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The paper expresses an attempt to tackle the problem due to the presence of micropollutants in wastewater which may be able to disrupt the endocrine system of some organisms. These kinds of compounds are ubiquitously present in municipal wastewater treatment plant (WWTP) effluents. The aim of this paper is to compare the fate of the alkylphenols-APs (4-(tert-octyl)) phenol, t-nonylphenol and 4-p-nonylphenol and the hormones (estrone, 17β-estradiol and 17α-ethinylestradiol) in a submerged anaerobic membrane bioreactor (SAMBR) pilot plant and in a conventional activated sludge wastewater treatment plant (CTP). The obtained results are also compared with the results obtained in a previous study carried out in an aerobic MBR pilot plant. The results showed that the APs soluble concentrations in the SAMBR effluent were always significantly higher than the CTP ones. Moreover, the analyses of the suspended fraction revealed that the AP concentrations in the SAMBR reactor were usually higher than in the CTP reactor, indicating that under anaerobic conditions the APs were accumulated in the digested sludge. The aerobic conditions maintained both in the CTP system and in the aerobic MBR favoured the APs and hormones degradation, and gave rise to lower concentrations in the effluent and in the reactor of these systems. Furthermore, the results also indicated that the degradation of APs under aerobic conditions was enhanced working at high solid retention time (SRT) and hydraulic retention time (HRT) values. 相似文献
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In recent years a completely autotrophic nitrogen removal process based on Anammox biomass has been tested in a few European countries in order to treat anaerobic supernatant and to increase the COD/N ratio in municipal wastewater. This work reports experimental results on a possible technical solution to upgrade the S. Colombano treatment plant which treats wastewater from the Florentine urban area. The idea is to use 50% of the volume of the anaerobic digester in order to treat external sewage sludge (as septic tank sludge) together with waste activated sludge and to treat the resulting effluent on a SHARON-ANAMMOX process in order to remove nitrogen from the anaerobic supernatant. Anaerobic co-digestion, tested in a 200 L pilot plant, enables low cost treatment of septic tank sludge and increases biogas production; however, it also increases the nitrogen load re-circulated to the WWTP, where nitrogen removal efficiency is already low (<50%), due to the low COD/N ratio, which limits predenitrification efficiency. Experimental results from a SHARON process tested in a lab-scale pilot plant show that nitrite oxidising bacteria are washed-out and steady nitrite production can be achieved at retention times in the range 1 - 1.5 days, at 35 degrees C. In a lab-scale SBR reactor, coupled with a nitration bioreactor, maximum specific nitrogen removal rate under nitrite-limiting conditions (with doubling time equal to about 26 days at 35 degrees C) was equal to 0.22 kgN/kgSSV/d, about 44 times the rate measured in inoculum Anammox sludge. Finally, a cost analysis of the proposed upgrade is reported. 相似文献
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The new water quality protection approach of the EU combines the control of emissions with instream Environmental Quality Standards (=EQS). Since 1 April 2006 and actually relevant in the version of 2010 in Austria, priority substances from list A of the EUROPEAN DIERECTIVE 76/464 and further EQS of relevant chemical substances (list B), identified by a national risk assessment, have to be reached to achieve a good ecological state in the surface water (Edict for Water Quality Standards, 2006; changes to the Edict for Water Quality Standards 2010). The practical assessment of these substances after point source emissions is prescribed in the Edict, but rarely carried out. In this paper, two substances, namely: (1) ammonium (list B); and (2) nonylphenol, an endocrine disrupting compound (list A) are presented to discuss: (i) the improvement of treatment efficiency due to the upgrade of a large Waste Water Treatment Plant (=WWTP); (ii) the relevance of mixing processes and modelling as a method to control EQS after point source emissions; and (iii) the improvement of water quality in the ambient surface waters. It is shown that the improved treatment in the case of nonylphenol leads to emission values which fall below the EQS, making an assessment unnecessary. In the case of ammonium emission, values are significantly reduced and violation of EQS is avoided, while mixing modelling is shown to be a suitable instrument to address the resulting instream concentrations at different border conditions. 相似文献
