Iranian Journal of

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Backgrounds and Objectives: Due to copper and zinc elements toxicity, a greatly attention to removal of those in order to reduce environmental pollution exist. This experiment was conducted to investigate the study of the effect of gravity single layer rapid sand filter on heavy metals (zinc and copper) removal efficiency in aquatic condition in different phosphate concentration.
Materials and Methods: this study applied a gravity single layer rapid sand filter with silica sand media. Experiments conducted for all of the states of Cooper and Zinc concentration in 25, 75, 125 and 175 ppm at different phosphate concentration present by varied discharge. Each state of Solutions pumped on top of the bed and discharge adjusted. Samples taken fromeffluent then acidified immediately with nitric acid. Metals concentration perused by atomic emission spectrometer with ICP source. Collected data analyzed by SPSS software.
Results: Founds from this study shown that maximum removal efficiency for copper and zinc was 98.89%and 78.60%respectively effect of discharge,metal concentration and phosphate concentration factors in removal efficiency of zinc and cooper, discharge and phosphate concentration bilateral effect on cooper removal efficiency, phosphate concentration andmetal concentration bilateral on zinc removal efficiency, are significant in 1%. In addition, phosphate concentration and discharge bilateral effect, metal concentration and discharge bilateral effect are significant on zinc removal efficiency in 5%. Finally, bilateral effects of discharge and metal concentration also metal concentration and phosphate concentration have not significant effect on cooper removal efficiency.
Conclusion: Gravity single layer of rapid sandy filter with silica sand media in order to cooper removal in low concentration can be used successfully. This method in high concentration of cooper and also different concentration of zinc had not successful result but in this condition, may be use

 

 

of a series of filter with more depth

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Backgrounds and Objective: In arid and semi-arid regions of the world, urban runoff as a source of water restoration and is considered valuable. Wastewater treatment, while preserving the environment, it can be considered as water source. The aim of this study to evaluate the possibility of using powder grain Peregrina in wastewater treatment in comparing with Alum and PloyAluminum Chloride (PAC).
Materials and Methods: Flocculation and coagulation tests were done by Jar test. Wastewater quality parameters were measured according to standard method.
Results: Studies have been showed that in optimum Peregrina concentration, efficiency of turbidity reduction, total hardness, calcium hardness, magnesium hardness, total E. Coli are 95.11, 38, 55.5, 46.6, 97 and 97 percent respectively. It is noted that turbidity reducing directly related with coli form reduction. As, with increasing turbidity reduction, coliform reduction is increased. The most reduction of E. coli with combination of Alum, Ploy Aluminum Chloride and Peregrina was 100 percent. In optimum concentration of Alum, Ploy Aluminum Chloride and Peregrina, the quality of treated wastewater would be in the range of environmental standards. Therefore, treated wastewater can be entering to surface water and reuse as irrigation water.
Conclusion: The results derived from this study showed that the treated wastewater can be use in a variety of irrigation except sprinkler irrigation due to burn the leaves of plants. (high electrical conductivity).Also, the low cost of seed Peregrina and good performance in the refining operations, it is suggested that Peregrina as a replacement for poly aluminum chloride and an alum to be used for wastewater treatment.

