首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
How and where to improve water quality within an agricultural watershed requires data at a spatial scale that corresponds with individual management decision units on an agricultural operation. This is particularly true in the context of water quality regulations, such as Total Maximum Daily Loads (TMDLs), that identify agriculture as one source of non-point source pollution through larger tributary watershed scale and above and below water quality investigations. We have conducted a systems approach study of 10 coastal dairies and ranches to document fecal coliform concentration and loading to surface waters at the management decision unit scale. Water quality samples were collected on a storm event basis from loading units that included: manure management systems; gutters; storm drains; pastures; and corrals and lots. In addition, in-stream samples were collected above and below the dairy facilities and from a control watershed, managed for light grazing and without a dairy facility or human residence and corresponding septic system. Samples were analyzed for fecal coliform concentration by membrane filtration. Instantaneous discharge was measured for each collected sample. Storm runoff was also calculated using the curve number method (SCS, 1985). Results for a representative dairy as well as the entire 10 dairy data set are presented. Fecal coliform concentrations demonstrate high variability both within and between loading units. Fecal coliform concentrations for pastures range from 206 to 2,288,888 cfu/100 ml and for lots from 1,933 to 166,105,000 cfu/100 ml. Mean concentrations for pastures and lots are 121,298 (SE=62,222) and 3,155,584 (SE=1,902,713) cfu/100 ml, respectively. Fecal coliform load from units of concentrated animals and manure are significantly more than units such as pastures while storm flow amounts were significantly less. Compared with results from earlier tributary scale studies in the watershed, this systems approach has generatedwater quality data that is beneficial for management decisions because of its scale and representation of current management activities. These results are facilitating on-farm changes through the cooperative efforts of dairy managers, regulatory agency staff, and sources of technical and financial assistance.  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.
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   

4.
A total of 1094 water samples from 326 springs, 207 streams, 183 dug wells, 151 piped supplies, 90 tube wells, 75 hand pumps, 60 rivers and 2 lakes were collected from eight northern and six north-eastern districts of India. Samples were analysed to assess their potability by estimating the level of heavy metals and bacterial (coliform and faecal coliform) contaminations. Iron was found in a maximum number (53%) of water samples from hand pumps, followed by lead in 43% of the tube wells, chromium in 16% of dug wells, cadmium in 13% of streams and manganese in 7% of hand pumps above their maximum admissible concentrations (MACs). Maximum metal pollution has been observed in a considerable number of water samples from Doda, followed by Almora, Mirzapur and Bankura. Hand pump water samples exhibited maximum metal pollution followed by dug well, spring, stream and river water samples. Contamination of coliform and/or faecal coliform bacteria ranged between 41% and 67% of water samples from open water sources but it was also less, i.e. 6–15% of water samples from tube wells and hand pumps. In general, 42–85% of water samples from districts surveyed, except from Jammu (18%) and Mirzapur (27%), were found to be bacteriologically unsatisfactory. Since toxic metals and pathogenic bacteria pose a risk to public health, monitoring of drinking water sources is required.  相似文献   

5.
耦合社会-经济因子探究工业点源和生活污染源污染负荷未来变化趋势,可为优化水环境规划和管理方案提供理论依据。选取沱江流域为研究区域,采用经济增长预测法、工业点源传统统计法、人口趋势灰色模型预测法和排污系数法分别计算了2020-2025年该区域28个县(市、区)的工业GDP值,工业点源废水排放量及主要污染负荷(COD、NH3-N、TN、TP),农村与城镇人口及生活污染源的主要污染负荷,并利用ArcGIS技术探究了工业点源和生活污染源主要污染负荷空间分布特征。结果表明:2020-2025年,工业GDP值总体呈逐年增加趋势,而工业废水排放量总体呈逐年减少趋势,预计到2025年,流域工业GDP值将增加至2.52×1012元,而工业废水排放量将减少至0.64×108 t。工业点源主要污染负荷表现为COD>NH3-N>TN>TP。沱江流域总人口数与生活污染源污染负荷呈逐年增加趋势,其中城镇人口与生活污染源污染负荷呈逐年增加趋势,农村人口与生活污染源污染负荷呈逐年减少趋势,且城镇人口及生活污染源污染负荷增加量大于农村人口及生活污染源污染负荷减少量。城镇、农村生活污染源的主要污染负荷表现为COD>NH3-N>TN>TP。工业点源和生活污染源主要污染负荷在空间上存在高度异质性。2025年,来自工业点源的主要污染负荷均呈上游较少,中、下游较多的特征;来自城市生活污染源的主要污染负荷均呈中、上游较多,下游较少的特征;来自农村生活污染源的主要污染负荷均呈中游较多,上、下游较少的特征。笔者提出耦合社会-经济因子预测流域污染负荷的方法可以推广到其他与社会经济指标相关联的流域工业点源、生活污染源污染负荷的预测研究中,以期为未来流域水环境管理与治理提供科学参考。  相似文献   

