膜曝气生物膜反应器生物膜影响因素分析

膜曝气生物膜反应器（MABR）是一种利用透气膜进行曝气,可以实现同步硝化反硝化的污水生物处理新工艺。本文阐述了膜曝气生物反应器生物膜的原理和特点,总结了国内外在该领域的研究成果,重点介绍了C／N、氧气压力、流速、生物膜厚度、温度和pH对生物膜性能的影响。     

Performance of a combined anaerobic reactor for municipal wastewater treatment at ambient temperature

A bench-scale experimental study was carried out to investigate the overall performance of a combined anaerobic reactor for treating pre-settled municipal wastewater at ambient temperature (18–28°C) in terms of substrate removal efficiencies, biogas, methane production, volatile fatty acid (VFA) profiles and effluent suspended solids (SS) concentration, etc. The tested reactor was a modified anaerobic baffled reactor (ABR). The second and third compartments were partly packed with supporting media. The experimental results were similar to, or compared favourably with, other anaerobic reactor systems for municipal wastewater treatment at ambient temperature and proved the technical feasibility of this compartmentalised reactor. Considering its simple structure and operation, it could be considered a potential reactor system for treating municipal and domestic wastewaters in tropical and sub-tropical areas of developing countries.     

Modeling of the denitrification/anaerobic digestion process of salmon fishery wastewater in a biofilm tubular reactor

The literature has paid scarce attention to the modeling of the denitrification-anaerobic digestion process in packed bed biofilm tubular reactors used to treat wastewater. The present study obtained a steady-state model for industrial salmon fishery wastewater treatment in a biofilm tubular reactor, including pH as a variable and the effect of biomass on hydrolysis. The axial profile of the reactor components and process efficiency were predicted with deviations below 6%. The optimal operating zone for the process was found at hydraulic retention time (HRT)>1.5d and inlet protein concentration (S(prot,0))<3000 mgTOCL(-1). Based on our results, we concluded that the removal of organic matter and nitrogen compounds depended mainly on HRT. The effluent pH was mainly affected by the C/N ratio, where a decrease increases pH. Organic matter removal was related with the anaerobic digestion process, while denitrification influenced mostly nitrate and nitrite removal.     

Microcosm wetlands for wastewater treatment with different hydraulic loading rates and macrophytes

Constructed wetlands (CW) usually require large land areas for treating wastewater. This study evaluated the feasibility of applying CW with less land requirement by operating a group of microcosm wetlands at a hydraulic retention time (HRT) of less than 4 d in southern Taiwan. An artificial wastewater, simulating municipal wastewater containing 200 mg L(-1) of chemical oxygen demand (COD), 20 mg L(-1) of NH4+-N (AN), and 20 mg L(-1) of PO4(3-)-P (OP), was the inflow source. Three emergent plants [reed, Phragmites australis (Cav.) Trin. ex Steud.; water primrose, Ludwigia octovalvis (Jacq.) P.H. Raven; and dayflower, Commelina communis L.] and two floating plants [water spinach, Ipomoea aquatica Forssk.; and water lettuce, Pistia stratiotes L.] plants were tested. The planted systems showed more nutrient removal than unplanted systems; however, the type of macrophytes in CW did not make a major difference in treatment. At the HRTs of 2 to 4 d, the planted system maintained greater than 72,80, and 46% removal for COD, AN, and OP, respectively. For AN and OP removal, the highest efficiencies occurred at the HRT of 3 d, whereas maximum removal rates for AN and OP occurred at the HRT of 2 d. Both removal rates and efficiencies were reduced drastically at the HRT of 1 d. Removals of COD, OP, and AN followed first-order reactions within the HRTs of 1 to 4 d. The efficient removals of these constituents obtained with HRT between 2 and 4 d indicated the possibility of using a CW system for wastewater treatment with less land requirement.     

