WASTEWATER TREATMENT METHOD AND WASTEWATER TREATMENT EQUIPMENT

PROBLEM TO BE SOLVED: To provide a wastewater treatment method and the like with which a supply amount of oxygen gas to microorganisms for clarifying wastewater is suppressed and furthermore BOD components, nitrogen components and phosphorus components in the wastewater can be sufficiently reduced.SOLUTION: The wastewater treatment method and the like are provided. The wastewater treatment method includes a first treatment step of cultivating microalgae in wastewater, and a second treatment step of treating by an activated-sludge process the wastewater in which the microalgae are cultivated in the first treatment step. The wastewater that includes first treated water treated in the first treatment step and contains a total nitrogen amount of 5-15 mg/L and a total phosphorus amount of 1-3 mg/L is treated in the second treatment step.SELECTED DRAWING: Figure 1 【課題】 排水を浄化する微生物への酸素ガス供給量を抑えつつ、排水中のＢＯＤ成分、窒素分、及びリン分のいずれも十分に減らすことができる排水処理方法などを提供することを課題としている。【解決手段】 排水中で微細藻類を培養する第一処理工程と、該第一処理工程にて前記微細藻類を培養した後の排水を活性汚泥法によって水処理する第二処理工程とを備え、第一処理工程後の第一処理水を含み全窒素量が５〜１５ｍｇ／Ｌであり且つ全リン量が１〜３ｍｇ／Ｌである排水を、第二処理工程にて水処理する排水処理方法等を提供する。【選択図】 図１