Study On Iron-carbon Micro-electrolysis For Treatment Of The Quaternary Ammonium Production Wastewater

Quaternary ammonium compounds production wastewater contains a lot ofbiodegradation of organic compounds and belongs to difficult biodegradation of high salinityorganic wastewater with high COD (1500-2500mg/L), high pH (9-10), high concentration ofsuspended solids, etc. Micro-electrolysis technology combines a number of functions, such aselectrochemistry, oxide deoxidation, physical adsorption and flocculation action,and the gainin the electrode surface reaction,produce strong oxidation active substances and treatment ofhigh concentration toxic refractory wastewater. This method has the advantages of highprocessing efficiency and easy operation, no produce toxic substances,no adding chemicalreagents, is "environmentally friendly" technology.Using micro-electrolysis, study the degradation of QACs production wastewater. Mainresearch contents as:(1)According to the characteristics of high concentrations of COD, thepretreatment method of wastewater was studied and the condition was optimized.(2) Toimprove the economic viability, comparative study of iron, carbon materials and combinations,while optimizing the reaction parameters and progression.(3)The degradation mechanism andcost analysis of micro-electrolysis QACs wastewater degradation process are be researched.By using GC-MS analysis method to study and analysis on the above experimental results, getthe following conclusion:(1)The processing scheme of QACs production wastewater is the three micro-electrolysis.Under the conditions of the iron-water volume ratio5%,original pH3,the reaction time90min,and the mass ratio of Fe/C1:2,one micro-electrolysis treatment effect was the best,CODremoval rate was87.35%. The orthogonal experiments showed that each factor on the orderof COD removal rate was as follow: the mass ratio of Fe/C>the iron-water volumeratio>reaction time>original. Under the conditions of the iron-water volume ratio3%,originalpH3,the reaction time15min,and the mass ratio of Fe/C1:3,two micro-electrolysis treatmenteffect was the best,COD removal rate was98%. Under the conditions of the iron-watervolume ratio2%,original pH2.5,the reaction time30min,and the mass ratio of Fe/C1:3,threemicro-electrolysis treatment effect was the best,COD removal rate was99.4%. The effluent could achieve requirements of pollutant discharge standard in Discharge standard ofintegrated wastewater discharge standard (GB8978-1996). Higher costs need to furtherprocess optimization to ensure economic feasibility.(2)Optimization experiments showed similar adsorption effect of activated carbon andcarbon powder. But the carbon powder has characteristics of wide source, low expense and ithas great environment worth, therefore, we recommend the use of carbon powder in the actualproject. Then umber of primary batteries formed by small particle size iron shavings contactwith waste is much bigger than the particle size,so recommend the use of machineryprocessing factory iron shavings directly. The treatment effectof combination treatment effect of carbon powder plus iron shavings and activated carbonplus iron shavings had little difference,and election of iron shavings plus carbon powder fromthe economic angle. When the reaction times for the six,the effluent could achieverequirements of pollutant discharge standard in Discharge standard of integrated wastewaterdischarge standard (GB8978-1996). The processing scheme has good performance inwastewater treatment (COD removal rate as99.43%), less processing cost (510.82yuan/twastewater), short reaction time (155min), and has other certain advantages, and has othercertain advantages.(3)Analysis of the effluent wastewater degradation in different stages through theGC-MS, it is concluded that micro-electrolysis degradation mechanism of the QACswastewater treatment: direct oxidation in wastewater is organic matter including alcohol, ether,acetone and formaldehyde in the anode surface is direct oxidation into saturated organiccompounds. The main organic pollutants, tetrapropyl ammonium hydroxide, inwastewater by·OH attack, causing the shedding of branched alkanes, formating thetripropylamine. The tripropylamine is further degraded into dipropylamine. Finally, sectiondipropylamine degradation into Diaethylamin. Reduce the number of chemical processes suchas a series of bond breaking and recombination or electron transfer of esters and amines,generating alcohols, hydrocarbons and other organic matter, finally, the rest beinghydrocarbon and amines with a strong stable structure.This topic using micro-electrolysis method to degradation of QACs production wastewater processing, for the wastewater treatment provides an effective new method;Meanwhile, to optimize the engineering application, improving the economic viability. Thisprocess don’t need to waste water dilution, has low processing cost, don’t need to waste heat, without adding electrolyte and other characteristics, the treatment effect is good, short stayingtime waste water, technological process is simple, has the significance of making use of wastecircularly, has the incomparable virtues than the other methods.