Pollution of river water

Chentical compositions of river water are determined mainly by inputs of ground water and surface water (rainwater, ice melted water), aerosol fall, biological activity, and evaporation. In addition to these processes, anthropogeitic influence (Appendix, Plate 36) is increasing in recent years. 

Element 1990 World production (gm/year) Unpolluted river flux (gm/year) Ratio of 1990 world production to unpolluted dissolved plus particulate river flux 

Source World production figures fi om mineral commodities summaries (1991) 

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Kobayashi, J. (1971) Relation between the "Itai-Itai" disease and the pollution of river water by cadmium from a mine. Proc. 5th Int. Conf. on Advanced Water Pollution Research, San Francisco and Hawaii, Vol. 1-25, pp. 1-7. Oxford Pergamon Press. 

The amount of dissolved solids in river water increases with the distance from its source. The chief sources of pollution of river-water are by the discharge into them of the sewage of towns and cities, or of the waste products of factories. 

Al-Muhandis M. H. (1977) Pollution of river water in Iraq. Hydro. Sci. Publ. 123, 467-470. 

Zoeteman, B.C.J., Harmsen, K., Linders, J.B.H. (1980) Persistent organic pollutants in river water and ground water of the Netherlands. Chemosphere 9, 231-249. 

Germain A, Langlois C. 1988. Pollution of the water and suspended sediments of the St. Lawrence River (Ontario, Quebec, Canada) by organochlorine pesticides, polychlorinated biphenyls, and other priority pollutants. Water Pollution Research Journal of Canada 23(4) 602-614. 

Ma, M. Wang, Y. Wang Z. 1999, Sample pretreatment for toxic assessment of organic pollutants in river water. Huanjing Kexue/Errviron. Sci. 20 80-83. 

Part 1, Alpine Water Resources, examines the hydrological basics, the impacts of climate change in the Swiss Alps, and human interventions in mountain waters. Part 11, Biogeochemistry and Pollution of Alpine Waters, deals with the chemistry of mountain rivers, the effects of acid deposition on high elevation lakes, the glaciers as archives of atmospheric deposition, and the occurrence of persistent organic contaminants. 

In particular, the priority pollutant phenols (PPP), identified by EPA since the 1970s are widespread water pollutants that must receive the greatest attention due to their recognized toxicity. For the separation of eleven PPP, an ion-interaction reagent (HR) RP HPLC/UV method has been developed that allows limits of detection lower than 30 J,g in river waters, after LLE in dichlo-romethane and a 500-fold pre-concentration [82]. Through on-line SPE followed by both UV and electrochemical detection [83], 16 priority phenols have been determined in water samples with the LOD value for chlorophenols lower than 1 ng L [84]. LODs at ng L levels were obtained for all the PPPs in samples of river water, employing a relatively small volume of sample through an on-line SPE HPLC/MS method with an APCI source. 

IP LLE methods are generally employed for the extraction of LASs from river waters and the solvent sublation method of Wickbold is still used for their extraction from seawater [85]. SPE methods making use of C18 and C8 phases are largely employed [85]. The amount of sorbent is optimized as a function of the degree of pollution and the average composition of river waters [85]. The performances of C18 disks and C18 cartridges are compared [85]. 

Point sources are mainly responsible for the pollution of surface waters (rivers, lakes, seas), whereas nonpoint sources mainly contribute to the pollution of groundwater resources. Moreover, releases from point sources can be treated by wastewater treatment plants, whereas nonpoint source releases can only be minimized. 

P 25.1 Assessing the Effect of River Water Pollution on the Quality of the Bank Filtrate Used for Drinking-Water Supply... 

Rivers make a considerable contribution to the level of pollution of Arctic water. The concentration of pollutant k in river 7 is 7K. Pollutant k enters compartment Qijk with velocity c7 reflecting the mass flow per unit time. Subsequently, the spreading of pollutant k in Q is described by other sub-blocks. 

Biochemical oxygen demand (BOD) is arguably the oldest total parameter used for the characterization of water quality. It was introduced in the first decade of the twentieth century as a test for the organic pollution of rivers. BOD is the amount of oxygen in mg L 1 required for the oxidation of the organic matter contained in water by biological action under standardized test conditions (usually a temperature of 20°C and an incubation time of 5 days).8 9 The test is often used to evaluate the efficiency of wastewater treatment processes. 

Membrane contactors can be effectively used also for disinfection purposes (e.g., water ozonation) [28] or for the oxidation of species present into water, for example, arsenic. Although the content of arsenic in seawater is today within the accepted limits, it is foreseen that in the future its concentration could increase, due to the increase of pollution of rivers and groundwaters. Usually, arsenic is contained in water as As(III) and As(V) forms, in different amounts. All arsenic-removal technologies have a better performance when arsenic is present in the pentavalent... 

Waste waters in the production of silicone monomers and polymers is an important economic issue. It is connected with environmental protection from air contamination and pollution of rivers, seas and other water bodies. Especially important in silicone production is the purification of acid waste waters from organic impurities (toluene, benzene, methyl alcohol, etc.). 

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