Behavior of Antibiotic-Resistant Fecal Coliforms in the Stream of a Sewage Treatment Plant in Tokyo

We are confronting a new threat in the prevalence of antibiotic-resistant bacteria followed by epidemic spread in aquatic environments in metropolitan areas because damage from river floods is increasing remarkably in Japan due to global extreme weather. The sewer penetration rate is about 100% in Tokyo and reclaimed water from sewage treatment plants accounts for over 50% of all water in both the down- and mid-stream areas of local rivers. The water quality of these rivers, which contain microflora, seems to be seriously affected by reclaimed water. In this study, we collected water samples on July 17, 2018 and examined the behavior of antibiotic-resistant fecal coliforms in the stream of a sewage treatment plant in Tokyo. Extended-spectrum β-lactamase (ESBL)-producing fecal coliforms with encoding genes were found;the CTX-M-1, CTX-M-9, TEM, and SHV groups were found to have survived in the final effluent to the river after sterilization with sodium hypochlorite.

The Effect of Physical Factors on Fecal Coliform Viability Rate in Sewage Sludge

Experiments were conducted on the survival rate of fecal coliform after spreading the sewage sludge for desiccation on sludge beds in an open field throughout the year. The ambient temperature, humidity, sunlight intensity and solar radiation were measured during the period of sludge desiccation. The maximum average temperature, sunlight intensity and solar radiation were recorded throughout the year. During May and August the minimum microbial counts were recorded after four weeks of sludge desiccation. Relative humidity did not have significant effect on survival rate. The minimum microbial counts were taken after four weeks of sludge drying. When the sludge was mixed with three different media, the maximum count of fecal coliform was presented when soil mixed with sludge and irrigated with treated sewage effluent (TSE). When soil mixed with sludge irrigated with well water, the number of fecal coliform count dropped significantly. The minimum count occurred when compost was used instead of sludge. This was a clear indication that the source of contamination was from sludge and was mostly contributed by the TSE irrigation. The use of dried sludge after four weeks of treatment had the lowest fecal coliform count and was safe to be used as fertilizer for farming. Oman is located in a semi-equatorial belt with arid environmental conditions which are ideal for elimination of microbial pathogens. Thus, sludge desiccation in such environmental conditions, specifically during the hot months of the year, is perfect for such practice.

Performance of a Horizontal Flow Constructed Reed Bed Filter for Municipal Wastewater Treatment: The Case Study of the Prototype Installed at Gaston Berger University, Saint-Louis, Senegal

In Saint-Louis, Senegal, a constructed wetland with horizontal flow reed beds (FHa and FHb) has demonstrated significant efficacy in treating municipal wastewater. Analyzing various treatment stages, the system showed only a slight temperature variation, from an influent average of 26.3°C to an effluent of 24.7°C. Electrical conductivity decreased from 1331 mS/cm to 974.5 mS/cm post-primary treatment, with suspended solids (SS) dramatically reduced from 718.9 mg/L to 5.7 mg/L in the final effluent. Biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) saw a notable decrease, from initial levels of 655.6 mg/L and 1240 mg/L to 2.3 mg/L and 71.3 mg/L, respectively. Nitrogenous compounds (N-TN) and phosphates () also decreased significantly, indicating the system’s nutrient removal capacity. Microbiological analysis revealed a reduction in fecal coliforms from 7.5 Ulog/100ml to 1.8 Ulog/100ml and a complete elimination of helminth eggs. The presence of Phragmites and Typha was instrumental in enhancing these reductions. The system’s compliance with the Senegalese standards for disposal into natural environments, WHO recommendations for unrestricted water reuse in irrigation, and the European legislation for water reuse was established. The effluent quality met the stringent criteria for various classes of agricultural reuse, illustrating the system’s potential for sustainable water management. This wetland model presents a robust solution for water-stressed regions, ensuring environmental protection while supporting agricultural needs. The study calls for ongoing research to further refine the system for optimal, reliable wastewater treatment and water resource sustainability.

酶底物光谱法与酶底物法检测水中大肠菌群的比较分析

采用新型酶底物光谱法和酶底物法对不同类型水样中总大肠菌群、大肠埃希氏菌及粪大肠菌群指标进行同步检测。两种方法各有优势,采用SPSS软件对检测结果处理后进行配对t检验,结果显示:两组总大肠菌群的数据P=0.057,相关系数r=0.904;两组大肠埃希氏菌的数据P=0.593,相关系数r=0.972;两组粪大肠菌群的数据P=0.136,相关系数r=0.986,表明两种检测方法具有相关性,且没有统计学意义上的显著性差异。采用酶底物光谱法检测有证质控样品,总大肠菌群、大肠埃希氏菌、粪大肠菌群的检测结果均在质控样真值范围内,证明该方法检测准确度符合要求。酶底物光谱法与酶底物法相比,反应原理类似,操作更加简便,具有仪器自动化和智能化快速检测、判读、存储、联网传输数据等优点,可满足实验室常规检测需求,在应急突发事件现场检测方面有较强的运用前景和优势。

