城市排水设施中恶臭源的产生及其治理对策的研究

城市排水设施中恶臭的产生有其必然性和极大的危害性,恶臭源的分布也具有一定的规律性。城市排水设施中产生的恶臭污染物主要是硫化氢气体。目前可以从恶臭源的抑制和收集处理两方面制定恶臭防治对策,采取向排水管道或窨井中加药或充氧等,抑制恶臭的产生;在污水处理厂或排水泵站中采用恶臭源封闭并用吸附法、氧化法和生物法集中除臭处理,均可获得较好的效果。     

Removal of estrogenicity in Swedish municipal sewage treatment plants

The human estrogen receptor alpha-test, hosted in a yeast strain, was used to quantify estrogenicity in three-week composite samples of untreated and treated effluents from 20 Swedish municipal sewage treatment plants. The treatment plants were selected to represent different treatment processes regarding chemical precipitation and microbial procedures. The discharge from Swedish domestic sewage treatment plants contained estrogenic compounds corresponding to <0.1-15 ng estradiol equivalents/L. Low levels of estrogenic activity were also found in a river receiving municipal effluents, 3.5-35 km downstream the outlet from a sewage treatment works. The range of estrogenicity in untreated, raw sewage effluents was found to be 1-30 ng estradiol equivalents/L. Generally, wastewater treatment reduced the estrogenicity and extended biological treatment was most effective in its removal. Activated sludge treatment tended to be more effective than trickling filters, whereas chemical precipitation using iron or aluminium salts without biological treatment showed little effectivity. The study showed that treatment methods in current use are able to eliminate or largely reduce estrogenicity in domestic wastewater.     

Characterization of sewage plant hydrocolloids using asymmetrical flow field-flow fractionation and ICP-mass spectrometry

Asymmetrical flow field-flow fractionation (AF⁴) was applied to characterize aquatic colloids from biological sewage plants and to infer information of colloidal loads, sources, and sinks within the plants, resp. the colloidal interaction with the aqueous phase and the sewage sludge. To characterize the colloids further, especially the distributions of colloid associated heavy metals, the AF⁴ system was coupled to an inductively coupled plasma mass spectrometer (ICP-MS). The size distribution is determined by AF⁴ with UV absorbance and fluorescence detection after a calibration by monodisperse polystyrene sulfonate standards (PSS). Samples from different sewage plants and from different depths and locations within a plant were compared. The fulvic/humic acid fraction with a particle diameter d_p<10 nm appeared to be comparable in all samples and decreases only slightly along the plants, whereas larger colloids with d_p>10 nm almost completely passed into the sewage sludge. The concentrations of the initial colloidal heavy metals decreased along the plants.     

Airborne enteric coliphages and bacteria in sewage treatment plants

The concentrations of airborne culturable microorganisms were determined in wastewater and sludge treatment processes of seven sewage treatment plants. Two types of coliphages, Salmonella and total viable bacteria were sampled by the BioSampler and the numbers of faecal coliforms and enterococci were obtained from the Andersen 6-stage impactor. The BioSampler recovered higher numbers of airborne coliphage viruses than has been measured with other liquid samplers in previous studies, suggesting that this sampler has improved efficiency for sampling airborne coliphages. Airborne coliphages were detected in many stages of the wastewater or sludge treatment process. The highest microbiological air contaminations were found in pre-treatment and aerated grit separation stages of the operation. This was attributed to aerosolisation of microorganisms by mechanical handling or forced aeration. Aeration and settling processes located outdoors caused low microbial concentrations, but the brush aerator released more microorganisms into the air. Our results emphasize the necessity for controlling the exposure of sewage workers to airborne microorganisms, especially in process areas that involve mechanical agitation or forced aeration of wastewater.     

Concentrations of nitrilotriacetate and certain metals in Canadian wastewaters and streams: 1971–1975

At 13 Ontario cities, representing a variety of populations and sewage treatment processes, grab samples were taken from the sewage treatment plant influent and effluent and from the receiving stream above and below the sewage outfall. The samples, taken once each month from November 1971 to March 1975 were analyzed for nitrilotriacetate (NTA), 9 metals, and phosphorus. From April 1971 to January 1973 household detergents in Canada contained an average of 6% NTA; after March 1973 they contained 15%. This increased usage of NTA was reflected in the NTA content of sewage influents, which rose from a median level of 1.3 mg l⁻¹ before the change to 3.2 mg l⁻¹ after the change. NTA levels in sewage effluent also increased somewhat, but much of the NTA disappeared in the sewage treatment processes. Even with the increased usage of NTA, the receiving streams below the sewage outfall contained only low levels of NTA: 97% of all samples during this period contained less than 0.5 mg l⁻¹, and the median concentration was 0.05 mg l⁻¹. Phosphorus concentrations in the sewages decreased at the time detergent compositions changed. Comparison of metal concentrations before and after the change, as well as metal-NTA correlation coefficients, failed to show clear evidence of an association between NTA concentration and metal concentration.     

