污水微生物气溶胶污染空气的指示菌选择

为了选择污水微生物气溶胶的现场调查指示菌,本文对曝气池、滴滤池及氧化塘三种类型污水处理厂附近空气中的细菌总数、真菌总数及肠道G(—)杆菌作了定量调查。结果表明以大肠菌群或肠道G(—)菌作为指示菌是适用的。     

某污水处理厂空气气溶胶中微生物检测

未经净化污水的排放引起水、食物型流行或爆发已有很多记述〔１－３〕，在污水处理过程中产生的微生物气溶胶可对周围空气造成污染虽然研究不多，但在国内外新近亦已引起重视〔４－５〕，上海医科大学郁庆福等曾对曝气池、滴滤池和氧化塘三种常用的污水生物处理厂周围空气气溶胶中微生物进行了调查，确证存在以Ｇ（－）杆菌为主的微生物气溶胶的污染〔６〕，用曝气的生物学方法处理污水产生的空气气溶胶而造成的空气污染尤其值得关注〔５〕。本调查对某日间处理１５万吨的大型污水处理厂露天开放式运作的反应池、污泥浓缩池和厂前区进行了多…     

城市污水处理厂恶臭和微生物气溶胶逸散研究

为了解污水处理厂恶臭及微生物气溶胶的散逸情况,对北京市某城市污水处理厂的格栅间、曝气池、污泥浓缩池和污泥脱水机房恶臭和微生物气溶胶进行检测,硫化氢和氨浓度最高的是污泥浓缩池和污泥脱水机房,其次是曝气池,最低的是格栅间。而曝气池逸散的异养细菌和真菌浓度最高,其次是污泥脱水机房,浓度最低的区域为格栅间和污泥浓缩池。各区域逸散出的优势异养细菌主要为假单孢菌(Pseudomona)和芽胞杆菌(Bacillus),而毛霉(Mucor)和青霉(Penicillium)为优势真菌菌属。污水处理厂恶臭和微生物气溶胶的产生和逸散机制存在差异,曝气作用更利于微生物从污水中的逸散。     

污水微生物气溶胶吸入感染危险性探讨

为了解污水微生物气溶胶对居民可能造成的危害,对污水厂附近居民住宅进行测定,结果在各层楼的窗口和阳台的空气中均分离到大肠菌群等 G(-)杆菌。测定污水微生物气溶胶颗粒大小发现:直径1～2μm占17.45—19.03％,2～6μm占60.90～61.67％,故至少有78.35～80.70％气溶胶能吸入至下呼吸道。污水微生物气溶胶颗粒大小组成的特点,增加了对下呼吸道的危险性。近年来 G(-)杆菌引起呼吸道、伤口等感染有增长趋势。作者详细讨论了这些细菌的致病性并认为污水厂附近居民吸入来自污水的微生物气溶胶,或通过污染创口或食入途径均可能致病。研究结果认为污水厂产生的微生物气溶胶对人的危害性不容忽视,是一个必须引起注意的环境保护新问题,建议有关部门采取预防措施并纳入环境保护条例之中。     

污水处理中微生物气溶胶扩散的检测

随着经济的发展和人民生活水平的提高 ,污水排出量增加 ,由污水引起水、食物的污染造成疾病的流行或爆发记述很多。但污水处理过程中微生物对空气的污染报道国内较罕见 ,我们对此进行了一些探讨。一、对象与方法1 污染指标菌选择 :选用大肠杆菌作为空气中来自污水的微生物指标 ,因其来源于粪便 ,污水中普遍大量存在 ,空气中正常情况下难以检出 ,故空气中检出时 ,应考虑污水气溶胶污染的可能。2 .对象 :安丘市污水处理厂曝气池 ,日处理污水 5 40 0ｔ,选择无污水流入的青云山公园人工湖作对照。3 .方法 :在对象下风向 1、2、5、10、2 0、5 0、…     