不同废水中活性氯与粪大肠菌群的相关性研究

活性氯具有特定的氧化性,能使微生物细胞内酶活性降低,导致细胞失活,从而使微生物死亡;在疫情期间,大量使用含氯消毒剂杀毒,对生态环境有着一定的影响,本文选取疫情期间废水中粪大肠菌群和总余氯含量为代表,直接测定了不同水样中所含粪大肠菌群以及使用哈希DR300便携式快速测定仪测定个水样中总余氯的含量,得到了废水中总余氯含量与粪大肠菌群具有一定的线性相关性。

固定酶底物法测定水中粪大肠菌群的优点及影响因素分析

固定酶底物法是一种常用的检测水中粪大肠菌群的方法,其优点包括操作简便、检测灵敏度高、结果可靠等。然而,该方法的准确性和稳定性受到多种因素的影响,如底物浓度、酶反应条件、水样处理等。为了进一步提高该方法的检测准确性和稳定性,研究人员可以从优化底物选择、优化反应条件、优化水样处理等方面进行探索。介绍了固定酶底物法测定水中粪大肠菌群的基本概念和研究背景,重点探讨了该方法的优点和影响因素。通过优化底物选择、反应条件和水样处理等方面的研究,进一步提高该方法的准确性和稳定性,有助于更好地应用固定酶底物法来监测水质,保障公共卫生安全。

Prevelance of total coliforms, faecal coliforms and <i>E. coli</i>in Rawalpindi vegetable markets

Nutritional value of vegetables and high prices of meat and meat originated food compel common people to consume plant originated food particularly salad vegetables. Microbial population of vegetable surfaces contains a large number of pathogenic bacteria including members of Enterobactereace like Escherichia coli (E. coli). A survey was conducted in three major markets of Rawalpindi, Pakistan. Tomato, lettuce, cabbage and cucumber samples were collected from three shops of each market. Each vegetable was analysed as unwashed and washed for total coliforms, faecal coliforms and E. coli by FAO (Food Quality Manual). About two hundred and fifty E. coli isolates were preserved, serotyped for presence of O157 serotype. Total coliforms, faecal coliforms and E. coli count exceeded the permissible limits in most samples. The highest Total coliforms were associated with cabbage (3.78 log10 cfu/g). Cucumber was the least contaminated by Total coliforms (2.15 log10 cfu/g). E. coli was detected in tomato, lettuce, cucumber and cabbage. Washed samples showed reduced bacterial population. Seventy six isolates of E. coli were biochemically characterized and serotyped for O157 antigen. A majority of strains could not be identified by serotyping. These findings conclude with high potentially pathogenic microbial load on salad vegetables and urge for preventive action on priority basis.

Coliforms and Helminth Eggs Removals by Coagulation-Flocculation Treatment Based on Natural Polymers

Wastewater from a municipal wastewater treatment plant (Mexico) was treated by a coagulation-flocculation using natural gums. The residual water was characterized in terms of organic load, and biological contaminants, i.e. total Coliforms (TC), fecal Coliforms (FC) and helminth eggs (HE). The sample has values of 2.8 × 107 MPN/100 ml, 8.48 × 106 MPN/100 ml and 470 HE/L is regarded to TC, FC and HH, respectively. The HE identified in the wastewaters were Diphyllobothrium latum, Ascaris lumbricoides, Hymenolepis nana and Toxocara canis. From several gums, Hydroxypropyl triammonium chloride guar gum (HPTAC-guar) was selected as the most adequate coagulant-flocculant for the class of municipal wastewater (MWW). A diminution of 82% for TC, 94% for FC and 99% for HE was obtained. Besides, the reduction of chemical oxygen demand (COD) and turbidity removals were 46% and 39% respectively. The natural gum mixed with Ca(OH)2, obtained removals of 52% for TC, 100% for HE, 47% for COD and 30% for turbidity.

Characterization of Springtime Coliform Populations at the End Creek Wetland Restoration (Union Co., Oregon, USA): A Three-Year Study

In 2005, a 550-acre tract of agricultural land containing two small streams near La Grande, Oregon was registered in the U.S. Federal Wetlands Reserve Program. This designation was part of a plan to reclaim and restore the wetland to its natural state. Initial efforts at the End Creek Restoration Project restored both End Creek and South Fork Willow Creek to a natural course through rechanneling, and several plantings had restored some of the native flora. Since its establishment, the End Creek streams and floodplain have become a reserve for summer steelhead (Oncorhynchus mykiss), a threatened anadromous salmonid, and many migratory birds. The threatened Columbia Spotted Frog has also established itself in some of the ponds. As part of an effort to establish a baseline for water quality, we monitored total springtime coliform and fecal coliform bacteria in three of the End Creek ponds for three years. The results of this study indicate that, throughout any given spring, the numbers of both coliform and fecal coliform bacteria can fluctuate markedly among ponds on any given day, and that in any particular pond the numbers fluctuate from week to week. In addition, our analysis suggests that in early spring, the numbers of these organisms also fluctuate from year to year. The causes of these fluctuations are not well understood, but are expected to reflect both springtime flooding and the migrations of source animals such as waterfowl and cervids. Information gathered from this study will help inform future management activities on the wetland.

