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1.
Water quality data at 12 sites within an urban, a suburban, and a rural stream were collected contemporaneously during four wet and eight dry periods. The urban stream yielded the highest biochemical oxygen demand (BOD), orthophosphate, total suspended sediment (TSS), and surfactant concentrations, while the most rural stream yielded the highest total organic carbon concentrations. Percent watershed development and percent impervious surface coverage were strongly correlated with BOD (biochemical oxygen demand), orthophosphate, and surfactant concentrations but negatively with total organic carbon. Excessive fecal coliform abundance most frequently occurred in the most urbanized catchments. Fecal coliform bacteria, TSS, turbidity, orthophosphate, total phosphorus, and BOD were significantly higher during rain events compared to nonrain periods. Total rainfall preceding sampling was positively correlated with turbidity, TSS, BOD, total phosphorus, and fecal coliform bacteria concentrations. Turbidity and TSS were positively correlated with phosphorus, fecal coliform bacteria, BOD, and chlorophyll a, which argues for better sedimentation controls under all landscape types.  相似文献   

2.
Fecal pollution may adversely impact water quality in coastal ecosystems. The goal of this study was to determine whether cattle were a source of fecal pollution in a South Carolina watershed. Surface water samples were collected in June 2002 and February through March 2003 in closed shellfish harvesting waters of Toogoodoo Creek in Charleston County, SC. Fecal coliform concentrations in 70 % of the water samples taken for this study exceeded shellfish harvesting water standards. Ribotyping was performed in order to identify animal sources contributing to elevated fecal coliform levels. Escherichia coli isolates (n?=?253) from surface water samples were ribotyped and compared to a ribotype library developed from known sources of fecal material. Ribotypes from water samples that matched library ribotypes with 90 % maximum similarity or better were assigned to that source. Less than half of the unknown isolates (38 %) matched with library isolates. About half (53 %) of the matched ribotypes were assigned to cattle isolates and 43 % to raccoon. Ribotyping almost exclusively identified animal sources. While these results indicate that runoff from cattle farms was a likely source of fecal pollution in the watershed, wildlife also contributed. Given the small size of the library, ribotyping was moderately useful for determining the impact of adjacent cattle farms on Toogoodoo Creek. Increasing the number and diversity of the wildlife sources from the area would likely increase the usefulness of the method.  相似文献   

3.
Sources of fecal coliform pollution in a small South Carolina (USA) watershed were identified using inexpensive methods and commonly available equipment. Samples from the upper reaches of the watershed were analyzed with 3M? Petrifilm? count plates. We were able to narrow down the study’s focus to one particular tributary, Sand River, that was the major contributor of the coliform pollution (both fecal and total) to a downstream reservoir that is heavily used for recreation purposes. Concentrations of total coliforms ranged from 2,400 to 120,333 cfu/100 mL, with sharp increases in coliform counts observed in samples taken after rain events. Positive correlations between turbidity and fecal coliform counts suggested a relationship between fecal pollution and stormwater runoff. Antibiotic resistance analysis (ARA) compared antibiotic resistance profiles of fecal coliform isolates from the stream to those of a watershed-specific fecal source library (equine, waterfowl, canines, and untreated sewage). Known fecal source isolates and unknown isolates from the stream were exposed to six antibiotics at three concentrations each. Discriminant analysis grouped known isolates with an overall average rate of correct classification (ARCC) of 84.3 %. A total of 401 isolates from the first stream location were classified as equine (45.9 %), sewage (39.4 %), waterfowl (6.2 %), and feline (8.5 %). A similar pattern was observed at the second sampling location, with 42.6 % equine, 45.2 % sewage, 2.8 % waterfowl, 0.6 % canine, and 8.8 % feline. While there were slight weather-dependent differences, the vast majority of the coliform pollution in this stream appeared to be from two sources, equine and sewage. This information will contribute to better land use decisions and further justify implementation of low-impact development practices within this urban watershed.  相似文献   

4.
于2006年4-6月在红沙港海域进行了四个航次调查,对海域中5个站位的海水样品进行了细菌学检测.结果表明,四个航次海水粪大肠杆菌群超标率最高为40%,异养细菌总数超标率均达60%以上.四个航次海水粪大肠杆菌单项污染指数平均值分别为0.755、1.792、2.215和0.578,异养细菌总数单项污染指数平均值分别为1.54、2.73、24.04和6.11.生物统计学分析显示,粪大肠杆菌群与异养细菌总数存在一定的正相关关系,其相关系数r2=0.439 9.红沙港海水已受到粪大肠杆菌和异氧细菌污染.  相似文献   

5.
粪大肠菌群酶底物法在环境监测中的应用研究   总被引:1,自引:0,他引:1       下载免费PDF全文
粪大肠菌群作为水体粪便污染的指示菌,对地表水的水质监测评价具有重要作用。采取较为精确、快速的粪大肠菌群检测方法,对控制流行疾病的发生和传播有重要的科学意义。从粪大肠菌群的检测意义、监测方法、标准化应用情况等方面进行归纳分析,提出推广和标准化酶底物法监测粪大肠菌群的迫切性。  相似文献   