Removal of dissolved estrogen in sewage effluents by β-cyclodextrin polymer

Substances with estrogenic activity are found in effluents of municipal sewage plants and dairy farms. These effluents have the potential to induce feminization in male fish. In this study, cyclodextrin polymers (CDPs) that are insoluble in both polar and non-polar solvents were selected for the removal of dissolved estrogens in the effluent of a municipal sewage plant. The removal capacity of CDPs was high in the order of β-CDP ≥ γ-CDP ? α-CDP. The mechanism for adsorption of estrogens to β-CDP was not only due to a host-guest interaction as molecular recognition by β-cyclodextrin (β-CD), but also due to adsorption by the polymer matrix. β-CDP of 0.2% (w/v) removed 17β-estradiol (E2) of about 70% from 10⁻¹¹ mol/L, and more than 90% from ≥ 10⁻¹⁰ mol/L. The removal ratios of E2 in the presence of cholesterols, which are contained at higher concentrations than estrogens in sewage effluents and are adsorptive competitor for β-CDP, were about 85% at a cholesterol/E2 molar ratio of 100 and > 90% at molar ratios of 0.1, 1, and 10. The effluent from a municipal sewage plant had estrogenic activity corresponding to 5.5 × 10⁻¹¹ molE2/L by yeast two-hybrid assay. The estrogens in the effluent were also removed > 90% by the β-CDP treatment. Therefore, β-CDP is able to remove dissolved estrogens over a wide range of concentrations in the presence of various contaminants such as wastewaters.     

Optimalization of coagulant dose in coagulation-flocculation of sewage

This article describes how the optimal coagulant dose in chemical treatment can be calculated from a limited number of raw sewage characteristics. Ferric chloride and aluminium sulphate were used as coagulants. In jar tests ten characteristics were determined in the sewage and for each separate sample of wastewater “optimal” coagulant doses were determined. There was a very high correlation between the “optimal” coagulant dose of aluminium sulphate and ferric chloride and one or two quality parameters of the influent. A comparison was made between aluminium sulphate and ferric chloride as coagulant. The findings were verified in two pilot plants. In one a constant coagulant dose m⁻³ influent was set; in the other plant the coagulant dose was also related to the orthophosphate content of the sewage. By this means a reduction of the coagulant dose was obtained of 35%, while on average the removal percentage of TOC was the same.     

污水处理厂水池结构设计问题探讨

近年来,在环保和治理工程快速发展的推动下,大型污水处理厂不断增多。在整个污水处理厂中,水池是较为重要的组成部分之一,它的结构设计质量优劣直接关系到污水处理效果。基于此点,本文就污水处理厂水池结构设计展开探讨。     

Field studies on coliphages and coliforms as indicators of airborne animal viral contamination from wastewater treatment facilities

The occurrence of animal viruses in the aerosol emissions of wastewater treatment facilities was evaluated by direct assay and by the use of coliforms and coliphages as indicator organisms. Coliforms and coliphages were compared and evaluated with regard to their suitability as indicators of airborne animal viral contamination from wastewater treatment facilities. Two plants, one with treatment by activated sludge and the other by trickling filtration, were studied. Field air sampling procedures used large-volume air samplers, with recirculation devices, and Andersen samplers. Airborne viruses were enumerated by a most probable number (MPN) procedure. Partially treated liquid sewage contained about 1.0 × 10² pfu l⁻¹ of animal viruses assayed on Buffalo Green Monkey (BGM) cells, 3.6 × 10⁵ and 5.0 × 10⁵ pfu l⁻¹ of coliphages, depending upon the E. coli host strain used for assay, and 2.0 × 10⁹ colonies l⁻¹ of coliform bacteria. No airborne animal viruses were recovered, airborne coliphage levels averaged 2.3 × 10⁻¹ and 3.0 × 10⁻¹ MPN m⁻³, coliforms from aerosol emissions were 2.1 × 10² colonies m⁻³. Ratios of coliphages to animal viruses indicate that wastewater treatment plants may be continuous sources of low level concentrations of animal virus aerosols. Evidence shows coliforms to be much less stable than coliphages in the airborne state. Coliphages may be a more acceptable indicator of airborne animal viral contamination than coliforms.     

