The Experts below are selected from a list of 36438 Experts worldwide ranked by ideXlab platform
Fiona Marshall - One of the best experts on this subject based on the ideXlab platform.
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the role of organic vs inorganic fertilizers in reducing phytoavailability of heavy metals in a wastewater Irrigated Area
Ecological Engineering, 2010Co-Authors: Anita Singh, Madhoolika Agrawal, Fiona MarshallAbstract:Long-term use of industrial and domestic wastewater for irrigation leads to accumulation of heavy metals in the soil and consequently in the edible portion of the plants. This study examined the role of fertilizers in reducing the heavy metal availability in the soil, and subsequent uptake in Beta vulgaris L. (var. All green). The effects of organic fertilizer as farmyard manure (FYM), commercial inorganic nitrogen, phosphorus and potassium (NPK) and a combination of FYM + N were compared with control having no fertilization on physico-chemical properties of the soil and heavy metal concentrations in the soil and plants. Soil treatments led to changes in the physico-chemical properties of the soil, modifying the phytoavailability of heavy metals. Phytoavailabilty of Cd, Cu, Pb, Zn, Mn, Ni and Cr was lowest in FYM- and highest in NPK- treated soil, compared to the untreated control. The yield of B. vulgaris was also highest in FYM-treated soil. As the application of FYM alone and in combination with N resulted in reduced heavy metal uptake and better yield, it may be considered an easy and cost-effective technique for reducing the levels of contamination in food crops.
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risk assessment of heavy metal toxicity through contaminated vegetables from waste water Irrigated Area of varanasi india
2010Co-Authors: Anita Singh, Rajesh Sharma, Madhoolika Agrawal, Fiona MarshallAbstract:In certain Areas of Varanasi city, waste water from Dinapur sewage treatment plant is used for irrigating vegetable plots. We quantified the concentrations of heavy metals, viz. Cd, Cr, Cu, Ni, Pb and Zn in soil, vegetables and the waste water used for irrigation. The waste water used for irrigation had the highest concentration of Zn followed by Pb, Cr, Ni, Cu and Cd. Continuous application of waste water for more than 20 years has led to accumulation of heavy metals in the soil. Consequently, concentrations of Cd, Pb and Ni have crossed the safe limits for human consumption in all the vegetables. Percent contribution of fruit vegetables to daily human intake for Cu, Ni, Pb and Cr was higher than that of leafy vegetables, while the reverse was true for Cd and Zn. Target hazard quotient showed health risk to the local population associated with Cd, Pb and Ni contamination of vegetables. Therefore, to reduce the health risk and the extent of heavy metal contamination, steps must be taken for efficient treatment of sewage. Regular monitoring of heavy metals in the vegetables grown in waste water Irrigated Areas is also necessary.
Binbin Jiang - One of the best experts on this subject based on the ideXlab platform.
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soil salinity and exchangeable cations in a wastewater Irrigated Area india
Journal of Environmental Quality, 2009Co-Authors: Trent W. Biggs, Binbin JiangAbstract:: The salinity and cation composition of water and soil were documented in a large (98 km(2)) wastewater-Irrigated Area (WIA) downstream of Hyderabad, India. The wastewater, which flows in a river that passes through the city, had a high to very high salinity hazard (EC = 1.1-3.0 dS m(-1)) that increased with distance from the city. The EC of soil Irrigated by wastewater sampled within 8 km of the city was 6.2 to 8.4 times the EC of soil Irrigated by uncontaminated groundwater. Between 57 to 100% of soil samples in the upper 10 cm within 8 km of the city exceeded the salinity tolerance of rice (Oryza sativa L.). Soil salinity fell rapidly after 8 km downstream and changed most in the upper 0 to 5 cm of the soil, indicating retention of cations in the upper soil horizon. The effect of wastewater irrigation on soil exchangeable cations was most evident for Na(+) (Exch-Na) near the city (<8 km downstream), where Exch-Na averaged 20 to 22 times the Exch-Na in soils Irrigated by groundwater outside the WIA. Exchangeable Mg(+) and K(+) correlated with clay percentage, though both still had higher concentrations near the city controlling for clay content. Near the city, where salinity and Exch-Na concentrations were highest, farmers had replaced rice with para grass [Brachiaria mutica (Forsk.)], which has higher salinity tolerance and expanding demand as a fodder crop. Salinity may constrain rice production in wastewater-Irrigated Areas of India and elsewhere.
Anita Singh - One of the best experts on this subject based on the ideXlab platform.
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the role of organic vs inorganic fertilizers in reducing phytoavailability of heavy metals in a wastewater Irrigated Area
Ecological Engineering, 2010Co-Authors: Anita Singh, Madhoolika Agrawal, Fiona MarshallAbstract:Long-term use of industrial and domestic wastewater for irrigation leads to accumulation of heavy metals in the soil and consequently in the edible portion of the plants. This study examined the role of fertilizers in reducing the heavy metal availability in the soil, and subsequent uptake in Beta vulgaris L. (var. All green). The effects of organic fertilizer as farmyard manure (FYM), commercial inorganic nitrogen, phosphorus and potassium (NPK) and a combination of FYM + N were compared with control having no fertilization on physico-chemical properties of the soil and heavy metal concentrations in the soil and plants. Soil treatments led to changes in the physico-chemical properties of the soil, modifying the phytoavailability of heavy metals. Phytoavailabilty of Cd, Cu, Pb, Zn, Mn, Ni and Cr was lowest in FYM- and highest in NPK- treated soil, compared to the untreated control. The yield of B. vulgaris was also highest in FYM-treated soil. As the application of FYM alone and in combination with N resulted in reduced heavy metal uptake and better yield, it may be considered an easy and cost-effective technique for reducing the levels of contamination in food crops.
