【作者】 陈建；

【导师】 金奇庭；

【作者基本信息】 西安建筑科技大学 ， 环境工程， 2005， 硕士

【摘要】 本文以垃圾渗滤液经上流式厌氧污泥床（UASB）+膜过滤（MF）这一复合反应器处理后的出水为实验对象,用一体式膜生物反应器（SMBR）对该水中高浓度氨氮的硝化特性以及该反应器中污泥特性的变化规律、膜通量衰减规律和恢复措施等方面进行了研究。 通过对不同容积负荷、不同停留时间下的SMBR中硝化特性的研究可知:以自养菌为优势菌种的反应器中,当氨氮的进水浓度在241.9～1987mg/L之间, SMBR对氨氮的硝化去除率在44.7～99.7%之间变化,相应出水氨氮在1.9～978.1mg/L之间。氨氮去除率随着容积负荷的增加而不断下降,当容积负荷小于1.5kgNH₄⁺-N/（m³·d）时,氨氮去除率基本上保持在80%以上,并具有较强的抗负荷冲击能力,同时,在一定时间内能持续保持较高的去除率。该容积负荷是活性污泥法脱氮硝化段或普通生物流化床硝化段容积负荷的3.75～15倍,表明SMBR在氨氮硝化方面具有良好的性能。在停留时间为12h、18h、24h但容积负荷相同的情况下,系统对氨氮的去除率无明显差异。 运行过程中,硝化污泥浓度从3.87g/L上升到7.29g/L,VSS/SS由0.8左右逐渐下降并最终稳定在0.75左右;污泥体积指数也从175mL/g下降到50mL/g左右并趋于稳定,表明污泥对这种缺少可生物降解有机物但又含有高浓度氨氮渗滤液的适应过程。本试验将污泥分成污泥混合液、离心上清液、细胞液、0.45微米膜过滤液等组分考察不同的组分对膜过滤的污染,可知离心上清液中的细小胶体和大分子粘性物质是造成膜污染的优势污染物;凝胶极化阻力与外部污染阻力之和的沉积层阻力是控制过滤过程的优势污染阻力,二者之和占总污染阻力的90%以上。污泥过滤沉积层比阻的数量级在10¹⁴～10¹⁶m/kg之间,压缩系数基本上大于0.75,说明SMBR污泥具有难以过滤且易于压缩的特性。 在运行过程中,膜会受到不同程度的污染。HRT对实际运行中的膜通量衰减速率影响较大,比较HRT为12、18、24h时的膜通量衰减情况时,HRT为12h时的膜通量衰减速率最大。膜受到污染后,本试验用了不同的方法对膜通量进行了恢复。通过比较可知,化学方法洗膜的更多还原

【Abstract】 The thesis takes the landfill leachate effluent from compound reactor, UASB and MF ,as the experimental object and uses the submerged membrane bioreactor （SMBR） to study the nitration characteristic of high concentration ammonia nitrogen, the sludge characteristic in the reactor, the decline regularity and the renewal measures of membrane flux. Experimental results show as follows.By the study on nitration characteristic of high concentration ammonia nitrogen in a submerged membrane bioreactor in different loading and different HRT, we can draw some conclusions. In the reactor which autotrophic bacteria was the dominant species, When the influent concentration of Ammonia-N was between 241.9 mg/L and 1987mg/L, the Ammonia-N removal rate of SMBR was between 44.7% and 99.7% and the corresponding effluent concentration was between 1.9 mg/L and 978.1mg/L. When Ammonia-N loading rate was less than 1.5kgNH3-N/（m³ ·d）, Ammonia-N removal rate of SMBR was more than 80% on the whole. At the same time, the SMBR had good ability to resist the loading impact and it could keep higher Ammonia-N removal rate at the fixed time. The loading rate was more 3.75-15 times than that of the nitration segment of activated sludge and common biological fluidized bed, indicating that SMBR had better nitrifying capacity. Ammonia-N removal rate of SMBR hadn’t evident difference in the same loading rate but different HRT such as 12h, 18h and 24h.During the running time, the nitration sludge concentration rose from 3.87g/L to 7.29g/L, VSS/SS gradually declined from 0.8 to about 0.75 and the sludge volume index also declined from 175mL/g to 50mL/g and become stabilization, which indicated that the sludge acclimatize itself to the surrounding of lacking of biodegradable organic substances but having high concentration ammonia nitrogen. Tiny colloids and high molecular-weight viscous substances of the sludge were the preponderant contaminations of membrane during filtrating. The membrane fouling resistance was mainlycompleted of polarization layer resistance and external fouling resistance with the distribution tests of resistance, and the sums of the two took over 90% of total fouling resistance. The specific cake resistance of sludge was 10¹⁴¹0¹⁶ m/kg and the cake compressibility of the sludge was more than 0.75 on the whole, indicating that the sludge of SMBR was filtrated difficultly but compressed easily. The membrane would be polluted on different level during the running process. HRT had more effect on the membrane flux decline velocity during the running time. Comparing HRT of 12h, 18h and 24h , the greatest membrane flux decline velocity happened in HRT of 12h. In the experiment, I used several methods to recover the membrane flux after the membrane polluted. The effect of chemic membrane washing was better than that of physic membrane washing. When cleaning out the membrane, the recovery of the membrane flux was limited and it was just about 35% in the experiment by hydraulic ways and 20% by empty aerating. The effect of oxidative way of NaClO was better than that of acid and alkali washing in the chemic methods. The contact time had influence on the effect of cleanout.更多还原