【作者】 朱邦辉；

【导师】 万金保；

【作者基本信息】 南昌大学 ， 环境工程， 2010， 硕士

【摘要】 工程化IC反应器处理柠檬酸废水形成了性能良好的厌氧颗粒污泥,本文对厌氧颗粒污泥的特性、形成过程和保活储存进行实验性研究,并将其应用于工程化IC反应器的再启动过程中。厌氧颗粒污泥呈完全黑色,外观为规则的椭圆形或球形,边界清晰,表面光滑,内部存在较多空隙,是基质和气体传输的通道；颗粒粒径在0.93～1.7mm之间占整个厌氧颗粒污泥的58.74%,是IC反应器处理有机物的主体；颗粒的平均沉降速度92.3m／h,含水率93.82%,VSS含量5.01%,灰分含量1.17%,其中VSS/TSS比值为0.81,表明颗粒内微生物含量较为丰富；颗粒中含有少量的K、Ca、Mg和Fe等金属元素,其中Ca含量最多,约为66.05mg/gTSS,影响了污泥的颗粒化进程。厌氧颗粒污泥的形成过程类似于结晶过程,柠檬酸废水中含有的大量Ca2+以CaC03的形式聚集于厌氧颗粒污泥的中央,为颗粒提供了支撑骨架的作用,微生物围绕CaC03不断生长繁殖,此外,Ca2+可通过吸附架桥作用加速污泥的颗粒化进程并且形成性能良好的厌氧颗粒污泥。保活储存试验表明,不同保存温度对厌氧颗粒污泥最大比产甲烷速率(Umax)的影响较大,在室温25℃条件下保存30d,60d和90d后,Umax分别从287.3mlCH4/(gVSS·d)下降到223.5mlCH4/(gVSS·d),164.4mlCH4/(gVSS·d)和93.7mlCH4／(gVSS·d)；在低温5℃条件下保存同等时间后,Umax依次只下降到266.4mlCH4/(gVSS·d),172.9mlCH4/(gVSS·d)和145.1mlCH4/(gVSS·d),下降幅度比室温25℃保存时小,分析原因在于室温25℃保存时期,颗粒内的微生物仍保持一定的活性,对残存的营养物质进行分解,而低温5℃保存时期,颗粒内的微生物基本进入“休眠”状态,暂时抑制了厌氧颗粒污泥的活性,使其在保存过程中避免遭受大的活性损失甚至永久失去活性；低温保存有利于厌氧颗粒污泥活性和完整性的保存,以便其在时间和空间发生较大变化后延续使用,发挥最大作用。将保存3个多月的厌氧颗粒污泥作为接种污泥,对工程化IC反应器进行再启动,接种污泥量15.3kgVSS／m3,进水pH值5.5～6.5,进水温度39～41℃,HRT18h,水力负荷1.09m3/(m2·h),初始容积负荷2.61kgCOD/(m3·d),通过先提高有机负荷再逐步提高进水流量的方式启动,启动初期IC反应器对COD去除率就达到70%以上,表明厌氧颗粒污泥活性的保存和恢复性较好,此外污泥颗粒化程度经历了由慢到快的增长过程,最后稳定在70%左右；IC反应器成功启动后,容积负荷最高为17.76kgCOD/(m3·d), COD去除效率稳定在82～87%之间,出水COD浓度<700mg／L,VFA≤300mg／L,ALK≥1500mg／LIC反应器的高负荷和精处理两个区域,可以按完全混合状态和平推流状态分别进行基质降解模型的推导,从而确定IC反应器处理柠檬酸废水的基质降解模型；从模型可知基质降解效率与高负荷区污泥浓度、水力停留时间和内循环量呈正相关,反应器结构的优化和厌氧颗粒污泥的培养是提高IC反应器基质降解效率的有效方法。更多还原

【Abstract】 IC reactor treating citric acid wastewater can form anaerobic granular sludge with good performance, this paper studied experimentally on the characteristics, the formation and preservation of anaerobic granular sludge, and it was applied to the re-start process of the IC reactor.Anaerobic granular sludge was with black color, regular elliptical or spherical shape, clear boundary, smooth surface, and many gaps within it which was the channel matrix and gas transmission; 58.74% of the anaerobic granular sludge with particle diameters in the range from 0.93mm to 1.7mm was the main body of IC reactor for the treatment of the organism; The average settling velocity of particles was 92.3m/h, the water content, VSS content, the ash content of anaerobic granular sludge were 93.82%,5.01%,1.17%, respectively, and the VSS/TSS ratio was 0.81, which showed that the anaerobic granular sludge consisted of a large number of microorganisms; Particles contain a small amount of K, Ca, Mg and Fe and other metal elements, Ca content up to about 66.05mg/gTSS which affected the process of sludge particles.Conservation of granules test the formation of anaerobic granular sludge was similar to the crystallization process. The wastewater contained massive amounts of Ca2+ in terms of CaCO3, which gathered in the center of the anaerobic granular sludge to provide a support framework for the particles. The microorganisms would grow around the CaCO3. In addition, the bridge and adsorption of Ca2+ in the particles can accelerate the formation of sludge particles and form good anaerobic granular sludge.Conservation of granules test show that the maximum specific methane production rate of anaerobic granular sludge (umax) was affected by different temperature for storage, after preservation for 30d,60d and 90d at 25℃, the umax fell to 223.5mlCH4/(gVSS·d),164.4mlCH4/(gVSS·d) and 93.7mlCH4/(gVSS·d) from 287.3mlCH4/(gVSS·d), respectively, and after preservation for same time at 5℃, the umax fell to 266.4mlCH4/(gVSS·d),172.9mlCH4/(gVSS-d) and 145.1mlCH4/(gVSS·d), respectively, the decrease was more prominent in the former than in the latter, the reason was that the microbial particles still maintain a certain activity with the residual nutrients were decomposed at 25℃, but at 5℃, the basic particles within the micro-organisms to enter "sleep" state, it temporarily inhibit anaerobic the activity of granular sludge to save the process to avoid being in the activity of large losses and even permanent loss of activity, Low-temperature preservation of anaerobic granular sludge can keep the activity and integrity, So that it can play the most effect with continue to use when time and space changed greatly.The anaerobic granular sludge which keep more than three months were selected as seed sludge, and it was applied to the re-start process of the IC reactor, when the biomass of inoculants was 15.3kgVSS/m3, the influent pH, temperature were within the range of 5.5-6.5,39～41℃, respectively, and the HRT, hydraulic loading and initial volume load were 18h,1.09m3/(m2·h),2.61kgCOD/(m3·d), respectively, by first raising the organic loading and then the quantity of influent was enhanced step by step, at the start-up initial stage, the COD removal efficiency of IC reactor reached 70%, which indicating that the activity of anaerobic granular sludge recovered well, besides, sludge granulation rate experienced from slow to fast growth process, and finally stabilized at about 70%; After the successful start-up of IC reactor, the maximum volume load can reach 17.76kgCOD/(m3·d), the removals of COD generally ranged from 82% to 87%, and the COD concentration in the effluent was less than 700mg/L, VFA was lower than 300mg/L, and ALK was not less than 1500mg/L.Substrate degradation models of high load and extract processing of IC reactor were deduced respectively in the state of complete mixture and plug flow. The model of IC reactor used for the citric acid wastewater treatment was confirmed as follows; the substrate degradation rate has a positive correlation with the sludge concentration at high load area, hydraulic retention time and the quantity of cycle. The optimization of reactor structure and the culture of the anaerobic granular sludge were effective ways to enhance the efficiency of the substrate degradation of IC reactor.更多还原