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risk assessment of heavy metal toxicity through contaminated vegetables from waste water Irrigated Area of varanasi india
2010Co-Authors: Anita Singh, Rajesh Sharma, Madhoolika Agrawal, Fiona MarshallAbstract:In certain Areas of Varanasi city, waste water from Dinapur sewage treatment plant is used for irrigating vegetable plots. We quantified the concentrations of heavy metals, viz. Cd, Cr, Cu, Ni, Pb and Zn in soil, vegetables and the waste water used for irrigation. The waste water used for irrigation had the highest concentration of Zn followed by Pb, Cr, Ni, Cu and Cd. Continuous application of waste water for more than 20 years has led to accumulation of heavy metals in the soil. Consequently, concentrations of Cd, Pb and Ni have crossed the safe limits for human consumption in all the vegetables. Percent contribution of fruit vegetables to daily human intake for Cu, Ni, Pb and Cr was higher than that of leafy vegetables, while the reverse was true for Cd and Zn. Target hazard quotient showed health risk to the local population associated with Cd, Pb and Ni contamination of vegetables. Therefore, to reduce the health risk and the extent of heavy metal contamination, steps must be taken for efficient treatment of sewage. Regular monitoring of heavy metals in the vegetables grown in waste water Irrigated Areas is also necessary.
Olivier Merlin - One of the best experts on this subject based on the ideXlab platform.
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an original interpretation of the wet edge of the surface temperature albedo space to estimate crop evapotranspiration seb 1s and its validation over an Irrigated Area in northwestern mexico
Hydrology and Earth System Sciences, 2013Co-Authors: Olivier MerlinAbstract:The space defined by the pair surface tempera- ture (T ) and surface albedo ( ), and the space defined by the pair T and fractional green vegetation cover (fvg) have been extensively used to estimate evaporative fraction (EF) from solar/thermal remote sensing data. In both space-based approaches, evapotranspiration (ET) is estimated as remotely sensed EF times the available energy. For a given data point in the T space or in the T fvg space, EF is derived as the ratio of the distance separating the point from the line identified as the dry edge to the distance separating the dry edge and the line identified as the wet edge. The dry and wet edges are classically defined as the upper and lower limit of the spaces, respectively. When investigating side by side the T and theT fvg spaces, one observes that the range cov- ered by T values on the (classically determined) wet edge is different for both spaces. In addition, when extending the wet and dry lines of the T space, both lines cross at 0.4 although the wet and dry edges of the T fvg space never cross for 0 fvg < 1. In this paper, a new ET (EF) model (SEB-1S) is derived by revisiting the classical physical in- terpretation of the T space to make its wet edge consis- tent with that of the T fvg space. SEB-1S is tested over a 16 km by 10 km Irrigated Area in northwestern Mexico dur- ing the 2007-2008 agricultural season. The classical T space-based model is implemented as benchmark to evalu- ate the performance of SEB-1S. Input data are composed of ASTER (Advanced Spaceborne Thermal Emission and Re- flection radiometer) thermal infrared, Formosat-2 shortwave, and station-based meteorological data. The fluxes simulated by SEB-1S and the classical T space-based model are compared on seven ASTER overpass dates with the in situ measurements collected at six locations within the study do- main. The ET simulated by SEB-1S is significantly more ac- curate and robust than that predicted by the classical T space-based model. The correlation coefficient and slope of the linear regression between simulated and observed ET is improved from 0.82 to 0.93, and from 0.63 to 0.90, respec- tively. Moreover, constraining the wet edge using air temper- ature data improves the slope of the linear regression between simulated and observed ET.
R W Dawson - One of the best experts on this subject based on the ideXlab platform.
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characterizing and comparing risks of polycyclic aromatic hydrocarbons in a tianjin wastewater Irrigated Area
Environmental Research, 2002Co-Authors: Xilong Wang, Shu Tao, R W DawsonAbstract:A probability risk assessment was conducted to characterize the ecotoxicity of three polycyclic aromatic hydrocarbons (PAHs), including benzo[a]pyrene, fluoranthene, and phenanthrene, to various species in a wastewater-Irrigated Area of Tianjin, China. The relative risk of these chemicals was investigated using joint risk probability distribution curves, which were generated based on the distributions of exposure and acute toxicity data. Risk at various exposure levels was discussed. The results indicated that among the three PAHs studied, the overall risk of phenanthrene was the highest, with that of benzo[a]pyrene the lowest, due mainly to their exposure concentrations. For lower exposure levels at which the percentage of species affected was less than 20%, the risk associated with benzo[a]pyrene was clearly higher than that of the other two chemicals.