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MicrosoftInternetExplorer4 Background and Objectives: Arsenic is one of the most toxically contaminants in groundwater and soils. Due to the ability of bio-accumulation of arsenic III in plants through irrigation with contaminated water and its entrance to the food chain, irreparable hazards would be caused. The aim of this research is the feasibility study of arsenic III removal from polluted water using calcium peroxide nanoparticles synthesized and also studying the effective parameters. Moreover, the adding effect of nanoparticles on the important parameters of irrigation would be assessed.
Materials and Methods: In this research, we first synthesized CaO₂ nanoparticles through chemical precipitation and then studied the arsenic removal efficiency from contaminated water samples. Nevertheless, the impact of the effective parameters including pH, initial arsenic III concentration, and CaO2 nanoparticles concentration were investigated. Finally, relevant results to nanoparticles effect on the important irrigation water quality parameters were presented.
Results: Our results showed that synthesized particles were in the range of 25-50 nanometers. In addition, the efficiency of the CaO₂ nanoparticles in arsenic III removal was 88 percent under following conditions:  irrigation pH range 6.5-8.5, nanoparticles dosage 40 mg/L, arsenic initial concentration 400 µg/L, and 30 minuts retention time. Moreover, the nanoparticles synthesized did not have any undesirable impact on significant parameters in irrigation water.
Conclusion: Generally, it can be concluded that CaO₂ nanoparticles based on the in situ chemical oxidation had significant effect on the reduction of arsenic III until lower than recommended standards for irrigation water. High rate of process and relatively short reaction time, and having no negative effects on the significant parameters of irrigation indicate that CaO₂ nanoparticles have significant potential in removal of arsenic III from contaminated water.

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Background and Objectives: Rivers are the most important resources supplying drinking, agricultural, and industrial water demand. Their quality fluctuates frequently due to crossing from different regions and beds as well as their direct relationship with their peripheral environments. Thus, it is essential to be considered the surveying and predicating changes in the water qualitative parameters in a river. In this study, in order to estimate some of the qualitative parameters (Total dissolved solids, electrical conductivity and sodium absorption rate) for Tehran Jajroud and Kermanshah Gharasu rivers, we used wavelet-artificial neural network (W-ANN) hybrid model during a statistical period of 24 years. Methods: We compared W-ANN model with ANN model in order to evaluate its capability in detecting signals and separating error signals for estimating water quality parameters of the abovementioned rivers. The evaluation of both models was performed by the statistical criteria including correlation coefficient, the Nash-Sutcliffe model efficiency coefficient (NS), the root mean square error (RMSE) and the mean absolute error (MAE). Results: The results showed that the optimized W-ANN with correlation coefficient of 0.9 has high capability to estimate SAR parameter in the stations studied. Moreover, we found that W-ANN had less error and higher accuracy in the case of EC and TDS parameters rather than ANN model. Conclusion: W-ANN proved high efficiency in forecasting of the water quality parameters of rivers, therefore, it can be used for decision making and assurance of monitoring results and optimizing the monitoring costs.

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Background and Objectives: Reuse of treated wastewater in agriculture is becoming more attractive due to the growing demand for water, particularly in arid and semi-arid regions like Iran.In some areas, industrial wastewaters distribute arsenic in the water and vegetables, among the other plants, are mainly irrigated by municipal and industrial wastewater. This study aimed to evaluate the outcome of radish irrigation using water contaminated with arsenic and zinc and to measure the zinc concentration in the edible parts of radish plant. Materials and Methods: The experiments were designed in the form of a factorial completely randomized design with three replications in which radishes were planted in pots about five kilograms. Arsenic concentration at four levels (0, 100,300 and 600 µg/l) and zinc concentration at three levels (0, 10, and 50 mg/l) were added to the irrigation water. The pots were equally irrigated once every 3 to 4 days. After harvesting and laboratory operations, zinc concentration was measured using atomic absorption spectroscopy. Results: The study indicated that zinc concentration in radish tubers is correlated with the concentration of zinc in water. The results of the analysis of variance table for the effect of zinc and arsenic-contaminated irrigation water on zinc concentration in radish roots, tubers and leafs show only one treatment (zinc concentration in water) on the property is significant at 5 and 1%. The results of the comparison table revealed that Zn uptake was decreased with increasing arsenic up to 300 µg/l. Conclusion: It was found that zinc concentration in radish roots, tubers, and leafs is correlated with the concentration of zinc in water. Moreover, there was a competition between the absorption of zinc and arsenic in plants. With increasing arsenic in irrigation water, transition of Zn was reduced to aerial part.