Study On Biochemical Treatment Of Straw Alcohol Wastewater And Degradation Of Major Pollutants

At present,in the background of the energy crisis and the emergence of fuel ethanol industry demand for increasingly elevated,alcohol is considered to be the most likely alternative energy fuel oil.Some ethanol preparation of domestic and foreign enterprises faith in "By Waste" principle,using non-food feedstock preparation of alcohol is widely recognized and developed with the use of crop straw. However, in its production process, it will produce a large number of refractory straw alcohol wastewater.Some research on the straw alcohol wastewater mostly limited to anaerobic and aerobic biological treatment and treatment effluent also cannot meet emissions standards.Therefore,the present study adopts anaerobic,aerobic,deep treatment process to treat the straw alcohol wastewater.Different factors were discussed and the various stages of operational control parameters were described,focused on the variation of COD and NH4+-N. Meanwhile,the changes at all stages of major pollutants in straw alcohol wastewater were researched and the main pollutants were highlighted. For furfural this major pollutants, COD and degradation were studied from a qualitative and quantitative point of view. The results showed that:(1) During straw alcohol wastewater continuously entering into the UASB, with the control of temperature is 34?, influent p H value is 7, HRT keeps for the four days, UASB reactors can reach the best removal efficiency of straw alcohol wastewater about COD, the removal rate can reach 69%. At this point, the effluent COD concentration was about 8100mg/L, p H is about 8.2, COD load of 4.5kg/(m3?d).(2) During anaerobic effluent of straw alcohol wastewater continuously entering into the aerobic treatment unit, with the control of temperature is 34?, influent p H value is 7.5, HRT keeps for the four days, aerobic treatment unit can reach the best removal efficiency, the removal rate can reach 75.3%. At this point, the effluent COD concentration was about 2100mg/L, p H is about 8.0, COD load of 1.53kg/(m3?d).(3) At the stage of depth processing, by single factor experiments, it ultimately determines to take aerobic wastewater 200 m L, controls Fe2+/H2O2 concentration ratio of 0.8: 1, H2O2 amount 3.5m L, adjusts the p H value 3.5,while controlling the reaction time was 30 min and TOC were degradated from the 2000mg/L to 285mg/L, the removal rate was 85.8%.(4) From the point of view of the whole process, after the anaerobic,aerobic,deep treatment, COD removal rate was 98.31%, TOC removal rate was 97.19%, TN removal rate was 93.70%, TP removal rate was 93.89%, NH4+-N removal rate was 94.63%, and they finally able to achieve emission standards of "urban sewage discharged into the sewer water quality standards"(CJ343-2010).(5) Straw alcohol wastewater contains mainly acids, alcohols, furfural, phenols, furans, phenols, ring alcohol-based, azo-based and organic molecules and other 50 kinds of organic matter, and they make more difficult degradate wastewater. Among them, the furfural content of the highest, accounting for about 5%, is the major pollutants in wastewater.Straw alcohol wastewater through anaerobic, aerobic biological treatment, organic molecules mainly containing acids, alcohols, furfural, phenols, furans, phenols, ring alcohol-based, azo-based and organic molecules have appeared effective removal and degradation, only part of the macromolecular azo-based and not sufficiently removed.