

处理方式改为浮污泥间歇曝气的农村污水处理厂优化运行

• 批准号: 11660239
• 负责人: NISHIMURA Naomasa
• 金额: $ 2.24万
• 依托单位: GIFU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11660239/
• 关键词: Intermittent aeration; Contact aeration; Nitrogen removal; Transparency; Rural sewage treatment plants; PACK test; Returned sludge; Poly iron (III) sulfate; 浮遊法; 嫌気性ろ床槽接触曝気方式; 窒素処理; MLSS; オキシデーション・ディッチ; 維持管理

Investigations were carried out on the rural sewage treatment plants, which treatment methods using the contact aeration tanks in combination with the anaerobic filter bed tanks were converted into intermittent aeration method using floating active sludge. The purpose of this study was to determine the optimum operation on these treatment plants for the removal of nitrogen, phosphorus and organic contaminant, and the following findings were obtained.1. For effective nitrogen removal, there was adequate duration of aeration, which varied with water temperature in treatment tank. Furthermore, total nitrogen in the final effluent water could be reduced within the range front 5 to 10 mg/L approximately, if the duration of aeration would be set adequately.2. Adequate duration of aeration for effective and stable disposal of nitrogen could be actually determined using the measured values of nitrate nitrogen and ammonia nitrogen obtained by a tiny test for water quality (PACK test ; Kyoritsu Chemical-Check Lab., Corp.) of the final effluent.3. In the case of small treatment plant, adequate duration of aeration for nitrogen removal would be so decreased by bypass flow through reaction tanks that the transparency of final effluent tended to indicate low values because of the inhibition from organic contaminant disposal that should progress in aerobic condition.4. Sludge concentration in reaction tanks was increased with MLSS ranging from about 4000 to 5000 mg/L by means of stopping the extraction of excess sludge and increasing the volume of returned sludge at the small plant mentioned above. The results showed that the transparency of final effluent improved considerably at values more than 100 cm.5. The injection of poly iron(III) sulfate into a reaction tank could decrease the concentration of total phosphorus in final effluent, though it would become necessary to dispose large quantity of excess sludge because the sludge conversion ratio would reach 100%.

以农村污水处理厂为研究对象，将接触曝气池与厌氧滤床池相结合的处理方法改为间歇曝气浮置活性污泥法。这项研究的目的是确定这些处理厂在去除氮、磷和有机污染物方面的最佳运行方式，并获得以下结果。对于有效的脱氮，曝气时间是充足的，该时间随处理池的水温而变化。此外，如果适当设置曝气时间，最终出水中的总氮可降低到约5~10 mg/L的范围内。有效和稳定地处理氮的充分曝气时间实际上可以使用通过微小的水质测试(包装试验；共同社化学检查实验室)获得的硝酸盐氮和氨氮的测量值来确定。最终的流出物。在小型处理厂的情况下，通过反应池的旁路流动会减少足够的曝气脱氮时间，最终出水的透明度往往会显示低值，因为有机污染物处理的抑制应该在好氧条件下进行。通过停止剩余污泥的提取和增加回流污泥的体积，提高了反应池中的污泥浓度，MLSS在4000~5000 mg/L左右。结果表明，最终出水透明度在100 cm以上时有较大提高。向反应池中投加聚合硫酸铁可以降低最终出水中总磷的浓度，但由于污泥转化率可达100%，因此需要处理大量剩余污泥。