خيارات البحث
النتائج 1771 - 1780 من 61,240
Quantifying source and dynamics of acidic pollution in a coastal acid sulphate soil area
2013
Phong, N.D. | To Phuc Tuong | Phu, N.D. | Nang, N.D. | Hoanh, Chu Thai
The in-depth knowledge on management and reducing annual acidic pollution is important for improving the sustainable livelihood of people living in areas with acid sulphate soils (ASS). This study involved a long-term (2001-2006), large-scale canal water quality monitoring network (87 locations) and a field experiment at nine sites to quantify the dynamic variability of acidic pollution and its source in a coastal area with ASS in the Mekong River Delta of Vietnam. Widespread acidic pollution (pH <5) of surface water occurred at the beginning of the rainy season, while pH of the canal water remained high (7-8) at the end of the rainy season and during the dry season. The study identified canal embankment deposits, made of ASS spoils from canal dredging/excavation, as the main source of acidic pollution in the surrounding canal network. The findings suggested that there was a linkage between the amount of acidic loads into canal networks and the age of the embankment deposits. The most acute pollution (pH ~ 3) occurred in canals with sluggish tidal water flow, at 1-2 years after the deposition of excavated spoils onto the embankments in ASS. The amount of acidic loads transferred to the canal networks could be quantified from environmental parameters, including cumulative rainfall, soil type and age of embankment deposits. The study implied that dredging/excavation of canals in ASS areas must be carried out judiciously as these activities may increase the source of acidic pollution to the surrounding water bodies.
اظهر المزيد [+] اقل [-]Sludge problems in some countries other than the United States [Land application, U.K., Scandinavia, France, Germany and Holland; United Kingdom; Netherlands; Germany, Federal Republic of].
1980
Jenkins S.H.
Explore the 'energy economics' of wastewater treatment and reuse.
1976
Roberts E.B. | Hagan R.M.
How to develop rational standards for ocean-discharge of metals [Waste disposal, water pollution].
1976
Bascom W.
Pollution of camel milk by heavy metals in Kazakhstan
2009
Konuspayeva G. | Faye B. | Loiseau G. | Diacono E. | Akhmetsadykova S.
Environmental contamination by heavy metals is a common fact in Central Asia. In the present study two sampling procedures were achieved: (i) Sampling of fodder, camel raw milk and shubat (fermented camel milk) in 8 farms closed to pollution sources from the South of Kazakhstan for copper, iron, manganese, zinc, arsenic and lead analysis, (ii) sampling of camel milk in 4 regions of Kazakhstan (63 samples) analyzed for lead, chrome and zinc contamination. In first sampling, camel milk contained 0.07 ± 0.04, 1.48 ± 0.53, 0.08 ± 0.03, 5.16 ± 2.17, <0.1 and 0.025 ± 0.02 ppm respectively for Cu, Fe, Mn, Zn, As and Pb. In shubat (fermented milk) the mean content was 0.163 ± 0.164, 1.57 ± 0.46, 0.088 ± 0.02, 7.217 ± 2.55 and 0.007 ppm respectively. Arsenic was detected in some samples of milk and shubat only. The trace elements concentration increase in shubat compared to milk but lead concentration decreased. No clear correlation was observed with fodder composition. In second sampling, the lead content was on average 250 ± 56 ppb in the camel milk with no significant differences between regions. The maximum value was observed at Atyrau (532 ppb). Zinc content in milk (5.42 ± 0.2 ppm) did not change significantly between regions. In reverse, chrome (59.5 ± 45.4 ppb) was higher in Shymkent region compared to others. These values were discussed according to the proximity of pollution sources. Specially, higher concentrations were experienced in fodder from pastures close to some industrial sites or high traffic road. (Résumé d'auteur)
اظهر المزيد [+] اقل [-]RHIZOtest: A plant-based biotest to account for rhizosphere processes when assessing copper bioavailability
2010
Bravin M. | Michaud A.M. | Larabi B. | Hinsinger P.
The ability of the free ion activity model (FIAM), the terrestrial biotic ligand model (TBLM), the diffusive gradients in thin films (DGT) technique and a plant-based biotest, the RHIZOtest, to predict root copper (Cu) concentration in field-grown durum wheat (Triticum turgidum durum L.) was assessed on 44 soils varying in pH (3.9e7.8) and total Cu (32e184 mg kg_1). None of the methods adequately predicted root Cu concentration, which was mainly correlated with total soil Cu. Results from DGT measurements and even more so FIAM prediction were negatively correlated with soil pH and over-estimated root Cu concentration in acidic soils. TBLM implementation improved numerically FIAM prediction but still failed to predict adequately root Cu concentration as the TBLM formalism did not considered the rhizosphere alkalisation as observed in situ. In contrast, RHIZOtest measurements accounted for rhizosphere alkalisation and were mainly correlated with total soil Cu. (Résumé d'auteur)
اظهر المزيد [+] اقل [-]How to design land application systems for agricultural utilization of sewage sludge [as a soil amendment].
1979
Imperial Valley leads the field in pesticide education, regulation, disposal [California].
1977
Finnell C.M.
Impacts of climate and management on water balance and nitrogen leaching from montane grassland soils of S-Germany
2017
Jin Fu | Gasche, Rainer | Na Wang | Haiyan Lu | Butterbach-Bahl, Klaus | Kiese, Ralf
