| At present our country dyestuff production has reached9X105tons, dye wastewater has become one of the key sources of pollution environment. The dye industry was wide variety, process complex, its waste water contains a lot of organic matter and salt, with high CODCr, big chroma, strong acid and alkaline, toxicity characteristics, it has always been a difficult problems of wastewater treatment. Azo dyes, in the dye is more than80%, is a kind of the most chromatography with low prices dyes which was the most widely used in textile, printing, dyeing, leather etc..Nowerdays in our country, the azo dye wastewater treatment is still a big problem, so the management technology research has important practical value and certain theoretical significance.The Gangu pigment factory industrial wastewater is this experiment’s study object,that belongs to the high concentration,difficulty to degrade and organic wastewater.In the production process produces two kinds of wastewater:one kind is the mother liquor wastewater,mainly produces in the pigment production chemical reaction process,floats the washing water by the reaction and the initial period primarily;another kind of wastewater to rinse the pigment and the flushing equipment,flushes ground.This pigment industrial wastewater have the following several obvious characteristics:(1)the high CODCr density, poor biodegradability,this industrial wastewater belongs to the model highly concentrated organic industrial wastewater.The partial mother liquor’s CODCr value reaches as high as above10000mg/L.(2)the water quality change is big, rinse water was mixed when it was dealing with practical production waste water, and similar different brands of the waste water discharge pigment concentration, the actual pollutant concentration will produce change.(3)the production is a single product, azo dye wastewater with high nitrogen content, can cause C:N:P microbial basic source of nutrition imbalanced, especially the phosphorus salt.Based on the above several characteristics,the economical and effective processing pigment wastewater is the question which this experiment mainly needs to solve.Through laboratory and field test, determined the azo dye wastewater treatment process and method:pretreatment of the production wastewater use collection storage+iron carbon electrolytic+coagulation precipitate process,after pretreatment wastewater was set into sewage treatment station,through the electrolytic+4biological systems+filter+active carbon adsorption+oxidative decomposition of the central treatment process, to ensure that the sewage treatment discharge standards was complianced.The experiments study the pH of raw water, hydraulic retention time (HRT), aeration time in micro-electrolysis unit, pharmaceutical dosage as well as the effect of pH in coagulation unit on the pretreatment are investigated.The experiment achieved the removal of CODCr and color of the process and determined the optimum process conditions.The results showed that:The red and yellow mother liquor wastewater,pretreating respectively,when the raw water pH=3, Fe/C volume ratio is1:1.5, hydraulic retention time of30min, aeration time of120min, can get25%～30%of the CODcr removal rate and the decolorization rate of more than95%; the red mother liquor by chemical oxidation,that is in the coagulation unit, under the conditions that dosage of0.1g/mL, pH=7can be obtained20%of the CODCr removal rate and90%of the decoloration rate. After pretreatment, the wastewater was set into4level bio-filter. Determined by the experiment,the filler used polyurethane foam. Wastewater through bio-filter processing, was colorless and transparent, CODCr content was less than100mg/L, it has reached the national integrated wastewater discharge standard. The wastewater treatment process method is feasible, and the effect is good. It is the technical method that is worth applicating and promoting. |
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