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城市污水处理厂不同污泥厌氧消化的产气研究 总被引:4,自引:0,他引:4
选取北京市某污水处理厂剩余污泥、初沉污泥和混合污泥作为研究对象,在中温(35℃)条件下,进行污泥产气速率和产气量的对照试验,结果表明:剩余污泥、初沉污泥和混合污泥的日平均产气量分别为218.8 mL/(d·L泥)、339.2 mL/(d·L泥)和419.4 mL/(d·L泥),总产气量分别为3.5 m3/m3泥、5.43 m3/m3泥和6.71 m3/m3泥,分别达到理论产气量的44.02%、72.79%和78.39%;剩余污泥、初沉污泥和混合污泥产气中CH4和CO2等主要组分含量的差异并不显著;从污泥的产气速率、产气量和消化性能分析,不同污泥之间的相互关系是:混合污泥>初沉污泥>剩余污泥,可见城市污水处理厂中初沉污泥(或混合污泥)比单独的剩余污泥更适宜于采用厌氧消化工艺. 相似文献
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污水处理厂污泥厌氧消化优化设计与运行探讨 总被引:1,自引:0,他引:1
对国内典型的污水处理厂污泥厌氧消化系统进行调研发现,厌氧消化系统的运行管理尚存在诸多问题。在总结白龙港污水处理厂污泥厌氧消化调试与运行管理经验的基础上,针对厌氧消化工艺存在的普遍性问题,提出了厌氧消化系统设计和运行管理方面的建议,以促进工艺设计优化,提高运行管理水平。 相似文献
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This paper presents the behaviour of a full-scale expanded bed reactor (160 m3) with overlaid anaerobic and aerobic zones used for municipal wastewater treatment. The research was carried out in two experimental steps: anaerobic and anaerobic-aerobic conditions, and the experimental results presented in this paper refer to four months of reactor operation. In the anaerobic condition, after inoculation and 60 days of operation, the reactor treating 3.40 kg CODm(-3)d(-1) for thetaH of 2.69 h, reached mean removal efficiencies of 76% for BOD, 72% for COD, and 80% for TSS, when the effluent presented mean values of 225 mg.L(-1) of COD, 98 mg.L(-1) of BOD and 35 mg.L(-1) of TSS. Under these conditions, for nitrogen loading of 0.27 kgN.m(-3)d(-1), the reactor generated an effluent with mean N-org. of 8 mg.L(-1) and N-ammon. of 37 mg.L(-1), demonstrating high potential of ammonification. For the anaerobic-aerobic condition (118th day) the system was operated with thetaH of 5.38 h presented mean removal efficiencies of 84% for BOD, 79% for COD, 76% for TSS, and 30% for TKN. The reactor's operation time was less than two months, which was not long enough to reach nitrification. Regarding the obtained results, this research confirmed that this reactor is configured as a flexible and adequate alternative for the treatment of sewage, requiring relatively small area and only thetaH of 10 h that can be adjusted to the local circumstances. 相似文献
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《Water science and technology》1998,37(4-5):95-98
An anaerobic enrichment culture was developed from an anoxic/anaerobic/aerobic activated sludge sequencing batch reactor using methyl ethyl ketoxime (MEKO), a potent nitrification inhibitor, as the sole carbon and energy source in the absence of molecular oxygen and nitrate. The enrichment culture was gradually fed decreasing amounts of biogenic organic compounds and increasing concentrations of MEKO over 23 days until the cultures metabolized the oxime as the sole carbon source; the cultures were maintained for an additional 41 days on MEKO alone. Turbidity stabilized at approximately 100 mg/l total suspended solids. Growth on selective media Plates confirmed that the microorganisms were utilizing the MEKO as the sole carbon and energy source. The time frame required for growth indicated that the kinetics for MEKO degradation are slow. A batch test indicated that dissolved organic carbon decreased at a rate comparable to MEKO consumption, while sulfate was not consumed. The nature of the electron acceptor in anaerobic MEKO metabolism is unclear, but it is hypothesized that the MEKO is hydrolyzed intracellularly to form methyl ethyl ketone and hydroxylamine which serve as electron donor and electron acceptor, respectively. 相似文献
