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PubMed2004

[GIS and scenario analysis aid to water pollution control planning of river basin].

The forward and backward algorithms for watershed water pollution control planning were summarized in this paper as well as their advantages and shortages. The spatial databases of water environmental function region, pollution sources, monitoring sections and sewer outlets were built with ARCGIS8.1 as the platform in the case study of Ganjiang valley, Jiangxi province. Based on the principles of the forward algorithm, four scenarios were designed for the watershed pollution control. Under these scenarios, ten sets of planning schemes were generated to implement cascade pollution source control. The investment costs of sewage treatment for these schemes were estimated by means of a series of cost-effective functions; with pollution source prediction, the water quality was modeled with CSTR model for each planning scheme. The modeled results of different planning schemes were visualized through GIS to aid decision-making. With the results of investment cost and water quality attainment as decision-making accords and based on the analysis of the economic endurable capacity for water pollution control in Ganjiang river basin, two optimized schemes were proposed. The research shows that GIS technology and scenario analysis can provide a good guidance to the synthesis, integrity and sustainability aspects for river basin water quality planning.

Algorithms↗
PubMed1979

The relationship between rainfall and well water pollution in a West African (Gambian) village.

Water pollution was monitored in six Gambian village wells over a period of 8 months spanning the 5-month monomodal rains and the pre- and post-rains dry periods. Faecal coliform (FC) and faecal streptococci (FS) counts were high throughout and there was a massive increase associated with the onset of the rains, maximum counts exceeding 5 x 10(5)/100 ml. This pattern was largely sustained throughout the rainy season. Some individual variations in patterns of pollution could be ascribed to well design, in particular lining of the shaft, but no well was protected from the seasonal increase in faecal pollution. The source of the increased pollution appeared to be a flushing in of faecal material of indeterminate or mixed human and animal origin, probably over considerable distances. Peaks of pollution not associated with rainfall episodes could have resulted from the practice of communal laundering in the near vicinity of the wells. Specific pathogens including Salmonella spp. were isolated only intermittently. Attention has been drawn to a problem complicating the standard method for assessing FC counts.

Animals↗
PubMed1996

[Expression of ras P21 oncoprotein in Syrian golden hamster embryo cells transformation induced by water pollutants].

Carcinogenic activities of organic pollutants in freshwater collected from Taihu Lake, Chaohu Lake and Dianshanhu Lake in Jiangsu Province were analyzed by in vitro Syrian hamster embryo (SHE) cell transformation and immunohistochemical methods. Results revealed organic pollutants in the originally collected water could, to the different extent, induce morphological changes of SHE cells, with a certain dose-response relationship. Expression of ras P21 oncoprotein increased in typical transformation cells of type I, which showed a positive immunohistochemical stain. And, ras P21 oncoprotein expressed to a certain extent in types I and II transformation cells during transition stage. It suggests water pollutants in the above-mentioned lakes had certain carcinogenic activities, and activation of ras oncogene may be one of the mechanisms to induce malignant transformation of SHE cells.

Animals↗
PubMed2004

The use of different enzymes in feral freshwater fish as a tool for the assessment of water pollution in South Africa.

Selected enzymes in the organs/tissues of two fish species (Oreochromis mossambicus and Labeo umbratus) were evaluated as biomarkers of water pollution in warm- and cold-water systems. The fish were caught using standard techniques during two high-flow and two low-flow surveys. The results indicated that the fluctuating enzyme activities measured were not a result of pollution but could be initiated as a result of (1) no or too little pollution, (2) handling of the fish, and (3) struggling in the nets. Furthermore, most of the enzymes are nonspecific for the specific pollutants present. It is concluded that the selected enzymes could not be successfully employed as biomarkers of water pollution when the organisms are sampled from a polluted water source.

Animals↗
PubMed1984

A tentative assessment of water pollution by the medaka egg stationing method: aerial application of fenitrothion emulsion.

To determine how centrum abnormalities in medaka could be used to indicate the degree of water pollution, several rearing experiments were carried out. Medaka eggs were placed at certain points on a stream flowing from an area in which fenitrothion emulsion (organophosphorous pesticide--MEP) was being applied aerially. There was sufficient probability that the eggs were exposed to the MEP. They were brought to the laboratory, and reared in dechlorinated water to adulthood. The external forms and vertebral centra of each adult fish were closely observed. It was found that the incidence of centrum-damaged fish in the exposure experiment groups was significantly higher than in the control and blank experiments, and the influence of the aerial application of MEP was clearly indicated in this manner. Consequently, it was confirmed that centrum abnormalities in medaka may be used as a biological index for indicating the degree of water pollution by agricultural chemicals.

Abnormalities, Drug-Induced↗
PubMed2002

Xenobiotics removal from polluted water by a multifunctional constructed wetland.

Removal efficiencies on xenobiotics from polluted water in a twin-shaped constructed wetland consisting of a vertical flow chamber with the crop plant Colocasia esculenta L. Schott and a reverse vertical flow one with Ischaemum aristatum var. glaucum Honda, were assessed by chemical analysis and bioassays. After a four-month period of application, removal efficiencies of the applied pesticides parathion and omethoate were 100% with no detectable parathion and omethoate in the effluent. For the applied herbicides, the decontamination was less efficient with removal efficiencies of 36% and 0% for 4-chloro-2-methyl-phenoxyacetic acid and dicamba, respectively. As shown by toxicity assay with duckweed Lemna minor L., growth retardation may occur if the water treated for herbicide removal is used in irrigation of sensitive cultivars in agriculture or horticulture. In contrast to I. aristatum var. glaucum Honda, the crop C. esculenta L. Schott has a high yield in biomass production as a valuable source of renewable energy.

Agriculture↗
PubMed2005

Adaptive management, monitoring, and the ecological sustainability of a thermal-polluted water ecosystem: a case in SW Spain.

The construction of the Almaraz nuclear power plant in Spain in the 1970s posed interesting environmental problems concerning the construction of a cooling reservoir (Arrocampo reservoir) to cool the steam condensers and the consequent heating of the reservoir's water. The socio-political context forced decision makers to set up a project for the monitoring and management of the environmental impacts derived from the construction and operation of the power plant. Numerous scientific and technical specialists collaborated with the representatives of social groups towards two goals: the improvement of the biodiversity and of the efficiency of the cooling system. These goals involved the monitoring and managing of the system with respect to different biological aspects, mainly limnology, ichthyology, avian fauna and vegetation. The management plan yielded numerous results. The control of the water eutrophy is one of the most important due to its repercussion on the rest of the ecosystem, especially the fish fauna. The development of the shore vegetation slowly increased the patchwork nature of the reservoir, leading to a greater diversity of the avian species. This paper describes the monitoring and management of the Arrocampo ecosystem, the condition before and after the construction of the reservoir and the results obtained concerning some biological communities.

Ecosystem↗
PubMed1990

Nitriles and isonitriles as interferents in cyanide determination in polluted waters.

The interference of nitriles and isonitriles in cyanide determination was studied using the pyridine-barbituric acid direct spectrophotometric method or the same method after distillation of the sample, a microdiffusion-potentiometric (ion-selective electrode) also being used. Phenylacetonitrile, benzonitrile, acrylonitrile, iminodiacetonitrile and acetonitrile were tested as nitriles. Benzyl isocyanide butyl isocyanide and 1-[(isocyanomethyl)sulphonyl]-4-methylbenzene were assayed as isonitriles. It can be concluded that both nitriles and isonitriles should be considered as interferents in all the methods of cyanide determination studied. The level of interference generally increases with the ratio of interfering compound to cyanide and is greatest for low cyanide concentrations.

Cyanides↗