Method and system for treating high-ammonia nitrogen photovoltaic waste water containing cadmium and thiourea

Abstract

The invention discloses a method and system for treating high-ammonia nitrogen photovoltaic waste water containing cadmium and thiourea. The high-ammonia nitrogen photovoltaic waste water containing cadmium and thiourea enters a primary comprehensive cadmium removing pool, NaOH, PAC and PAM are added in order for carrying out a coagulation reaction, cadmium precipitates are added into the waste water, NaOH is added for adjusting a pH value and the waste water enters a distillation stripper, and at the same time ammonia nitrogen in the waste water is recycled and converted into 16-19% ammoniacal liquor; effluent enters a secondary integrated cadmium removing pool, NaOH, TMT, PAC and PAM are added in order for carrying out a coagulation reaction, and a secondary treatment is carried out for residual cadmium substances in water; effluent enters an advanced oxidation pool, agent H2SO4, FeSO4, H2O2, and NaClO are added in order, and oxidation and decomposition are carried out for thiourea substances and residual ammonia nitrogen in the waste water; effluent enters a coagulative precipitation tank, agent NaOH, TMT, PAC and PAM are added in order, residual cadmium in water and oxidation products in the advanced oxidation technology are removed, and water quality of discharged water reaches a B grade standard in 'wastewater quality standards for discharge to municipal sewers' (GJ343-2010).

Description

technical field [0001] The invention relates to a treatment process in the field of environmental protection technology, specifically a method and system for treating photovoltaic wastewater containing high ammonia nitrogen, cadmium and thiourea, which is mainly used in ammonia nitrogen, cadmium and thiourea in the production wastewater of copper indium gallium selenium thin film solar cells, etc. Disposal and recycling of substances. Background technique [0002] With the development of solar photovoltaic technology, copper indium gallium selenide thin film solar cells have been widely promoted and applied in the photovoltaic industry due to their low production cost, non-fading, and good low-light performance. The photoelectric conversion efficiency of this type of solar cell ranks first among all kinds of thin film solar cells, close to that of crystalline silicon solar cells, and the cost is one-third of that of crystalline silicon cells. It is known internationally as "...

AI Technical Summary

Problems solved by technology

In foreign countries, due to the difference in environmental protection regulations and acceptance standards of municipal treatment facilities, the wastewater discharged from this production line only needs to treat the cadmium substance before it can be discharged, and the ammonia nitrogen substance and thiourea substance do not need to be treated by the manufacturer itself, so for this type Wastewater, there is no supporting treatment process package for import in foreign countries

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