Assessing the East Bay of Galveston Bay, Texas for Coliform Bacteria in Recreational Water

The Galveston Bay beach is a widely used recreational area that remains a concern in terms of water quality. There are many factors that contribute to its pollution such as fecal matter entering the bay due to overflow of the sewage system and run offs. Thus, evaluating the water quality for fecal matter and other pollutants is continuously monitored by citizen scientists and research groups throughout the Galveston Bay. The investigation utilizes the colorimetric response of coliform at three test sites along the East Bay of Galveston. Each response is positive for coliform that may indicate the presence of fecal matter. Other scientists have denoted the presence of fecal matter in the Galveston Bay at two sites using enterococci indicator which may be more associated with human fecal matter. The analyses show that the recreational water is likely not a threat since its levels were low. However, the need for analyses based on EPA protocols and standards is necessary to better access water pollution due to fecal matter in the Galveston Bay area.

秸秆对猪粪静态兼性堆肥无害化和腐熟度的影响

为促进猪粪静态兼性堆肥产品无害化和腐熟,通过添加玉米秸秆调控堆体物理结构特性和碳氮比,采用传统自然发酵方式进行为期90d的静态兼性堆肥试验,分别设置纯猪粪处理(P)和秸秆调控处理(PC)研究静态兼性堆肥过程腐熟度指标、粪大肠菌群以及微生物群落结构演变特征。结果表明,秸秆调控增加了堆体孔隙率(提高19.41%),促进氧气向堆体内部扩散,增强了好氧微生物对有机质的降解,降低NH_(4)^(+)-N,可溶性有机氮(dissolved total nitrogen,DTN)等植物毒性物质含量,提升了堆肥腐熟度,两组处理堆肥产品种子发芽指数分别为40.84%(P)和114.60%(PC)。静态兼性堆肥经过30~40 d自然发酵后,粪大肠菌群数量达到卫生安全标准,堆体温度、NH_(4)^(+)-N和有机酸含量均会影响粪大肠杆菌的活性。堆体中微生物以厚壁菌门、放线菌门、变形菌门等与木质纤维素降解相关的菌门为优势菌门,堆体自上而下由好氧菌属演替为厌氧菌属,并形成好氧、兼性、厌氧的微生物分层。秸秆调控增加了堆体的好氧区域,促进和提高了猪粪静态兼性堆肥无害化和腐熟度。

尾菜再生水不同灌溉处理对土壤理化性质及粪大肠菌群分布的影响

为探讨尾菜再生水与自来水不同灌溉处理对土壤理化性质和指示性病原菌分布的影响,采用室内土柱淋溶试验,设置充分灌溉(田间质量持水率的90%)和非充分灌溉(田间质量持水率的70%)2个灌水梯度,18 d为一个灌水周期,累计灌溉16期,分别在第72、144、216、288 d进行分层取样,研究再生水在不同灌溉条件下土壤质量的时空分布特征,为尾菜再生水农田回用提供理论依据及实践基础。结果表明,与自来水灌溉相比,再生水灌溉条件下,无论是充分灌溉还是非充分灌溉,均显著提高表层土壤可溶性盐(EC)含量和粪大肠菌群(FDC)数量,对土壤pH值无显著影响;提高土壤总氮(TN)、总磷(TP)、总钾(TK)和有机质(OM)含量,随着灌溉次数的增加,土壤营养元素在各土层表现出一定的累积效应,且有向深层土壤迁移的趋势;相关性分析表明,FDC与pH、EC、TN、TP、TK呈显著正相关(P<0.05),与OM呈正相关(P>0.05)。综上所述,尾菜再生水长期灌溉有利于土壤TN、TP、TK和OM含量的累积,一定程度上增加土壤养分,提高土壤肥力,但存在盐害和致病菌污染风险。

酶底物法和多管发酵法在废水粪大肠菌群检测中的对比

近年来,酶底物法被广泛应用于水质总大肠菌群、粪大肠菌群和大肠埃希氏菌的检测分析,从而有效地应对突发环境事件。本文结合酶底物法和多管发酵法的优缺点,对二者检测结果的相关性进行试验验证,并分析酶底物法的主要影响因素。研究表明,在粪大肠菌群检测中,酶底物法结果与传统的多管发酵法相关性很好,温度是酶底物法的主要影响因素。酶底物法操作简便,适用于突发环境事件的应急监测。

