نتایج جستجو برای: agricultural pesticides and irrigational returned water flow

تعداد نتایج: 17034756  

2012
Kees Vink Matthijs Bonte

Groundwater and raw water pollution risks of pesticides were assessed by analyses of groundwater samples and by modelling groundwater flow and chemical transport with a coupled model ‘train’ consisting of: a regional Modflow model for simulation of groundwater flow in the saturated zone (IBRAHYM, TNO 2007)) a 1-D model for simulation of water and pesticide transport in the unsaturated zone (PEA...

Shobhana Menon, Tanveer Alam Hashmi

Pesticides are chemical substances used to control pests in an effort to increase crop production and quality, and food storage. The levels of pesticides in different environmental compartments, such as water, soil, agricultural foods, and products of animal origin, have become a relevant issue. In this study, the levels of pesticide residues in Sabarmati River of Gujarat, India, have been inve...

Journal: :The Science of the total environment 2007
D C Gooddy S A Mathias I Harrison D J Lapworth A W Kim

Agrochemical contamination in groundwater poses a significant long term threat to water quality and is of concern for legislators, water utilities and consumers alike. In the dual porosity, dual permeability aquifers such as the Chalk aquifer, movement of pesticides and their metabolites through the unsaturated zone to groundwater is generally considered to be through one of two pathways; a rap...

Journal: :Environmental toxicology 2005
J L Bouldin J L Farris M T Moore S Smith W W Stephens C M Cooper

Contaminants such as nutrients, metals, and pesticides can interact with constructed wetlands and existing drainage ditches used as agricultural best-management practices. Our research has shown that the presence of macrophytes and a hydrologic regime aid in the transfer and transformation of pesticides associated with agricultural runoff. This study consisted of application of both atrazine (t...

2013
S. LAZIC D. SUNJKA I. MILOVANOVIC P. JOVANOV N. GRAHOVAC

Pesticides are used worldwide within agriculture to protect crops and ensure the quantity and quality of the harvest. However, intensive and inappropriate pesticides application can directly or indirectly affect different parts of the environment, especially water source. Besides the occurrence of pesticides in drinking water, control of pesticide presence in surface and groundwater is also ver...

2008
Yasser El-Nahhal Jamal Safi

Contamination of water resources with pesticides residues becomes a pressing problem in Gaza due to the frequent application of pesticides in the intensive agricultural system. This study tests the potential of using organo-bentonite as a porous material to remove bromoxynil residues from contaminated water. Bentonite surfaces were activated for removal of bromoxynil residues from water by simp...

Journal: :Environmental toxicology and chemistry 2008
Lori A Sprague Lisa H Nowell

To examine the effect of urban development on pesticide concentrations in streams under low-flow conditions, water samples were collected at stream sites along an urban land use gradient in six environmentally heterogeneous metropolitan areas of the United States. In all six metropolitan areas, total insecticide concentrations generally increased significantly as urban land cover in the basin i...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده مهندسی عمران 1391

one of the most commonly used techniques to reduce the corrosion rate of rebar in concrete is addition substances named corrosion inhibitors into the concrete. corrosion inhibitor is chemical compounds that were added to concrete to prevent corrosion of steel in concrete. sodium nitrate is a type of anodic inhibitors that this study investigatesthe effect of this inhibitor on the properties of ...

Journal: :Archives of environmental contamination and toxicology 2003
P B Key M H Fulton J A Harman-Fetcho L L McConnell

Freshwater drainage canals in South Florida are utilized to manage water in agricultural, urban, and water conservation areas and, as a result, collect urban and agricultural storm runoff that is discharged into the Atlantic Ocean and Gulf of Mexico. Pesticides in this runoff may be toxic to the biota inhabiting these waters. This study evaluated the effects of contaminants in South Florida can...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تحصیلات تکمیلی علوم پایه زنجان - دانشکده فیزیک 1392

in the first part of this thesis we explored wetting and its dynamics for small droplets. first, we showed how a simple feature of water droplets on a surface, i.e. laplace pressure, can be exploited to build a micropump. we investigated capillary pumping in microchannels both experimentally and numerically. putting two droplets of different sizes at the in/outlet of a microchannel, will ge...

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