6.
The distribution of fecal coliforms was investigated and determined in Izmir Bay from 1996 to 2005. Izmir Bay severely was polluted from industrial and domestic discharges during decades. In early 2000, a wastewater treatment plant began to treat domestic and industrial wastes. This plant treats the wastes about 80% capacity after 2001. The sampling periods cover before and after treatment plant. Assessment method for determining the number of fecal coliform has evolved membrane filtrations. Maximum surface fecal coliform concentration was 4.9 × 105 cfu 100 ml???1 in 1996–2000 period. Following the opening treatment system, fecal coliform density decreased 2.1 × 104 cfu 100 ml???1 during 2001–2005. A continuous improvement can be sustained in the water quality if direct inflow of untreated wastewater is prevented.  相似文献   

7.
Environmental pollution is one of the major problems being facedtoday due to the advent of extensive industrialization. Heavy metals are the most important contaminants in wastewater that are present in abundance and are toxic. Heavy metal contentsof sewage in the industrial estate of Aligarh (U.P.) have beendetermined by atomic absorption spectrophotometry. The analysisof samples collected from six different locations revealedsignificantly high levels of Fe, Zn, Cu, Cr and Ni. Certainbacteriological (Total bacterial count, Total coliform, Fecal coliform, and Fecal Streptococci) parameters of domestic and industrial sewage as well as soils were monitored from March1990 to January 1993. Total bacterial count, total coliform,fecal coliform and fecal streptococci were found to be lowestin all the samples of industrial wastewater compared to thosein domestic sewage and soil systems. The soil however, contained highest total culturable bacterial population. In view of the common practice of the application of sewage to agricultural land in the neighbouring area, the discharge ofindustrial wastewater without proper treatment into public sewers should be strictly prohibited.  相似文献   

8.
This study investigates the applicability of multivariate statistical techniques including cluster analysis (CA), discriminant analysis (DA), and factor analysis (FA) for the assessment of seasonal variations in the surface water quality of tropical pastures. The study was carried out in the TPU catchment, Kuala Lumpur, Malaysia. The dataset consisted of 1-year monitoring of 14 parameters at six sampling sites. The CA yielded two groups of similarity between the sampling sites, i.e., less polluted (LP) and moderately polluted (MP) at temporal scale. Fecal coliform (FC), NO3, DO, and pH were significantly related to the stream grouping in the dry season, whereas NH3, BOD, Escherichia coli, and FC were significantly related to the stream grouping in the rainy season. The best predictors for distinguishing clusters in temporal scale were FC, NH3, and E. coli, respectively. FC, E. coli, and BOD with strong positive loadings were introduced as the first varifactors in the dry season which indicates the biological source of variability. EC with a strong positive loading and DO with a strong negative loading were introduced as the first varifactors in the rainy season, which represents the physiochemical source of variability. Multivariate statistical techniques were effective analytical techniques for classification and processing of large datasets of water quality and the identification of major sources of water pollution in tropical pastures.  相似文献   

9.
The United States Environmental Protection Agency (USEPA) recommends the use of Escherichia coli (E. coli) and enterococci as indicators of enteric pathogens in fresh waters; however, fecal coliform analyses will remain important by virtue of the large amount of historic data collected in prior years. In this study, we attempted, in a real-world situation (i.e., a rural inland watershed in the Piedmont of South Carolina) to compare different bacterial indicators and methods to one another. We compared fecal coliforms, enumerated by membrane filtration with E. coli, enumerated by a commercialized enzyme substrate method and observed E. coli/fecal coliform ratios of 1.63 and 1.2 for two separate tests. In the same watershed, we observed an E. coli/fecal coliform ratio of 0.84 when we used the commercialized enzyme substrate method for both enumerations. Given these results, users of such data should exercise care when they make comparisons between historic membrane filtration data and data acquired through the use of the more modern enzymatic methods. Some sampling and side-by-side testing between methods in a specific watershed may be prudent before any conversion factors between old and new datasets are applied.  相似文献   

10.
Bacteria holding-time experiments of up to 62 h were performed on five surface-water samples from four urban stream sites in the vicinity of Atlanta, GA, USA that had relatively high densities of coliform bacteria (Escherichia coli densities were all well above the US Environmental Protection Agency criterion of 126 colonies (100 ml)???1 for recreational waters). Holding-time experiments were done for fecal coliform using the membrane filtration modified fecal coliform (mFC) agar method and for total coliform and E. coli using the Colilert®-18 Quanti-Tray® method. The precisions of these analytical methods were quantified. Precisions determined for fecal coliform indicated that the upper bound of the ideal range of counts could reasonably be extended upward and would improve precision. For the Colilert®-18 method, analytical precisions were similar to the theoretical precisions for this method. Fecal and total coliform densities did not change significantly with holding times up to about 27 h. Limited information indicated that fecal coliform densities might be stable for holding times of up to 62 h, whereas total coliform densities might not be stable for holding times greater than about 27 h. E. coli densities were stable for holding times of up to 18 h—a shorter period than indicated from a previous studies. These results should be applicable to non-regulatory monitoring sampling designs for similar urban surface-water sample types.  相似文献   

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