| As a renewable energy, Fuel ethanol is considered the most promisingalternative to today’s fossil, It can be got by saccharification, fermentation processwhen use biomass substances as raw materials; The use of cellulosic materialswhitch does not been widely developed to produce fuel ethanol has become theinevitable trend of development in the world. However, the cellulose fuel ethanolproduction process will produce a large number of organic wastewater, It will causegreat harm to the ecological environment if we discharge it without water treatment.The wastewater for study was obtained from a cellulose fuel ethanolproduction pilot plant, By analyzing the characteristics of wastewater quality,Multi-faceted methods were proposed to treat the wastewater. Iron-carbonmicro-electrolysis-Fenton reagent-coagulation and sedimentation method wasused to pretreat the wastewater, two-phase anaerobic-aerobic combined processand CSTR-MFC combined process were used as methods for wastewater biologicaltreatment after whitch electro-catalytic oxidation was used for wastewater furthertreatment. Simultaneously joint experiments of wastewater reuse were done by thepilot plant.Water quality data results were analyzed by Chinese National Standard Method,COD was around165806mg/L, Biochemical oxygen demand (BOD) was around44280mg/L, B/C of the waste water was about0.26, COD:TN:TP of the waste waterwas about1381:5.98:1,52kinds of organic compounds whitch contain toxicsubstances such as Phenol and furfural were detected by GC-MS, The results showthat the wastewater is a kind of organic wastewater which is difficult to bebiodegradable.COD, TOC, B/C ratio were selected as evaluation parameters for wastewaterpretreatment study, After Iron-carbon micro-electrolysis-Fentonreagent-coagulationand sedimentation pretreatment COD and TOC removal rate can be achieved as37.65%and31.3%, B/C increased from0.27to0.42, The biodegradability ofwastewater was improved greatly.It took a period of139days by using two-phase anaerobic-aerobic combinedreactor system to treat cellulosic ethanol production wastewater, The final effluent keep stable, The COD of SBR effluent was around340mg/L, Total COD removalrate can be achieved as96.84%, Biogas (methane,68.5%) was produced fromEGSB, Acidogenic bacteria colonies, methanogens colonies and filamentousbacteria colonies were observed by scanning electron microscopy.CSTR-MFC reactor run two periods(300hours each), The results show that ahigher output power(10.06W/m~3) can be got in four circuits situation than Singlecircuit situation (0.57W/m~3); Also a higher COD removal rate(above50%) can beachieved than conventional CSTR(about50%)Electrocatalytic Oxidation was used to treat EGSB effluent and SBR effluent,COD removal rate can be achieved as44%and70%, Also chroma of SBR effluentreduced from2000times to80times. COD indicator and chroma indicator of SBReffluent after treatment can achieve relevant emission standards.The results of reuse joint experiments show that EGSB effluent and SBReffluent achieved a higher cellulose conversion rate(86.39%and86.22%) than cleanwater(85.93%) in saccharification process, and SBR effluent can advance8h tocomplete fermentation which is very suitable for fermentation, but EGSB effluentused for the fermentation will have a inhibitory effect, Yeast began breeding after88h in fermentation process, not conducive to fermentation... |
PDF Full Text Request