【作者】 王洪娟；

【导师】 于德爽；

【作者基本信息】 青岛大学 ， 环境科学， 2007， 硕士

【摘要】 目前在高盐废水的生物处理中，有关盐度对生物处理系统影响的利弊及高盐环境下有机物和氨氮处理效果的研究结论还不统一。对常温下高盐废水中有机物和氨氮降解的动力学研究、低温高盐双重不利因素对有机物和氨氮去除的影响、低温对活性污泥系统的影响及生物学分析报道较少。针对这些问题，本文采用序批式活性污泥反应器（SBR）模拟高盐废水进行试验，主要研究了常温（20℃）时不同污水盐度对有机物去除和生物脱氮的影响及动力学分析；此外，试验还研究了低温对活性污泥系统的影响；在6℃～20℃范围内缓慢降温和快速降温两种不同降温方式对有机物和氨氮去除的影响，并对此进行了生物学分析。这些研究对高盐废水生物处理研究进展有一定的促进作用。试验结果表明，常温（20℃）下当盐度超过10.5g╱L时，有机物的去除率和生物脱氮效率整体上随着盐度的升高而下降。在pH值为8.0左右、溶解氧在2.0～3.0mg╱L、污泥浓度为3000mg／L的试验条件下，进水COD为360mg／L左右时，海水比例由30％（盐度为10.5g╱L）升高到50％（盐度为19.5g╱L）时，COD去除率由87％降为82％，盐度对COD去除率影响不大；当海水比例超过50％升高至70％（盐度为24.5g／L）时，COD去除率下降至68％，盐度对COD去除率影响明显；进水氨氮浓度为62mg╱L左右时，海水比例分别为30％、50％、70％时，氨氮去除率分别为91％、86％、80％，盐度对氨氮去除率影响不大；当海水比例超过70％达到100％（盐度为35g╱L）时，氨氮去除率下降明显，为67％。当海水比例超过30％时，生物硝化过程出现了亚硝酸盐积累现象，实现了短程硝化反硝化；根据一周期内COD和氨氮的降解曲线，应用泰姆斯图解法求得30％、50％、70％海水比例下COD降解的反应速率常数分别为0.7886h^-1、0.7504h^-1、0.7273h^-1；30％、50％、70％、100％海水比例下氨氮降解的反应速率常数分别为0.2717h^-1、0.139h^-1、0.118h^-1、0.1079h^-1。数据显示随着海水比例的升高，COD和氨氮降解的反应速率速率常数减小。另外污水盐度的增加还造成了反硝化速率下降。在低温条件下（6℃～15℃），50％海水比例时随着温度的降低COD和氨氮去除率下降。通过试验证实了快速降温比缓慢降温对活性污泥处理效果的影响更大。在pH值为8.0左右、溶解氧在2.0～3.0mg／L、污泥浓度为3000mg／L的试验条件下，在缓慢降温过程中，进水COD浓度在360mg／L左右时，15℃、10℃、6℃时的COD去除率分别为69.84％、56.24％、46.54％；进水氨氮浓度为39mg╱L左右时，在以上各温度下氨氮的去除率分别为77％、46％、28％。快速降温过程中，在与以上条件相同的情况下，15℃、10℃、6℃时COD去除率分别为69％、37％、26％，氨氮的去除率分别为73％、35％、19％。与COD去除率相比，低温对氨氮的去除影响更大。从生物学角度分析，中温菌活性随着温度降低而减弱，水温低于10℃时，中温菌一般不再具有代谢外源物质的能力，对污水中有机物和氨氮起去除效果的是耐冷菌。低温条件下活性污泥的吸附性能和沉降性变差。在6℃～15℃范围内，海水比例为50％的污水中硝化菌同时受到温度和高盐双重因素的不利影响。首先高盐抑制了硝酸菌的生长造成生物硝化过程出现亚硝酸盐积累，同时低温对亚硝酸菌的活性也产生了抑制作用。硝化反应中，氨氮降解速率明显高于亚硝态氮增长速率，并且温度越低，两者相差程度越大。15℃、10℃、6℃时氨氮降解速率分别为0.0239gNH₃—N／gMLSS.d、0.0174gNH₃—N／gMLSS.d、0.0104gNH₃—N／gMLSS.d，在以上各温度下亚硝态氮的增长速率分别为0.0128gNO₂—N／gMLSS.d、0.0065gNO₂—N／gMLSS.d、0.00234gNO₂—N／gMLSS.d。这说明低温下氨氮的降解主要用于生物同化，只有一小部分转化为亚硝态氮。更多还原

