SHORT TERM BENTHIC COLONIZATION DYNAMICS IN AN AGRICULTURAL STREAM RECOVERING FROM SLAUGHTERHOUSE EFFLUENTS1

ABSTRACT: The purpose of this study was to assess short term, macroinvertebrate colonization dynamics and biofilm accumulation in two agricultural streams, one of which had been recently exposed to chronic, intermittent organic effluents from a slaughterhouse. During the winter and summer, macroinvertebrates and biofilm were collected from brick substrates from four or three sites in the streams on a geometric time schedule (1, 2, 4, 8, 16, and 32 days of exposure). Invertebrate total densities stabilized quickly, but the mass of biofilm increased throughout the study periods. Invertebrate community indices (diversity, evenness, dominance, richness) differed between the unaffected, “agricultural reference” sites and the affected sites, below the point source. All sites were dominated by Baetis bicaudatus (mayfly), Hydrobia sp. (gastropod), and Dugesia tigrina (Turbellaria). Response of these taxa differed between seasons and exposure to organic effluents. Stream invertebrate colonization processes showed evidence of the perturbation after the inflow of organic effluents had stopped from the slaughterhouse. Chronic organic enrichment reduced the species richness in the potential pool of colonists. Three months after the organic inputs had stopped, colonization timing and community structure was not yet at levels evident in reference and upstream sites.     

零价铁-反硝化菌在地下水硝酸盐污染修复中的应用

综述了应用零价铁-反硝化菌复合体系去除地下水中硝酸盐氮污染的研究进展.脱氮技术主要包括物理化学法、化学还原法和生物反硝化法,但单独使用任何一种方法都无法得到令人满意的处理效果.以零价铁在水中厌氧腐蚀所释放的氯气供给微生物进行反硝化,可以同时解决这两种技术单独使用时所存在的弊端.在此复合体系中,主要反应包括产氨、析氢和反硝化,降低脱氮产物中的氨氮比例就要减少产氨反应的发生几率.此外,使用纳米铁代替零价铁和反硝化细菌复合,可以大大提高脱氮反应速率.然而,该技术的研究在国内外尚处于起步阶段,在反应机理、产物控制、条件优化等方面都存在不足,还需要深入研究.     

固定化包埋亚硝酸菌短程脱氮与同步除磷工艺研究

为实现常温下低碳源城市生活污水的低能耗脱氮除磷,采用固定化技术和厌氧/好氧/缺氧(AOA)工艺耦合与游离组进行了对比实验研究。在温度为25±1℃、pH为8.0±1、DO为1±0.5 mg/L和HRT为9 h的条件下,两组运行结果表明,固定组具有较高的硝化效率和较强的适应能力,亚硝氮的积累率可以稳定维持在70%以上,对NH4+-N、COD和TP的去除率分别为92.2%、87.2%和81.3%,明显优于游离组。     

曝气浸没固定生物膜反应器处理化粪池出水

研究了以丝瓜络作为生物膜载体的曝气浸没固定生物膜反应器在处理化粪池出水时的可行性以及运行性能。结果表明,丝瓜络生物膜反应器可以在2周内成功启动;水力停留时间(HRT)对COD和氨氮的去除效果有显著影响,在水力停留时间为4 h的条件下,系统对COD和氨氮的去除率分别达到了78.5%和96.4%。另外,系统有较强抗有机污染物冲击负荷的能力,当COD和氨氮的进水浓度分别为59.3 mg/L和15.9 mg/L时,系统对有机污染物的去除效果较佳,去除率分别达到了80.0%和98.9%。     

