Method for reducing content of phosphorus and COD in wastewater

Abstract

The invention discloses a method for reducing the content of phosphorus and COD in wastewater. The method includes the steps of: 1. conducting two filtering treatment on phosphorus-containing wastewater to obtain dephosphorized water, then adding a sodium carbonate solution for reaction, and conducting standing and calcium precipitation to obtain calcium carbonate and calcium removed purified water; 2. mixing hydrochloric acid with calcium carbonate for dissolution to obtain a calcium chloride solution; and 3. mixing the calcium chloride solution with phosphorus-containing wastewater, carryingout reaction and filtering to obtain calcium orthophosphate and dephosphorized water, and subjecting the dephosphorized water to treatment as step 1 again. According to the invention, comprehensive treatment is carried out on the phosphorus-containing wastewater generated in the process of producing mixed rare earth chloride from monazite concentrate, calcium phosphate is extracted from the phosphorus-containing wastewater, the additional value income of the product is increased, at the same time, the treated purified water is further used in the recovery link of rare earth prior dissolved slag, thus realizing the comprehensive utilization of water resources and maximizing the utilization of water resources.

Description

technical field [0001] The invention belongs to the technical field of phosphorus-containing wastewater treatment, and specifically relates to a method for reducing phosphorus content and COD content in wastewater. Background technique [0002] Monazite is a relatively common accessory mineral in intermediate-acid igneous rocks and metamorphic rocks, and also exists in some sedimentary rocks. It is a phosphate mineral containing cerium and lanthanum, a rare earth mineral, and rare earth elements are used in black and nonferrous metallurgy, glass and ceramic production, electronics, electric lighting, television and laser technology, chemical industry, medical treatment and agricultural production widely used in the field. The rare earth chloride produced from monazite concentrate can be used as raw material for electrolysis of mixed rare earth metals, rare earth alloys and extraction of single rare earth elements, and can also be used as raw material for petrochemical catal...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a method for reducing phosphorus content and COD content in wastewater in order to solve the problem of complex treatment of a large amount of phosphorus-containing wastewater in the existing rare earth chloride production process and large capital investment of enterprises

Images