Novel technology for processing dye wastewater by combining advanced oxidation technology with biofilm process

Abstract

The invention discloses a novel technology for processing dye wastewater by combining an advanced oxidation technology with a biofilm process. The traditional technology is large in energy consumption, high in cost and troublesome in operation when used for processing the dye wastewater. The novel technology comprises the following steps of feeding the dye wastewater into an advanced oxidation pond, and adjusting the pH value to 3.5+ / -0.2; adding H2O2 and Fe<2+>, stirring and reacting for 45 minutes, and then adjusting the pH value to 7.5+ / -0.2; feeding the effluent of the advanced oxidation pond into a two-stage biofilm system to carry out biological aerobic degradation reaction; feeding the effluent of a second-stage biofilm reaction system into a settling pond, discharging a part of effluent after standing for 30 minutes, and back-flushing by using the other part of effluent, wherein the effluent indexes are as follows: the chemical oxygen demand (COD) is below 80mg / L and the chromaticity is smaller than 60. The novel technology has the advantages of being good in dye wastewater treatment effect, free of secondary pollution, low in energy consumption, low in water treatment cost, and capable of protecting the environment, thereby being beneficial to development of a dyeing enterprise.

Description

[0001] technical field [0002] The invention relates to environmental protection technology, in particular to a treatment method for dye wastewater. Background technique [0003] At present, dyestuff companies mainly produce acid dyes, neutral dyes, mordant dyes and dye intermediates. The wastewater produced in the dye production process is high COD, high chroma, high salt content and low BOD 5 The mixture of mother liquor of / COD and washing water will cause great pollution to the environment and water resources. COD stands for Chemical Oxygen Demand (Chemical Oxygen Demand), which refers to the amount of oxidant consumed when using a strong oxidant to treat water samples under certain conditions; it is an index indicating the amount of reducing substances in water. The greater the chemical oxygen demand, the more Water pollution is more serious. BOD is Biochemical Oxygen Demand (Biochemical Oxygen Demand), which refers to the oxygen demand for microbial decompositio...

AI Technical Summary

Problems solved by technology

[0005] (1) It is based on aromatic hydrocarbons and heterocyclic compounds and has chromogenic groups, which are easily oxidized to produce quinoid compounds with strong color development ability, giving Dye wastewater treatment poses great difficulties

[0006] (2) Organic matter has good water solubility, complex structure, and more than 97% contain benzene ring structure, which is difficult to degrade; with the upgrading of dye products and the emergence of new dyes , the structure of organic matter in wastewater is more complex, which brings difficulties to the treatment of dye wastewater

[0007] (3) In addition, wastewater often contains baking soda, emulsified oil, organic solvents, and petroleum substances, which increase the consistency of wastewater and generate a large amount of foam, which increases the difficulty of treatment

[0008] (4) The COD in the dye mother liquor wastewater is as high as 10000mg / L; the chroma is as high as 12000 times; the salt content is as high as 9000mg / L; sub> 5 / COD is 0.1); when mixed with washing wastewater, its concentration decreases, but if it is directly discharged into the water body, it will cause great harm to the environment

[0012]A. Adsorption by activated carbon adsorbent, the disadvantage is that regeneration is difficult and the cost is too high

[0013] B. Biological activated carbon adsorption method is limited by the concentration of microorganisms. When the concentration of microorganisms is low, the degradation effect is poor; when the concentration of microorganisms is high, the pores of activated carbon are blocked, resulting in poor adsorption effect

[0014]C, microporous resin adsorption, limited adsorption capacity, can not meet the treatment requirements of dye wastewater, and after the adsorbent is saturated, it is easy to form secondary pollution

[0015] (3) Electrochemical analysis methods: such as electro-oxidation technology, photo-oxidation technology, microwave synergy technology, electric floatation and micro-electrolysis, etc. Although these methods have good treatment effects , does not produce secondary pollution, and has the advantages of small footprint, but its disadvantage is that it consumes a lot of energy, and it is easy to scale and block the dye wastewater with high salt content, which increases the treatment cost

[0016] (4) Biological treatment method: The cost of biological treatment method is low, but in the case of high salt content, the degradation effect is affected due to the unsatisfactory effect of strain domestication

[0017] Chinese Patent Publication No.: CN 101659500A, introduces "a dye wastewater treatment system", in which the aerobic pool is connected to advanced oxidation treatment, although the treated water can Reach the target, but this method consumes a lot of energy, has high processing costs, and is cumbersome to operate

[0018] Chinese Patent Publication No.: CN101955303A, introduced "a treatment method for dye wastewater", developed by our research group, the method uses "flocculation precipitation-hydrolysis acidification-good Oxygen-reverse color” main process, although the effluent after treatment can meet the standard discharge, but in actual operation, it is found that the operation management of this process is complicated and the energy consumption is high

Images