不同碳源和泥龄对反硝化聚磷的影响

在4个SBR装置(1#~4#)中,对4种不同比例的丙酸/乙酸合成废水采用厌氧/缺氧方式驯化富集反硝化聚磷菌(DPB),研究了碳源浓度和污泥龄对除磷的影响。实验结果表明:(1)厌氧段碳源COD浓度越高,释磷越充分,溶解性正磷酸盐(SOP)去除率越高;但当碳源COD浓度超过某个浓度值时,未反应完全的有机物残留于后续缺氧段对缺氧吸磷产生抑制作用。(2)污泥龄SRT=15 d时,活性污泥的性能较好,达到了较好的除磷效果。(3)在相同碳源浓度和相同的污泥龄下,随着丙酸/乙酸比例的提高,SOP的去除率逐渐的降低。说明在厌氧/缺氧环境下,碳源中丙酸比例的提高不利于系统中磷的去除。高乙酸含量的碳源更适合反硝化除磷系统。     

Dairy washwater treatment using a horizontal flow biofilm system

In Ireland, dairy farmyard washwater commonly comprises farmyard run-off and dairy parlour washings. Land-spreading is the most widely used method for treating this wastewater. However, this method can be labour intensive and can cause, in some cases, the degradation of surface and ground waters, mainly due to nitrogen contamination. In this study, a horizontal flow biofilm reactor (HFBR) with step-feed was constructed and tested in the laboratory, to remove organic carbon and nitrogen from a agricultural strength synthetic washwater (SWW). The HFBR had an average top plan surface area (TPSA) of 0.1002 m(2) and consisted of a stack of 45 polystyrene horizontal sheets--15 sheets embedded with 25 mm deep frustums above 30 sheets with 10 mm deep frustums. The frustums acted as miniature reservoirs. The sheets were alternately offset to allow the wastewater to flow horizontally along each sheet and vertically from sheet to sheet down through the reactor. Biofilms developed on the sheets and treated the wastewater. During the 212-d study, the total hydraulic loading rate based on the TPSA of the sheets was 35 l m(-2) d(-1). SWW was pumped for 10 min each hour, in a step feed arrangement at a rate of 23.33 l m(-2) d(-1) on to the top sheet during Phases 1 and 2, and 11.67 l m(-2) d(-1) onto Sheet 16 during Phase 1 (days 1-92) and onto Sheet 30 during Phase 2 (days 93-212). The substrate loading rate during Phases 1 and 2 was 94.8 g total chemical oxygen demand (COD) m(-2) d(-1) and 10.5 g total nitrogen (TN) m(-2) d(-1), based on the TPSA. At steady state in Phase 2, the unit achieved excellent carbon removal of 99.7% 5-day biochemical oxygen demand (BOD(5)) and 96.7% total COD, equivalent to TPSA removal rates of 67.5 g BOD(5)m(-2)d(-1) and 91.7 g COD m(-2) d(-1). The nitrogen removal percentages were 98.3% total ammonium-nitrogen (NH(4)-N(t)) and 72.8% TN, which equated to TPSA removal rates of 4.8 g NH(4)-N(t) m(-2) d(-1) and 7.6g TN m(-2) d(-1). No sloughing of solids or clogging of media occurred during the study. The unit was simple to construct and operate, with little maintenance.     

滤料粒径对BAF小尺度下流场形态及挂膜速度的影响

为探讨颗粒粒径对曝气生物滤池(BAF)运行效果的影响,采用数值模拟和实验研究方法分析了滤料粒径对曝气生物滤池流场形态及挂膜速度的作用机理.选用5个颗粒尺寸结构空间作为计算区域,利用Fluent软件对相同颗粒间隙、不同颗粒粒径下BAF小尺度下的流场形态进行模拟分析,并通过对3种粒径下流线图、速度矢量图、压力分布及湍流强度变化的对比分析,发现颗粒粒径为3 mm时流场形态最好,最有利于气水混合及氧传质的进行.同时,为验证模拟结果的正确性,对同种材质、相同运行条件下3种不同颗粒粒径进行挂膜速度对比,通过考察挂膜启动28 d的COD去除率变化及污泥生物量的对比分析,发现颗粒粒径为3 mm时,运行最为稳定,系统运行第16 d时就达到了80%的COD去除效率.     

