H.R. Mohammadpouran; A. Fotovat; Gh. Haghnia; A. Halajnia; M. Chomsaz
Abstract
Abstract
Chromium is among the metals that has numerous applications in various industries due to its specifications. Widespread use of this metal in different industries has unfortunately been accompanied by its increased release into environment and this entails numerous environmental hazards. In ...
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Abstract
Chromium is among the metals that has numerous applications in various industries due to its specifications. Widespread use of this metal in different industries has unfortunately been accompanied by its increased release into environment and this entails numerous environmental hazards. In the first phase of the research that was conducted to evaluate the effect of the leather processing companies' sewage on chromium behavior on soil, samples of soil affected by the sewage of leather processing companies were studied Hexavalent chromium and chromium distribution ratio in exchangeable organic, carbonated and residual fractions of these soils were examined. The second phase of this research was conducted to assess the effect of time, chromium, soil texture and soil organic mater on chromium distribution in soil fractions. In this phase of the research also the reduction process of hexavalent chromium with time was evaluated. In the evaluation of the soils affected with chromium in Charmshahr area of Mashhad the contamination was observed in 45-centimeter depth of the soil. In sequential extractions of these soils it was shown that 90% of the chromium was in the residual fraction. The chromium distribution order in various fractions of these soils was as follows:
Exchange fraction> Organic fraction> Carbonated fraction> residual fraction
The results showed that time had an important effect on the chromium distribution in various soil fractions especially in short term. Treatments of this section had not a significant effect on the chromium distribution in various fractions statistically except in limited cases. Among the most important results of this phase, we can cite the increased contribution (percentage) of chromium to exchangeable fraction with increased level of chromium in soil and this is so important from the environmental point of view.
Key word: Chromium, Organic matter, Fraction
Saeed Bagherifam; A. Lakziyan; S.J. Ahmadi; A. Fotovat; M.F. Rahimi
Abstract
Abstract
Uranium is a radioactive heavy metal. Development of nuclear industries and application of phosphate fertilizers contain uranium impurity resulted in soil contamination with uranium. A Pot experiment had been conducted under controlled condition. The experiment carried out in completely randomized ...
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Abstract
Uranium is a radioactive heavy metal. Development of nuclear industries and application of phosphate fertilizers contain uranium impurity resulted in soil contamination with uranium. A Pot experiment had been conducted under controlled condition. The experiment carried out in completely randomized design with two factors, including two plants (soybean and sunflower) and six levels of uranium (0, 50,100,250,500 and 1000 mg/kg). Plants harvested after 40 days of experiment and before the generative stages. Soil samples were extracted by DTPA and AAAcEDTA. Uranium concentration in plant tissue increased by increasing the uranium in soil. The ratio of uranium in root:shoot was between 20-100 in sunflower and soy bean. Extraction efficiency of DTPA and AAAcEDTA increased by increasing of uranium in soil. The results of the experiment showed that AAAcEDTA extracts more uranium in all applied uranium concentrations. Both extractants had a good correlation with uranium in plants; however, extraction efficiency of AAAcEDTA was well correlated by uranium concentration in plant tissues. The results of the experiment suggest that AAAcEDTA is suitable extractant for uranium as phytoavailability indicator.
Key word: Uranium, phytoavailability, laser fluorometry, sunflower and soybean
M.H. Ravanbakhsh; A. Fotovat; Gh. Haghnia
Abstract
Abstract
In order to study the chemical behavior of nickel and cadmium in the presence of organic matter, an experiment with two different soils (4 and 30 percent CaCO3), two different texture (8 and 40 percent clay), two levels of nickel (0 and 100 mg.kg-1), two levels of cadmium (0 and 25 mg.kg-1) ...
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Abstract
In order to study the chemical behavior of nickel and cadmium in the presence of organic matter, an experiment with two different soils (4 and 30 percent CaCO3), two different texture (8 and 40 percent clay), two levels of nickel (0 and 100 mg.kg-1), two levels of cadmium (0 and 25 mg.kg-1) and organic matter in the form of sewage sludge in two levels (0 and 100 t. ha-1), at three times (0, 30, 60 days) in a completely randomized design with three replications was carried out. Concentration of cations, anions, dissolved organic carbon and pH were measured in soil extracts. Soil solutions were speciated for chemical forms of nickel and cadmium by MINTEQA2 model. The results of this study showed that nickel, cadmium and dissolved organic carbon in sewage sludge treated soils increased significantly. The amount of available nickel and cadmium decreased significantly with time. Nickel and cadmium in sandy loam soil was significantly higher than clay soil. Sewage sludge application decreased the amount of free hydrated cadmium significantly. In solution phase the proportion of free hydrated cadmium and nickel was higher in soil with 4 percent lime. In contrast, in soil with high lime, the percentage of nickel and cadmium in the form of carbonate was higher. In general, it seems that in the study soils calcium carbonate plays a key role in chemical behavior of nickel and cadmium in solution phase. Therefore, it can be expected that the recommended threshold by environmental protection agencies should be higher in calcareous soils.