农民居住区流行病的感染与污灌的关系

最近Hichey等的调查表明,含有不同毒力的病原菌气溶胶在污水曝气过程中可排放到附近的人群居住区。污水气溶胶不仅在污水处理过程中形成,在污水灌溉中,特别是在使用喷洒系统时也会形成。一些报告证明污水喷洒灌溉系统附近地区空气中有病原微生物的扩散,并讨论了对     

质谱仪鉴定革兰氏阴性杆菌的评价

目的：比较质谱仪鉴定革兰氏阴性杆菌结果与全自动微生物鉴定仪的一致性。方法：连续收集革兰氏阴性杆菌371例,同时使用质谱仪和全自动微生物鉴定仪对其进行鉴定,分别在菌属和菌种的水平比较两者鉴定结果的一致性。结果：两种方法鉴定革兰氏阴性杆菌的一致性很高,菌属和菌种的一致性分别为97.0%和93.8%,Kappa一致性检验结果分别为0.828和0.773。结论：质谱仪鉴定革兰氏阴性杆菌与全自动微生物鉴定仪一致性很好。     

某污水处理厂微生物气溶胶污染调查

目的了解某污水处理厂空气污染状况。方法从微生物学角度连续二年进行多次的空气气溶胶中微生物检测。结果该厂空气中检出致病菌（金黄色葡萄球菌和肺炎双球菌）及条件致病菌（大肠杆菌和草绿色链球菌等）,且大部分菌谱与污水中菌谱相同。厂内各采样点的细菌总数和大肠菌群数明显高于清洁对照点。结论厂内空气已受到生产过程中产生的微生物气溶胶的污染。     

污水处理厂曝气池周围空气中微生物的测定与评价

采用平皿沉降法，对石家庄市桥西污水处理厂曝气池周围空气中细菌和真菌的数量进行了全年４个季度的测定，分析微生物数量受环境条件的影响，为污水处理行业的卫生防护及预防疾病和建立行业标准提供依据。     

某污水处理厂微生物气溶胶污染调查

目的了解某污水处理厂空气污染状况.方法从微生物学角度连续二年进行多次的空气气溶胶中微生物检测.结果该厂空气中检出致病菌(金黄色葡萄球菌和肺炎双球菌)及条件致病菌(大肠杆菌和草绿色链球菌等),且大部分菌谱与污水中菌谱相同.厂内各采样点的细菌总数和大肠菌群数明显高于清洁对照点.结论厂内空气已受到生产过程中产生的微生物气溶胶的污染.     

Enteroviruses in sewage: comparison of different technologies for wastewater treatment and reuse

Seven wastewater treatment plants were twice sampled to compare their different technologies for the removal of enteroviruses. These technologies are extended aeration, oxidation ditch, stabilization pond, aerated stabilization pond, submerged fixed film reactor, trickling filter and trickling filter followed by activated sludge in El-Serw, El-Rahamna, El-Adliya, Daqahla, El-Barashiya, Sohag and El-Fayoum wastewater treatment plants, respectively. Virus counts of raw sewage ranged between 2.7 x 10(3) and 20 x 10(3) PFU/L and for treated effluents was between 0 and 6 x 10(3). The percentage of virus removal was varied where trickling filter and tickling filter followed by activated sludge reduced virus counts by 95.7 and 99.9, respectively. Extended aeration removed 64.2%, oxidation ditch 66.5%, stabilization pond 44.9%, aerated stabilization pond 13.34%, and submerged fixed film reactor removed 53.4%. The neutralization test revealed five types of enteroviruses, poliovirus types 1,2 and 3 and Coxsackievirus types B4 and B5. The isolated polioviruses were vaccine strains. From the frequency distribution of the detected viruses, poliovirus type 2 was the most dominant.     

Broadcast of microbial aerosols by stacks of sewage treatment plants and effects of ozonation on bacteria in the gaseous effluent.

