جستجوی مقالات مرتبط با کلیدواژه « آلودگی آب های زیرزمینی » در نشریات گروه « پزشکی »

Today, the pollution caused by landfills is considered as one the serious environmental threats, including groundwater resources. The purpose of this research, the use of mathematical models and numerical with high precision in determining and explaining the current situation and relatively accurate predictions, to examine the groundwater pollution caused by leakage of leachate centers around landfill.
In this research, The MODFLOW, MODPATH and MT3DMS models was used to estimate the speed of movement of pollution, tracing path and simulate the process of transfer of leachate producedat San Angelo landfill site in the United States to the downstream drinking water well. Also Three scenarios of a) improved bedding of landfill bottom and reduced leachate penetration to 25%; b) Reducing the amount of extraction downstream drinking water well to 20%; c) landfill Movement as much as 100m to upstream were evaluated.
The results of the modeling showed that in the current situation, the leachate produced landfill reaches the downstream well going through a distance of 608 meters in 2158 days. By applying three scenarios in the numerical model was seen that the leachate reaches to the downstream well by passing a distance of 613, 618, and 667 m in 4000, 3250 and 4000 days, respectively.
Therefore, in the field of locating the landfill and leakage of leachateto groundwater, numerical models can be used to predict the direction and speed of pollution movement and to make management decisions for reducing the time and distance of arriving the pollution at the groundwater.

Groundwater is the most important source of water supply in industries and agricultures; therefore the need to protect this valuable resource against pollution is felt more than ever. In this study, the possible impact of Yazd municipal solid waste landfill was investigated on the chemical quality of the area’s groundwater. Groundwater samples were collected from three wells around the landfill, one located at the upstream and two located at the downstream. The following parameters were measured: pH, electrical conductivity (EC), chloride (Cl-), nitrate (NO3-), total hardness, alkalinity and heavy metals including lead (Pb), cadmium (Cd), copper (Cu) and zinc (Zn). The data statistical analysis was performed by SPSS t-test and Microsoft Excel was used to draw the curves. The groundwater’s pH in downstream was significantly lower than the pH in upstream (P = 0.038). also the values of EC, Cl-, NO3-, total hardness and alkalinity were significantly higher in downstream (P < 0.05). However no increase was observed in heavy metal obtained from downstream groundwater of the landfill. The study findings indicated that the chemical quality of groundwater improves by increasing the distance from the landfill. Therefore it is better to avoid utilizing the groundwater closed to the landfill. However, the best practice is insulating the landfill’s floor to control the movement of the current contaminations into the groundwater.

Ground water is considered as a valuable resource for drinking, agricultural, and industrial uses. As human activities are known to affect water quality, studies of this source are necessary to maintain quality standards. Despite heavy agricultural and industrial activity in the Lenjanat region (Isfahan), there has been no evaluation of ground water quality in this area.In this research project, chemical parameters such as anions, cations and heavy metals were determined in 16 wells over four seasons. The yearly averages of the parameters calculated and displayed by the graphs.The results showed that "Lenjanat" ground water qualifies as very hard water. Most chemical parameters such as BOD, Cod: TDS, EC, S04 of wells number 1,2,3 and 14 exceed drinking water standards. The wastewater lagoons of the Isfahan Steel Mill may be polluting well No. 3 and the other three wells. Wells No.4 and 5, located in the lower areas of Munitions Factories, showed a ver's high COD.Due to the west-to-east direction of surface slopes (from munitions factories towards the above-mentioned wells) the water could be polluted by waste material from the industry. It seems that severe pollution of ground water exists around these factories and extensive studies are required to determine the type of organic and inorganic waste and the exact source of pollution in order to control groundwater quality.