城镇污水处理厂消毒处理技术的探讨

2020年2月1日,生态环境部印发《关于做好新型冠状病毒感染的肺炎疫情医疗污水和城镇污水监管工作的通知》(环办水体函[2020]52号),其中特别指出“地方生态环境部门要督促城镇污水处理厂切实加强消毒工作,确保出水粪大肠菌群数指标达到《城镇污水处理厂污染物排放标准》(GB 18918-2002)要求”。目前我国城镇污水处理厂所采用的消毒处理技术主要包括紫外、臭氧、次氯酸钠、二氧化氯,以及这些处理方式的组合。其中次氯酸钠消毒是目前污水处理厂应用最多的消毒处理方式,然而对于次氯酸钠消毒的工艺参数和运行效果尚缺乏统一的认识,在次氯酸钠投加量、消毒接触时间等关键参数上均存在问题,综述了次氯酸钠投加量,消毒接触时间,水温,氧化还原电位(ORP),氨氮浓度等参数对次氯酸钠消毒效果影响的研究,以期为城镇污水处理厂消毒杀菌提供理论指导。

基于纸片法评估水质样品的色度对粪大肠菌群测定的影响

为了评估水质样品的色度变化对粪大肠菌群测定的干扰,采用纸片法对7个色度样品进行检测分析。结果显示:在接种粪大肠菌群数一致且菌液无稀释的情况下,随着水质样品色度的增加,可判读的阳性纸片数会逐渐减少,当样品色度增加到32倍、64倍、128倍、256倍和512倍时其纸片的阳性反应均显示不可判读。以色度0样品的粪大肠菌群测定值为参比,色度1样品的粪大肠菌群测定值与其无显著性差异,其余5个样品(色度2、色度3、色度4、色度5和色度6)的粪大肠菌群测定值存在极显著差异。水质样品色度变化会干扰纸片法阳性纸片的判读,从而在一定程度上降低其测定有色水质样品粪大肠菌群结果的准确性和可靠性。

检测时间和保存方式对饮用水源水中粪大肠菌群测定的影响

研究了检测时间、保存方式和分析方法对饮用水源水中粪大肠菌群检测结果的影响。通过在不同季节采集样品,采取常温保存、冷藏保存、不同的检测时间间隔和不同的检测方法4种处理方式,对粪大肠菌群检测结果进行差异性分析。结果表明:在冬季,检测时间和保存方式对粪大肠菌群检测结果的影响不明显,不具有统计学意义(P>0.05);在夏季,检测时间和保存方式对粪大肠菌群检测结果影响极显著(P<0.001),其差异性在取样0.5 h后即显现出来。无论是在冬季,还是在夏季,不同检测方法之间的差异都无统计学意义(P>0.05)。

环境监测中粪大肠菌群的监测方法及运用

近些年,我国进行粪大肠菌群监测的工作已经取得初步成效,粪大肠菌群的一些环境标准在逐步完善,但在实际监测过程中依面临着许多问题,其中包括样品采集与保存问题、实验室研究及质量管理等。为了提高环境监测中粪大肠菌群监测的有效性,相关工作人员需要探索行之有效的检测方法。

酶底物法检测地表水中粪大肠菌群的时间因素探索

与传统的方法测定水中的粪大肠菌群相比,酶底物法操作简便,使用越来越多。探讨了培养时间、定量盘冷藏保存时间及季节这些时间因素的影响,发现在定性要求时定量盘全黄的,可不必等到24 h;结束培养后如不能及时读数,可将定量盘冷藏保存一段时间再读数,或拍照与标准阳性比色盘照片对比读数;较热月份粪大肠菌群出现高值的可能性会高于其他月份。

多管发酵法测定水质粪大肠菌群的改进及探索

对比水质粪大肠菌群多管发酵法的实验条件,方法中初发酵温度温度为37℃,培养24 h,初发酵假阳性情况较多,进行复发酵工作量大,通过探索改变初发酵温度,即接种后的试管置于44.5℃培养箱,培养24 h,完成初发酵检验过程,减少初发酵中假阳性管数,从而减少检测复发酵工作量,甚至缩短检验时间,更适宜日常工作中大批量粪大肠菌群检测样品。

滤膜法与酶底物法检测污水中粪大肠菌群的比较分析

采用滤膜法和酶底物法对污水中粪大肠菌群进行同步检测。比较数据结果显示,两种方法具有相关性,且没有统计学意义上的显著性差异。酶底物法具有操作简便,检测时间短、快速准确,可较大程度避免假阳性、假阴性结果等优点,有利于提高工作效率,预期在将来有广泛普及使用的趋势,值得推荐。