Urban sewage treatment process applicable to quasi-IV class water standard

Abstract

The invention provides an urban sewage treatment process applicable to a quasi-IV class water standard. The invention relates to the field of urban sewage treatment, and discloses the sewage treatmentprocess which meets requirements of quasi-IV class water. The sewage treatment process comprises the following steps: urban sewage is treated through primary treatment (mainly through processing units such as coarse and fine grids, a grit chamber, a regulating tank and the like) so that garbage of relatively large particle size, floating matter, suspended solid, sandstone and the like in the sewage can be removed; effluent after the primary treatment enters a multi-stage AO composite IFAS biochemical system to remove most of the organic matter, total nitrogen, total phosphorus and other pollutants; the effluent from IFAS enters a A2O tank, and the effluent from the A2O tank enters a secondary settling tank for solid-liquid separation; supernatant liquid discharged from the secondary settling tank enters a high-speed settling tank, and a phosphorus removal agent and a coagulant are added for reaction and precipitation; the effluent from the high-speed settling tank enters a high-precision filter cloth filter tank, and the sewage is filtered to remove SS; and the effluent enters a disinfection tank for disinfection treatment and is discharged after reaching the quasi-IV class waterstandard.

Description

technical field [0001] The invention belongs to the field of urban sewage treatment, and is particularly aimed at the whole-process sewage process of newly-built sewage plants or existing sewage plant upgrading and reconstruction projects meeting Class IV water environmental protection requirements. Background technique [0002] In recent years, the Ministry of Environmental Protection recently announced the national "Pollutant Discharge Standards for Urban Sewage Treatment Plants" (Draft for Comment), which has added relevant indicators for special discharge limits. The main indicators refer to "Surface Water Environmental Quality Standards (3838-2002 )" class IV water indicators. [0003] "Pollutant Discharge Standards for Urban Sewage Treatment Plants" (GB18918) (Draft for Comment) [0004] The maximum allowable emission concentration (daily average value) of basic control items Unit: mg / L [0005] [0006] Beijing, Tianjin, Guangdong, Jiangsu, Zhejiang and other reg...

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Problems solved by technology

[0009] The problem to be solved by the present invention is to provide an urban sewage treatment process applicable to quasi-IV water standards, so as to overcome the problems of low organic pollutant removal degree, insufficient carbon source, low denitrification efficiency, and poor system synergy in the prior art. Defects, making urban sewage treatment more cost-effective and stable

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