机构地区: 湖南大学环境科学与工程学院
出 处: 《环境科学学报》 2007年第11期1809-1817,共9页
摘 要: 以氨氮浓度较高的垃圾渗滤液为处理对象,分析研究了不同供氧策略对SBBR反应器实现短程硝化厌氧氨氧化的影响.在4种不同供氧策略(a、b、c和d的总供氧时间分别为16h、12h、12h和8h;好氧/厌氧交替频率分别为4h/2h、3h/3h、2h/2h和2h/4h)下同步启动反应器,保持各反应器内环境温度为(30.0±0.5)℃,并控制曝气阶段溶解氧(DO)浓度为(1.2±0.1)mg·L-1.实验结果表明,反应器内的微生物经过124d的驯化和增殖,具有一定的脱氮能力,但是效果不同,其中,采用总供氧时间为12h,好厌氧交替频率为2h/2h供氧策略的反应器c效果最好,氨氮去除率达到96.6%左右,而且抗氨氮冲击负荷的能力最强,最大的氨氮容积负荷为0.186g·(L·d)-1;在曝气阶段由于DO浓度的限制,亚硝酸盐出现积累;缺氧阶段,由于厌氧氨氧化细菌和反硝化细菌的协同作用,亚硝酸盐氮和氨氮同时被去除,且没有硝酸盐的积累.从4个反应器和渗滤液原水中提取细菌总DNA,通过PCR-DGGE技术获得DGGE图谱.分析图谱中各泳道的条带数目和条带亮度、各泳道间的相似性系数Cs值,结果表明,不同供氧策略对反应器内的细菌多样性和种群结构产生了较大影响. The influence of different aeration strategies on the start-up of short-cut nitrification-anaerobic ammonia oxidation in four sequencing batch biofilm reactors(SBBRs) was studied. The reactors were used for treatment of landfill leachates with high concentrations of ammonia nitrogen. The reactors were started up simultaneously using four aeration strategies in which the full aeration time was 16h, 12h, 12h and 8h and the aerobic/anaerobic alternation frequency was 4h/2h, 3h/3h, 2h/2h and 2h/4h, respectively. The ambient temperature was kept at (30.0 ± 0.5 )℃. During the aeration period, the dissolved oxygen(DO) concentration was controlled at( 1.2 ±0.1 )mg· L^ -1. The experimental results showed that after a 124-day-long period of microorganism proliferation and acclimation, the reactors were able to remove ammonia nitrogen, however, the effect was different in each reactor. Reactor c which used an aeration strategy with a full aeration time of 12h and aerobic/anaerobic alternation of 2h/2h had the best effect and could best resist shock loading. The removal efficiency and volume loading of ammonia nitrogen reached 96.6% and 0. 186 g ( L. d) ^-1, respectively. In the aeration period, nitrite accumulated as a result of the limiting DO concentration. In the anoxic period, anammox bacteria cooperated with denitrifying bacteria, so nitrite and ammonia nitrogen were eliminated at the same time without nitrate accumulation. All microbial DNA was extracted from sampleswhich were collected from natural landfill leachate and the biofilms of the four reactors. DGGE maps of the extracted DNA were obtained through PCRDGGE. The quantity and brightness of each band in each lane of the map and the coefficients of similarity(Cs) between the lanes were analyzed. The results showed that the different aeration strategies greatly influenced the bacterial diversity and composition.
领 域: [环境科学与工程]