An integrated device and method for denitrification and decalcification of wastewater

Abstract

The invention discloses wastewater denitrification and decalcification integrated device and method. The integrated device comprises a reaction zone, a separation zone and a sludge reflux system, wherein the reaction zone comprises more than two reaction sections, the reaction sections are connected end to end to form an annular flow reaction tank, each reaction section comprises a first anaerobicsection and more than one anoxic section, wherein the first anaerobic section and the anoxic section are connected in sequence, and the anoxic section comprises an anoxic section B and an anoxic section A which are connected in sequence; the separation area is divided into a physicochemical sludge scraping area and a biochemical sludge scraping area; a middle water distribution tank and a sludgehopper are sequentially arranged on the water inlet side of the separation area, and a dross tank and a water collecting tank are sequentially arranged on the water outlet side of the separation area.According to the invention, chemical agents do not need to be added, nitrogen and calcium are removed at the same time, physicochemical sludge and biochemical sludge are separated, the removal efficiency is high, the process automation control degree is high, operation is easy, installation is convenient, and running is mature and stable.

Description

technical field [0001] The invention relates to an integrated device and method for denitrification and decalcification of industrial waste water such as metal pickling waste water and fluorine-containing waste water of photovoltaic cells, and belongs to the field of waste water treatment engineering application. Background technique [0002] Industrial wastewater such as metal pickling wastewater and fluorine-containing wastewater from photovoltaic cells basically use lime precipitation to neutralize acid or precipitate pollutants to adjust pH to alkaline, especially in the solar cell production industry, where the mixed wastewater pollutant is mainly hydrogen Fluoric acid, fluosilicic acid, nitric acid, etc. Generally, the fluorine content of wastewater is about 2000mg / L, and the total nitrogen concentration is about 600mg / L. Usually, two-stage coagulation reaction precipitation is used to remove F ions. The fluoride removal agents are lime and calcium chloride, while the ...

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Problems solved by technology

[0003] In the prior art, the main problems are: in the lime precipitation-based process, in order to achieve the standard discharge of metal ions or F ions, Ca ions are often added in excess, which increases the pollution of Ca in wastewater, and the removal of fluorine The concentration of calcium in the effluent can reach 400-600mg / L, which directly affects the effect of the subsequent biochemical denitrification process, and will also increase the investment and treatment costs of the subsequent reclaimed water reuse system

The chemical precipitation method needs to add chemical agents, while the filtration and adsorption method is usually suitable for a small scale of treatment. Generally, in order to prolong the reaction time, the filtration and separation equipment will be heightened, which often leads to difficulties in indoor installation, and the filter material needs to be replaced regularly. The internal structure is complicated. High cost, difficult operation, improper handling will cause secondary pollution

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