【作者】 李正；

【导师】 祁佩时；

【作者基本信息】 哈尔滨工业大学 ， 环境科学与工程， 2009， 博士

【摘要】 抗生素废水水质成分复杂,含有发酵残余基质及营养物、微生物菌丝体、中间代谢产物、溶媒提取过程萃余液、蒸馏釜残液、发酵滤液等,导致该类废水具有有机物浓度高、pH变化大、生物抑制性强等特点,废水处理难度大。随着更加严格的制药工业水污染物排放标准的颁布和实施（GB21903-2008发酵类制药工业水污染物排放标准）,制药废水,特别是抗生素类制药废水如何达标排放是目前国内外水处理行业研究的热点,也是制药行业亟待解决的难点。因此,寻找技术经济可行的抗生素废水处理技术十分必要。针对抗生素废水水质特点及新的排放标准要求,提出了水解酸化-悬浮载体复合MBR处理抗生素废水的技术路线。水解酸化试验结果表明:在进水水质波动较大的情况下（COD范围为1670⁴200mg/L ; SS范围为270⁷30mg/L）,出水水质相对稳定。对影响水解酸化效果的主要参数HRT和温度进行了考察,结果表明:要想达到较好的水解酸化效果（酸化度在50%左右,出水VFA在1500mg/L以上）,HRT应控制在10h,温度应控制在20℃³0℃。水解酸化长期运行结果表明:水解酸化极大地改善了废水的生物降解性能,BOD₅/COD由0.29上升到0.49,SCOD/COD由0.67提高至0.92。悬浮载体复合MBR处理经水解酸化预处理抗生素废水的试验结果表明:当HRT为12¹8h时,COD去除率在91%⁹4%,出水COD小于200mg/L;当HRT在24h以上时, COD去除率稳定在95%左右,出水COD小于100mg/L,均满足《发酵类制药工业水污染物排放标准》中的相关标准。对影响悬浮载体复合MBR处理效果的主要影响因素DO和温度进行了考察,对比了悬浮载体复合MBR与普通MBR对经水解酸化预处理的抗生素废水的处理效果,在相同运行条件下,悬浮载体复合MBR对COD、氨氮和TN的去除效果均优于普通MBR,去除率分别提高了4.8%、8.2%和8.3%。在分析活性污泥和生物膜共存系统动力学的基础上,通过对系统有机物的物料衡算,构建了活性污泥生物膜共存的悬浮载体复合MBR有机物降解动力学模型,为实际工程应用奠定了理论基础。在试验条件下求得载体生物膜COD半饱和常数K s,COD,sp=114.36 mg/L,载体生物膜最大COD降解速率q|^)_{m ,COD,sp}=3.04mg/（个·d）,最大比基质降解速率常数Vmax=0.62d^-1,基质饱和常数K_s=147.65mg/L,有机物降解速率常数K=V_max/Ks=0.004。根据模型对出水COD进行了模拟预测,与实际测定数据相对比,模拟值与实测结果基本吻合。对悬浮载体复合MBR的污泥产率系数Y与衰减系数K_d进行求解,在SRT=100d、HRT=24h、MLSS=12¹5g/L条件下,Y=0.09,Kd=0.0144,均小于普通MBR的Y=0.1327,K_d=0.0177。采用中心复合设计试验和响应面法确定了影响膜临界通量的主要操作条件。试验结果表明:临界通量随污泥浓度的增大而减小;曝气量在0.05⁰.15m³/h范围内,临界通量随着曝气量的增加呈先增大后减小趋势,当曝气量在0.1m³/h时,临界通量最大;载体含量在5%¹5%范围内,临界通量随载体填充量的增加呈先增大后减小,填充量为10%时达到最大值。基于响应曲面法对污泥浓度、曝气量、载体含量对临界通量影响进行了双因子交互效应分析。结果表明:污泥浓度、曝气量、载体含量均是影响悬浮载体复合MBR膜临界通量的主要因素;曝气量、污泥浓度及载体含量对膜临界通量的影响从大到小依次为污泥浓度>曝气量>载体含量。建立了影响膜临界通量的数学模型,模型预测值与试验值的最大相对误差为6.58%,模型对试验结果具有良好的预测效果,且模型对于膜临界通量具有一定的外推预测效果。得到临界通量的最优操作条件为:污泥浓度5000mg/L、曝气量0.1m³/h、载体含量10.85%。恒通量连续操作条件下,载体添加延长了运行时间,达到30kPa临界TMP条件,悬浮载体复合MBR需要89h,为普通MBR的2.6倍。膜TMP的平均上升速率（dP/dt）为0.33kPa/h,为普通MBR的37.5%。通过SEM和共聚焦显微镜对污染膜表面的微观结构进行了观察,结合ISA3d软件分析了滤饼层的微观结构参数,通过与普通MBR进行对比研究,揭示了悬浮载体对膜污染速率延缓的主要机理。结果表明:相同运行时间条件（34h）,悬浮载体对膜污染速率的延缓主要表现在增大了滤饼层空隙率和减小了滤饼层质量,悬浮载体复合MBR膜表面的滤饼体积和滤饼厚度分别为3.2×105μm³和9.45μm,均小于普通MBR膜表面的5.4×105μm³和12.6μm,膜表面滤饼比阻为普通MBR的25%。达到相同TMP（30kPa）条件,悬浮载体复合MBR的滤饼体积、平均滤饼厚度、空隙率均大于普通MBR反应器。滤饼层空隙率的增大,抵消了由于膜表面滤饼质量增大对膜阻力增大的负面影响,增强了膜过滤性能。更多还原

【Abstract】 The quality of antibiotic wastewater is very complicated and hard to treat, which contains fermentation residue substrates and nutrients, microbial mycelium, intermediate metabolites, raffinate of solvent extraction process, distiller raffinate, fermentation filtrate and so on, leading to the wastewater characteristic of high concentrations of organic matter, large pH variations, strong biological inhibition, etc. In addition, with the promulgation and implementation of more stringent pharmaceutical industry water pollutants discharge standards （GB21903-2008.Discharge standards of water pollutants for pharmaceutical industry）, how to make the pharmaceutical wastewater, especially the antibiotic wastewater, achieve the discharge standards becomes not only a hotspot for water treatment industry at home and abroad, but also a nodus for the pharmaceutical industry to be solved urgently. Consequently, it is necessary to investigate