Characteristics Of Anaerobic Digestion And Methane Recovery Of Pots Of Water And Pit Bottom Water Of Liquor Enterprise

The distilled spirit wastewater is one kind of organic wastewater that are ofhigh concentration and easy to be degraded. It is characterized as deepchromaticity, great variation of both water quality and volume, intermittentdischarge and so on. It is analyzed that one ton of65degrees distilled spiritneed60ton water and produce about48ton wastewater which is so largepollutant discharge. In our country only minority scale distilleries ownwastewater control facilities running well, while there is little equipment forrecycling methane from anaerobic process. And in small distilleries methaneis of so low gas yield as well as difficult recycling that substandardwastewater or wastewater without treatment is discharged commonly. There isnot a mandatory provision of recycling methane produced in anaerobicprocess for small and medium size distilleries. But it is encouraged to recyclemethane for the heat source of anaerobic process or the fuel of power boiler.At the same time, along with the development of Liquor Industry theenvironment problems become more and more serious. Therefore the study onthe recycling of wastewater in small and medium size distilleries hasimportant significance to the work of energy saving and emission reduction.It is noticed by author that there are scarcely researches on the property andtreatment methods of high concentration organic wastewater and recyclingmethane produced in anaerobic process in small and medium size distilleries,let alone the experiment researches about personality differences ofwastewater along with different productive technology in different type ofdistilleries and what optimized measures should be employed in the treatmentof wastewater. The article not only introduces the productive technology ofboth sauce sweet model liquor and fen-flavor liquor and the origin, propertyand characteristic of their wastewater, but also compares the two’scharacteristics of anaerobic methane-production. The study is mainly on the comparative analysis and conditioning tests ofbottom pot water, bottom cellar water and their mixed liquor separately fromone sauce sweet model distillery in Maotai Town and another fen-flavormodel distillery in Daye City. Further this study discusses the difference ofrecycling methane from anaerobic fermentation in two types of distilled spiritwastewater. The results of the testing demonstrates that the treatment effect ofbottom pot water alone is better than that of bottom cellar water alone underthe circumstances of either hyperthermy anaerobic or mesotherm anaerobic.And comparing with mesotherm anaerobic the treatment effect under thecircumstances of hyperthermy anaerobic is generally better. When treatedalone under the circumstances of both hyperthermy anaerobic and mesothermanaerobic, the treatment effect of bottom pot water and bottom cellar water insauce sweet model liquor is superior to that in fen-flavor liquor. The treatmenteffect of mixed sauce sweet model liquor is superior to bottom pot water orbottom cellar water alone. Furthermore, while the volume ratio of bottom potwater and bottom cellar water is5:1and the inflow COD is24000mg/L, theCOD removal and volume of methane anaerobic-production both achieve thebest condition. The result is the same to fen-flavor liquor, except that theinflow COD is22000mg/L. When mixed bottom pot water and bottom cellarwater with the optimal proportion, the COD in effluent and the rates ofdegradation in two types of wastewater are more or less the same. Yet thequantity of methane produced in sauce sweet model liquor wastewater isslightly higher than that in fen-flavor. Moreover the best removal rates ofCOD are90.22%and88.99%respectively. In conclusion, sauce sweet modelliquor wastewater is easier to be treated than fen-flavor liquor wastewater.The important parameters in anaerobic methane-production of distilled spiritwastewater are pH value, HRT and cumulant of volatile fatty acid (VFA). Thebest pH value is7.0. Before hydraulic retention time (HRT) is16h, the gasproduction rate of methane is not high and the COD removal rate is low because of the rising trend of VFA concentration. It indicates that theanaerobic process turns into hydrolysis acidification phase. After HRT is16h,VFA concentration lower and the gas production rate of methane is rising sorapidly that the COD removal rate is improved soon. And the COD removalrate gets the peak value when HRT is48h.