游离氨调控对污泥高含固厌氧消化反应器性能的影响

发布时间：2018-03-29 04:04

本文选题：游离氨　切入点：氨抑制　出处：《环境科学》2017年02期

【摘要】：污泥高含固厌氧消化系统中,过高的游离氨(free ammonia nitrogen,FAN)浓度被认为是影响其产气性能的主要因素之一.通过降低pH和提高总氨氮(total ammonia nitrogen,TAN)浓度两种方法,考察了进料含固率为15%的中温半连续污泥高含固厌氧消化反应器在这两种游离氨调控措施下的性能表现.结果表明,随着TAN的提高,FAN从(400±174)mg·L~(-1)提升至(526±25)mg·L~(-1),日产沼气量从(11.9±0.3)L·d-1降低到(10.3±0.2)L·d-1,挥发性固体(volatile solid,VS)降解率降低了33.7%;同时,当通过降低pH使得FAN从(330±99)mg·L~(-1)下降至(47±13)mg·L~(-1)时,日沼气产量也从(14.4±1.1)L·d-1下降到(10.8±0.3)L·d-1,VS降解率降低了26.9%,系统性能并没有随着FAN的下降而提升.随着pH调控的停止,游离氨浓度逐步回升至300 mg·L~(-1),系统性能也恢复至调控之前的水平,表明pH调控的过程产生了游离氨浓度控制之外的抑制性作用.最后,通过对细菌和古菌的多样性分析以及甲烷菌的定量PCR分析,可以发现两个反应器系统产气性能的变化都伴随着细菌种群结构的明显变化.污泥高含固厌氧消化系统中过高的FAN(500 mg·L~(-1))使得降解蛋白的细菌的主要种群由Tepidimicrobium和Proteiniborus转变为Anaerobranca.而通过降低pH来控制游离氨浓度之后,一些糖类和蛋白质类发酵细菌的活性也受到影响,并导致这些物质水解效率的下降,进而由于产甲烷菌的基质供给量的不足而削弱系统的产气性能.
[Abstract]:The high concentration of free ammonia nitrogenin in anaerobic digestive system is considered to be one of the main factors affecting the gas production of sludge. Two methods are adopted to reduce pH and increase the concentration of total ammonia nitrogenTAN. The performance of a medium temperature semi-continuous sludge reactor with a solid content of 15% under these two free ammonia regulation measures was investigated. With the increase of TAN, the degradation rate of VSs decreased from 400 卤174)mg L ~ (-1) to 526 卤25)mg L ~ (-1), from 11.9 卤0.3 L ~ (-1) to 10.3 卤0.2 L ~ (-1) d ~ (-1), and from 330 卤99)mg L ~ (-1) to 47 卤13)mg L ~ (-1). The daily biogas production also decreased from 14.4 卤1.1 L d -1 to 10.8 卤0.3 L d -1 vs degradation rate decreased 26.9%, and the system performance did not increase with the decrease of FAN. With the stop of pH control, the concentration of free ammonia gradually increased to 300mg / L, and the system performance returned to the level of pre-regulation. The results showed that the process of pH regulation had inhibitory effect beyond the control of free ammonia concentration. Finally, the diversity of bacteria and ancient bacteria and the quantitative PCR analysis of methane bacteria were analyzed. It can be found that the change of gas production performance of the two reactor systems is accompanied by the obvious change of bacterial population structure. The excessive FAN(500 mg / L ~ (-1) in the anaerobic digestive system with high sludge content makes the main population of protein-degrading bacteria transfer from Tepidimicrobium and Proteiniborus. Become Anaerobranca. And by lowering pH to control the concentration of free ammonia, The activity of some fermentative bacteria of carbohydrate and protein was also affected, which resulted in the decrease of hydrolysis efficiency of these substances, which weakened the gas production performance of the system because of the insufficiency of the substrate supply of methanogenic bacteria.
【作者单位】：同济大学环境科学与工程学院污染控制与资源化研究国家重点实验室;
【基金】：国家自然科学基金项目(51308402,51538008) 国家科技支撑计划项目(2014BAC31B01)
【分类号】：X703.1

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