Treatment of high-strength pet food wastewater using two-stage membrane bioreactors.

A two-stage membrane bioreactor was used to treat dissolved-air-flotation pretreated, high-strength pet food wastewater characterized by oil and grease concentrations of 50 000 to 82 000 mg/L and total chemical oxygen demand (COD) and five-day biochemical oxygen demand (BOD5) concentrations of 100 000 and 80 000 mg/L, respectively, to meet stringent surface discharge criteria (i.e., BOD5, total suspended solids [TSS], and ammonium-nitrogen [NH4(+)-N] of < 10 mg/L at an overall hydraulic retention time of 6.3 days). Organic contaminants were removed primarily in the first stage, followed by almost complete removal of ammonia in the second stage. Despite a rise in poorly biodegradable COD in the second stage, overall removal of TSS, BOD5, COD, and ammonia was 100, 99.9, 95.2, and 99.7%, respectively, thus readily achieving the required criteria. Consistent nitrite accumulation over a period of more than 100 days, even at dissolved oxygen concentrations of more than 2.5 mg/L, was remarkable. A residual alkalinity requirement for nitrification was quantified. Membrane performance was extensively studied in this work.     

Seasonal performance of an outdoor constructed wetland for graywater treatment in a temperate climate

The seasonal treatment efficiency of a pilot-scale constructed wetland system located outdoors in a semi-arid, temperate climate was evaluated for graywater in a comprehensive, 1-year study. The system consisted of two wetland beds in series--a free water surface bed followed by a subsurface flow bed. Water quality monitoring evaluated organics, solids, nutrients, microbials, and surfactants. The results showed that the wetland substantially reduced graywater constituents during fall, spring, and summer, including biochemical oxygen demand (BOD) (92%), total nitrogen (85%), total phosphorus (78%), total suspended solids (TSS) (73%), linear alkylbenzene sulfonate (LAS) surfactants (94%), and E. coli (1.7 orders of magnitude). Except for TSS, lower removals of graywater constituents were noted in winter--BOD (78%), total nitrogen (64%), total phosphorus (65%), LAS (87%), and E. coli (1.0 order), indicating that, although wetland treatment slowed during the winter, the system remained active, even when the average water temperature was 5.2 +/- 4.5 degrees C.     

粉煤灰-混凝-SBR法处理高浓度洗涤剂废水

针对车间合成洗涤剂生产废水浓度高、可生化性差、负荷大等特点,采用粉煤灰吸附-混凝进行物化处理和SBR法生物处理洗涤剂废水.运行结果表明:在常温下,当处理车间废水初始COD为6000～7000 mg/L、LAS为600～650 mg/L时,物化处理COD和LAS去除率分别为76.4%和77.1%,其中粉煤灰、PAC的投加...     

曝气生物流化床处理高氨氮粪便污水

应用好氧曝气生物流化床反应器处理动车集便器粪便污水,研究反应器同步硝化反硝化脱氮及去除COD效能,以及DO对处理效能的影响,通过镜检观察反应器内微生物特性,探究反应器同步硝化反硝化脱氮机理。结果表明,反应器维持DO在2.5 mg/L左右时,对粪便污水中氨氮、TN和COD的去除率分别达99.8%、84.1%和95.5%,在好氧曝气生物流化床反应器中,实现同步硝化反硝化脱氮并去除有机物。分析认为,反硝化脱氮主要发生在生物膜内的厌氧微环境,反硝化反应主要由厌氧反硝化菌完成,曝气生物流化床反应器同步硝化反硝化脱氮机理主要从微环境理论解释。     

不同pH条件下酵母菌处理高含油废水的研究

在使用混合酵母菌菌株处理高浓度含油废水中，研究了序批式反应器（SBR）内酵母菌在不同起始pH条件下对废水的处理效果。通过与pH中性或碱性条件比较发现，pH4～5的条件在酵母菌的发泡抑制、菌体生长以及COD／油去除等方面均显示出更好的效果，pH5是系统运行的最佳条件。长达100d的SBR连续运行试验表明，系统可以在pH=5条件下长期、稳定运行。     

不同pH条件下酵母菌处理高含油废水的研究

在使用混合酵母菌菌株处理高浓度含油废水中,研究了序批式反应器(SBR)内酵母菌在不同起始pH条件下对废水的处理效果.通过与pH中性或碱性条件比较发现,pH 4～5的条件在酵母菌的发泡抑制、菌体生长以及COD/油去除等方面均显示出更好的效果,pH 5是系统运行的最佳条件.长达100d的SBR连续运行试验表明,系统可以在pH=5条件下长期、稳定运行.     

Low-pressure catalytic wet-air oxidation of a high-strength industrial wastewater using Fenton's reagent.

