Fecal coliform densities in a Western watershed

This paper describes the areal distribution of fecal coliform densities within the stream system of the South Platte River basin in Colorado. Low densities, e.g., 0 to 99 fecal coliforms per 100 ml, were found in mountain streams, while higher densities, e.g., 10000 to 100000 and above were found in plains streams. About 49 % of the plains stations and 3 % of the mountain stations were not in compliance with the Colorado secondary contact recreation standard of 2000 fecal coliforms per 100 ml. The higher fecal coliform densities were associated with discharges from wastewater treatment plants. This is significant from a public health standpoint since the tainted waters are spread throughout the South Platte basin to irrigated lands via streams, canals, and reservoirs. Because of current federal and state policy encouraging land treatment and reuse, such practice should be reviewed with respect to compliance with proposed fecal coliform standards, and whether such standards should be adopted.     

Evaluation of Urban Groundwater Contamination from Sewage Network in Kuwait City

To investigate the possible contamination of groundwater by wastewater leaked from the underground sewage network, water samples from 29 monitoring wells, drilled at strategic locations across Kuwait City and the adjacent residential areas, were analyzed for their inorganic and organic constituents including isotopic composition (oxygen-18 and deuterium) that can be used as tracers for source identification. As a non-conventional method, statistical processing in the form of hierarchical cluster and discriminant function analyses of the inorganic and organic data was used to group the wells according to the degree of possible contamination of groundwater. It was concluded from this analysis that more than half of the wells (17) showed little evidence of such contamination. Sample from only one of the wells suggested high degree of contamination (concentrations of total coliform bacteria (TCB) and fecal coliform bacteria (FCB) >2,000 MPN/100 ml and boron (B) concentration >11 mg/l) whereas another well appeared significantly contaminated (TCB?>?2,000 MPN/100 ml; FCB?>?900 MPN/100 ml; B?>?4 mg/l). Three of the wells were possibly contaminated (1,000?<?TCB?<?2,000 MPN/100 ml; 15?<?FCB?<?500 MPN/100 ml; 3?<?B?<?11.5 mg/l), and the rest of the seven wells were classified as possibly not contaminated (TCB?>?2,400 MPN/100 ml; FCB?<?40 MPN/100 ml; B?<?5 mg/l). The overall conclusion was that the leakage from sewage network was affecting groundwater in localized areas only. Isotope data, available for water samples from eight of the monitoring wells, tended to support the aforesaid conclusions. However, because of the use of bailing as the sampling method and lack of actual leakage surveillance, further studies need to be carried out to strengthen the reliability of these findings.     

Microbiological Quality and Antibiotic Resistance Analysis of a Brazilian Water Supply Source

Water samples of the Passaúna River, Curitiba/Paraná (Brazil), were analyzed to determine total and thermotolerant coliform counts and Escherichia coli in order to provide information on human impacts on the water supply. Samples were collected and analyzed monthly, from March 2006 to February 2007, at five different locations along the river, and the multiple tube method was used to obtain total and thermotolerant coliform counts. The results varied from 130 MPN/100 mL to 1.6?×?10⁶ MPN/100 mL for total coliforms, while for thermotolerant coliforms the variation was between 40 MPN/100 mL and 5?×?10⁵ MPN/100 mL. The E. coli strains isolated from the samples were tested with 13 different antibiotics to determine their antibiotic resistance. The isolated strains were constantly sensitive to seven of the 13 antibiotics tested, and resistant to at least one of the other antibiotics. The results indicated that two factors could influence the increased contamination on this river, viz., seasonality parameters and domestic wastewater discharges. The determination of antibiotic resistance indices aimed to provide information on the anthropogenic influence. Only one of the locations investigated was considered critical due to the anthropogenic influence, with significant impacts from irregular domestic wastewater discharges.     