In the aeration basins of sewage treatment plants, compressed air is supplied to diffusers near the bottom of tanks to aid in the conversion by aerobic bacteria of dissolved and suspended solids of sewage into particles that will settle. Air bubbles breaking at the air-water interface will aerosolize bacteria that concentrate in the uppermost microlayer. The microbiological output of a plant in New York City with such a system was monitored. Samples of the gaseous effluent were collected inside the aeration building, inside the building''s stack, 300 meters upwind (background sampler), and 300 meters downwind (test sampler), using Andersen samplers. Among the genera identified in the atmosphere in and around the plant were Mycobacterium, Klebsiella, and Streptococcus, all potentially pathogenic. The disinfection power of ozone, which is generally used for odor control, was also tested. Samples were taken from the ozone mixing chamber in the stack of the thickentng tank building. No significant difference in general bacterial counts could be detected at different levels of ozone production. It appears that in the air, ozone is an ineffective bactericidal agent. Results in this preliminary study demonstrate the need to evaluate the hazard of microbial aerosols generated by sewage treatment plants similar to the one studied. The possibility of such hazards is of special interest where facilities are located upwind of populations especially susceptible to infections, because of age of debility. Correlations with epidemiologic data are indicated.     

氧化塘对有机致突变物净化效果的研究

本文研究1988～1990年不同季节城市污水经生物氧化塘处理前、后水及鱼体中有机物的致突变活性,研究发现处理后的水及鱼体活性有所减弱,经统计学证明差异显著。提示氧化塘处理对有机污染物致突变活性具有一定的净化作用。     

Maximizing total nitrogen removal from onsite-generated wastewater

The research reported here examined the use of hydraulic loading strategies to maximize nitrogen removal from onsite-generated wastewater. These strategies are made practical by the inherently intermittent flow of onsite-generated wastewater. Experimentation was conducted at the Western Regional Wastewater Pretreatment Facility in Montgomery County, Ohio, with an established, full-scale onsite wastewater treatment system rated at 500 gallons per day. The onsite wastewater treatment unit was fed primarily with domestic wastewater that had passed through fine screens and grit removal. The dosing schedule was intermittent, representing what would be expected from onsite-generated wastewater. Oxidation occurred in the aeration tank and potentially on the solid-liquid filtration socks within the aeration tank. All major wastewater characterization parameters were monitored during the approximately one-year study, including five-day biochemical oxygen demand (BOD;), total suspended solids (TSS), nitrate, total nitrogen, pH, and alkalinity. Excellent removal of BOD5 and TSS resulted, with the effluent concentration of each parameter substantially and consistently below 10 mg/L for all operating conditions. Excellent total nitrogen removal occurred, typically to below 10 mg/L of nitrogen when the instantaneous flow of wastewater was low, even when the daily hydraulic loading was high. The removal of nitrogen was attributed to microbial biodegradation. This result indicates that the onsite wastewater treatment unit has an inherent denitrification capacity that can be matched with an equalized-hydraulic-loading strategy. The practical ability to equalize and reduce instantaneous loading results from the inherently intermittent nature of the flow associated with onsite wastewater treatment.     

Studies on the effects of ionization on bacterial aerosols in a burns and plastic surgery unit.

The effect of the ionization of the air on the decay of bacterial aerosols was studied in a Burns and Plastic Surgery Unit. Ions were generated by free corona needles. The air content of bacteria measured by settle plates was found to be smaller during the ionization period than during the controls period. The number of individual phage typed Staph. aureus strains was especially found to be lower during ionization. The opposite potential increased the disappearance of bacteria from the air. The size of skin particles carrying bacteria is not optimum, but the results obtained show that the ionization may have applications in controlling airborne infection.     

Energy forest irrigated with wastewater: a comparative microbial risk assessment

In this study, risks for human infection associated with irrigation of municipal wastewater on short rotation willow coppice (Salix) were evaluated in three countries. The aim was also to determine the reduction of indicator organisms and pathogens in the treatment plants. Two of the field sites were chosen for further evaluation by QMRA (quantitative microbial risk assessment) applied to three scenarios: accidental ingestions of wastewater, exposure to aerosols and ingestion of groundwater. The risks of infection for bacteria (Salmonella), virus (rotavirus) and protozoa (Giardia, Cryptosporidium) were characterised as probability of infections per exposure and number of infections per year.     