Biological reduction of chlorate in a gas-lift reactor using hydrogen as an energy source

Chlorate release into the environment occurs with its manufacture and use. Biological reduction of chlorate offers an attractive option to decrease this release. A hydrogen gas-lift reactor with microorganisms attached to pumice particles was used for the treatment of wastewater containing high concentrations of chlorate. The microorganisms used chlorate as an electron acceptor and hydrogen gas as a reducing agent. After a start-up period of only a few weeks, chlorate reduction rates of 3.2 mmol L(-1) h(-1) were achieved during continuous operation. During this period, a hydrogen consumption rate of 14.5 mmol L(-1) h(-1) was observed. Complete removal of chlorate was maintained at hydraulic retention times of 6 h. This study clearly demonstrates the potential of hydrogen gas-lift bioreactors for the treatment of chlorate-containing waste streams.     

Para-chlorophenol containing synthetic wastewater treatment in an activated sludge unit: effects of hydraulic residence time

Due to the toxic nature of chlorophenol compounds present in some chemical industry effluents, biological treatment of such wastewaters is usually realized with low treatment efficiencies. Para-chlorophenol (4-chlorophenol, 4-CP) containing synthetic wastewater was treated in an activated sludge unit at different hydraulic residence times (HRT) varying between 5 and 30 h while the feed COD (2500 mg l(-1)), 4-CP (500 mg l(-1)) and sludge age (SRT, 10 days) were constant. Effects of HRT variations on COD, 4-CP, toxicity removals and on settling characteristics of the sludge were investigated. Percent COD removals increased and the effluent COD concentrations decreased when HRT increased from 5 to 15 h and remained almost constant for larger HRT levels. Nearly, 91% COD and 99% 4-CP removals were obtained at HRT levels above 15 h. Because of the highly concentrated microbial population at HRT levels of above 15 h, low effluent (reactor) 4-CP concentrations and almost complete toxicity removals were obtained. High biomass concentrations obtained at HRT levels above 15 h were due to low 4-CP contents in the aeration tank yielding negligible inhibition effects and low maintenance requirements. The sludge volume index (SVI) decreased with increasing HRT up to 15 h due to high biomass concentrations at high HRT levels resulting in well settling sludge with low SVI values. Hydraulic residence times above 15 h resulted in more than 90% COD and complete 4-CP and toxicity removals along with well settling sludge.     

内循环三相生物流化床处理生活污水的试验研究

对内循环三相生物流化床处理生活污水进行了试验研究,探讨了生物膜的形成和水力停留时间及曝气量对处理效果的影响。结果表明：在HRT为6h,曝气量为0.6m3/h,进水COD和NH4＋-N分别为240.2~298.7mg/L和29.1~68.9mg/L条件下,平均COD去除率为83%,NH4＋-N去除率为95.1%。     

Treatment of domestic wastewater using an anaerobic baffled reactor followed by a duckweed pond for agricultural purposes

The treatment and reuse of domestic wastewater using an anaerobic baffled reactor (ABR) followed by a duckweed pond (DWP) were the main theme of the present study. The ABR was fed continuously with domestic wastewater at four HRTs ranging from 8 to 24 h and corresponds to organic loading rates ranging from 0.67 to 2.1 kg COD/m³/day. The ABR effluent was fed to a DWP operating at 10 and 15 days. The performance of the ABR at the four HRTs gave satisfactory results. Chemical oxygen demand (COD) removal was between 68 and 82%. Fecal coliform removal was between 1 to 2 logs. The 12- and 18-h hydraulic retention times (HRTs) gave close results, as indication of the possible selection of the 12-h HRT as the optimum operation for the ABR based on economic advantage. The ABR compartmentalized structure gave results higher than those produced by the one-stage digester and similar to those produced by the two-phase anaerobic digestion process. Duckweed ponds as post-treatment operated at 10 days and 15 days gave the best results at 15-day HRT, where it was possible to remove 73.4% of nitrogen and 65% of phosphorus and produce protein-rich dry duckweed of 105 kg/ha/day on average. The removal of fecal coliform (FC) in duckweed ponds was 3–4 logs. The final treated domestic sewage characteristics proved its compliance with the Egyptian standards for reuse in restricted irrigation.     

