Phosphorus-standard emission treatment method of agrochemical wastewater based on ultrafiltration-reverse osmosis

Abstract

The invention provides a sewage treatment method, and in particular relates to a phosphorus-standard emission treatment method of agrochemical wastewater based on ultrafiltration-reverse osmosis. According to the method, agrochemical wastewater is treated by an early pre-treatment process and subjected to sand filtration, two-stage UF (ultra-filtration), resin softening and two-stage RO (reverse osmosis) treatments, and the whole recycling rate of a system is more than or equal to 90 percent; the generated thick water with high phosphorus concentration flows through a thick water chemical phosphorus removing system, so that the total phosphorus of thick water is reduced to less than or equal to 4mg / L; the thick water is mixed with RO producing water with total phosphorus concentration less than or equal to 0.1mg / L, the outlet total phosphorus is less than or equal to 0.5mg / L, and standard emission of wastewater can be realized. The method has the advantages that adverse factors causing RO system pollution and blockage can be solved, so that the RO system is enabled to run stably under high recycling rate; the thick water is dephosphorized, so that the capture rate of a chemical agent can be improved, and the problems that the producing water with low phosphorus content and high-concentration dosage still cannot reach the standard can be solved; the whole system has a high automatic degree, is convenient to operate and manage, and runs stably.

Description

technical field [0001] The invention relates to a sewage treatment method, in particular to an ultrafiltration-reverse osmosis-based treatment method for agrochemical wastewater discharge of phosphorus up to the standard. Background technique [0002] Ultrafiltration (UF) is generally used as a pretreatment of high-precision treatment processes to provide sufficient water for subsequent processes and ensure stable and good operation of subsequent process systems. At present, the ultrafiltration process is combined with reverse osmosis, nanofiltration and other processes to form a double-membrane process, which is more and more widely used in the fields of pure water preparation, water treatment and reclaimed water reuse. [0003] Ultrafiltration membranes can be divided into coil ultrafiltration, hollow fiber submerged ultrafiltration, hollow fiber pressure ultrafiltration, tubular ultrafiltration, and flat plate ultrafiltration according to the membrane module configuration...

AI Technical Summary

Problems solved by technology

Through the method of the invention to treat low-concentration phosphorous-containing wastewater, through a targeted pretreatment process, the problem of fouling at a high recovery rate of the RO system is solved, and the RO system can run stably at a recovery rate of ≥ 90%. The RO concentrated water is oxidized and dephosphorized, and the concentrated water is mixed with the product water to achieve the overall stable compliance

Dephosphorization of concentrated water can improve the capture efficiency of chemicals and reduce the amount of chemicals used. Although the overall process line is long, the system has a high degree of automation, simple management and maintenance, and fundamentally solves the problem of unreachable discharge.

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