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It has been demonstrated that the combination of anaerobic-aerobic treatment is the best technological and economical solution for the treatment of high loaded wastewater. Where in the past aerobic treatment systems were still very acceptable due to the very good treatment efficiency, simplicity and robustness of the technology, this has, in most cases, been changed due to very stringent sludge disposal legislation. The anaerobic pretreatment takes care of approximately 80-90% of the overall treatment efficiency at high loading rates and low sludge production and low energy costs. The aerobic posttreatment takes care of the absolute high removal efficiency and nitrogen and phosphorus removal. Because of the low organic loading rate of the aerobic posttreatment also in this stage the sludge production is low. The combination of anaerobic-aerobic treatment results in a compact system capable of reaching high treatment efficiency at low sludge production and lower energy consumption. Waterleau Global Water Technology has developed LUCAS anaerobic-aerobic system that combines an Upflow Anaerobic Sludge Blanket (UASB) reactor with an aerobic, constant-level cyclic activated sludge system, which is very suitable for the treatment of high loaded wastewaters in general and brewery waste water in particular. It has been proven from several full scale upgrading projects that the UASB system is best suitable for implementation in the aerobic plants that have to be extended in capacity. 相似文献
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硫酸盐还原菌及其在废水厌氧治理中的应用 总被引:3,自引:0,他引:3
硫酸盐还原菌(SRB)在废水处理方面有独特的优势,在厌氧环境中能以硫酸盐作为电子受体降解有机污染物。本文阐明了SRB处理废水中污染物的机理,综述了国内外利用SRB处理重金属离子废水、含硫酸盐有机废水和酸性矿山废水的研究进展。最后总结了目前在工程应用方面尚存在的问题。 相似文献
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K?ppala Association has the responsibility to receive and treat wastewater from 11 municipalities situated just north of Stockholm in Sweden. Running a tunnel system, 60 km long, and a treatment plant meets this responsibility. The plant is situated in Liding?, northeast of Stockholm. The load 2002 corresponds to about 520,000 p.e. During the 1990s the plant was upgraded and expanded to meet an increasing population and more stringent discharge limits. Nitrogen removal was introduced. The expansion was done in two steps; the first step comprised a new plant beside the old one both situated in rock. This part, which included the filtration step, was taken into operation in 1998. Then the old plant was upgraded to the same technical standard as the new part. His Majesty the King of Sweden inaugurated the whole new and upgraded plant in April 2000. A total of 1.3 billion Swedish crowns were invested corresponding to about 140 million euro. The plant's performance is good. There is no trouble keeping the discharge limits, 10 mg/l for BOD7 and total nitrogen and 0.3 mg/l for phosphorus. However the bio-P process has not been altogether successful. We haven't been able to fulfill our goal to reduce the use of iron sulphate. We will during 2003 go on in our investigations concerning running the plant with a combination of bio-P and chemical precipitation. 相似文献
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This paper presents the design and operational performance data of an anaerobic/aerobic hybrid side-stream Membrane Bioreactor (MBR) process for treating paper mill effluent operated over a 6 month period. The paper mill effluent stream was characterized by a chemical oxygen demand (COD) range of between 1,600 and 4,400 mg/L and an average BOD of 2,400 mg/L. Despite large fluctuations in COD feed concentration, stable process performance was achieved. The anaerobic Expanded Granular Sludge Bed (EGSB) pre-treatment step effectively lowered the organic loading by 65 to 85%, thus lowering the MBR COD feed concentration to consistently below 750 mg/L. The overall MBR COD removal was consistent at an average of 96%, regardless of the effluent COD or changes in the hydraulic retention time (HRT) and organic loading rate (OLR). Combining a high-rate anaerobic pre-treatment EGSB with a Modified Ludzack-Ettinger (MLE) MBR process configuration produced a high quality permeate. Preliminary NF and RO results indicated an overall COD removal of around 97 and 98%, respectively. 相似文献
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