辐照对调味品和脱水蔬菜中大肠菌群杀灭效果的研究

6kGy辐照可以使调味品和脱水蔬菜中的大肠菌群最可能数 (MPN)符合国家卫生标准的要求。通过对 1 88个辐照过的调味品的检验 ,未发现在大肠菌群中出现耐辐射的新菌株。目前出现误判“大肠菌群超标”的原因主要是由于菌检技术不过关所致 ,其中复发酵和革兰氏染色挑菌不是来自同一菌株是造成误判的最主要原因。     

Fecal coliform and E. coli estimates,tip of the iceberg

Pure cultures of E. coli, Klebsiella and Enterobacter, obtained from hospital patients and from natural waters were tested for their growth patterns by spread plate and membrane filtration procedures at the following temperatures; 35°, 41.5°, 43°, 44.5°, and 35°C for 4 h followed by 18 h at 44.5°C. Results indicated that 44.5°C incubation produces the lowest population estimate and that the application of the membrane filtration technique also reduced the potential population. Three water samples collected during June, August and November were tested for fecal coliform and E. coli populations, with 11 different media (broth and agar) and incubation temperatures of 35°, 41.5°, 43°, 44.5°, and 35°C for 4 h followed by 18 h at 44.5°C. During the study, isolates were collected from all positive MPN tubes at each temperature and from each MF medium-temperature regime, 24 to 50 isolates were collected. From the isolate data corrected coliform (oxidase negative), fecal coliform and E. coli population estimates were made. A sample of feces was diluted in lake water and maintained at 20°C for 56 days. Samples were collected at various times and tested for fecal coliform densities using five media and the same temperature regime as for the lake water samples. Data from these studies indicate that, depending on the age of the population being measured, the temperature of the water sample, and the temperature-media-procedure combination used, fecal coliform and E. coli population estimate techniques measure from 5 to 100% of the potential population.     

Indicator bacteria concentrations as affected by hydrologic variables in the Apalachicola river,Florida

Concentrations of fecal coliform and fecal Streptococcus bacteria were monitored in the Apalachicola River, Florida, at various river stages. Bacteria transported by the river may eventually be assimilated by estuarine filter feeders, including shellfish. Sources along the river contributed to relatively high coliform and coliform: Streptococcus ratios at a few sites upstream, but there was a general decreasing trend in coliform numbers in a downstream direction. The data suggested that coliform densities depend not only on discharge, but also on factors such as whether the river stage is rising or falling, whether the flood is in an early or late phase, and the volume of the current peak relative to earlier peaks. A regression model indicated that 53 % of fecal coliform variability could be accounted for by river discharge and 32% could be accounted for by other hydrologic characteristics of the flood.     

Fecal contamination of Finnish fresh waters in 1962–1984

We investigated fecal contamination of Finnish lakes and rivers on the basis of 132 476 observations of total coliform bacteria (TC), thermotolerant coliform bacteria (ThC) and fecal streptococci (FS) enumerated in a nationwide monitoring programme during the period 1962–1984. The number of analyses of TC was 19 672, of ThC 16 456 and of FS 96 348. The waters were classified into three groups, influenced mainly by municipal wastewaters, industrial wastewaters or diffuse loading. Annual median bacterial concentrations were used for presenting the trends. All the concentrations decreased until about 1976, except TC concentrations in the industrialized and diffuse load areas. Since 1976 the concentrations decreased more slowly or occasionally even increased, especially those of TC. In the whole data the dynamics of bacterial loads (CFU s^?1) were similar to those of annual median bacterial concentrations. The most probable explanations for the declining bacterial concentrations are increase in the human population served by wastewater treatment plants, improved sewage treatment processes, decreased wastewater volumes of the forest industry and decrease in the number of cattle. The monitoring programme continues.     