Wastewater from the Afyon Alkaloids Factory (Afyon, Turkey) was subjected to low-pressure catalytic wet-air oxidation (CWAO) using Fenton's reagent, and the optimal reaction conditions were investigated. The CWAO using Fenton's reagent was applied to the factory effluent, diluted factory effluent, and aerobically pretreated wastewater. To find the optimum quantities of reagents, ferrous iron (Fe(+2))-to-substrate ratios of 1:10, 1:25, and 1:50 and hydrogen peroxide (H2O2)-to-Fe(+2) ratios of 1, 5, and 10 were investigated, and the treatment was carried out at different temperatures. High chemical oxygen demand (COD) removals were obtained at 50 degrees C, with the Fe(+2)-to-substrate ratio range between 1:10 and 1:25. The change in H2O2-to-Fe(+2) ratios did not cause any considerable effect. Also, the percentages of COD removals were nearly the same, so the ratio H2O2:Fe(+2):1 is recommended. Aerobic pretreatment seems to be effective. On the other hand, no enhancement was observed in the case of the diluted wastewater.     

农村重力流灰水收集系统的恶臭气体时空分布规律

为探究农村重力流灰水收集系统的恶臭气体时空分布规律,构建了一套中试研究装置并研究了其全流程的恶臭气体质量浓度。结果表明：在相对静止的灰水储水池中,苯乙烯(C₈H₈)是质量浓度最高的恶臭气体(平均质量浓度为55.68 mg·m⁻³),二硫化碳(CS₂)的质量浓度最低(平均质量浓度为0.11 mg·m⁻³);灰水收集系统在早晨(6:00—8:00)和傍晚(17:00—19:00)的恶臭气体质量浓度较高,其OU平均值分别是其他时段OU平均质量浓度的1.82~23.7倍和1.87~24.41倍;灰水收集系统中的跌水井和管道变径处是恶臭气体质量浓度较高的区域,其OU平均值分别是其上下游区域OU平均值的1.2倍和1.6倍。在农村重力流灰水收集系统的运维过程中,应该关注C₈H₈和C₂SH₆等气体的浓度变化以更好的控制恶臭逸散问题。     

蚯蚓生物滤池对小城镇污泥处理效果简

针对小城镇污泥的处理问题,提出了蚯蚓生物滤池解决方案,为此在实验中设置了无蚯蚓对照组,并对污泥的稳定性、污泥性状、蚯蚓与微生物的协同作用以及污泥含有的各种元素存在状态进行了研究,通过蚯蚓生物滤池处理后污泥有机质含量平均相对减少量为11.1%,溶解性化学需氧量（SCOD）增加,滤液中氨氮（NH₃-N）含量由20.6~23.9 mg/L降至1.9~4.6 mg/L、滤液中硝态氮（NO₃^--N）含量由0.2~9.5 mg/L升高到42.0~50.8 mg/L,因此,实验结果表明,蚯蚓生物滤池能显著提高污泥的稳定性,改善污泥脱水性能,有利于污泥后续处理。     

Kinetics and stoichiometry of aerobic sulfide oxidation in wastewater from sewers-effects of pH and temperature.

Kinetics and stoichiometry of aerobic chemical and biological sulfide oxidation in wastewater from sewer networks were studied. In this respect, the effects of temperature and pH were investigated in the ranges 10 to 20 degrees C and 5 to 9, respectively. The temperature dependency of sulfide oxidation kinetics was described using an Arrhenius relationship. The effect of pH on the rate of chemical sulfide oxidation is related to the dissociation of hydrogen sulfide (H2S) to hydrogen sulfide ion (HS(-)), with HS(-) being more readily oxidized than H2S. Biological sulfide oxidation exhibited the highest rates at ambient wastewater pH, and the reaction was inhibited at both low and high pH values. Chemical sulfide oxidation was found to produce thiosulfate and sulfate, while elemental sulfur was the main product of biological sulfide oxidation. Based on the investigations, general rate equations and stoichiometric constants were determined, enabling the processes to be incorporated to conceptual sewer process models.     

美国某污水处理厂工艺设计及运行效果

介绍了美国某污水处理厂的处理工艺流程、主要构筑物构成及其设计参数,通过对该污水处理厂一年内运行效果的调研,分析评价了该污水厂的进出水水质指标;该水厂工艺流程对TSS、BOD5、COD、NH3-N、TP和浊度的年平均去除率分别可以达到97.7％、97.7％、93.5％、82.6％、95.2％和97.9％,各项出水水质均优于我国《城镇污水处理厂污染物排放标准》(GB18918-2002)一级A标准,通过对该水厂工艺的介绍和分析,为我国污水厂的建设及改造升级提供了一定的参考依据.     

