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951.
Abstract

The adsorption–desorption and leaching of flucetosulfuron, a sulfonylurea herbicide, was investigated in three Indian soils. Freundlich adsorption isotherm described the sorption mechanism of herbicide with adsorption coefficients (Kf) ranging from 17.13 to 27.99 and followed the order: Clayey loam?>?Loam?>?Sandy loam. The Kf showed positive correlation with organic carbon (OC) (r?=?0.910) and clay content (r?=?0.746); but, negative correlation with soil pH (r = ?0.635). The adsorption isotherms were S-type suggesting that herbicide adsorption was concentration dependent and increased with increase in concentration. Desorption followed the sequence: sandy loam?>?clayey loam?>?loam . Hysteresis (H) was observed in all the three soils with H?<?1. Leaching of flucetosulfuron correlated positively with the soil pH; but, negatively with the OC content. Sandy loam soil (OC- 0.40%, pH ?7.25) registered lowest adsorption and highest leaching of flucetosulfuron while lowest leaching was found in the loam soil (pH ? 7.89, OC ? 0.65%). The leaching losses of herbicide increased with increase in the rainfall intensity. This study suggested that the soil OC content, pH and clay content played important roles in deciding the adsorption–desorption and leaching behavior of flucetosulfuron in soils.  相似文献   
952.
Environmental Science and Pollution Research - Metalloids are a subset of particular concern to risk assessors and toxicologists because of their well-documented potential hazards to plant system....  相似文献   
953.
Environmental Monitoring and Assessment - Evaporation is an important meteorological variable that has a great impact on water resources. In the current research, climatology data, and seasonal...  相似文献   
954.
Environmental Science and Pollution Research - A Correction to this paper has been published: https://doi.org/10.1007/s11356-021-14155-3  相似文献   
955.
Journal of Material Cycles and Waste Management - Solidification/stabilization (S/S) of hazardous waste using cement for immobilization of contaminants has been recognized as Best Demonstrated...  相似文献   
956.
Environmental Science and Pollution Research - Protein hydrolysate was prepared from Acetes indicus which is a major bycatch among non-penaeid prawn landings of India. Hydrolysis conditions (enzyme...  相似文献   
957.
Data from seven Management Systems Evaluation Areas (MSEA) were used to test the sensitivity of a leaching model, Pesticide Root Zone Model-2, to a variety of hydrologic settings in the Midwest. Atrazine leaching was simulated because it was prevalent in the MSEA studies and is frequently detected in the region's groundwater. Short-term simulations used site specific soil and chemical parameters. Generalized simulations used data avail. able from regional soil databases and standardized variables. Accurate short-term simulations were precluded by lack of antecedent atrazine concentrations in the soil profile and water, suggesting that simulations using data for less than five years underestimate atrazine leaching. The seven sites were ranked in order of atrazine detection frequency (concentration > 0.2 μg L-1) in soil water at 2 m depth in simulations. The rank order of the sites based on long-term simulations were similar to the ranks of sites based on atrazine detection frequency from groundwater monitoring. Simulations with Map Unit Use File (MUUF) soils data were more highly correlated with ranks of observed atrazine detection frequencies than were short-term simulations using site-specific soil data. Simulations using the MIJUIF data for soil parameters were sufficiently similarity to observed atrazine detection to allow the credible use of regional soils data for simulating leaching with PRZM-2 in a variety of Midwest soil and hydrologic conditions. This is encouraging for regional modeling efforts because soil parameters are among the most critical for operating PRZM-2 and many other leaching models.  相似文献   
958.
959.
Natural radioactive materials under certain conditions can reach hazardous radiological levels. So, it becomes necessary to study the natural radioactivity levels in soil to assess the dose for the population in order to know the health risks and to have a baseline for future changes in the environmental radioactivity due to human activities. The natural radionuclide (226Ra, 232Th, and 40K) contents in soil were determined for 26 locations around the Upper Siwaliks of Kala Amb, Nahan and Morni Hills, Northern India, using high-resolution gamma-ray spectrometric analysis. It was observed that the concentration of natural radionuclides viz., 226Ra, 232Th and 40K, in the soil varies from 28.3 ± 0.5 to 81.0 ± 1.7 Bq kg−1, 61.2 ± 1.3 to 140.3 ± 2.6 Bq kg−1 and 363.4 ± 4.9 to 1002.2 ± 11.2 Bq kg−1 respectively. The total absorbed dose rate calculated from activity concentration of 226Ra, 232Th and 40K ranged from 71.1 to 162.0 nGy h−1. The radium equivalent (Req) and the external hazard index (Hex), which resulted from the natural radionuclides in soil, were also calculated and found to vary from 149.4 to 351.8 Bq kg−1and from 0.40 to 0.95 respectively. These values in Upper Siwaliks area were compared with that from the adjoining areas of Punjab. The radium equivalent activities in all the soil samples were lower than the limit (370 Bq kg−1) set in the Organization for Economic Cooperation and Development (OECD) report and the dose equivalent was within the safe limit of 1 mSv y−1.  相似文献   
960.
The mobilisation of metals (Al, Fe, Cd, Cu, Mn, Ni, Pb, Sn, Zn) from contaminated estuarine sediment has been examined using commercially available surfactants. Metal release by the anionic surfactant, sodium dodecyl sulphate (SDS), increased with increasing amphiphile concentration up to and above its critical micelle concentration (CMC). Metal mobilisation by the bile acid salt, sodium taurocholate, and the nonionic surfactant, Triton X-100, however, did not vary with amphiphile concentration. SDS was the most efficient surfactant in mobilising metals from the sample, and Cd, Cu and Ni were released to the greatest extents (12-18% of total metal at [SDS] > CMC). Metal mobilisation appeared to proceed via complexation with anionic amphiphiles and denudation of hydrophobic host phases. Surfactants may play an important role in the solubilisation of metals in the digestive environment of deposit-feeding animals and, potentially, in the remediation of metal-contaminated soil and sediment.  相似文献   
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