a feasible technology in technology and economy for the treatment of antibiotic wastewater. Depending on the characteristic of antibiotics wastewater and new discharge standards, the hydrolytic acidification-suspended carrier hybrid MBR technology was proposed. The results of hydrolytic acidification showed that the effluent quality was relatively stable under a large fluctuation influent quality （COD was 1670⁴200mg/L; SS was 270⁷30mg/L）. HRT and temperature as the main operation parameters of hydrolytic acidification were investigated, results showed that the performance of hydrolytic acidification was better under the condition of HRT was 10h and the temperature was controlled at 20℃³0℃（acidifying degrees was around 50%, the effluent VFA was above 1500mg/L）. The long-term operation results of acid hydrolysis acidification indicated that the biodegradability of wastewater was improved greatly, BOD5/COD increased from 0.29 to 0.49, SCOD/COD improved from 0.67 to 0.92. The effluent of hydrolytic acidification using suspended carrier hybrid MBR to treat the antibiotic wastewater showed that the COD removal rate was 91%⁹4% and the effluent COD was less than 200mg/L when the HRT was 12¹8h. When the HRT was more than 24h, COD removal rate stabilized around 95% and the effluent COD was less than 100mg/L, the quality met the related water pollutants emission limit （Discharge standards of water pollutants for pharmaceutical industry, Fermentation products categegory）. Compared the suspended carrier hybrid MBR with the common MBR in the treatment efficiency after the pretreatment of antibiotics wastewater using hydrolytic acidification, under the same operating conditions, COD, ammonia nitrogen and TN removal efficiencies of suspended carrier hybrid MBR were better than those of common MBR, the removal rate increased by 4.8%, 8.2% and 8.3%.On the basis of the activated sludge and biofilm coexistence system dynamics analysis, the MBR organic matter degradation kinetic equation of activated sludge and biofilm coexistence suspended carrier hybrid MBR was built for the practical application and establishing the theoretical foundation through the material balance of organic matter. Under the experimental conditions, the COD half-saturation constant ( K_s,COD,sp) of carrier biofilm was 114.36 mg/L, the largest COD consumption rate ( q|^_{m ,COD,sp}) of carrier biofilm was 3.04mg/（number·d） , the maximum specific substrate degradation rate constant (V_max) was 0.62d^-1, substrate saturation constant （K_s） was 147.65mg/L. Organic matter degradation rate constant (K = V_max/Ks) was 0.004. The effluent COD was simulated by the model. Comparing with the experimental data, the result was in accordance with the practical operation. By numerically solved of suspended carrier hybrid MBR sludge yield coefficient Y and attenuation coefficient Kd, the conclusion was Y = 0.09, K_d = 0.0144, which were less than those in common MBR （Y=0.1327,K_d=0.0177） under the condition of SRT = 100d, HRT = 24h, MLSS = 12¹5g/L.The central composite design and response