Sh. Amirmoradi; P. Rezvani Moghaddam; A. Koocheki; Shahnaz Danesh; A. Fotovat
Abstract
Introduction: Accumulation of heavy metals in agronomic soils continuously by contaminated waste waters not only causes to contamination of soils but also it affects food quality and security. Cadmium and lead are one of the most important heavy metals due to long permanence and persistence in soil can ...
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Introduction: Accumulation of heavy metals in agronomic soils continuously by contaminated waste waters not only causes to contamination of soils but also it affects food quality and security. Cadmium and lead are one of the most important heavy metals due to long permanence and persistence in soil can cause problems to human and animal health. Some medicinal plants are able to accumulate of heavy metals from contaminated soils. Heavy metals are not able to enter in the essential oil of some aromatic plants. Study of these plants helps human to select them for cultivating the resistant medicinal plants in contaminated soils.
Materials and Methods: This experiment was carried out in the research greenhouse of agriculture faculty of Ferdowsi university of Mashhad in 2011. Seeds were cultivated in planting aprons into peat moss medium. Then the uniform plantlets were transferred into soil in the plastic boxes (30×50×35 cm) at two leaf stage. In each box 6 plantlets were sown with distance of 15 cm on the planting rows and 20 cm between rows. Experiment was set up as factorial on the basis of randomized complete block design with three replications. The first factor was cadmium concentrations consisted of 0,10,20,40 mg per kilogram and the second factor was lead concentrations consisted of 0,100,300 and 600 mg/kg. Plants were irrigated during of15 weeks with cadmium and lead nitrogen nitrate solutions and then irrigated with distilled water. The differences of nitrogen amounts in treatments were compensated with ammonium nitrate on the basis of differences between level of the highest treatment and the treatment which obtained lower amount of nitrogen. Plants were harvested after 180 days at the beginning of flowering. All shoots and roots were weighted separately as fresh weight and then were dried under shading and then were weighted. The essential oil sage was determined by using of 30 grams of dried sage leaves with distillation method with Clevenger. Cadmium and lead contents in shoot and root were measured by wet digestion method (digestion by Perchloric and Nitric acid). Cadmium and lead contents were detected by atomic absorption apparartus. Data were analyzed by MSTATC software and all means were compared by DMRT at 5% of probability.
Result and Discussion: Results argued that fresh weight of sage at 40 mg/kg of cadmium were decreased 4.61% as compare as control. Dry weight of sage decreased at 600 mg/kg of lead 11.08 % as compare of control. Mean comparisons indicated that at the highest concentrations of cadmium and lead fresh and dry weight of sage were dropped. Growth decrement due to toxicity of cadmium causes to photosynthesis and respiration decline, carbohydrate metabolism decreasing and leaf chlorosis. Researchers observed lead ions by interfering with water balance lead to water stress. High concentrations of lead may cause to decrease the availability of water for plant and high concentrations of cadmium causes to disturb the protein synthesis and lead to protein decline in plant cells. Plant height of sage was declined at 40 mg/kg and 600 mg/kg as compared as control 14.17 and 10.83, respectively. Essential oil in sage was dropped in high levels of cadmium and lead as compare of control 12 and 14.51, respectively. Researchers stated that cadmium concentrations of 2,6 and 10 mg/lit and 50,100 and 500 mg/kg of lead had no significant effect on peppermint, but caused to drop the essential oil percentage of dill and basil.
Disturbance of carbon nutrition in plant cells during the photosynthesis process by heavy metals lead to a decrease in the essential content. The most cadmium absorption by sage shoots belonged to 40 mg/kg and 600 mg/kg of cadmium and lead, respectively and then 40 mg/kg cadmium and 300 mg/kg lead were ranked as second treatment. Increase of cadmium and lead concentrations in irrigation water led to increase of these heavy metals into sage shoots. Increase of lead and cadmium concentrations caused to antagonistic effects of cadmium and lead absorption into shoots of sage. In this experiment cadmium and lead concentrations of all treatments were too below to detect by atomic absorption apparatus. In this study cadmium and lead could not enter to essential oil. Researchers stated that high doses of cadmium, lead, zinc and copper concentrations could not enter into essential oil in sage. Some researchers showed that cadmium, lead and copper were not transferred to essential oil of peppermint, dill and basil during the essential oil distillation process. This finding confirmed that selection of medicinal plants as alternative plants with crops in cadmium and lead contaminated soils.
Conclusion: Fresh and dry weight of Sage in the condition of contaminated soil by 100 mg/kg cadmium and 600 mg/kg lead were declined 4.61 and 5.16 % as compare as control, respectively. At the highest doses of cadmium and lead the essential oil of sage were dropped but, these heavy metals were not detected in essential oil. So, it is seems that this medicinal plant may be applied in the contaminated soil or in the condition of using of contaminated irrigated water by cadmium and lead.
S.A. Ghassemi; Sh. Danesh
Abstract
In this research a fuzzy decision making model was presented to assess and rank various water desalination methods and ultimately select the best alternative. The desalination alternatives which were investigated included Reverse Osmosis, Electrodialysis, Multi-Stage Flash Distillation, Multi-Effect ...