Treatment of low-strength soluble wastewater using an anaerobic baffled reactor (ABR)

Treatment of low-strength soluble wastewater (COD approximately 500 mg/L) was studied using an eight chambered anaerobic baffled reactor (ABR). At pseudo steady-state (PSS), the average total and soluble COD values (COD(T) and COD(S)) at 8h hydraulic retention time (HRT) were found to be around 50 and 40 mg/L, respectively, while at 10h HRT average COD(T) and COD(S) values were of the order of 47 and 37 mg/L, respectively. COD and BOD (3 day, 27 degrees C) removal averaged more than 90%. Effluent conformed to Indian standards laid down for BOD (less than 30 mg/L). Reactor effluent characteristics exhibited very low values of standard deviation indicating excellent reactor stability at PSS in terms of effluent characteristics. Based on mass balance calculations, more than 60% of raw wastewater COD was estimated to be recovered as CH(4) in the gas phase. Compartment-wise profiles indicated that most of the BOD and COD got reduced in the initial compartments only. Sudden drop in pH (7.8-6.7) and formation of volatile fatty acids (VFA) (53-85 mg/L) were observed in the first compartment due to acidogenesis and acetogenesis. The pH increased and VFA concentration decreased longitudinally down the reactor. Residence time distribution (RTD) studies revealed that the flow pattern in the ABR was neither completely plug-flow nor perfectly mixed. Observations from scanning electron micrographs (SEM) suggest that distinct phase separation takes place in an ABR.     

Evaluation of municipal wastewater treatment plants with different technologies at Las Rozas, Madrid (Spain)

Eight small-scale municipal wastewater treatment plants were evaluated over a period of 19 months in the suburb of Las Rozas in Madrid (Spain). Four plants used compact extended aeration, two used conventional activated sludge, two used conventional extended aeration, one used a rotary biodisc reactor and the other used a peat bed reactor. The best results were obtained from the plants that used conventional technologies and the biodisc. Conventional activated sludge and extended aeration had higher removal efficiencies for ammonia, TSS, COD and BOD(5) and produced good quality final effluents for final disposal in accordance with the discharge standard. Empirical equations that correlated the concentration of dissolved oxygen in the effluents with the efficiencies of TSS, ammonia, COD and BOD(5) removals for all plants evaluated were obtained. The performance of the plants using compact extended aeration was affected more than those using conventional technologies or rotary biodisc when the capacity exceeded that of its initial design.     

Characterization of municipal and dairy wastewaters with 30 quality parameters and potential wastewater treatment by biological trickling filters

This study aimed to characterize raw municipal and dairy wastewaters. The quality of the collected wastewaters was determined by measuring 30 quality parameters, such as phenols, oxidation-reduction potential, oil and grease, total organic carbon (TOC), manganese, total viable count of bacteria (TVC), salinity, and biodegradability. Results were compared with wastewater disposal standards. This study also aimed to describe the potential application and performance of biological trickling filters (BTFs) in municipal and dairy wastewater treatment. Detailed reviews of trickling filter models were explained. Results revealed that two wastewater samples exceeded standard limits. The raw municipal and dairy wastewaters need treatment prior to disposal to the natural environment. Additionally, BTFs are efficient municipal and dairy wastewater treatments.     