宠物干粮食品辐照杀菌工艺参数的确定

依照国内外学者的研究结果和国际辐照饲料工艺规范的规定,研究了宠物干粮食品辐照杀菌工艺,确定了各项技术指标,并就主要技术指标的确定依据进行了阐述。该技术规定：辐照前宠物干粮食品细菌总数≤5×104 MPN/100g,霉菌≤4.5×104 CFU/g,沙门氏菌≤1×103 CFU/25g,辐照后细菌总数≤1000 CFU/g,大肠菌群≤30 MPN/100g,霉菌≤25 CFU/g,沙门氏菌不得检出,宠物干粮食品辐照杀菌的最低有效剂量为4.0 kGy,最高耐受剂量为15.0 kGy。辐照产品箱中最小吸收剂量应不小于最低有效剂量,最大吸收剂量应不大于产品的最高耐受剂量。     

江苏省大中型沼气工程调查及沼液生物学特性研究

近年来,中国大中型沼气工程发展迅速,然而有关沼气工程运行情况的研究甚少。为探索沼气工程运行中存在的问题,该文对江苏省21家畜禽养殖场大中型沼气工程进行了实地调查,并采集发酵料液以及出料样品,分析了进出料液COD(化学需氧量)质量浓度、沼液产气潜力、粪大肠菌群数等指标。结果表明:江苏省沼气工程设计施工规范,配套设施较完备,但运行效率低,沼气、沼液处理或利用能力低。大多数沼气工程以处理养殖废水为主,发酵料液固体质量分数<3%,62%的出料沼液的COD质量浓度达到5000mg/L以上;沼液残余产气潜力较大,在35℃条件下,有12家沼气工程的沼液残余产甲烷量达100mL/L以上。沼气发酵处理可以显著降低粪大肠菌群含量,平均可减少92.9%,但厌氧消化后的沼液中仍含有较高浓度粪大肠菌群,不能达到无害化要求。该调查结果可为畜禽养殖场沼气工程的健康稳定运行与管理提供科学依据。     

Culture-Dependent and Culture-Independent Methods in Evaluation of Emission of Enterobacteriaceae from Sewage to the Air and Surface Water

The number of Enterobacteriaceae, with particular attention given to the presence of Escherichia coli and Klebsiella pneumoniae, was determined in hospital effluents and municipal wastewater after various stages of purification. The emission of these microorganisms to the ambient air near wastewater treatment plant (WWTP) facilities and to the river water, which is a receiver of the WWTP effluent, was also studied using fluorescence in situ hybridization (FISH) and cultivation methods. The number of Enterobacteriaceae determined by cultivation and fluorescence methods in different kinds of sewage sample ranged from 0.5?×?10(3) to 2.9?×?10(6)?CFU/ml and from 2.2?×?10(5) to 1.3?×?10(8) cells/ml, respectively. Their removal rates during treatment processes were close to 99?%, but the number of these bacteria in the WWTP outflow was quite high and ranged from 5.9?×?10(3) to 3.5?×?10(4)?CFU/ml and from 1.1?×?10(5) to 6.1?×?10(5) cells/ml, respectively. In the river water and the air samples, the number of Enterobacteriaceae was also high and ranged from 4.1?×?10(3) to 7.9?×?10(3)?CFU/ml and from 3 to 458?CFU/m(3), respectively. The numbers of these microorganisms obtained from fluorescence and cultivation methods were statistically and significantly correlated; however, the analysis of the studied samples indicated that the FISH method gave values up to 10(3)-fold times greater than those obtained by the cultivation method. From a sanitary point of view, this means that the number of viable fecal bacteria is systematically underestimated by traditional culture-based methods. Thus, the FISH proves to be a method that could be used to estimate bacterial load, particularly in air samples and less contaminated river water.     

