【作者】 杨洁；

【导师】 季民；

【作者基本信息】 天津大学 ， 环境工程， 2005， 硕士

【摘要】 厌氧消化是污泥稳定化和资源化处理最经济有效的方法。但由于污泥属于难降解生物固体,厌氧消化存在反应速度慢,消化时间长,池体体积庞大,生物气中甲烷含量低等缺点。为了提高厌氧消化效率,在污泥进行厌氧消化前进行破解预处理,即破坏污泥絮体结构,使污泥中微生物的细胞壁破裂,细胞内含物溶出,可加速污泥的水解过程,从而达到缩短消化时间,减少消化池容积,提高甲烷产量的目的。在各种预处理条件下,超声波是一种有效的方法。本试验研究了污泥超声波预处理后,对厌氧消化反应的促进作用。试验中控制超声波声能密度分别为2W/mL和1.36W/mL,超声破解时间分别为5min、10min和15min,并通过改变污泥投配率控制消化时间。研究超声声能密度、超声作用时间,对污泥厌氧消化过程中产气量、有机物去除率和消化速率的影响。试验结果表明,在两种声能密度下,污泥超声破解后进行厌氧消化,生物气产量随破解时间和投配率的增加而增加。与控制组相比,污泥超声破解可以提高有机物的去除率,并且随投配率的增加有机物去除率不降低反而会有所上升。当投配率为12.5%时,在2W/mL声能密度,各个破解时间下,TCOD和VS的去除率分别介于38.3%～42.47%,31.14%～34.13%;在1.36W/mL声能密度,各个破解时间下,TCOD和VS去除率分别介于31.15%～38.37%,38.5%～40.14%。污泥超声破解可以减少污泥量(以VSS表示)。在2W/mL声能密度下,投配率为12.5%时,各个破解时间下VSS的去除率介于34.13%～38.66%。在1.36W/mL声能密度下,污泥破解5min,投配率为12.5%时,VSS的平均去除率为35.46%。通过两个声能密度对厌氧消化促进作用的综合分析比较,当破解时间和投配率相同时,在2W/mL声能密度下,厌氧消化的甲烷比产率和VSS去除率高于1.36W/mL声能密度下厌氧消化的甲烷比产率和VSS去除率。在1.36W/mL声能密度下,厌氧消化中VS去除率稍高于2W/mL声能密度下VS去除率。但是,在1.36W/mL声能密度下,处理单位污泥的产气量却低于2W/mL声能密度下处理单位污泥的产气量。更多还原

【Abstract】 Anaerobic digestion is the most commonly applied technique for stabilization ofwaste activated sludge. However, the waste activated sludge is difficult to degrade,which results in the slow degradation, long residence time and large fermenter volume.If some methods are applied as pretreatment to disintegrate the sludge flocs anddisrupt bacterial cells’wall, the hydrolysis can be improved a lot, so that the residencetime can be shortened, fermenter volume be reduced, methane production besignificantly increased. Ultrasonic disintegration is an effective method in variouspretreatmental techniques. The aim of this experiment is to study the upgrading ofanaerobic digestion of ultrasonic pretreatment.The ultrasonic densities in the experiment are 2W/mL and 1.36W/mLrespectively , and the disintegration times are 5min,10min and 15min,respectively.The digestion time is controlled by the dilution rate. The effects of the ultrasonicdensity and disintegration time on the biogas production and the removal efficiency oforganic matters are studied.It has been found that the biogas production is increased with the argument ofdisintegration time and the dilution rate in the anaerobic digestion after ultrasonicpretreatment at two ultrasonic densities. Compared to the fermenter operated with thenon-pretreated sludge, the removal efficiency of organic matters can be improved andnot be decreased with the increasement of the dilution rate in the anaerobic digestionof disintegrated sludge. When the dilution rate is 12.5%, at 2W/mL, the removalefficiencies of TCOD and VS at disintegration time 5min,10min and 15min are 38.3%～42.47%,31.14%～34.13%, respectively;At 1.36W/mL, the TCOD and VSremovals at disintegration time 5min,10min and 15min are 31.15%～38.37%,38.5%～40.14%, respectively. The sludge mass expressed in VSS can be reduced in theanaerobic digestion of pretreated sludge. At 2W/mL, when the dilution rate is 12.5%the removal efficiency of VSS at disintegration time 5min,10min and 15min is34.13%～ 38.66%. At 1.36W/mL, when the dilution rate is 12.5% and thedsintegration time is 5min,the average removal efficiency of VSS is 35.46%. Finally,after a comprehensive analysis based on the upgrading of anaerobic digestion ofdisintegrated sludge, the specific methane production and the removal efficiency ofVSS at 2W/mL are higher than that at 1.36W/mL. The removal efficiency of VS at1.36W/mL is higher than that at 2W/mL, but the biogas production produced per unitvolume of degradede sludge at 1.36W/mL is lower than that at 2W/mL.更多还原