Anaerobic zero-valent iron sewage treatment method

Abstract

The invention relates to an anaerobic zero-valent iron sewage treatment method, belonging to the sewage treatment technical field. The anaerobic zero-valent iron sewage treatment places zero-valent iron in an anaerobic reactor and utilizes the environmental conditions of the anaerobic isolated air to largely reduce the formation rate of the rust of zero-valent iron and avoid the formation of hardening; meanwhile, the method uses the reducing action of metal iron to increase the anaerobic reductive atmosphere, balance the pH and increase the effect of the anaerobic organism. A circulating pumpis adopted for sewage backflow so as to increase the overflow load of an iron / activated carbon layer and the reaction effect of zero-valent iron, improve the fluidization effect of sludge to increasethe anaerobic process efficiency. In a sewage treatment system, ferrous iron contained in the discharged sewage is oxidized to Fe(OH)3 with the air and the coagulation generated in the process can further purify the sewage. Long-term experiment research shows that the decolorizing rate of the sewage treatment method for dye wastewater can teach 85%-95%, the COD can be reduced by more than 50% andthe biodegradability can be increased to more than 0.3.

Description

technical field [0001] The invention relates to a sewage treatment method for anaerobic zero-valent iron, belonging to the technical field of waste water treatment. Background technique [0002] At present, the treatment methods of industrial wastewater mainly include conventional physical and chemical methods and biochemical methods. Physicochemical methods mainly include coagulation-sedimentation, adsorption, Fenton, photoelectric catalysis, etc.; biochemical methods mainly include aerobic, anaerobic, and hydrolytic acidification-aerobic methods. Coagulation sedimentation is not effective for printing and dyeing wastewater with strong solubility; adsorption method is suitable for the treatment of weakly polar organic substances, and is generally used at the end of the treatment process. Fenton uses the strong oxidizing OH free radicals to decolorize the dye molecules, but strong acidic conditions are required, and the residual H 2 o 2 It has a great impact on the subseq...

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Problems solved by technology

[0004] However, the biggest problem of zero-valent iron in practical application is the hardening of the iron filings bed: the rust formed by the iron filings contacting the air causes adhesion between the iron filings, blocks the flow of water, causes local channeling or short circuit, and seriously affects the efficiency of sewage treatment

However, so far, no patents or reports have been found that put zero-valent iron (internal electrolysis) in the anaerobic reactor to realize the coupling of two unit processes and apply it to the treatment of refractory sewage

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