Showing 5 results for Nickel
M. Hoodaji, A. Jalalian,
Volume 8, Issue 3 (10-2004)
Abstract
Soil pollution and accumulation of heavy metals in crops in industrial areas are the most important bioenvironmental problems that threaten the life of plants, animals and humans. The objective of this study was to determine Ni, Mn and Cd distribution in soil and crops shoots around the Mobarakeh Steel Plant. In this study, we separated 50 zones based on soil utility maps taking into consideration the dominant wind direction (south-western to north- eastern). In each zone, soil was sampled at 0-5, 5-10, 10-20 and 20-40 cm depths (200 samples) and DTPA-extractable concentrations of Ni, Mn and Cd were determined in soil samples. Also 36 plant samples from shoots of 18 main crops were collected in the region and the concentrations of heavy metals were determined in crop samples.
Results showed that maximum DTPA-extractable concentrations of Ni and Mn were in the northeast of the region in the 0-5 cm layer (4.2 and 312 mg/kg.soil, respectively) and decreased in 5-10,10-20 and 20-40 cm layers (2.7,2.7,2.1 and 200,212,146 mg/kg.soil, respectively). The concentrations of Ni and Cd in shoots of crops were undetectable with atomic absorption method. The concentration of Mn in rice shoots was 716.6 mg/kg.dry.m. It was higher than USEPA standards (15-100 mg/kg.dry.m).
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A. Mohammadi, M. A. Bahmanyar,
Volume 18, Issue 68 (9-2014)
Abstract
In order to investigate the cumulative effect of three-year application of municipal solid waste compost (C) and the compost accompanied with chemical fertilizer (CF) on the concentrations of some heavy metals in various organs of rice plant, a field experiment with completely randomized design in three replications was performed in 2009. Treatments were as follows: Control (without C and CF), CF (100 kg urea, 100 kg super phosphate and 100 kg potassium sulphate per ha), 15, 30 and 45 tons of C without CF, 15, 30 and 45 tons of C with 25%, 50% and 75% CF. Results showed that application of compost in three years would increase the amounts of Ni, Pb, Cd and Cr in different organs of rice plant. Also, application of C accompanied with CF increased the amount of Ni, Pb, Cd and Cr in various organs of rice compared to C. The highest concentration of nickel and lead (9.1 and 7.8 mg.kg-1 respectively) were obtained in grains in 45 ton C + 50% CF per ha treatment. Meanwhile, the maximum content of cadmium in grain (1.6 mg.kg-1) in 30 ton C + 75% CF ha-1treatment, and the highest amount of chromium in grain (1.8 mg.kg-1 ) resulted from 30 ton + 25% CF ha-1treatment.
J. Abedi Koupai, S. S. Eslamian, S. Y. Hasheminejad, R. Mirmohammad-Sadeghi,
Volume 18, Issue 69 (12-2014)
Abstract
Phytoremediation models are important to understand the processes governing phytoremediation and the management of contaminated soils. Little effort has been made for evaluating the potential of the phytoremediation of metals based on the mathematical models. Therefore, the purpose of this study was modeling the phytoremediation of the nickel-contaminated soils. For this purpose, a model was recommended for estimating the rate of the phytoremediation of nickel from the soil by means of relative transpiration reduction and concentration of nickel in the plant functions. To evaluate the model, soil was contaminated with different levels of nickel by nickel nitrate. Then, the pots were filled with contaminated soil and Basil (ocimum tenuiflirum L.) seeds were planted. To avoid the dry tension, the pots were weighed and irrigated to the point of field capacity (FC) at short time intervals (48 hours). The plants were harvested in four times. At each harvesting stage, the relative transpiration values and nickel concentration in the soil and plant samples were measured. The performance of the model was evaluated by statistical methods such as Maximum Error, Root Mean Square Error, Coefficient of Determination, Efficiency of Model and Coefficient of Residual Mass. Results demonstrated that in the case of nickel contamination in soil, changes in the relative transpiration of Basil can be measured by the two proposed models and the linear model (R2=0.94) has a better performance compared to the nonlinear one (R2=0.84). Also the model obtained from the combination of linear function and nickel's concentration in soil has a relatively good (R=0.7) fit with the measured values of the remediation rate of nickel in soil.
S. Falahati, E. Adhami,
Volume 19, Issue 71 (6-2015)
Abstract
Current study conducted to evaluate the effects of vermicompost and zeolite on the kinetics of nickel (Ni) fixation. Treatments consisted of a factorial combination of two vermicompost levels (zero and 2 w/w percent), three zeolite levels (zero and 4 w/w percent of zeolite of Firoozkoh, and Semnan) and two soil textures (clay and sandy loam) in three replications. All treatments were spiked with 50 or 100 mg Ni kg-1. DTPA extractable Ni was determined after 5, 10, 20, 30, 60 and 90 days. Ni availability was higher in sandy loam texture. Vermicompost application increased Ni availability in sandy loam texture in all the designated times. Zeolite application had no significant effect on Ni availability. The trend of Ni availability decrease was composed of two distinct stages with high and low Ni fixation rates. In the first step which continued up to 30 d, the available Ni fixation rate was high and then decreased sharply. Ni fixation data was suitably prescribed using simple Elovich and exponential equations. It seems that vermicompost has a greater effect to prevents Ni fixation and to retain it in available form in light texture soils. On the other hand, it seems that zeolite does not have any considerable effect on Ni fixation in calcareous soils.
T. Rahimi, A. Moezzi, S. Hojati,
Volume 22, Issue 1 (6-2018)
Abstract
Biochar is a soil amendment that has a high capacity to adsorb heavy metals. The aim of this study was to identify the influence of cow manure and its biochar on nickel adsorption and to determine the best models to describe the kinetics of Ni retention. Accordingly, cow manure and its biochar were added to the soils at the levels of 0, 2 and 4%, and samples were incubated for 90 days. Soil samples were equilibrated with 100 mg L-1 Ni solutions for periods of 1 to 2880 min. Then, the concentration of nickel was measured. The Ni adsorption data were fitted to seven commonly used kinetic models. The results showed that cow manure and its biochar application in all times and levels increased nickel adsorption more than the control. There was also a significant difference (P<0.05) between cow manure and its biochar. Application of 4% biochar, as compared with the same level of cow manure, and the control, increased the Ni adsorption by 23 and 44%, respectively. Power function was the best fitted model describing the patterns of Ni adsorption, as evidenced by the relatively high values of R2 and the low values of SE. However, the Elovich function had some R2 similar to that of power function, but it could not be used as an adequate function to investigate the kinetics of nickel adsorption due to their high values of SE. The zero order, the first order, the second order, the third order, and parabolic diffusion equations were not well fitted to the Ni adsorption data.
