Fixed carrier-supported biofilm and activated sludge coupled sequencing sewage treatment device and process

Abstract

The invention discloses a fixed carrier-supported biofilm and activated sludge coupled sequencing sewage treatment device and process. The fixed carrier-supported biofilm and activated sludge coupledsequencing sewage treatment device comprises a reaction unit, a water feeding unit and a chemical feeding unit, wherein the water feeding unit and the chemical feeding unit are connected with the reaction unit through pipes; the side surface of the reaction unit is provided with, sequentially from top to bottom, an overflow port, a water drainage port and a sludge drainage port, and the side surface of the reaction unit is also provided with a backflow device for returning sludge-water mixtures at the bottom of the reaction unit to the top of the reaction unit; the inside of the reaction device is provided with, sequentially from top to bottom, carrier filler, a stirring unit and an aeration unit, wherein the carrier filler is fixed in an area above the water drainage port and under the overflow port; the aeration unit is fixed onto the bottom surface of the reaction unit. The fixed carrier-supported biofilm and activated sludge coupled sequencing sewage treatment device and process can meet the special emission limit of effluent water quality, which is specified in Discharge Standard of Pollutants for Municipal Sewage Treatment Plant (Exposure Draft), and can achieve an effluent ammonia nitrogen concentration less than 0.5 mg / L and a total nitrogen concentration less than 10 mg / L.

Description

technical field [0001] The invention relates to a batch type sewage treatment device and process coupled with a fixed carrier biofilm and activated sludge, and belongs to the technical field of sewage treatment. Background technique [0002] At present, the vast majority of urban sewage treatment plants in my country use A 2 / O process, inverted A 2 / O process and oxidation ditch process for simultaneous denitrification and phosphorus removal of sewage, and a few of them use SBR process, CASS process, CAST process, UNITANK process and UNITANK deformation process. [0003] The above process generally has the following disadvantages in the actual operation process: [0004] 1) The output of excess sludge is large and the treatment and disposal are difficult: the output of excess sludge in urban sewage treatment plants is large, and the excess sludge contains a large amount of harmful substances such as refractory organic pollutants, heavy metals, and pathogenic microorganism...

AI Technical Summary

Problems solved by technology

The cost of sludge incineration is too high, and the comprehensive cost of incinerating and disposing of 1 ton of wet sludge with a moisture content of 80% is about 600 yuan

Due to the heavy metals contained in the residual sludge, there is a safety hazard in agricultural applications

At present, the vast majority of excess sludge is disposed of through landfill. Although the cost of sludge landfill is low, heavy metals and toxic organic substances in excess sludge are easily dissolved, which will pollute soil, groundwater, etc., and cause new environmental pollution problems;

[0005] 2) Difficulty adapting to the ever-increasing discharge standards: At present, the relevant state departments are studying and revising the "Pollutant Discharge Standards for Urban Sewage Treatment Plants" (GB18918-2002), and released a draft for comments, adding "special discharge limits", requiring Special discharge limits are implemented in areas with high density of land development, weak environmental carrying capacity, small environmental capacity, fragile ecological environment or prone to serious environmental pollution problems. For areas with prominent water eutrophication problems, the TN value of the effluent from sewage treatment plants is required. ≤10mg / L

However, the TN value of the effluent of many sewage treatment plants that implement the first-level A discharge standard in my country is mostly above 10mg / L. In some areas, eutrophication of the water body is very easy to occur, and it is urgent to upgrade the standard.

At present, the conventional activated sludge process is difficult to meet the requirements of deep denitrification (the TN value of the effluent is ≤10mg / L), and the addition of a three-stage process is limited by the site and investment, and it is difficult to implement standard upgrading.

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