长江三角洲地区污水污泥与健康安全风险研究Ⅰ.粪大肠菌群数及其潜在环境风险

粪大肠菌群(FecalColiform,FC)是判定污泥土地安全利用的重要指标之一。通过实地调查取样,收集了长江三角洲地区的南京、苏州、上海、杭州等15个城市的污水处理厂的48份污泥样品,测定了其粪大肠菌群数,旨在了解污泥中FC的数量与潜在污染风险;并在污泥自然风干过程的第7、14、21、28天分别取样测定了FC的数量和水分含量,以观察风干过程中FC和水分的动态变化及其与风干时间的关系。研究结果表明,污泥中FC的最大可能数(MPN)的范围在0～3.41×106(MPNg-1,DW),平均为3.79×105(MPNg-1,DW),检出率达89.6%。不同类型污泥中FC的数量差别较大,“河流”污水处理厂污泥和污泥制品的FC数量最低,以生活污水为主的污泥和混流污水污泥中FC数量较高。污泥风干过程中FC数量和水分含量均随风干时间的延长而减少,但FC数量有回升现象。总之,污泥样品的FC数量差异较大,部分污泥样品的数量超过了污泥农用的病原物标准,为了保护生态环境和人类健康,防止二次污染,污泥土地利用时需考虑FC数量,采取相应控制措施。     

Evaluation of On-site Wastewater Disposal Systems in Mississippi Coastal Areas

Groundwater and surface water contamination have been linked to inadequate or failing on-site residential wastewater treatment and disposal systems. The potential for groundwater contamination in coastal areas with shallow water tables is higher; subsequently the ability of soil, microorganisms, and vegetation to mitigate pollutants may be reduced. This study evaluated the performance of the four types of on-site wastewater treatment and disposal systems predominantly used on the Mississippi Gulf Coast. One type of system was deemed inappropriate for this region as none of the dozens of installations examined were functioning acceptably. Of the remaining three types, subsurface water samples were collected from representative sites using lysimeters and monitoring wells. Apart from general performance evaluation of these systems, seasonal changes translating into possible variation in disposal efficiencies and groundwater contamination were investigated. Statistical analysis of variations in organics (COD and BOD₅), nitrogen (TKN and NH ₄ ⁺ ?CN), and fecal coliform concentrations was used to identify probable deficiencies in systems tested and to recommend changes to governing standards.     

Effects of municipal wastewater on soil chemical properties in cultivating turfgrass using subsurface drip irrigation

Knowing the concentrations of the nutrient elements in soils is important due to their toxic effect on humans and the environment. The aims of this study were to assess the effects of water quality, depths, and distances of lateral installation on soil chemical properties during turfgrass cultivation. A field experiment was conducted using a Split-Split-Plot design based on the randomized complete block (RCB) design with two treatments (well water and wastewater) and eight sub-treatments (45 and 60 cm distance of the laterals and 15, 20, 25, and 30 cm depths of laterals) in three replicates on a sandy loam soil, in Shahrekord, Iran. Soil samples were collected from 0 to 30 and 30 to 60 cm depth for measuring nitrate (NO₃^?), electrical conductivity (EC), and pH at the end of the experiment. During the experiment, fecal coliform was also measured at the soil surface. Results indicated that by increasing lateral distance, NO₃^? level increased in both layers. With installing laterals in deeper levels, NO₃^? concentration decreased at the beginning, then increased in the first layer, whereas in the second layer, NO₃^? concentration decreased. In addition, installing laterals in deeper depth caused an increase in soil EC in the top layer, but a decrease in the lower layer. However, the results showed that there was no significant effect of the treatments (well water and wastewater) and the sub-treatments (distance and depths of laterals) on soil pH. The results also show that with increasing laterals depth, fecal coliform level decreased at the soil surface.     

Effect of heavy metals on growth population of a fecal coliform bacterium Escherichia coli in aquatic environment

The data on the effects of the concentrations (0.5, l, 2, 5 mg L^?1) of the heavy metals, Hg, As, Pb, Cu, Cd, and Cr on changes in growth population of a fecal coliform bacterium Escherichia coli (in term of number of E. coli per 100 mL water) showed a gradual decline in growth population of the fecal coliform bacterium with the increase of exposure time, as well as concentrations of the metals over control data. The effects were markedly recorded with the treatment of 5 mg L^?1. In general, the harmful effects of the metals on growth population of E. coli were found by the treatments in the order: Cd>Ph>Cu>As>Hg>Cr.     

