Biological treating method for decreasing comprehensive toxic of urban waste water

Abstract

The sewage flow with three different biological unit successively which are anaerobic unit, anoxic unit and aerobic unit. The time which sewage stay the unit are 2.5-3.9h, 2.5-3.5h and 6.0-7.5h respectively. He sludge age is 15-20 days, the mixture fluid returning ratio is 100%-20%. The sludge returning ratio is 100%. To determine the toxin of import and export waster water in the method of determination of acute aoxicity. So the toxin reduction ratio reach to 82% compared to the method of slued treatment, it is improved 20%-50%. The technology can also remove the N and P, the removal rate of N is 90.05%, the BOD is 81.25% and the SS is 77.17%. The effluent quality can meet all the routine standard and decrease the loading rate in the following treatment. The decreasing rate of toxin is used to access a biological treatment firstly in invention and the invention also provide a economical and efficiently method to resource the city wastewater.

Description

technical field [0001] The invention relates to a technique for reducing toxicity in urban sewage by adopting a biological treatment method. Background technique [0002] Municipal sewage is a mixed sewage composed of domestic sewage, industrial wastewater and initial rainwater (because the drainage system of many cities adopts a combined drainage system). Among them, although industrial wastewater has been treated, it still contains various toxic and harmful organic synthetic compounds that are difficult to degrade; and in domestic sewage, with the extensive use of synthetic detergents, cosmetics, medicines, etc., especially the increasing car washing industry, it is also There are a variety of toxic and harmful compounds; the initial rainwater contains rubber synthetic substances produced by the wear and tear of automobile tires, gasoline, and pollutants such as sulfate and nitrate brought in from the air. Therefore, urban sewage contains a variety...

AI Technical Summary

Problems solved by technology

However, in fact, reaching the COD standard does not necessarily mean that the toxic organic substances in the wastewater also meet the standard, because some toxic and refractory organic substances (such as toluene, xylene, etc.) cannot be oxidized when measuring COD, so they do not appear as COD part, but it actually still exists in the water

The more serious problem is that so far, sewage plants have not treated sewage with the goal of reducing the comprehensive toxicity of sewage.