四川望佳人工湿地系统生活污水净化效果

取样监测分析了望佳人工湿地系统各组成单元对COD、TN、NH3-N、TP和SS的去除效果。在水力负荷为0.18 m3/m·d、温度为8~19℃、p H为6~8的条件下,分析结果表明,各单元COD、TN、NH3-N、TP和SS的系统去除率满足:人工快渗池>厌氧调节池>1号表流湿地>潜流湿地>氧化塘>2号表流湿地>1号水平潜流湿地>2号水平潜流湿地,其中人工快渗池单元的系统去除率平均值分别为21.21%、22.74%、22.49%、25.58%和30.85%。监测期间COD、TN、NH3-N、TP和SS的总去除率平均值分别为89.41%、90.27%、89.89%、89.89%和92.28%,系统出水达《城镇污水处理厂污染物排放标准》GB18918-2002一级标准的B标准。监测表明,该湿地设计偏于保守,还可以优化设计单元以减少建设和运行成本。     

Integrated catalytic wet air oxidation and aerobic biological treatment in a municipal WWTP of a high-strength o-cresol wastewater

This study examines the feasibility of coupling a Catalytic Wet Air Oxidation (CWAO), with activated carbon (AC) as catalyst, and an aerobic biological treatment to treat a high-strength o-cresol wastewater. Two goals are pursued: (a) To determine the effect of the main AC/CWAO intermediates on the activated sludge of a municipal WasteWater Treatment Plant (WWTP) and (b) To demonstrate the feasibility of coupling the AC/CWAO effluent as a part of the influent of a municipal WWTP. In a previous study, a high-strength o-cresol wastewater was treated by AC/CWAO aiming to establish the distribution of intermediates and the biodegradability enhancement. In this work, the biodegradability, toxicity and inhibition of the most relevant intermediates detected in the AC/CWAO effluent were determined by respirometry. Also, the results of a pilot scale municipal WWTP study for an integrated AC/CWAO-aerobic biological treatment of this effluent are presented. The biodegradation parameters (i.e. maximum oxygen uptake rate and oxygen consumption) of main AC/CWAO intermediates allowed the classification of the intermediates into readily biodegradable, inert or toxic/inhibitory compounds. This detailed study, allowed to understand the biodegradability enhancement exhibited by an AC/CWAO effluent and to achieve a successful strategy for coupling the AC/CWAO step with an aerobic biological treatment for a high-strength o-cresol wastewater. Using 30%, as COD, of AC/CWAO effluent in the inlet to the pilot scale WWTP, the integrated AC/CWAO-biological treatment achieved a 98% of total COD removal and, particularly, a 91% of AC/CWAO effluent COD removal without any undesirable effect on the biomass.     

一株反硝化细菌的分离鉴定及脱氮能力

本研究从水产养殖环境中分离出39株反硝化细菌,并从中筛选出具有较强反硝化能力的菌株DB-33,对其脱氮能力测定的结果表明,在培养基中亚硝酸盐氮浓度高达54．16mg／L,硝酸盐氮浓度高达306．91mg／L时,DB-33菌株对其去除率均达99％以上,且在去除过程中氨氮不累积;在模拟养殖水体中,DB-33可将亚硝酸盐氮和硝酸盐氮分别在24h和第3天彻底去除,对氨氮48h的去除率也可达51．52％。通过形态学特性和生理生化分析以及16SrDNA基因序列分析,菌株DB-33初步鉴定为施氏假单胞菌（Pseudomonasstutzeri）。     

Metal stoichiometry in predicting Cd and Cu toxicity to a freshwater green alga Chlamydomonas reinhardtii

In this study, we quantified the accumulation and toxicity of cadmium and copper in a freshwater green alga, Chlamydomonas reinhardtii, under different phosphate conditions. The accumulated Cd and Cu concentrations increased significantly with increasing ambient P concentrations and free metal ion concentrations. The metal:P ratio remained independent of the ambient P concentration. For the three pulse-amplitude-modulated parameters, the median inhibition concentrations were 1.5-1.6x and 2.0x higher, but the medium inhibition cellular quota was 2.2x and 1.2x lower for cells maintained at 0.1 microM P than for cells maintained at 10 microM P for Cd and Cu, respectively. Furthermore, the difference in metal toxicity decreased (for Cd) or disappeared (for Cu) when the toxicity was expressed by the metal:P ratio in the cells, indicating that the stoichiometry of metals and P can be better used to predict the toxicity of metals. It is necessary to consider the stoichiometry of metals in predicting metal toxicity in phytoplankton.     

