A recycling device and process for high-hardness nitrate wastewater

Abstract

The invention discloses a recycling device and process for high-hardness nitrate wastewater, including a denitrification pulse pool, a calcium mud separation pool, a biochemical pool, and an MBR membrane pool. Pool type, the denitrification pulse pool includes a primary denitrification pulse pool and a secondary denitrification pulse pool, the calcium mud separation pool includes a primary calcium mud separation pool and a secondary calcium mud separation pool, and the calcium mud separation pool The pool includes a central water distribution area, a central separation area, and a bottom concentration area. The calcium mud separation pool has a water inlet area, a separation area, a concentration area, and an automatic sludge discharge control device; there is a denitrification and calcium removal system in front of the biochemical pool. Afterwards, there is an MBR biofilm system; the MBR membrane pool is a recycling treatment device after aerobic biochemistry. The invention can avoid the calcification of the activated sludge and reduce the activity, reduce the calcium carbonate hardness of the wastewater while denitrifying, has high pollutant removal efficiency, and has good environmental protection and economic benefits.

Description

technical field [0001] The invention relates to a biochemical treatment improvement and recycling process for fluorine-containing wastewater in the solar cell industry, and belongs to the fields of wastewater treatment and water resource recycling. Background technique [0002] In the acid-base etching production process of the solar cell industry, a large amount of acid-base wastewater will be produced. The pollutants in the wastewater are mainly hydrofluoric acid, fluorosilicic acid, nitric acid, etc. The fluorine content of the wastewater is as high as 2000mg / L or more, and the total nitrogen is generally about It is 400-600mg / L. The common treatment process is calcium fluoride precipitation method. The dosing agent is milk of lime and calcium chloride. The fluoride ion is removed through two-stage coagulation reaction precipitation, and the removal of total nitrogen adopts biochemical denitrification process. . [0003] The main problems existing in the existing process...

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Problems solved by technology

[0003] The main problems existing in the existing process are: the high hardness nitrate wastewater after defluoridation has high calcium hardness, the biochemical sludge is prone to calcification, and the denitrification efficiency is low, which leads to the instability or even paralysis of the biochemical system, and the high hardness wastewater will Cause scaling or clogging of recycling process equipment, deep recycling treatment is difficult, and maintenance costs are high

[0006] The chemical precipitation method needs to add chemicals; the investment cost of membrane method and adsorption method is high, and the consumables need to be replaced regularly, which is only suitable for small water volume occasions; the structure of ion exchange, electrodialysis and other process equipment is complex, and the operation and maintenance are difficult. Improper will cause secondary pollution

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