复合式厌氧污泥床反应器处理城市生活污水的研究

复合式厌氧污泥床反应器是一种改进的厌氧处理工艺，可有效去除城市生活污水中的污染物，并提高了污水的可生化性，是一种较为理想的城市污水强化一级处理工艺。本文对该工艺，装置的特点和效果进行分析,并展望其应用前景。     

UAFSB反应器处理畜禽废水的快速启动

对UASB反应器进行改型,得到UAFSB,并结合UASB反应器快速启动的驯化方式,比较分析用畜禽废水直接启动加颗粒活性炭与未加颗粒活性炭的运行过程和结果。试验结果表明：絮状污泥接种后经过54天的驯化,进料COD浓度由800mg／L提高到5000mg／L,去除率基本稳定在90％以上,均达到预期目的;在污泥中掺入颗粒活性炭,反应器的启动时间有所缩短、抗冲击能力有所加强。     

城市污水处理技术探讨

本文对城市污水处理技术进行了分类分析综述,阐明了当前污水技术发展趋势及应用情况。也对随着经济发展我国水处理标准制订的演变进行了说明。论述了现有城市污水处理厂工艺适扩和投资背景。     

Toxicity identification and high-efficiency treatment of aging chemical industrial wastewater from the Hangu Reservoir, China

The Hangu Reservoir, located in Binhai New Area, Tianjin, China, receives mixed wastewater from a chemical industrial park. The aging chemical industrial wastewater is less biodegradable and contains complex hazardous substances, thus having an adverse effect on local ecological service function of the reservoir and on local economic and social development. In this study, key toxicants in the aging chemical industrial wastewater from the Hangu Reservoir were systematically identified by the toxicity identification evaluations (TIEs), and the treatment efficiency of the aging chemical industrial wastewater was examined and optimized by a municipal wastewater treatment process simulated in a laboratory. According to the TIE results using and wheat seeds as tested organisms, Cl, Cu, Pb, and Zn were identified as key toxicants in the aging chemical industrial wastewater, with concentrations of 7349.11, 0.01, 0.07, and 0.07 mg L, respectively, which were confirmed by subsequent spiking approaches. Based on the TIE results, the aging chemical industrial wastewater could be classified as high-salinity wastewater. The co-treatment of the aging chemical industrial wastewater and municipal wastewater may be an effective and low-cost method. The treatment efficiency of the mixed wastewater increased with an increase in the volume ratio of municipal wastewater to aging chemical industrial wastewater. When the volume ratio was 10:1, the best removal efficiencies of chemical oxygen demand, total N, and total P were up to 85.1, 89.3, and 96.5%, respectively, whereas the toxicity unit of the treated wastewater was reduced to 0.50.     

Public consultation on artificial aquifer recharge using treated municipal wastewater

A questionnaire was prepared and distributed among professionals from various fields, in an effort to gather public perception regarding recharge of groundwater using treated municipal wastewater. This was done as part of a study to assess the feasibility of implementing Soil Aquifer Treatment (SAT) using treated municipal wastewater in parts of central India. This paper presents the perception of people toward artificial recharge and determines the primary concerns among members of the public, so that these can be addressed while carrying out pilot studies. This is the first such public survey that has been carried out in India.The questionnaire was sent to approximately 500 people through e-mail and was uploaded on a popular online portal that deals with water and sanitation issues. 194 correctly filled questionnaires were collected, the results of which are presented in this paper. 87 (45%) questionnaires were filled by environmental professionals including members of the research community, teachers and public health and municipal corporation officials. The rest were filled by members of the general public, including 15 students and 48 non-environmental professionals. Out of 194 respondents, 64.4% were in favor of using treated municipal wastewater for artificial recharge of groundwater, 28.4% opposed and 7.2% remained indifferent.This survey revealed that the primary concern among respondents was the effectiveness of wastewater treatment in India, and not the recharge technique itself. More than 50% of those who support SAT expressed uncertainty as to whether secondary effluent from wastewater treatment plants is being treated to a quality suitable for injecting into the aquifer.     

