Some effects of land use on bacteriological water quality in a recreational lake

A study was conducted to detect the source of fecal indicator bacteria and the resulting degree of bacteriological water quality impairment of Mississippi Lake, a shallow eutrophic lake in southern Ontario, Canada. The lake was intensively sampled during two 5-day periods in late May-early June, and in July of 1976. The main detectable sources of fecal coliform were cattle watering sites, farms, public beaches, some flooded and substandard septic tanks, and a bird sanctuary. The impairment of water quality was localized to shoreline locations near the suspected source of the input of bacteria. After rainfall, about a 10-fold increase was noted in the levels of fecal coliforms and fecal steptococci in all lake surface water sampled. The effect was short-lived lasting only 2 or 3 days after the main rainfall. The levels of indicator bacteria were low and did not exceed maximum levels set down for Water Quality Management in Ontario, of 1000 TC(100 ml)⁻¹ and 100 FC(100 ml)⁻¹ at recreational areas. For this lake and six others in southern Ontario, the LOG of spring densities of aerobic heterotrophic bacteria correlated significantly with the LOG of mean summer chlorophyll a concentration (r = 0.80).Cottagers on Mississippi Lake were surveyed for their swimming habits and for the incidence of disease associated with swimming. The largest cause of disease associated with bathing, 57 of 67 reported infections, was infection of the ear; 3.28% of bathers at shoreline cottages suffered ear infections. The frequency of ear infections in the population of swimmers was significantly associated with the amount of swimming in the lake. Males and females were infected at equal rates. Young people suffered a significantly higher rate of ear infections than adult bathers. Frequency of water contact was probably greater in young people than in adults and may explain the greater number of ear infections in young swimmers. These studies provided the basis for recommendations designed to improve lakewater quality.     

Comparison of drinking water treatment process streams for optimal bacteriological water quality

Four pilot-scale treatment process streams (Stream 1 - Conventional treatment (coagulation/flocculation/dual media filtration); Stream 2 - Magnetic ion exchange (MIEX)/Conventional treatment; Stream 3 - MIEX/Conventional treatment/granular activated carbon (GAC) filtration; Stream 4 - Microfiltration/nanofiltration) were commissioned to compare their effectiveness in producing high quality potable water prior to disinfection. Despite receiving highly variable source water quality throughout the investigation, each stream consistently reduced colour and turbidity to below Australian Drinking Water Guideline levels, with the exception of Stream 1 which was difficult to manage due to the reactive nature of coagulation control. Of particular interest was the bacteriological quality of the treated waters where flow cytometry was shown to be the superior monitoring tool in comparison to the traditional heterotrophic plate count method. Based on removal of total and active bacteria, the treatment process streams were ranked in the order: Stream 4 (average log removal of 2.7) > Stream 2 (average log removal of 2.3) > Stream 3 (average log removal of 1.5) > Stream 1 (average log removal of 1.0). The lower removals in Stream 3 were attributed to bacteria detaching from the GAC filter. Bacterial community analysis revealed that the treatments affected the bacteria present, with the communities in streams incorporating conventional treatment clustering with each other, while the community composition of Stream 4 was very different to those of Streams 1, 2 and 3. MIEX treatment was shown to enhance removal of bacteria due to more efficient flocculation which was validated through the novel application of the photometric dispersion analyser.     

Effects of whole lake mixing on water quality and phytoplankton

This paper describes the effect of artificial mixing of two Oklahoma lakes with a downflow pump on water quality and algal biomass. Artificial pumping in Arbuckle Lake (951 ha), advanced autumnal turnover, but never destratified the lake completely. Ammonia decreased in the epilimnion, while sulfide (H₂S) declined and dissolved oxygen (DO) increased in the hypolimnion. Other water quality parameters did not change. Near-bottom concentrations of manganese (Mn²⁺) increased, indicating pumping did not affect water chemistry near deep sediments (> 16 m). Pumping did not change significantly the depth of the Secchi disc or algal biomass as measured by chlorophyll a. The algal flora was dominated by diatoms at all times, and the density of blue-green algae was always low. Pumping kept Ham's Lake (41 ha) destratified, but seldom produced completely isothermal conditions or isochemical concentrations of DO. There was no drastic change in other water quality parameters. However, artificial mixing decreased water clarity and increased algal biomass by a factor of about 2.5, probably by reducing sinking rates of the phytoplankton. Artificial mixing apparently eliminated a fall pulse of Microcystis.     