Selection of Tolerant Plants and Their Arrangement to Restore a Forest Ecosystem Damaged by Air Pollution

Wastewater and groundwater has been used for irrigation in the Valsequillo District, east central Mexico, for nearly 50 years. The environmental impact of wastewater on groundwater in the unconfined shallow aquifer is evaluated by means of hydrogeological, microbiological, hydrogeochemical and isotopic evidences. The shallow aquifer consists of upper Tertiary volcano-sedimentary rocks with a calcite-rich matrix. Groundwater from wells near the wastewater canal had similar total coliforms concentrations as the wastewater (～100 MPN 100 mL^-1). The hydraulic head in near-canal wells had a recovery of 10 m until 1983, indicating shallow recharge from wastewater. A bicarbonate vs. calcium plot shows a well-defined mixing process between wastewater and unaffected groundwater. Stable isotopic data (δD and δ¹⁸O) show characteristic signatures for wastewater and non-impacted groundwater, and define a mixing line between those end-members and groundwater affected by wastewater infiltration. Tritium data indicate that non-impacted groundwater is ‘pre-atomic hydrogen bomb’ (>50 yr), whereas the wastewater has a ‘younger’ signature. Tritium data from wells inside the district clearly indicate a mixing process between waste and groundwater. These results demonstrate the interaction and hydrochemical processes between wastewater and shallow groundwater at the site.     

Peat leachmound treatment of residential wastewater in sub-Arctic Alaska

In many areas of the North, conventional septic systems cannot be installed or have failed because of inadequate drainage. Conventional domestic, on-site wastewater may contaminate shallow water tables and surface waters. The effectiveness of two pilot peat leachfields in treating septic wastewater was investigated for approximately two years by comparing the quality of the untreated wastewater collected from the septic system lift stations to the quality of the peat leachate. The quality of the leachate, based on parameters such as BOD, COD, TSS, NO₃-N, TKN, total-P, pH, fecal and total coliform bacteria, color, turbidity, and DO, is similar to wastewater that has undergone tertiary treatment. Temperatures below the leachmound distribution pipes ranged between 1° and 6 °C. Clogging of the interstices with an organic slime was not encountered. The results of the study show that peat leachmounds can be adopted to treat residential wastewater in rural sub-Arctic Alaska and other northern tier countries without compromising ground or surface water quality.     

Composting of Aged Reed Bed Biosolids for Beneficial Reuse: A Case Study in New Jersey,USA

Reed beds with Phragmites australis (common reed) have been utilized to decrease the water, nutrient, and volatile solids content of sewage sludge. An efficient disposal/reuse option was sought for reed bed biosolids accumulated over a 15-year period at a wastewater treatment facility in New Jersey, USA. The study facility had 14 reed beds, each with 1000 wet tons capacity, which were full, and so the solids needed to be removed. Because P. australis is considered an invasive species in New Jersey and several other states in the United States, disposal or reuse of solids containing this plant is regulated. Composting was examined as a potential treatment for destroying the plant's reproductive rhizomes. The high temperatures achieved during composting were also tested to determine if regulatory criteria for pathogen reduction could be met, making the composted product suitable for unrestricted land application. Preliminary studies indicated the sludge had stabilized to the point where self-heating did not occur. Among the carbon amendments tested in the laboratory to stimulate compositing activity, Phragmites above-ground biomass was determined to be most suitable. In a field test, Phragmites above-ground biomass was mixed with reed bed biosolids at a 1:2 (w/w) ratio. The temperatures achieved resulted in complete mortality of Phragmites rhizomes. In laboratory tests, rhizomes placed in a drying oven at 50°C for 24 h, or 55°C for 12 h, showed 100% plant mortality. However, under field conditions pile temperatures could not be maintained long enough for the sludge to meet the USEPA 503 biosolids time-temperature pathogen rule requirements for unrestricted land application, even though sample fecal coliform counts did meet regulatory limits.     