Occurrence of 'thermophilic' campylobacters in sewage and their removal by treatment processes

Removal of thermophilic campylobacters from sewage at three different stages of treatment at a trickling filter sewage works has been assessed. Samples of incoming sewage, primary sedimentation effluent and final effluent were taken daily from 06.00 h to 20.00 h for 5 consecutive days and the numbers of campylobacters determined by using a most probable number method. Each sample was cultured using 2 h pre-enrichment followed by enrichment in Preston broth for 48 h and detection by plating. Over 78% of the incoming campylobacters were removed after primary sedimentation and less than 0.1% remained in the final effluent. Campylobacter jejuni biotype I and biotype II constituted 81.5% and 15.9% respectively of the 232 isolates tested. Serotypes common in sewage were common in human faeces. It appears that the trickling filter sewage works removes most of the campylobacters entering the sewage works, but large numbers, estimated to be approximately 10(10), are released into the environment daily from a local sewage works.     

Chemical treatment of textile wastewaters: statistical characterization,colour and sulfide removal

One of the major problems encountered in the textile industry is production of highly colored large volumes of wastewater. It is often not possible to predict the characteristics of textile wastewaters by using reported values in the literature because every textile industry is unique with respect to the type of production and the technology and chemicals used in production. Furthermore, the concentrations of pollutants in textile wastewaters vary according to the wastewater management practices and amount of water used in the production. In the first part of this study, wastewater characteristics of a cotton mill textile industry were determined by using the normal and log-normal II distribution functions for flow, COD, TOC, pH and colour. These parameters were measured in the effluent of the equalization tank and the statistical fits were evaluated by using the chi-Square test. It was found that flow and TOC values fitted normal distribution; COD values fitted log-normal II distribution. On the other hand, pH and colour did not fit in to aforementioned distributions. In the second part of this study, the treatment of textile wastewater by coagulation/flocculation/precipitation (CFP) was investigated. Lime, iron and aluminum salts with anionic polielectrolite combination were used as coagulants. Aluminum salts and the combination FeSO4 + lime + polielectrolite were used to remove the colour from mixed textile wastewaters, successfully. On the other hand, FeSO4 + lime + polielectrolite was more effective than aluminum salts to remove the colour from wastewater of indigo dyeing process. In the third part of this work, the removal of sulfide arising from indigo dyeing was investigated. Sulfide removal was accomplished by chemical oxidation and catalyzed air oxidation and removal efficiencies up to ninety percent were found. Chemical oxidation using sodium hypochlorite resulted in color removal too; however, dosages of hypochlorite have to be carefully monitored in order to avoid toxic effects of excess chlorine in water.     

Behavior of drug resistant fecal coliforms and R plasmids in a wastewater treatment plant

Fecal coliforms were isolated from the inlet, the primary sedimentation tank, the activated sludge digestion tank, the final settling tank, the outlet and the return activated sludge drain at the municipal wastewater plant in Ube City, and examined for drug resistance and presence of R plasmids. Drug concentrations employed to distinguish resistant isolates from sensitive isolates were 25 micrograms/ml for tetracycline, kanamycin, chloramphenicol and streptomycin, 50 micrograms/ml for ampicillin, nalidixic acid and rifampicin, and 200 micrograms/ml for sulfisoxazole, respectively. Of a total of 900 isolates, 45.7% were drug resistant and 51.1% of them carried R plasmids. The further along that wastewater had progressed through the treatment process the greater the tendency was for appearance of the multiresistant isolates. These isolates also were shown to simultaneously carry transferable R plasmids. Observed resistant patterns of R plasmids were mainly multiple and encoded to resistance to tetracycline, chloramphenicol, streptomycin and sulfisoxazole. It became clear that multiplication of R plasmids took place in the activated sludge digestion tank. This study show that drug resistance transfer mediated by these R plasmids may occur in actual wastewater treatment plants.