6.
为了更为有效地治理酸雨污染,根据南充市环境监测中心站提供的2009—2017年降水监测数据,对南充市城区酸雨污染情况进行了分析及源解析。结果表明:2009—2017年,南充市降水pH从4.60波动上升至5.6以上,酸雨频率波动下降,酸雨污染情况有所改善;[SO4^2-]/[NO3^-]从4.92下降至0.86,酸雨污染类型从硫酸型转变为硝酸-硫酸型。同时,对比分析2014—2016年大气污染物排放源可知,NOx排放源中,工业污染源占比由14%降至11%,生活污染源由2%上升至5%;SO2排放源中,工业污染源占比由62%降至43%,生活污染源由38%上升至57%,表明南充市SO2污染已从以工业污染源为主转变为工业污染源与生活污染源并重。  相似文献   

7.
为科学评价黄河流域的水质状况及工业企业污染源现状,根据黄河流域2018—2019年地表水和饮用水水源地水质监测数据,建立了综合反映流域水环境质量和可定量分析排名的城市水质指数;利用大数据技术分析工业企业水污染物排放数据,研究建立了企业环境信用动态评价体系。研究结果表明:2018—2019年,黄河流域城市水环境质量得到一定程度的改善,城市地表水环境质量优和良等级数量从17个增加到19个,饮用水水源地优等级城市数量从7个增加到11个;但黄河流域中游地区水污染问题较为严重,需要重点加强水污染控制。水质污染主要以点源工业污染为主,COD和氨氮排放量较多,COD和氨氮年日均排放浓度平均值分别为51.1、3.1 mg/L,工业废水处理率偏低;山西、陕西、河南等"高"风险企业数量较多,分别达到3 047、1 630、1 442家。建议加强黄河流域上下游、左右岸、干支流协同配合,加大水污染防治工作的深度和力度。  相似文献   

8.
Bottom sediments reflect in general the relative contamination of a sea area. Therefore, a great deal of monitoring work has been dedicated to the analysis of bottom sediments. Izmir Bay is a very important pollution centre in Turkish Aegean coast region due to a densely populated community, industrial complex and maritime transportation, and there are many streams flowing into the bay that pass through a number of industrial and agricultural areas. It had received the majority of domestic and industrial wastewaters until the wastewater treatment plant was constructed. It is well known that sediments play an important role as reservoirs of a fraction of the pollution in aquatic systems. Therefore, sediment samples were collected monthly from three stations which are located in the inner part of the bay during the period January to December 2003. Temporal variations and seasonal changes on their 210Po and 210Pb contents were examined, and the activity concentrations of 210Po and 210Pb were found to vary from 43±6 to 132±12 and 27±5 to 91±9 Bq kg???1 dry wt, respectively. The highest values of those natural radionuclides were measured at Kar??yaka Station because of the current systems of the bay. Seasonally, the 210Pb levels were found to increase during the winter time for all the stations.  相似文献   

9.
农业面源污染防治的监测问题分析   总被引:1,自引:0,他引:1  
近年来,农业面源污染已成为许多国家和地区水环境质量改善的主要影响因素,开展农业面源污染监测将为深入打好污染防治攻坚战提供重要支撑。该文系统分析当前我国农业面源污染监测存在的主要问题,综合考虑国内外经验,提出如下建议:采取空间嵌套式的布局模式优化地表水环境监测点位,充分发挥环境监测的预测预报和风险评估功能;建立包括污染源、产排污系数和空间传输过程的农业面源污染全过程监测网络;定期开展土壤氮、磷养分含量评估和地下水硝酸盐氮测定和评估;建立完善数据整合与共享机制。  相似文献   