A water quality index for lake beaches

Discriminant analysis of ten years of data from seven beaches located on three lakes in Gatineau Park (Québec) leads to a canonical vector accounting for most of the variability of the three microbial count variables recorded. This discriminant axis orders the beaches along a cline of increasing pollution. It is then transformed into a microbial water quality index calibrated for the given set of beaches, which is in turn used to study the medium-term variability and the long-term evolution of water quality of the beaches.     

Some effects of pulp and paper wastewater on microbiological water quality of a river

A study was conducted to detect the source of fecal indicator bacteria and measure the resulting impairment of water quality of the Sturgeon River at Sturgeon Falls, Ontario, Canada. The bacteriological water quality of the river above the dam at Sturgeon Falls was fairly good, while below the dam the water quality was degraded. The principal input of fecal indicator bacteria was traced to the paper mill at Sturgeon Falls. The impairment of water quality was detected all the way to recreational areas near the mouth of the river. The impaired stretch of the river had diminished aesthetic appeal. Other sources of indicator bacteria could be masked by the large numbers of similar bacteria discharged from the paper mill. The principal fecal coliform was Klebsiella pneumoniae. In pulp mill wastes the fecal origin of this bacterium can be disputed, and so its presence in large numbers interfered with the interpretation of fecal coliform results. K. pneumoniae is also an opportunistic pathogen which causes infections in humans. Thermotolerant oxidase positive bacteria which were isolated from the paper mill wastes, register as false positives in the fecal coliform test causing problems in interpretation. Pseudomonas aeruginosa was detected in the pulp mill wastewater, and at a level of 82 PA 100 ml⁻¹ in recreational areas of the river. This was considered to be of some hazard to users of the water. In addition, Escherichia coli was detected in the mill wastewater, at about 200 EC 100 ml⁻¹, and this probably indicated some measure of fecal pollution though likely of animal origin. Finally the nutrient rich wastewater led to an approx. 50-fold increase in density of aerobic heterotrophic bacteria in the river water, as well as the production of a slimy filamentous growth on surfaces, stones and wooden pilings, in the river. The principal organism in this slime was the fungus Leptomitus.     

环鄱阳湖地区城镇化对其水循环的影响分析

介绍了环鄱阳湖地区的城镇化发展状况,以鄱阳湖为中心的城镇建设正在以加速的进程扩张,由于这种强烈的人类活动,势必导致鄱阳湖流域水循环系统的改变,还介绍了城镇建设引起的水文响应方方面面,为今后城镇化建设积累了经验。     

Gull droppings and their effects on water quality

Droppings collected over periods of 24 h, from four species of captive gulls of the genus Larus, were examined for total coliforms, faecal coliforms, faecal streptococci and Clostridium perfringens. Samples were also monitored for salmonellae and representative groups of samples analysed for nutrient content. The occurrence of several types of droppings, characterized by their colour and consistency, was recorded. Daily loads of coliform bacteria indicated that the outputs of the two larger species of gull approximated to values quoted for man; values for other indicator bacteria were however considerably lower in all gull species. Salmonellae were not detected. Daily loads of Kjeldahl nitrogen from each bird varied from 608 to 1819 mg, and total phosphorus from 3 to more than 115 mg, according to species.     

A semi-operative approach to lake water quality retrieval from remote sensing data

A semi-operative approach to retrieve chlorophyll-a concentration from airborne/spaceborne spectrometer observations has been developed and tested using the airborne imaging spectrometer (AISA) data from 11 lakes located in southern Finland. The retrieval approach is empirical and requires nearly simultaneous in situ training data on water quality for the determination of regression coefficients. However, the training data does not have to be collected from every lake under investigation. Instead, the results obtained indicate that reliable estimates on the level of chlorophyll-a (chl-a) for an individual lake can be achieved without employing in situ data representing this specific lake. This enables the estimation of water quality from remotely sensed data for numerous lakes with the aid of reference data only for a few selected lakes representing the region under investigation. In addition, it is shown that the remotely sensed spectrum shape characteristics are highly affected by the trophic and humic state of the lake water.     

