【作者】 张萍；

【导师】 冼萍；

【作者基本信息】 广西大学 ， 环境工程， 2008， 硕士

【摘要】 针对木薯酒精废液有机污染物、悬浮物浓度高与成分复杂等特点,本研究采用酵母菌—SBR组合工艺处理木薯酒精废液,考查酵母菌的生物降解特性,探索不同影响因素对酵母菌处理木薯酒精废液的影响,研究后续处理工艺（SBR）的工况条件与基质降解动力学行为,旨在探讨酵母菌—SBR工艺处理木薯酒精废液的可行性,为工程设计提供依据。木薯酒精废液COD为14660～30140mg/L,BOD₅为7000～14467mg/L,经酵母菌处理后,COD去除率可达83.2～86.4%,BOD₅去除率达91.4～92.2%。利用小型批量实验得到最佳实验控制参数:接种量1‰（v/v,活菌数为4.1×10⁶个/mL）,系统溶解氧2～3mg/L,进水pH值5.0-5.5,温度30℃,曝气时间72h,BOD₅:N:P为400:2:1。由于进水有机物浓度高,经酵母菌处理后,出水COD浓度为2000～3500mg/L,需要联合后续深度处理以保证出水水质。使用综合水质指标法及微生物呼吸速率法对经酵母菌处理后的木薯酒精废液进行水质分析,两种指标一致表明,经酵母菌处理后的木薯酒精废液BOD₅/COD值约为0.30左右,可生化性较好,可采用SBR工艺作为二级处理工艺。酵母菌出水运用SBR处理6h,废水COD可降解到100mg/L以下。最佳工艺条件为限制性曝气、曝气量0.375m³/h、不调节废液pH值、进水时间20min、曝气时间6h、沉淀时间20min、出水时间20min、闲置时间0h。在最佳工艺条件下,对经酵母菌处理后的木薯酒精废液进行SBR基质降解动力学研究。结果表明:常温下,以COD质量浓度作为基质浓度,其降解规律符合Monod方程,该废水中含有不可生物降解有机物质量浓度约为63mg/L,减速增值速度常数K_m为0.0024,通过将实测值与理论计算值比较表明,废水在反应器所需停留时间的理论值与实测值吻合较好,说明木薯酒精废液经酵母菌处理后的SBR基质降解动力学模型推导合理。利用酵母菌—SBR工艺处理木薯酒精废液,系统的COD、BOD与SS去除率均在99%左右,出水COD可降解到100mg/L以下,达到《污水综合排放标准》GB8978-1996一级排放标准。所求取的酵母菌生物降解特性条件与SBR基质降解动力学模型可为木薯酒精废液的工程实践提供理论参考依据。更多还原

【Abstract】 Targeting the removal of high organic matter,high total suspended solid（TSS）and complex component of cassava alcohol wastewater,the combination process of yeast and sequencing bath reactor（SBR）was studied in this paper.The biodegradation characteristics and some major factors influencing the COD removal rate in yeast treatment were investigated.Also,the work conditions and kinetic analysis of SBR post-treatment were studied.This paper aims at studying the feasibility of cassava alcohol wastewater treatment using the combination process of yeast and SBR,so as to offer the basis for engineering design.The COD concentration of cassava alcohol wastewater ranged between 14,660 and 30,140mg/L,BOD₅ concentration was in the range of 7,000～14,467mg/L.After yeast pretreatment,the COD removal rate could reach 83.2%to 86.4%,and the BOD₅ removal rate was ranging from 91.4%to 92.2%.Operating the experiments on a pilot scale continuously, the optimal controlled parameters were as follows:inoculation amount 1%o（v/v,the live bacterium was 4.1×l0⁶per milliliter）,dissolved oxygen 2～3mg/L,influent pH 5.0～5.5, temperature 30℃,aeration time 72h,BOD₅:N:P was equal to 400:2:1.Due to the high organic content in the influent,after yeast pretreatment,the effluent COD concentration was in the range of 2,000～3,500mg/L.In order to ensure that the effluent would meet the National Standard for discharge,the effluent which was pretreated by yeast need to be combined with a post-treatment.The results of integration water-quality experiment and microorganism respiration rate experiment revealed that the BOD₅/COD ratio of wastewater pretreated by yeast was about 0.3,the wastewater was easy to be biodegraded,so the SBR could be applied to the post-treatment.Effluent was treated by SBR for 6 hours,and its COD concentration was reduced to less than 100mg/L.The optimal running parameters were as follows:restricted aeration,0.375m³/h of aeration rate,unadjusted pH,20minutes fill time,6hours aeration time, 20minutes settling time,20minutes decant time,and no idle time.It took 7 hours for each cycle to run.The kinetic analysis of substrate degradation in SBR was studied under optimal conditions.The results showed that the rule of organic biodegradation complied with the Monod equation under constant temperature;the non-biodegradation value was 63mg/L;the decelerated increment velocity constant was 0.0024.When the kinetic equation was used,the results showed that the practical treatment time matched with theoretical treatment time,and the formula derivation of organics biodegradation model was proven.Using the combination process of yeast and SBR in the cassava alcohol wastewater treatment,the COD and BOD removal rates reached 99%;the effluent COD concentration was reduced to less than 100mg/L,which complies with Grade one of the National Standard （GB8978-1996）for discharge.The optimal running parameters of yeast and kinetic model of SBR were crucial to the engineering design of cassava alcohol wastewater treatment processes.更多还原