10.
A one-year monitoring program was carried out to assess the degree of pollution in three creeks on the northern coast of the United Arab Emirates (UAE), through measuring for chemical nutrients such as phosphate, ammonium, nitrate, nitrite and dissolved oxygen, in addition to enumerating selected microbial communities such as the heterotrophic bacteria, salt tolerant heterotrophic bacteria, Gram-negative bacteria, total coliform and faecal coliform bacteria. The results indicated that Dubai and Sharjah creeks have occasional unusually high nutrients levels with sharp fluctuations and wide spatial and temporal variations, suggesting the presence of an anthropogenic sources of pollution, creating these conditions, near the sampling sites. These sources includes several wastewater outlets and recreational facilities. Ajman creek had much less nutrients levels. The microbial counts in the three creeks had a distinct pattern where numbers peaked in mid spring (May) and autumn (October) and were relatively low during the summer and winter months. Total and faecal coliform fluctuated depending on several factors including the presence of nearby recreation and commercial areas, but were at no time consistently high. It was concluded that there is no major pollution problem in these creeks and recommendation were made to prevent it in the future.  相似文献   

11.
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   

12.
根据南京市5家市政水厂水源保护区的污染源调查结果建立了长江南京段水动力和有限体积法水质数学模型,并结合各污染源的污染强度和排放规律,分析了枯水期在不同水文情况下,污染源排放对饮用水源地水质的影响.有限体积法的模拟结果与常规分析的监测结果均表明,水厂受污染程度为:上元门水厂>北河口水厂>城北水厂>浦口水厂>城南水厂.主要污染源为水量较大,且有一定污染的入江河流.  相似文献   

13.
随着环境空气质量精细化管理要求的提高,在应对重污染天气过程中,对大气污染源排放清单的时间分辨率提出了更高的要求。文章从固定源、移动源、油气储运源等方面探讨了大气污染源动态排放清单编制技术方法,并选取某城市进行了应用计算。结果表明,通过获取动态更新的数据,移动源的船舶、机动车、飞机可以逐时分析污染物排放量变化;固定源和油气储运源可以逐日分析。同时与相关指南算法进行定量比较,探讨了精细化改进方法及可能存在的问题,为建立更精细化动态排放清单提供有益参考。  相似文献   

14.
The distribution of trace metals (spatial and temporal) and sedimentary fractions were investigated to identify the concentrations and sources of trace metals within Kogarah Bay, NSW, Australia. A total of 59 surface sediments and six subsurface samples from core of the sediment were collected. The contamination factor and pollution load index indices used to evaluate environmental effects of trace metals. The study area was found to be uncontaminated with Cr and Ni, moderately contaminated with As and considerably contaminated with Cu, Zn and Pb. The concentrations of Cr and Ni were below both effect range low and effect range median, while As, Cu, Zn and Pb were slightly above effect range low. The highest concentrations of these trace metals such as Cu, Zn and Pb were found in the north, northwest and southeast of the bay, close to discharge points, stormwater outlets and around boatyards and watercrafts. The spatial distributions of metals were strongly related to muddy particles and organic matter. The temporal sediments of metals declined with increased sediment depth, which reflects accumulation of trace metals since European settlement in this area. Furthermore, the source of the trace metals was found to be stormwater outlets, gasoline fumes, boatyards and other human activities.  相似文献   

15.
洮滆水系湖库富营养化生态风险的特点与比较   总被引:3,自引:0,他引:3       下载免费PDF全文
茅东水库、长荡湖、涌湖、太湖竺山湾是洮滆水系从上游到下游排列的4大典型湖库,2008年的监测分析表明,氮、磷是该水系湖库富营养化的主要污染因子,并沿流域呈加剧趋势,上下游TP质量浓度为0.081~0.296 mg/L,差异小,而TN质量浓度为0.314~5.67 mg/L,差异大,长荡湖到涌湖是洮滆水系首要污染物TN快...  相似文献   