Phosphorus partitioning in a shallow lake: implications for water quality management

This paper describes the seasonal partitioning of phosphorus (P) across the sediment–water interface in Loch Leven, Scotland, and discusses the implications for future lake management strategy with respect to recovery from eutrophication. In a 10‐month survey, surface water total phosphorus (TP) concentrations were highest in late summer and lowest in early spring. In contrast, sediment TP concentrations were highest in mid‐winter and lowest in late summer. Water discharge at the main outflow of the loch was highest when water‐column TP was low and sediment TP high, and vice versa. Monthly sediment P uptake/release values showed significant cycling between the water‐column and the sediment and showed seasonal variation in four release‐sensitive P pools. Regulating the water level to increase flushing during sediment release periods and decrease flushing during uptake periods has the potential to significantly enhance the recovery of shallow lakes and reservoirs following historic nutrient loading.     

Impact of inland pollution sources on the bacteriological water quality of the Southern Ganghwado Bay Area,South Korea

The bacteriological pollution of water is a serious global environmental issue. The pollution of water by human and animal wastes can be a source of hazardous pathogens, which may pose serious health risks. In this study, we evaluated the microbiological water quality in the southern Ganghwado Bay area, South Korea. A total of 30 samples (14 discharge water samples from the drainage area and 16 sea water samples from the adjacent area) were analyzed for the concentrations of total coliforms (TC) and fecal coliforms (FC) in November 2013. The highest concentration of FC (28,000 MPN/100 mL) was found at site L1 (inland). The highest mean concentrations of coliforms were found at sites W9 (sea water) and W11 (sea water), with TC and FC concentrations of 33 MPN/100 mL. In conclusion, site L1 located near W9 and W11 is clearly identified as the main source of pollution at Dongmak Beach.     

施工油污对供暖系统水质的影响与危害

依据全国统一安装工程预算定额和锅炉水质标准,分析了供暖系统和其他热用户施工中的机油、铅油等油污杂质的影响及危害,提出了控制锅炉给水含油量的意义和对策。     

斑马鱼生物学效应的研究进展及在水质监测中的应用

主要从不同污染物胁迫介绍了斑马鱼的呼吸行为、运动行为、群体行为等行为学效应,以及个体、器官、细胞、分子等多种水平的毒理效应,同时对斑马鱼行为学和毒理效应在水质监测和水环境评价方面的应用做出介绍和展望,得出综合斑马鱼的行为变化和毒理效应两个方面能更准确地表征水体污染类型及污染程度。     

Some chemical and physical relationships on lake ontario

Submersible recording water chemistry and current instruments were concurrently operated on a submerged tower located approximately 2.5 km offshore on Lake Ontario. This area is influenced by several large sewage treatment plant discharges with the closest discharge 1.6 km away. The instruments were 3.0 m off the bottom in 9.6 m of water and operated primarily during the months of June and November, 1970. One-thousand fivehundred and seventy-four hourly measurements were made of currents, temperature, dissolved oxygen, conductivity, pH and turbidity. The measurements were validated with field measurements by other methods. Time series analyses of the collected data showed that time variations of water chemistry for 8–15 h cannot be explained by water movements for distances of 2 km from a major waste discharge. A measure of the biological activity as well as other chemical and physical processes is required to determine concentrations of the measured chemical parameters. Current magnitudes with a mean value of 3.5–6.0 cm s⁻¹ are not the primary mechanism responsible for the distribution of water chemistry in this location for the 8–15 h period. The need for the evolution of reliable recording chemistry instruments which can be used in the offshore regions of the lakes is clearly indicated to effect a better understanding of the near shore chemistry at distances of 2 km from known waste discharges. Long-term period (greater than 15 h) temporal variations of the measured water chemistry are related to water movement patterns.     

Seasonal development of a turbid hydrothermal lake plume and the effects on the fish distribution

Measurements of the suspended particle concentration in a lake demonstrate the presence of a turbid hydrothermal plume. The plume, generated from a warm source develops upward carrying a suspension of particles from the bottom. It is found that the vertical structure of the plume depends on the stratification of the water column, which in turn depends on the seasonal meteorological conditions. During the stratified period of the lake, the plume is constricted to the hypolimnion zone. At the beginning of the summer season, the plume reaches the bottom of the metalimnion meanwhile at the end of this season the plume does not. In the mixed period of the lake, the plume develops in the whole water column and reaches the surface of the lake, where particles accumulate and spread around the center. Measurements of the vertical fish distribution in the stratified period show that the plume can constrict the fish habitat due to an increase of suspended particles transported by the plume.     