河间束城污水处理厂工程投资效益分析

根据《"十二五"全国城镇污水处理及再生利用设施建设规划》,我国将在"十二五"期间大规模加大对污水处理厂的投资力度和建设力度,在此背景下,论文以河间束城污水处理厂工程为研究对象,对该污水处理厂的财务效益、社会效益和环境效益进行分析研究,从货币量化的角度分析该项目所带来的综合收益,为今后污水处理厂建设,特别是镇一级污水处理厂的建设提供借鉴。     

污水再生利用双膜法工艺浓水水质分析

分别对某生活污水处理厂及进水含有工业废水的混合污水处理厂的双膜工艺(CMF+RO)浓水水质进行了调查,结果表明:混合污水处理厂双膜工艺浓水中TDS、Mg2+、Ca2+、Cl-、SO42-、CODCr、TOC、BOD5、TP、NH3-N、TN均高于生活污水处理厂。对浓水中有机物组分的GC-MS分析表明,两个污水处理厂双膜工艺浓水中残存的有机物均属于难生物降解物质,以酚类和酯类为主,且混合污水处理厂双膜工艺浓水中残留有机物的组成较复杂。     

Elimination of pharmaceuticals in sewage treatment plants in Finland

The occurrence of eight pharmaceuticals (beta-blockers: acebutolol, atenolol, metoprolol and sotalol; antiepileptic: carbamazepine; fluoroquinolone antibiotics: ciprofloxacin, norfloxacin, ofloxacin) were assessed in the raw and treated sewage of 12 sewage treatment plants (STPs) in Finland. The average concentrations in the raw and treated sewage ranged from 100 to 1060 ng L(-1) and from <24 to 755 ng L(-1), respectively. The average daily loads ranged from 36 to 405 mg/1000 inh and from 2 to 302 mg/1000 inh, respectively. In the treatment plants, fluoroquinolones were eliminated by >80%. Carbamazepine was not eliminated during the treatment and in fact even higher concentrations were frequently found in the treated than in the raw sewages. The increase in concentration was shown to be most likely due to enzymatic cleavage of the glucuronic conjugate of carbamazepine and release of the parent compound in the treatment plant. The beta-blockers were eliminated in average by less than 65% and the elimination varied greatly between the treatment plants. Especially the dilution of raw sewage by rainwater and a consequent decrease in the hydraulic retention time of a treatment plant was found to deteriorate the elimination of the beta-blockers. The work shows that especially carbamazepine and the beta-blockers may reach the recipient waters and there is a need to enhance their elimination in the sewage treatment plants. In this attempt, a denitrifying biofilter as a tertiary treatment could be of minor importance since in this study it did not result in further elimination of the target compounds.     

小榄污水处理厂鼓风机房的技术改造

针对污水厂鼓风机运行过程中经常发生喘振、需频繁更换轴承以及CASS生物池的溶解氧较难调节等问题，通过技术改造和工艺调整，解决了改造前存在的问题，达到了节能降耗的目的。     

Monitoring the biological activity of micropollutants during advanced wastewater treatment with ozonation and activated carbon filtration

A bioanalytical test battery was used to monitor the removal efficiency of organic micropollutants during advanced wastewater treatment in the South Caboolture Water Reclamation Plant, Queensland, Australia. This plant treats effluent from a conventional sewage treatment plant for industrial water reuse. The aqueous samples were enriched using solid-phase extraction to separate some organic micropollutants of interest from metals, nutrients and matrix components. The bioassays were chosen to provide information on groups of chemicals with a common mode of toxic action. Therefore they can be considered as sum indicators to detect certain relevant groups of chemicals, not as the most ecologically or human health relevant endpoints. The baseline toxicity was quantified with the bioluminescence inhibition test using the marine bacterium Vibrio fischeri. The specific modes of toxic action that were targeted with five additional bioassays included aspects of estrogenicity, dioxin-like activity, genotoxicity, neurotoxicity, and phytotoxicity. While the accompanying publication discusses the treatment steps in more detail by drawing from the results of chemical analysis as well as the bioanalytical results, here we focus on the applicability and limitations of using bioassays for the purpose of determining the treatment efficacy of advanced water treatment and for water quality assessment in general. Results are reported in toxic equivalent concentrations (TEQ), that is, the concentration of a reference compound required to elicit the same response as the unknown and unidentified mixture of micropollutants actually present. TEQ proved to be useful and easily communicable despite some limitations and uncertainties in their derivation based on the mixture toxicity theory. The results obtained were reproducible, robust and sensitive. The TEQ in the influent ranged in the same order of magnitude as typically seen in effluents of conventional sewage treatment plants. In the initial steps of the treatment chain, no significant degradation of micropollutants was observed, and the high levels of dissolved organic carbon probably affected the outcome of the bioassays. The steps of coagulation/flocculation/dissolved air flotation/sand filtration and ozonation decreased the effect-based micropollutant burden significantly.     