16.
为了解石家庄市2016年春季大气颗粒物的铅污染特征及来源,利用单颗粒气溶胶质谱仪(SPAMS),分析了大气中含铅颗粒的化学成分。结果表明: 研究期间大气环境中含铅颗粒数浓度共出现11次跳跃式升高,跳跃时间段内石家庄均处于轻度污染过程。从成分分析来看,含铅颗粒分为纯铅颗粒、Pb与K(Pb-K)、OC(Pb-OC)、Cl(Pb-Cl)、混合颗粒等八大类。观测结果表明:Pb-K颗粒最多,占到含铅颗粒的84.4%;其次为纯铅颗粒,占比为13.0%。与石家庄市污染源谱库比对进行来源解析,得到Pb-K颗粒主要来自生活垃圾焚烧源, 纯铅颗粒主要来自工业源。结合石家庄市大气污染源排放清单和后向气流轨迹分析,推测含铅颗粒可能来自市区西南方向某区县的生活垃圾焚烧企业。  相似文献   

17.
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   

18.
As part of an assessment of land-based sources of pollution in Jobos Bay, Puerto Rico, sediment samples were collected at 43 sites to characterize concentrations of a suite of pollutants, including metals. Fifteen major and trace metals (Ag, Al, As, Cd, Cr, Cu, Fe, Hg, Mn Ni, Pb, Sb, Se, Sn, and Zn) were measured along with total organic carbon and grain size in surficial sediments. For most metals, maximum concentrations were seen in the eastern bay; however, values were still within concentration ranges found in other estuarine systems. In contrast, silver was higher in the western region. In general, metal distribution in the bay was positively correlated with grain size. Additionally, correlations between Al and other metals suggest natural sources for metals. The data presented here suggest that, although the Jobos Bay watershed contains both urban centers along with industrial and agricultural developments, anthropogenic inputs of metals may be negligible.  相似文献   

19.
In this investigation, concentrations of physico-chemical and bacteriological qualities of water samples from the major streams within the Owabi watershed in Kumasi, Ghana, were measured at five different locations. The streams were moderately soft and neutral, having a mean pH range of 7.08 ± 0.2 to 7.88 ± 0.6. Total dissolved solids, total suspended solids, grease and oil, alkalinity, and the major ion levels varied significantly at each sampling site. Nutrient levels were however low and did not show any clear variation at sample locations. The bacteriological quality of the water was poor, rendering it unsafe for domestic purposes without treatment. The poor bacteriological quality was due to direct contamination by animal and human wastes. The streams have an appreciable self-purification capacity which is stressed by persistent pollution overloads caused by expanding human activities within the catchment. Cluster analysis performed on the data to determine pollution patterns between the streams depicts that River Owabi was less polluted, Rivers Akyeampomene and Sukobri were moderately polluted, while River Pumpunase was highly polluted.  相似文献   

20.
Efficient management of deteriorating water bodies can be achieved by determining the sources of faecal pollution. Resourceful techniques for discrimination of the sources of Escherichia coli in surface water have recently been developed, including the use of river water to facilitate faecal indicator surveillance, identification of sources of faecal contamination and employing relevant management practices to maintain water quality. This study was conducted to employ microbial source tracking (MST) techniques for the determination of the sources of faecal pollution based on a water quality investigation of the physico-chemical characteristics and coliform count point of the Tirumanimuttar River. To accomplish this, an MST library-based antibiotic resistance analysis, serotyping and the genomic tool rep-PCR techniques were applied, and the obtained results were analysed statistically. Among 135 and 70 E. coli isolates present in the library and water samples collected from the river and nearby well water sources, respectively, most showed intrinsic, high or moderate resistance to antibiotics. Isolates from human and pig faecal sources were 92% homologous with the samples from the river, whereas isolates from sewage and dairy cattle showed 89% and 80% homology, respectively. These findings indicated that the Tirumanimuttar River is subjected to stress from anthropogenic activities and runoff contaminated with agricultural and human faecal contamination. The sources of faecal pollution identified in this study may facilitate the monitoring and management of the Tirumanimuttar River.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号