Investigations of pipe-borne pollution in Benin City,Nigeria

Two important environmental parameters could be identified as being the main causes of pipe borne water contamination in the City of Benin. These are the combined effects of rainfall and excessive construction work and, secondly, the lack or inadequacy of plumbing codes. To study the combined effects of rainfall and excessive construction on the contamination of water, samples were tested for total coliform using the multiple-tube fermentation test. Sites were chosen to allow for the comparison of the coliform counts in areas of comparatively insignificant construction to areas of excessive public construction. Results show that in the areas of heavy public construction, the curves for both the rainfall and the coliform counts in the consumer lines were skewed in the same manner. The peak rainfall was in September (437.I mm) which corresponds to peak coliform number in the consumer lines for both Zone A (62 coliforms/100 ml) and Zone B (60 coliforms/100 ml) for the same month. When compared to the area of insignificant public construction as shown in Zone C, rainfall had little or no effect on the coliform counts either at the pumping station or in the consumer line. The maximum number of coliforms recorded for the consumer line was 5/100 ml during the month of June. Results suggest that the high counts of coliforms in the Benin City water supply could be attributed primarily to the effects of construction which resulted in pipe breakage. During heavy rainfall and flooding, water under flood pressure enters the pipes through cracks, improperly tightened joints and damaged pipes. The improper enforcement of plumbing codes or lack of such codes was also identified as another cause of the water contamination as shown in Zone D. A study of the effects of water pipes passing through septic tank drain fields also shows that such effluents served as another source of major contamination. The highest recorded number for coliforms for the pipe-borne water just before entering the septic tank drain field was 12/100 ml and after it passed through the field the number had gone up to 60/100 ml. Artificial contamination of the septic tank effluents to try to detect leaks in the water pipes passing through the absorption field was investigated. The bacterial contaminant could be recovered in the pipe-borne water and the quantity was skewed in the same manner as total rainfall between periods of sampling.     

洪水胁迫因子对千岛湖水质的影响与风险评价研究

研究表明1996年洪灾中千岛湖总体水质在多年走势图中出现“污染峰”现象,表明外来面源污染是主要污染源。对比分析洪灾前后水质变化表明,千岛湖水体受洪灾的影响仅局限于当年,通过水体的缓冲和自净能力的恢复,各项污染指数在灾后均能迅速恢复至正常状态。洪灾年中其水质污染指数排序及负荷比均为百亩畈>航头岛>街口和三潭岛,4断面总负荷占全湖的72%。洪灾年中综合污染指数对全湖分担率最高为大肠杆菌(高达46.6%,为洪灾年中水质最大污染因素)和总N,其他各项目分担率很低,对洪灾年中总体水质几无影响,而总Cd、氨氮和总Pb该年上升偏离正常年份中的变化趋势,尤其是总Cd和总Pb指数灾年过后仍不能回落,显示出洪灾对水质影响带来重金属污染的“滞后效应”。     

Reduction in the Acute Toxicity of Explosive Wastewater Containing Toxic Nitroaromatic Compounds by a Nanoscale Zerovalent Iron Pretreatment Process

The feasibility of using nanoscale zerovalent iron (nZVI) treatment for reducing the acute toxicity of explosive wastewater, such as 2,4,6-trinitrotoluene (TNT) red water which contains highly toxic nitroaromatic compounds (NACs), has been investigated. The water quality was evaluated before and after nZVI treatment using several different analytical techniques, including UV?CVis spectroscopy, X-ray photoelectron spectroscopy, high-performance liquid chromatography, and gas chromatography/mass spectroscopy. The acute toxicity of the wastewater was tested using a luminescence bacterium bioarray. The results indicated that the most significant toxic NACs, such as dinitrotoluene sulfonates, had been effectively removed from the TNT red water by nZVI together with the small amounts of other NACs. Following 1?h of the nZVI processing treatment, the acute toxicity of the TNT wastewater was reduced by approximately 94?%. This treatment would therefore be useful for the pretreatment of wastewaters prior to the application of a biological process. The reduction in the biotoxicity of the wastewater was based on the reductive conversion processes and adsorption behaviors of nZVI.