猪场废水厌氧生物处理FAN抑制及其调控对策的研究  

Inhibition of Anaerobic Digestion of Swine Wastewater Caused by Free Ammonia Nitrogen and its Control Strategies

作　　者：唐崇俭[1] 郑平[1] 金仁村[1] 胡宝兰[1] 余燚[1] 陈建伟[1] 黄武 

机构地区：[1]浙江大学环境工程系,浙江杭州310029 [2]浙江省沼气太阳能科学研究所,浙江杭州310012

出　　处：《高校化学工程学报》2008年第4期697-702,共6页Journal of Chemical Engineering of Chinese Universities

基　　金：浙江省重大科技攻关项目(2005C13004)

摘　　要：通过稀释降低废水浓度和采用磷酸铵镁沉淀法除铵预处理,研究了猪场废水厌氧生物处理的运行性能。UASB(upflow anaerobic sludge blanket)反应器的运行结果表明,游离氨氮(free ammonia nitrogen,FAN)是猪场废水厌氧生物处理的重要障碍因子,其临界抑制浓度为100～120mgN·L-1;猪场废水FAN浓度为140～230mgN·L-1,高于临界FAN抑制浓度;对猪场废水直接进行厌氧生物处理,COD(chemical oxygen demand)去除率为8.1%～15.6%,容积产气率为0.32L·L-1·d-1,反应液挥发性脂肪酸(volatile fatty acid,VFA)浓度高达2000mg·L-1,表现出典型的运行障碍;FAN超过临界抑制浓度后,可触发对厌氧生物处理过程的抑制,致使反应液VFA高于2000mg·L-1,进而加剧抑制效应,引起反应器功能崩溃。将pH控制在适宜厌氧生物处理的下限区间,稀释进水将FAN降低到临界抑制浓度以下,以及采用磷酸铵镁沉淀法进行除铵预处理,均可缓解猪场废水厌氧生物处理的运行障碍,COD去除率升至60.0%～72.2%,VFA去除率高达90.0%,容积产气率升高至1.50～1.92L·L-1·d-1。Through diluting the treated swine wastewater previously and pretreating it by magnesium ammonium phosphate precipitation, the performance of anaerobic treatment process for swine wastewater was investigated in a UASB （upflow anaerobic sludge blanket） reactor. The experimental results show that the threshold inhibition concentration of free ammonia nitrogen （FAN） for the anaerobic digestion is 100-120 mg N·L^-1. Since the FAN concentration of swine wastewater tested （140-230 mg N·L^-1） is higher than the FAN threshold inhibition concentration, typical process dysfunction will occur if the anaerobic treatment of the swine wastewater is conducted directly, during which the chemical oxygen demand （COD） removal efficiency and biogas production rate are only 8.1%-15,6% and 0.32 L·L^-1·d^-1, respectively; the volatile fatty acid （VFA） concentration in the effluent is 200 mg·L^-1 or more. It was believed that when FAN concentration is beyond its threshold inhibition value, the anaerobic digestion process will be inhibited with sharp increase of effluent VFA concentration （i,e,, 2000-2500 mg·L^-1）, Unfortunately, high VFA concentration may also contribute towards inhibition of the anaerobic digestion and result in the failure of the reactor operation, The experiments demonstrate that controlling the pH value of the influent and diluting the treated swine wastewater to ensure the FAN concentration below its threshold inhibition value are useful strategies for anaerobic digestion of swine wastewater. Moreover, it was found that the nitrogen pretreatment by magnesium ammonium phosphate precipitation can relieve the free ammonia inhibition of the anaerobic digestion process.

关 键 词：猪场废水 厌氧生物处理 游离氨 调控对策 

分 类 号：X703[环境科学与工程—环境工程]