Dephosphorizing technology for waste water treatment of high efficiency, low cost and no pollution

Abstract

The sewage dephosphorizing process includes the following steps: A. spreading a bearing layer of 200 mm thickness and a 3-5 mm size limestone filter material layer of 800-1000 mm thickness in the filter pond; B. filtering the sewage with phosphorus concentration of 2.83-5 mg/L in the filter pond, with the contact time between the sewage and the filter material being controlled in 5-30 min and flow rate being controlled in 2-5 m/hr; and C. air and water reverse flushing on the filter material after continuous running of 48-96 hr. The present invention simulates natural dephosphorizing process with slowly released calcium from limestone to react with phosphorus, and makes the effluent reach the draining standard in low cost without pollution.

Description

technical field [0001] The invention relates to a sewage treatment technology, in particular to a dephosphorization treatment technology for urban sewage and phosphorus-containing factory wastewater. Background technique [0002] At present, the dephosphorization treatment of urban sewage and phosphorus-containing factory wastewater mainly adopts biological methods and physical and chemical methods. The biological treatment method is an anaerobic-anoxic-aerobic and reflux method used when the influent concentration of phosphorus is lower than 2mg / L. This method can discharge up to the standard, but it increases civil engineering and power consumption, and when the influent concentration of phosphorus is greater than 2mg / L, it is difficult to meet the discharge standard by using biological treatment methods, so the country has adjusted the discharge standard of phosphorus from 0.5mg / L Increased to 1.5mg / L. Most of the physical and chemical treatment methods use the method o...

AI Technical Summary

Problems solved by technology

This method can discharge up to the standard, but it increases civil engineering and power consumption, and when the influent concentration of phosphorus is greater than 2mg / L, it is difficult to meet the discharge standard by using biological treatment methods, so the country has adjusted the discharge standard of phosphorus from 0.5mg / L Increase to 1.5mg / L

Most of the physical and chemical treatment methods use the method of adding aluminum salt and iron salt. Although the treated water can be discharged up to the standard, the operating cost is high and has a certain impact on the environment; in addition, if aluminum salt and iron salt are added to the biological treatment Between the sedimentation tank, aluminum salts and iron salts will react with the sludge, increasing the amount of aluminum salts and iron salts, increasing the treatment cost, and reducing the activity of the return sludge; if aluminum salts and iron salts are added to the sediment After the pool, although the dosage and cost of aluminum salt and iron salt can be reduced, the cost is still high, and a sedimentation tank needs to be built, which increases the project investment