surface method were used to confirm the main operation parameters on affecting membrane flux. Experimental results showed that the critical flux decreased as the mix liquid suspended sludge concentration decreased. The critical flux was first increased and then decreased as the aeration intensity increased, while the aeration intensity was 0.05⁰.15m³/h, the maximum critical flux was obtained when the aeration intensity was 0.1m³/h. The critical flux was first increased and then decreased as the carrier filling amount increased, when the carrier filling amount was 5% to 15%, the maximum critical flux was obtained when the filling amount was 10%. Based on Response Surface Method, the effect of the sludge concentration, aeration intensity and carrier filling amount on critical flux was analyzed using two-factor interaction effect. The result showed that the mixed liquid suspended sludge concentration, aeration rate and carrier filling amount were main factors of impacting the membrane critical flux in suspended carrier hybrid MBR. The effect of the mixed liquid suspended sludge concentration, aeration intensity and carrier filling amount on membrane critical flux was in sequence that sludge concentration > aeration rate > carrier filling amount. The mathematical model of membrane critical flux was built, and the maximum relative error of the predictive value and experimental value was 6.58%, which indicated that the model prediction had a good effect and had a certain extrapolated prediction for the membrane critical flux. The optimal operating conditions for the critical flux were the mixed liquid suspended sludge filling amount was 10.85%. Under the constant flux continuous operation, adding carrier extended running time to achieve the critical TMP conditions 30kPa, suspended carrier hybrid MBR needed 89h, and it was 2.6 times than common MBR. The TMP average rising rate in suspended carrier hybrid MBR process was （dP/dt） 0.33 kPa/h, which was 37.5% in the common MBR process.SEM and confocal microscopy analysis on the surface of polluted membrane, combined with an analysis of ISA3d software on the micro-structural parameters of filter cake layer, revealed the main mechanism of suspended carrier on membrane fouling delay rate. Results showed that the suspended carrier on membrane fouling delay rate was mainly manifested by increasing cake porosity and decreasing filter cake layer weight under the same operation time （34h）. The filter cake volume and thickness of suspended carrier hybrid MBR membrane surface were 3.2×105μm³ and 9.45μm, respectively, which were less than common MBR membrane surface 5.4×105μm³ and 12.6μm, and the cake surface specific resistance of the common MBR was only 25%. To achieve the same TMP （30kPa） conditions, the filter cake volume, average cake thickness and porosity of suspended carrier hybrid MBR were larger than those of common MBR. The increased cake porosity offseted the negative impact of membrane resistance, which was increased by cake weight and enhanced the performance of the membrane filtration.更多还原