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In this research a fuzzy decision making model was presented to assess and rank various water desalination methods and ultimately select the best alternative. The desalination alternatives which were investigated included Reverse Osmosis, Electrodialysis, Multi-Stage Flash Distillation, Multi-Effect Distillation, Vapor Compression and Ion Exchange. The model was carried out in three steps: problem definition, fuzzy computations and ranking of alternatives. The hierarchy structure used for problem definition included 5 levels of: goal, main criteria, sub-criteria, factors, and desalination alternatives. The criteria, sub-criteria and factors and the relative importance of each were determined based on the experts' opinions and the literature results. In the next step, by using Chang's extent analysis, various desalination alternatives were evaluated on the basis of the selected criteria, sub-criteria and factors. For assessment of accuracy and its practical application, the model was used in a case study concerning quality management of the brackish water from a number of wells located in the City of Torbat-e-Heydaryieh. The results of the research indicated that the Electrodialysis process, with the final weight of 0.255, was the best method of desalination for the investigated wells. The sensitivity analysis also showed that the fuzzy model has a low degree of sensitivity in regard to the changes in criteria weights, meaning that the results are adequately reliable. The results furthermore pointed out that the fuzzy analytical hierarchy process can be used as an efficient tool for systematic decision making in the area of qualitative water resource management.
S.A. Ghassemi; Sh. Danesh; A. Alizadeh
Abstract
Abstract
One of the major aspects of water resources management in the arid and semi-arid regions is the use of unconventional water sources such as effluents from wastewater treatment plants. As a result, assessment of water supply potential as well as fertilizer values of these unconventional water ...
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Abstract
One of the major aspects of water resources management in the arid and semi-arid regions is the use of unconventional water sources such as effluents from wastewater treatment plants. As a result, assessment of water supply potential as well as fertilizer values of these unconventional water sources is an important issue in any comprehensive resource management program. In this study, the water supply potential and fertilizer values of the effluents from the City of Mashhad wastewater treatment plants (Olang, Parkand-Abad #1 & Parkand-Abad #2) was assessed based on: 1) the effluents' nitrogen and phosphorus contents, 2) common types of agricultural crops in the region (wheat, barley, tomato), and 3) the crops water and fertilizer requirements over their growing season. The results of this research indicated that the water supply potential of the effluents from above mentioned wastewater treatment plants for irrigation of wheat, barley and tomato are equivalent to 962, 870 and 729 hectares, respectively. Moreover, based on the results of the integrated model used in this research, the use of the effluents can provide 87.2, 74.4 and 133.6 kg.ha-1 available nitrogen and 36.7, 31.7 and 62.0 kg.ha-1 phosphorus for wheat, barley and tomato, respectively. In terms of economic assessments, the water value of the effluents corresponded to 89.6×106 Rials for wheat, 67.4×106 Rials for barley, and 125.0×106 Rials for tomato. In terms of fertilizer value, the corresponding economic assessment represented values of 1.97×109, 1.44×109, and 4.68×106 Rials. In general, the net results of the economic analysis performed indicated that the use of the effluents from the City of Mashhad wastewater treatment plants in agriculture can reduce the cost of production by 33, 31 and 28 percent for wheat, barley and tomato, respectively.
Keywords: Wastewater, Agriculture, Water Resource, Nitrogen, Phosphorus, Economic Analysis
M. Khayami; Sh. Danesh; S.R. Khodshenas; K. Davary
Abstract
Abstract
In this research the thermal stratification of the water in the Torogh Dam Basin and the resulted changes in its quality with respect to temperature, salinity and dissolved oxygen was investigated using the Dynamic Reservoir Simulation Model. The results indicated that in wet years such as ...
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Abstract
In this research the thermal stratification of the water in the Torogh Dam Basin and the resulted changes in its quality with respect to temperature, salinity and dissolved oxygen was investigated using the Dynamic Reservoir Simulation Model. The results indicated that in wet years such as 1998, when the average annual precipitation and the resulted inflows to the basin is higher than its long-term average, the water level in the basin reaches above 50 m. Under such conditions, thermal stratification starts from mid-spring and lasts to the end of summer, and establishes through the total depth of the basin. Consequently, considerable changes in water quality occur through the depth. However in dry years such as year 2000, the water level in the basin diminishes considerably (16 to 20m in depth) and thermal stratification either does not establish or if establishes, it is incomplete, starts much earlier and persists for much shorter periods of time. On the basis of the model’s results, the differences observed in the average temperatures of the surface and deep layers of the basin during the spring and summer seasons of 1998 were 10◦C and 11◦C, respectively while in the spring of 2002, the observed difference was only 1.5◦C. The results of the study also showed concurrent occurrence of salinity stratification with thermal stratification which results in increase in salinity with increase in depth. The difference between salt concentration of the surface and deep water layers of the basin was observed to be 43 mg/lit in the spring of 1998 and 10 mg/lit for the summer of the same year. In regard to the dissolved oxygen concentration, the simulation results showed a difference in the range of 0 to 9 mg/lit between the surface and deep water layers. With the start of stratification, oxygen concentration decreases gradually with depth., such that in July the lowest 10m layer of the basin becomes completely anaerobic, providing conditions for production of undesired odors, tastes and color. During the period of 1998 to 2004 (period of data analysis and simulation run), the water quality of the basin was observed to be uniform in autumn and winter months indicating a complete mixing condition in the basin.
Key Words: Water Quality Models, Thermal Stratification, Water Salinity, Dissolved Oxygen, Dam’s Basin.