耐冷高效亚硝酸盐型反硝化细菌的分离、筛选与鉴定

在10℃条件下,以亚硝酸钠为唯一氮源从长期淹水的冬水田中分离得到了12株亚硝酸盐型反硝化细菌.采用乙酸钠为唯一碳源,以高效去除亚硝酸盐氮和总氮且产生较低生物量氮为主要指标筛选出了一株反硝化能力最强的亚硝酸盐型反硝化细菌,命名为Y-12.研究发现,该菌在20℃条件下,对亚硝酸盐氮和总氮的去除率分别为99.87%和57.74%,产生了3.25 mg·L-1的生物量氮;在15℃条件下,对亚硝酸盐氮和总氮去除率分别为99.48%和51.53%,产生了3.00 mg·L-1的生物量氮.对其16S rRNA基因序列进行分析,发现该菌与恶臭假单胞菌(Pseudomonas putida)的同源性达到99%;对其特异性磷脂脂肪酸进行分析,发现与恶臭假单胞菌(Pseudomonas-putida-biotype A)的相似指数为0.469,初步鉴定为恶臭假单胞菌.     

电活性生物膜阳极构建及其对2，4，6-三氯酚同步降解和产电

为实现氯酚（CPs）的高效降解和资源化利用,探究微生物燃料电池（MFC）体系优势功能菌,揭示生物降解路径.接种、驯化长春市南郊污水处理厂的厌氧活性污泥,获得生物膜阳极以构筑MFC-2,4,6-TCP体系,基于扫描电子电镜（SEM）、16S rRNA分析测序方法,考察生物膜阳极微生物的附着情况和优势菌种,基于电化学阻抗（EIS）、循环伏安（CV）和线性扫描伏安（LSV）等电化学分析手段,表征生物阳极的电化学性能和氧化还原能力.结果表明,生物膜阳极微生物种类丰富,其中Geobacter和Acinetobacter分别为MFC-2,4,6-TCP体系产电和降解驯化期的优势功能菌,体系最大输出电压可达0.55 V,最大功率密度为428.65 mW·m-2,对2,4,6-TCP的降解和矿化率可达97.5%和85.4%.随着MFC循环次数的增加,微生物代谢途径多样化,产电菌逐渐演替为协同菌,且优势功能菌对2,4,6-TCP降解的中间产物（环己醇）,其毒性远低于氯酚或苯酚,更利于被微生物利用.该结果可为氯酚废水的实际处理提供新策略和技术参考.     

3种填料A.ferrooxidans挂膜效果及对模拟酸性矿山废水中Fe2+生物矿化能力比较

氧化亚铁硫杆菌（A.ferrooxidans）介导的生物矿化方法可促使酸性矿山废水（Acid Mine Drainage,AMD）中Fe离子向次生铁矿物转变. 采用固定化的方式来提高A.ferrooxidans密度有助于强化Fe²⁺的生物矿化能力.选取流化床19孔填料、弹性填料、悬浮球填料作为挂膜对象, 通过多批次的连续培养来考察3种填料的A.ferrooxidans挂膜能力及稳定挂膜所需周期,继而比较3种挂膜填料对模拟AMD中Fe²⁺的生物矿化能力,并估算A.ferrooxidans有效生物量.结果表明,3种填料（5.00 g）的A.ferrooxidans挂膜能力依次为弹性填料（1.76 g）＞流化床19孔填料（0.90 g）＞悬浮球填料（0.78 g）（干重）,且挂膜启动至稳定状态至少需要4批次.X射线衍射分析（X-ray diffraction,XRD）表明,3种填料表面 含矿生物膜均为施氏矿物和黄钾铁矾的混合物.以游离态A.ferrooxidans的Fe²⁺氧化速率作为参比,估算出流化床19孔填料、弹性填料、悬浮球填料生物膜中A.ferrooxidans有效生物量依次为1.67×10⁸、8.52×10⁸、1.92×10⁸ cells·g^-1 （干基）.研究还发现,等同Fe²⁺生物氧化速率下, A.ferrooxidans挂膜填料比游离态A.ferrooxidans具有更强的AMD矿化驱动能力.