厌氧消化与两级串联SNAD-IFAS组合工艺处理垃圾渗滤液研究

Research on anaerobic digestion combined two-stage tandem-type SAND-IFAS process for treatment of landfill leachate

利用厌氧反应器(UASB)与固定生物膜-活性污泥(IFAS)反应器探究厌氧消化、同时亚硝化-厌氧氨氧化-反硝化(SNAD)工艺对垃圾渗滤液的处理效果.控制UASB的温度为32℃,pH为8.0~8.3,在水力停留时间(HRT)为24 h时COD去除率为44.9%,出水碳氮比在1.3∶1左右,完全可以满足后续SNAD工艺需求.两级串联SNAD-IFAS反应器共运行96 d,UASB出水稀释后作为SNAD工艺的进水.独立调控两池的温度、DO浓度、pH,SNAD1池分别为32℃、0.1~0.2 mg·L^-1、7.8~8.0,SNAD2池分别为32℃、0.08~0.14 mg·L^-1、7.5~7.8.在进水TN和COD浓度分别为602.3 mg·L^-1和878.1 mg·L^-1时,SNAD工艺对TN和COD的去除率分别达到83.3%和39.4%.高通量测序结果表明反应器内具有典型的SNAD工艺微生物群落结构,亚硝化菌(AOB)主要存在于活性污泥中,厌氧氨氧化细菌(AnAOB)和反硝化菌(DNB)主要富集在生物膜上.SNAD1池与SNAD2池的生物膜均以AnAOB作为优势菌种,其丰度分别达到26.21%和30.82%.

An integrated configuration combining up-flow anaerobic sludge bed(UASB)with the simultaneous partial nitrification,anammox and denitrification-integrated fixed biofilm activated sludge(SNAD-IFAS)was constructed for the treatment of landfill leachate.The temperature and pH of UASB were controlled at 32℃and 8.0-8.3,respectively.The removal efficiency of COD reaches 44.9%when the hydraulic retention time(HRT)is 24 h and the C and N ratio is around 1.3∶1 which could meet the requirement of continued SNAD process completely.The two-stage tandem-type SNAD-IFAS reactors were operated for 96 d and it used the diluted effluent of UASB as the influent.The temperature,DO concentration and pH were regulated independently as 32℃,0.1-0.2 mg·L^-1 and 7.8-8.0 in SNAD1 pond,as 32℃,0.08-0.14 mg·L^-1 and 7.5-7.8 in SNAD2 pond.In stable phase,the TN and COD removal efficiencies of SNAD process are 83.3%and 39.4%with the concentration of TN and COD reaches 602.3 mg·L^-1 and 878.1 mg·L^-1,respectively.The result of high-throughput pyrosequencing indicates that the typical microbial community structure of SNAD process is formed in the reactors.Ammonium oxidizing bacteria(AOB)tends to grow in the suspended sludge while the anaerobic ammonium oxidizing bacteria(AnAOB)enriches in biofilms.The biofilms in SNAD1 pond and SNAD2 pond are both dominated by AnAOB,whose abundance attains 26.21%and 30.82%,respectively.