Key words: Soil Solution, Heavy metals, Doc
M. Mohammadi; A. Fotovat; Gh. Haghnia
Abstract
Abstract
In order to investigate the removal of copper, nickel, zinc and chromium from industrial waste water by a sand–soil–organic matter filter column, this experiment was conducted at a completely randomized design with sixteen treatments and four replications. P.V.C tubes (columns) with 66.5 ...
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Abstract
In order to investigate the removal of copper, nickel, zinc and chromium from industrial waste water by a sand–soil–organic matter filter column, this experiment was conducted at a completely randomized design with sixteen treatments and four replications. P.V.C tubes (columns) with 66.5 cm height and 10 cm diameter were chosen and filled from down to top by coarse gravel (15 cm), sand (15 cm), soil (2.5 or 5 cm), organic matter (15 cm) and fine gravel (5 cm), respectively. Then, 1100 ml of electroplating industry waste water was added to the filter and 30 ml of leachate was collected and transferred to the laboratory for measurement of pH and heavy metals concentrations by atomic absorption spectroscopy technique. The action was repeated at nine pore volumes for each filter. The results showed that application of this filter led to increased pH to neutral and low alkaline range and often meaningful decreased heavy metals concentrations in the leachates during nine pore volumes. The probable mechanisms (such as adsorbtion, precipitation, ion exchange and chelation) by which the filter led to changes in the chemical properties of leachate were also discussed. Generally, it seems that the application of sand–soil–organic matter filter column was effective and therefore, could be advisable for the removal of studied heavy metals from industrial waste water.
Keywords: Waste water, Heavy Metals, Adsorption.
A. Hosseinipour; Gh. Haghnia; A. Alizadeh; A. Fotovat
Abstract
Abstract
Due to the necessity of wastewater reuse in arid regions and the necessity of investigation on the fate of added materials into the soil, a greenhouse experiment was carried out with polyethylene columns (150 cm in length and 11 cm in diameter) filled with a sandy loam soil during 7 periods ...
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Abstract
Due to the necessity of wastewater reuse in arid regions and the necessity of investigation on the fate of added materials into the soil, a greenhouse experiment was carried out with polyethylene columns (150 cm in length and 11 cm in diameter) filled with a sandy loam soil during 7 periods of 15 days. A statistical factorial design was used. Raw and treated wastewaters from Parkandabad treatment plant were applied to the columns under continuous and intermittent flood irrigations. The results showed that PO4-P and Cd were retained by the soil while a large portion of soluble cations and anions, NO3-N and TOC as well as a part of Ni were leached out. The type of wastewater had a significant effect on transport percentage of elements except K and Mg. The transport percentage of all elements (with the exception of NO3-N and PO4-P) was higher for treated as compared to raw wastewater. Ca, HCO3 and Ni were significantly affected by the mode of application. For the intermittent flood conditions more Ca was leached out, while a reverse case was observed for the other two elements. Due to relatively rapid leaching of soluble cations especially Ca and Mg, NO3-N and TOC from the soil, and also high amount of heavy metals and TOC in raw wastewater, disposal of wastewaters (especially raw wastewater) should be managed carefully.
Key words: Column study, Raw and treated wastewater, Continuous flooding, Intermittent flooding,Transport perecentage
N. Ghorbanzadeh; Gh. Haghnia; A. Lakziyan; A. Fotovat
Abstract
Abstract
Blood meal contains large amount of nitrogen and iron that can be supplied to plants instead of chemical fertilizers. Nitrogen is the most important nutrient for corn plant. The main objective of this study was to determine the capability of blood meal to release nitrogen and iron and its consequence ...
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Abstract
Blood meal contains large amount of nitrogen and iron that can be supplied to plants instead of chemical fertilizers. Nitrogen is the most important nutrient for corn plant. The main objective of this study was to determine the capability of blood meal to release nitrogen and iron and its consequence effect on corn growth. An experiment under laboratory and greenhouse conditions was conducted in the form of a completely randomized design with 6 treatments and 3 replications. The treatments included 3 levels of blood meal (1.5, 3 and 6 ton/h), urea fertilizer (200 kg/h), Fe EDDHA (5 kg/h), and the control. The results of soil incubation demonstrated that release of iron from blood meal was similar to Fe EDDHA and the amount of iron reached to its highest level after 30 days of adding to the soil. Nitrogen was released from all levels of blood meal slower than urea, and the amount of inorganic nitrogen in blood meal was less than urea. The results of corn growth showed that the application of blood meal one month before planting could provide the needed nitrogen and iron and have a positive effect on its growth.
Key words: Blood meal, Nitrogen, Iron, Corn