Retracted: Study of the change of water quality for a lake in Central China

Water environment has undergone several state changes, and the factors responsible for causing these water state changes are different. In this paper, a fuzzy comprehensive-quantifying assessment (FCQA) is proposed to evaluate the water quality changes for a representative lake in central China in recent decades. The innovation assessment method develops an index, S_mid, by applying a quantifying method to the fuzzy comprehensive assessment (FCA). The water quality of the lake is evaluated, and the temporal and spatial variations are analysed based on the data of 1991–2006. The Gray Filling Model [GM (1,1)] was used to predict the water quality trends in the subsequent 5 years, and the possible factors responsible for causing water environmental changes were analysed. The temporal and spatial variations of water quality show that there is a strong relationship between human activities and the water quality, and that excessive pen fish farming is the key internal pollution source threatening the lake at present.     

Retrieval of water quality from airborne imaging spectrometry of various lake types in different seasons

The suitability of the AISA airborne imaging spectrometer for monitoring lake water quality was tested in four surveys carried out in southern Finland in 1996-1998. Altogether, 11 lakes were surveyed and the total number of stations with concurrent remote sensing and limnological measurements was 127. The ranges of the water quality variables were: the sum of chlorophyll a and phaeophytin a 1-100 microg l(-1), turbidity 0.4-26 FNU, total suspended solids 0.7-32 mg l(-1), absorption coefficient of aquatic humus at 400 nm 1.2-14 m(-1) and secchi disc transparency 0.4-7 m. For the retrieval analyses, 24 AISA channels in the 450-786 nm range with a channel width of 6-14 nm were used. The agreement between estimated and observed water quality variables was generally good and R2 for the best algorithms was in the range of 0.72-0.90 over the whole dataset. The channels used for May were, in most cases, the same as those for August, but the empirical parameters of the algorithms were different. After seasonal grouping, R2 varied from 0.84 to 0.95. The use of apparent reflectance instead of radiance improved the estimation of water quality in the case of total suspended solids and turbidity. In the most humic lake, the empirical algorithms tested were suitable only for the interpretation of total suspended solids and turbidity.     

An optimization model for water quantity and quality integrated management of an urban lake in a water deficient city

This paper presents an optimization model for water quantity and quality integrated management of an urban lake in a water deficient city. A representative water quantity and quality safeguard system served urban lake, including multi-source water supply facilities, recirculating water purification facilities and surplus water discharge facilities, is widely used in Chinese water deficient cities. Because it is complicated, any mismanagement will result in water quality deterioration, water waste and high operation cost. The presented model attempts to achieve the objectives of controlling water pollution, reducing economic cost and improving water utilization efficiency through an optimized operating water safeguard system. The model is applied to Qingjing Lake in Tianjin, China. Results show that the model plays a more positive role for water quantity and quality integrated management.     

Short term effects of nutrient enrichment on the quality of irrigation water

The input of reclaimed effluents to an operational irrigation reservoir in the form of sporadic pulses produced changes in the behavior of the reservoir and in the quality of its outflow. A clogging event of strainers, that affected drip irrigation network, was connected to high concentrations of algae and zooplankton. Growth of these depends not only on nutrients supplied by effluents, but also on independent parameters such as depth of the reservoir. Application of a filterability test enabled estimation of the filterability capacity of the water and suggested a complicated clogging-effluent relationship.     

The effects of UV disinfection on drinking water quality in distribution systems

UV treatment is a cost-effective disinfection process for drinking water, but concerned to have negative effects on water quality in distribution system by changed DOM structure. In the study, the authors evaluated the effects of UV disinfection on the water quality in the distribution system by investigating structure of DOM, concentration of AOC, chlorine demand and DBP formation before and after UV disinfection process. Although UV treatment did not affect concentration of AOC and characteristics of DOM (e.g., DOC, UV_254, SUVA₂₅₄, the ratio of hydrophilic/hydrophobic fractions, and distribution of molecular weight) significantly, the increase of low molecular fraction was observed after UV treatment, in dry season. Chlorine demand and THMFP are also increased with chlorination of UV treated water. This implies that UV irradiation can cleave DOM, but molecular weights of broken DOM are not low enough to be used directly by microorganisms in distribution system. Nonetheless, modification of DOM structure can affect water quality of distribution system as it can increase chlorine demands and DBPs formation by post-chlorination.