Showing 3 results for Nitrate.
A. Jafari Malekabadi, M. Afyuni, S. F. Mousavi, A. Khosravi,
Volume 8, Issue 3 (10-2004)
Abstract
In recent decades, the use of nitrogen fertilizers has increased irrespective of their effects on soil properties, agricultural products and, particularly, on environmental pollution. Nitrate easily leaches from soils into groundwater. The objective of this study was to determine temporal and spatial nitrate concentrations in groundwater in agricultural, industrial and urban regions in some parts of Isfahan Province. Water samples were collected monthly from 75 agricultural, industrial, and urban wells of Isfahan, Najaf-abad, Shahreza, Natanz and Kashan during January-May 2001. The results indicated that NO3-N concentrations in most of the regions studied were higher than the standard level (10 mg/l) and nitrate pollution must be reckoned among the most serious problems of sustainable agriculture and exploitation of groundwater resources. Average NO3-N concentration in different wells ranged from 1.03 to 50.78 mg/l (4.64 to 228.5 mg/l as nitrate). The average NO3-N concentration in groundwater of Najaf-abad, Shahreza, Isfahan and Natanz-Kashan was 17.56, 14.6, 16.04, and 8.24 mg/l and 95.5, 100, 84 and 33.3 % of total wells in these regions had nitrate concentrations above the standard level, respectively. Maximum NO3-N concentration was detected in the agricultural region south of Najaf-abad (64.6 mg/l). Nitrate pollution in most of the sampling areas was mainly linked to agricultural activities. The average NO3-N concentration in groundwater of all agricultural, industrial, and urban regions, except for urban regions of Natanz and Kashan, were above the standard level. Generally, nitrate concentration level in groundwater increased with time and was maximum in March and April.
M. M. Jowkar, H. Salehi,
Volume 10, Issue 3 (10-2006)
Abstract
Tuberose is one of the tropical and subtropical bulbous cut flowers cultivated extensively in most floricultural regions of Iran. Although it has a high potential for a long vase life after harvest, tuberose declines rapidly at home. In order to overcome this problem, two experiments were conducted on a local cultivar, “Goldorosht-e-Mahalat”, using a completely randomized design. To find a suitable preservative which provides the longest vase life for tuberose, the experiment was carried out by applying the carelessness of most consumers: not recutting stem ends nor changing the vase solutions. In the first experiment the preservative solutions were: sucrose (1, 2 and 3%), silver thiosulphate (0.4, 0.8 and 1.2 mM), silver nitrate (50, 100 and 150 mgl-1), citric acid (150, 300 and 450 mgl-1) and tap water as the control. In the early days of the experiment, silver thiosulphate caused severe burning of the florets, silver nitrate caused the wilting of the florets and bent the end of the flower spikes and sucrose didn’t have any positive effect, but decreased the vase life. The longest vase life belonged to citric acid, after which the control (tap water) was placed. The second experiment was conducted to determine the role of the water quality and citric acid. The treatments were: sterilized distilled water, citric acid made with sterilized distilled water (150, 300 and 450 mgl-1) and tap water as the control. The longest and the shortest vase life belonged to sterilized distilled water and the control (tap water) respectively. The citric acid prepared with sterilized distilled water had a desirable effect on the vase life of cut tuberose flowers. This effect increased with the increment of the acid up to 450 mgl-1.
R. Lalehzari, S. H. Tabatabaei,
Volume 17, Issue 65 (12-2013)
Abstract
Shahrekord aquifer is depleted by almost 800 deep and semi-deep wells, the majority of which are agricultural wells and some have urban usage. In southern parts of the plain, the water table has fallen strongly because of immoderate discharge and decreased the quality of water by urban wastewater. The main objective of this study is investigation of subsurface dam construction and its effects on water table in consumption locations, reduction of deliveries costs and interception of contaminant transport. Therefore, the Shahrekord aquifer model was simulated with hydrodynamic coefficients calibration by PMWIN5.3 Software. The southern outlet of plain (near Bahram-Abad village) was selected to study subsurface dam construction, then a horizontal-flow barrier in this place was set with mean hydraulic conductivity equal to 0.5 m/day. Water table situation and nitrate concentration were analyzed using ArcGIS9.2 software before and after dam construction. The results showed that the subsurface dam rises groundwater level in 4 kilometers distance of upstream areas. Also, the available volume of water increased about 1.5 Mm3. Nitrate concentration didn't show to be considerably different from the initial state. But, it is likely that contamination in the storage resource will rise because it is located near Shahrekord water treatment plant and also due to the discharge of wastewater wells.