【Abstract】 Now the viewpoint whether the effects of salinity on biological treatment systemwas good or not and the removal effects of organics and ammonia in the high salinityenvironment were not consistent in the biological treatment of high salinity wastewater.The reports about the kinetics research on the degradation of organics and ammonia in thehigh salinity wastewater at normal temperature and the effects of double adversefactors-low temperature and high salinity on the removal of organics and ammonia werelacking. What’s more, the research on the effects of low temperature on activated sludgesystem and the analysis in view of biology in the high salinity wastewater were rare. As tothese questions, in this paper the effects of different wastewater salinity on organics andammonia removal as well as kinetics analysis were mainly studied by Sequencing BatchReactor （SBR） process. Besides the effects of low temperature on activated sludge systemand two styles of temperature drop-low temperature drop and sharp-temperature drop onorganics and ammonia removal were studied within 6℃～20℃. As to these contents, theanalysis in view of biology was illustrated. These researches were promotive to thebiological treatment of high saline wastewater.Experimental results showed that the efficiency of organics and ammonia removaldecreased with the salinity increasing at normal temperature （20℃） when wastewatersalinity was over 10.5g/L. The experimental parameters were: pH:8.0;dissolved oxygen:2.0～3.0mg/L; mixed liquid suspended solid concentration: 3000mg/L; At the influentCOD concentration of 360mg/L, when the seawater proportion increased from 30％（Thesalinity was 10.5g/L） to 50％（The salinity was 19.5g/L）, COD removal efficiencydecreased from 87％to 82％. The effect of salinity on COD removal efficiency was notobvious; When the seawater proportion was over 50％and reached 70％（The salinity was24.5g/L）, the effect of salinity on COD removal efficiency was obvious and decreased to68％. At the influent ammonia concentration of 62mg/L, when the seawater proportionwas 30％, 50％and 70％, ammonia removal efficiency was 91％, 86％and 80％respectively. The effect of salinity was not remarkable. When the seawater proportion wasover 70％and reached 100％（The salinity was 35g/L）, ammonia removal efficiencydecreased remarkably to 67％. When seawater was above 30％, nitrite was accumulatedduring biological nitrifying process and shortcut nitrification-denitrification was achieved.According to the curves of COD and ammonia degradation during a circle, the value ofthe degradation rate constant of organics and ammonia at different proportion of seawaterwere worked out through Thomas illustration. The value of the COD degradation rate constant at 30％, 50％and 70％seawater was 0.7886h^-1, 0.7504h^-1 and 0.7273h^-1respectively; The value of the ammonia degradation rate constant at 30％, 50％, 70％and100％seawater was 0.2717h^-1, 0.139h^-1, 0.118h^-1 and 0.1079h^-1 respectively. These datashowed that the degradation rate constant dropped with the seawater salinity increasing.Besides, denitrification rate reduced due to the increase of salinity in the wastewater.When seawater proportion was 50％, the removal efficiency of organics andammonia reduced with the temperature dropping, within 6～15℃. Experiments showedthat the activated sludge system got worse effect when temperature dropped fast. Theexperimental parameters were: pH: 8.0;dissolved oxygen: 2.0～3.0mg/L;mixed liquidsuspended solid concentration: 3000rag/L; At the influent COD concentration of360mg/L, during the process of low temperature drop the COD removal efficiency of 15℃,10℃and 6℃was 69.84％, 56.24％and 46.54％respectively. At the influent ammoniaconcentration of 39mg/L, the ammonia efficiency of 15℃, 10℃and 6℃was 77％, 46％and 28％respectively. At the same experimental parameters, during the process of sharptemperature drop the COD removal efficiency of 15℃, 10℃and 6℃was 69％, 37％and26％respectively. The ammonia efficiency of 15℃, 10℃and 6℃was 73％, 35％and19％respectively. Compared to organics removal efficiency, low temperature had worseeffect on ammonia. In the view of biology, the activity of mesophilic microorganismreduced with the temperature dropping. When the wastewater temperature was below10℃, the principle force to decompose organics and ammonia in wastewater werecold-adapted microorganism, for the mesophilic microorganism nearly had no ability tometabolize allogenic materials at such low temperature. The adsorption and settlingperformance of activated sludge became worse at low temperature.Nitrifying bacteria in the wastewater containing 50％seawater were affectedadversely by low temperature and high salinity within 6℃～15℃. First of all, nitrate’sgrowth was restrained because of high salinity, thus nitrite was accumulated duringbiological nitrification. At the same time, the activity of nitrosomas was inhibited at lowtemperature. During the process of nitrifying, the rate of ammonia degradation was higherthan that of nitrite growth. The difference was more obvious at the lower temperature.The ammonia degradation rate of 15℃, 10℃and 6℃was 0.0239gNH₃—N/gMLSS.d, 0.0174gNH₃—N/gMLSS.d and 0.0104gNH₃—N/gMLSS.d respectively; Atthe same temperature, the nitrite growth rate of 15℃, 10℃and 6℃was0.0128gNO₂—N/gMLSS.d、0.0065gNO₂—N/gMLSS.d and 0.00234gNO₂—N/gMLSS.drespectively. This showed that ammonia degradation was mainly due to biologicalassimilation at low temperature. Only a small part of ammonia was converted to nitrite.更多还原