Synthetic musk emissions from wastewater aeration basins

Wastewater aeration basins at publicly owned treatment works (POTWs) can be emission sources for gaseous or aerosolized sewage material. In the present study, particle and gas phase emissions of synthetic musks from covered and uncovered aeration basins were measured. Galaxolide (HHCB), tonalide (AHTN), and celestolide (ADBI) were the most abundant, ranging from 6704 to 344,306 ng m⁻³, 45-3816 ng m⁻³, and 2-148 ng m⁻³ in the gas phase with particle phase concentrations 3 orders of magnitude lower. The musk species were not significantly removed from the exhaust air by an odor control system, yielding substantial daily emission fluxes (∼200 g d⁻¹ for HHCB) into the atmosphere. However, simple dispersion modeling showed that the treatment plants are unlikely to be a major contributor to ambient air concentrations of these species. Emission of synthetic musk species during wastewater treatment is a substantial fate process; more than 14% of the influent HHCB is emitted to the atmosphere in a POTW as opposed to the <1% predicted by an octanol-water partition coefficient and fugacity-based US EPA fate model. The substantial atmospheric emission of these compounds is most likely due to active stripping that occurs in the aeration basins by bubbling air through the sludge.     

The trophic potential of sewage effluent resulting from various levels of treatment

On Italy's Adriatic coast there are a large number of aerobic sewage treatment plants, the majority of which do not feature high-efficiency tertiary treatment processes. In order to investigate the relationship between these plants and the trophic potential of the water they discharge, we constructed a pilot plant capable of reproducing the sewage treatment process with four different levels of purification on a rising scale of efficiency in terms of the best-known macronutrients (nitrogen and phosphorus). Water samples taken at various points on the plant for each of the four operating modes underwent laboratory assessment to establish their trophic potential in relation to a dinoflagellate alga (Prorocentum micans). We were thus able to demonstrate that after biological treatment alone the sewage water has a high eutrophication effect; this gradually decreases as the nutrients are removed and virtually disappears when the plant is providing maximum removal at full efficiency.     

The effects of tertiary wastewater treatment on the prevalence of antimicrobial resistant bacteria

The effects of tertiary wastewater treatment on the prevalence of antimicrobial resistant bacteria were investigated in two large-scale municipal treatment plants during a period of six months. Total and relative numbers of resistant bacteria were determined in raw sewage, treated sewage and anaerobically digested sludge by bacteriological counts on media selective for coliforms (MacConkey agar) and Acinetobacter spp. (Baumann agar). In addition, the level of antimicrobial susceptibility was determined by the disc-diffusion method in 442 Acinetobacter isolates identified by colony hybridisation with a genus-specific DNA probe. Independent of the different antibiotics and media used, the total numbers of resistant bacteria in treated sewage were 10-1000 times lower than in raw sewage. Based on linear regression analysis of data on bacteriological counts, the prevalences of antimicrobial-resistant presumptive coliforms and Acinetobacter spp. in treated sewage and digested sludge were not significantly higher compared with raw sewage. On the contrary at one plant, statistically significant decreases were observed in the prevalence of ampicillin-resistant presumptive Acinetobacter spp. (p = 0.0188) following sewage treatment, and in the prevalence of either ampicillin-resistant presumptive Acinetobacter spp. (p = 0.0013) or ampicillin- and gentamicin-resistant presumptive coliforms (p = 0.0273 and p = 0.0186) following sludge treatment. The results obtained by bacteriological counts were confirmed by antimicrobial susceptibility testing of Acinetobacter isolates. Based on logistic regression analysis, isolates from treated sewage and digested sludge were generally not significantly more resistant compared with isolates from raw sewage. Based on these evidences, it was concluded that tertiary wastewater treatment did not result in a selection of antimicrobial resistant bacteria.     

污水处理厂中建筑设计的协调统一

介绍了某污水处理厂的建筑设计,阐述了该污水厂的污水处理区、污泥处理区和生产辅助区的布置,分析了污水处理工艺对建筑的影响,探讨了该厂区的规划建筑特色,积累了污水处理厂的建筑设计经验。     

The droplet size and height effects in ammonia removal in a spray tower

Ammonia removal from lime treated sewage by spraying down through an unpacked air stripping tower was carried out on pilot plant scale. The effect of droplet size, tower height and tower geometry on ammonia removal was studied together with an instantaneous ammonia release obtained at the spraying nozzle, which was dependent on the nozzle design.     

污水处理厂建设监理工作要点探析

污水处理厂是城镇污水处理的终端,做好污水处理厂建设工程监理控制工作,有利于加快污水处理厂建设。本文对污水处理厂建设监理工作要点进行探析,从测量放线、地基与基础工程、主要构筑物施工以及设备安装与调试方面做了详细阐述。