Method for removing and recovering phosphorus in sewage

Abstract

The invention discloses a method for removing and recovering phosphorus in sewage, which comprises the following steps: to-be-treated sludge enters a high-load anaerobic-aerobic membrane bioreactor (AP / O-MBR) for phosphorus release, phosphorus removal and solid-liquid separation to obtain first-stage reaction effluent and first-stage reaction effluent sludge; the sludge discharged from the first-stage reaction enters a multi-section flat sheet membrane sludge concentration tank for sludge concentration to obtain second-stage reaction effluent and second-stage reaction discharged sludge; and the secondary reaction discharged sludge enters a heating dissolution tank to be heated and stirred, and phosphorus-rich supernatant and dephosphorized sludge are obtained through a solid-liquid separation device. The total phosphorus concentration of effluent can be reduced to 0.1 mg / L or below under the condition that no chemical agent is added; meanwhile, the problem of chemical sludge is avoided, and phosphorus is easier to recover in form; on one hand, the concentration of the sludge is increased, the phosphorus content of the sludge per unit volume is increased, and phosphorus-rich supernatant with higher concentration is obtained; and on the other hand, the sludge volume and the heating energy consumption of heating dissolution are greatly reduced.

Description

technical field [0001] The invention relates to the field of sewage MBR treatment, in particular to a method for removing and recovering phosphorus in sewage. Background technique [0002] It is generally believed that phosphorus is a one-way flow of non-renewable resources in the natural environment, but with the rapid development of society and economy, phosphorus resources are continuously consumed, and the shortage of phosphorus resources has become increasingly prominent in my country and even in the world. For environmental water bodies, phosphorus in urban domestic sewage is a pollutant, but at the same time it is a scarce resource for the development of human society. The sewage treatment process usually transfers the phosphorus in the sewage to the sludge. If the phosphorus in the sludge can be recovered, the recycling of phosphorus resources can be realized to a certain extent. [0003] MBR is an efficient sewage treatment technology that combines biological treat...

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Problems solved by technology

[0004] The invention aims at the poor effect of MBR biological phosphorus removal in the prior art, and the problem that chemical phosphorus removal will cause residual sludge to contain chemical agents and phosphorus recovery is difficult. The invention proposes the use of high-load AP / O-MBR to extract The method of removing and recovering phosphorus, by controlling the design and operating parameters, most of the phosphorus in the influent is transferred to the excess sludge, and the total phosphorus concentration in the effluent can be reduced to below 0.1mg / L; sludge containing a large amount of phosphorus is concentrated and dissolved in the phosphorus-rich supernatant after heating, which is conducive to the subsequent recovery of phosphorus

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