Treatment of landfill leachate by irrigation of willow coppice - Plant response and treatment efficiency

Landfill leachates usually need to be treated before discharged, and using soil-plant systems for this has gained substantial interest in Sweden and in the UK. A three-year field study was conducted in central Sweden to quantify plant response, treatment efficiency and impact on groundwater quality of landfill leachate irrigation of short-rotation willow coppice (Salix). Two willow varieties were tested and four irrigation regimes in sixteen 400-m² plots. The willow plants did not react negatively, despite very high annual loads of nitrogen (≤2160 kg N/ha), chloride (≤8600 kg Cl/ha) and other elements. Mean annual growth was 1.5, 9.8 and 12.6 tonnes DM/ha during years 1-3. For one of two willow varieties tested, relative leaf length accurately predicted growth rate. Irrigation resulted in elevated groundwater concentrations of all elements applied. Treatment efficiency varied considerably for different elements, but was adequate when moderate loads were applied.     

一株高效降酚菌的分离鉴定及降酚特性研究

以苯酚为唯一碳源,采用逐量分批的方法从被酚类物质污染的土壤中驯化、筛选、分离降酚菌,利用形态学、培养特性、生理生化反应以及分子手段鉴定所得菌株,研究了该菌株生长与降酚的关系以及其降酚能力,并设计引物检测降酚酶基因。结果表明,获得的一株高效降酚菌GDYW-0027经鉴定为不动杆菌属(Acinetobacter),它的生长速率与苯酚的降解速率基本同步,48h内对高质量浓度(2.2g/L)苯酚的降解率为86.73%;在菌株GDYW-0027中检测到苯酚羟化酶及邻苯二酚2,3双加氧酶基因片段,推测其采用间位开环方式打开苯环。     

短期有机冲击下船用景观一体化反硝化除磷装置的处理效能

为高效、稳定处理船舶生活污水,研究了船用景观一体化反硝化除磷装置面对短期水质波动的效能变化,采用富集反硝化聚磷菌(DPAOs)的ABR-CSTR连续流组合工艺耦合生态单元处理船舶生活污水,对比了ABR进水容积负荷(VLR)为1.2 kg·(m³·d)⁻¹、COD为350 mg·L⁻¹的基准条件,通过短期内提高进水中有机底物的浓度,来模拟1.5倍和2.0倍进水有机负荷的有机冲击,此外通过控制硝化液回流比及溶解氧获得应对冲击的调控策略。结果表明：在2种短期冲击下,COD去除率分别为94.1%和92.6%,出水BOD和TN可达标,生物单元出水磷平均为0.76 mg·L⁻¹和1.14 mg·L⁻¹,缺氧吸磷量为7.13 mg·L⁻¹和5.82 mg·L⁻¹,生态单元可深度降解氮磷及缓冲波动;在1.5倍VLR下,调整硝化液回流比由200%至300%,反硝化吸磷量由7.10 mg·L⁻¹升至7.41 mg·L⁻¹,在2.0倍冲击下,提高硝化液回流比对系统除磷帮助甚微,将DO从1.5 mg·L⁻¹升至2.0 mg·L⁻¹,吸磷量由5.17 mg·L⁻¹升至6.01 mg·L⁻¹,系统反硝化除磷效果得以提升;污泥特性方面,ABR内MLVSS/MLSS比值和EPS量随有机底物浓度的提高而上升,厌氧段EPS增幅最大,可由154.5 mg·g⁻¹升至164.2 mg·g⁻¹和183.4 mg·g ⁻¹。ABR-CSTR-生态单元一体化装置面对短期有机冲击具有稳定处理效果,研究结果可为船舶生活污水的治理提供参考。     

Nutrient stoichiometry in Sphagnum along a nitrogen deposition gradient in highly polluted region of Central-East Europe

We investigated the variation of N:P and N:K ratio in ombrotrophic Sphagnum plants along a gradient of atmospheric N deposition from 1 to 2.5 g m⁻² year⁻¹ in Central-East Europe. The N:P and N:K ratio in Sphagnum capitula increased significantly along the N deposition gradient. Sphagnum species from the Cuspidata section were characterised by significantly lower ratios at low N deposition. When we compared the observed N:P ratios in Sphagnum plants with the values reported in a previous European-wide study, we found a correspondence in nutrient stoichiometry only for a few bogs: higher P concentration in Sphagnum capitula caused a lower N:P ratio in most of the study bogs so that Sphagnum plants still seem N-limited despite their N saturation. Interaction between summer water table decrease and aerial liming of surrounding forests is proposed as an explanation for this discrepancy. Local forestry practice interacting with climate thus alter N:P stoichiometry of Sphagnum along the N deposition gradient.