The formation of aerobic granular sludge for the treatment of real landfill leachate using a granular sequencing batch reactor at a constant volume

Leachate generated in a landfill may not be treated by conventional biological treatment due to its nature and complexity. The process of forming aerobic granules in batch sequencing reactors having features such as; reducing the settling process time and saving energy consumption and high decomposition rate have been noticed by researchers. In the present study, the structure of sequencing batch reactors (SBRs) was evaluated for the formation of granules, which were subsequently utilized for the treatment of landfill leachate. The experiment was initiated by using the GSBR, containing 1200 ml with different apparatuses, to develop granular sludge, and synthetic wastewater was added to reinforcement. The selected parameters for the operational hydraulic retention time (HRT) of the wastewater (6-h cycles) included feeding, idle, aeration, settling, and discharge. Furthermore, the controlled conditions were the dissolved oxygen (DO) range of 2–2.2 mg/L, temperature range of 20–23℃, and pH of 7.5–8.3. The chemical oxygen demand (COD), mixed liquor suspended solids (MLSS), and sludge volume index (SVI) daily were measured at the influent and effluent of GSBR reactor. The main properties of aerobic granular sludge were identified during the research procedures, and the remarkable settling and potent, high-density microbial structure of the granules were confirmed. The mean size of the formulated granules was estimated at 7.46 ± 1.8 mm, and the volume of the biomass also increased from approximately 1607 to 4137 mg/L through the granulation process. Moreover, 98% of the influent chemical oxygen demand (COD) could be removed by the formulated granular sludge, and the final-stage organic loading rate was estimated at 5.65 COD/m³/day. According to the results, GSBRs could be employed for the formulation of aerobic granular sludge for the treatment of landfill leachate.     

生物接触氧化法在炼油废水回用处理中的应用

利用生物接触氧化法对炼油厂的外排污水进行深度处理,在曝气时间大于3h的情况下,可以有效地降低COD、氨氮,伴随硝化反应的发生,出水的碱度也下降。当停留时间足够时,水气比对水中溶解氧的浓度影响不大,较低的有机物浓度成为微生物降解活动的限制因素。经过生物接触氧化处理后的污水的腐蚀速率反而升高,体现出微生物的腐蚀作用和硝化反应的作用。     

混合化工污水处理工艺的试验研究

本文介绍了利用混凝沉淀一生物接触氧化法治理混合化工污水的试验工艺选择,对生化进水的预处理工作进行了初步的探索,在生化试验中,研究了水力停留时间和有机负荷对污水处理效果的影响,并观察了微生物的生长和发展规律,初步探讨了其动力学模型,试验证明：本法能有效地处理混合化工污水,在适宜的条件下,ＣＯＤｃｒ、ＢＯＤ５的去除率可达５５％和９０％以上,色度和ＳＳ的去除率分别可达８０％和５０％以上。     

Estrogenic activity in the environment: municipal wastewater effluent, river, ponds, and wetlands

Estrogenic activity of regional water samples was evaluated. Samples obtained from wetlands and ponds involved in various agricultural land uses, from three river sites over four seasons, and from municipal wastewater effluent held in storage lagoons were evaluated. The estrogen-responsive cell line MCF-7 BOS was used in the E-screen assay to determine 17beta-estradiol equivalents (E2 Eq) of water samples extracted by solid-phase extraction. Estrogenic activity in surrounding wetlands and ponds from different land uses was not different, with 10(-12) M E2 Eq (0.3 ppt). Estrogenic activity of Red River samples was within the same range as wetland-pond samples. The highest activity was found downstream from municipal wastewater treatment effluent discharge sites, in winter when river flow was lowest (approximately 6 x 10(-13) M E2 Eq). Results showed that 7 of 20 wetland-pond samples and 5 of 12 river samples were below the limits of quantitation (approximately 3 x 10(-14) M E2 Eq). Toxicity was found in fall and summer river samples upstream from municipal wastewater release sites. The timing of toxicity did not coincide to the presence of elevated fecal coliforms. Estrogenic activity in wastewater effluent from lagoons decreased over time (approximately 25 to 5 x 10(-13) M E2 Eq) with an apparent half-life of 8 d for one lagoon. The median concentration of detectable estrogenic activity in regional water samples was approximately 50-fold less than the median 17beta-estradiol concentration of estradiol detected in some U.S. streams in previous studies.