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by
Ramin Nabizadeh |
Total Records (
4 ) for
Ramin Nabizadeh |
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Ramin Nabizadeh
,
Kazem Naddafi
and
Reza Saeedi
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Biosorption of lead (II) and cadmium (II) from aqueous solutions in batch system by protonated brown algae Sargassum sp. biomass was studied. The data obtained from experiments of single-component biosorption isotherms were analyzed using the Freundlich, Langmuir, Freundlich-Langmuir and Redlich-Peterson isotherm models. The Redlich- Peterson equation was found in the best fitness with the experimental data. The other models too described the isotherms of Pb2+ and Cd2+ biosorption with relatively high correlation coefficient (R2>0.93). According to the Langmuir model, the maximum uptake capacities (qm) of Sargassum sp. for Pb2+ and Cd2+ were obtained 1.70 and 1.02 mmol g-1, respectively. The optimum initial pH values for biosorption of Pb2+ and Cd2+ were determined as 4.5 and 5.0, respectively. The effect of Na+, K+, Mg2+ and Ca2+ (light metal ions) on equilibrium capacities of Pb2+ and Cd2+ biosorption was studied in the binary system at initial heavy metal ion concentration of 1 mmol L-1 and various initial concentrations of light metal ion. The effect of Na+ and K+ on the biosorption of Pb2+ was not significant, but Mg2+ and Ca2+ decreased the equilibrium capacity of Pb2+ biosorption. The presence of Na+, K+, Mg2+ and Ca2+ in solution affected the biosorption of Cd2+ considerably, so that equilibrium uptake of Cd2+ was reduced at initial concentration 6 mmol L-1 of Na+, K+, Mg2+ and Ca2+ by 10, 17, 5 and 56%, respectively. |
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Golrokh Koushiar
,
Ramin Nabizadeh
,
Ghasemali Omrani
,
Hashem Nikoomaram
and
Masoud Monavari
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Health care waste management is considered as one of the critical task of any solid waste management program. In this research the current status of hospital wastes management in Rasht city which is the capital city of Gilan province with about 2.4 million populations, has been reviewed. The necessary data were collected through the questionnaire with 150 questions. The gathered data converted to the quantitative measure to evaluate the different management component. The results showed that in 83.33% the waste management rank was considered as poor. In 8.33% the waste management rank is very poor and in 8.33% the rank is medium. According to the results of this study, a comprehensive practical program should be initiated to improve the present status of hospital waste management in the city. The data of this research can be used as a baseline data for future monitoring of any hospital waste management program in the Rasht city. |
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Ramin Nabizadeh
,
Mahsa Jahangiri-rad
and
Mohammad Rafiee
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Batch adsorption experiments were conducted to evaluate the effects of the
initial nitrate concentration, ionic strength and contact time on the nitrate
removal efficiency by functionalized polyacrylonitrile coated with iron oxide
nanoparticles (PAN-Oxime- Fe2O3). All tests were performed
in 100 mL solution at constant temperature of 25°C and mixing rate of 150
rpm. The residual nitrate concentration in the solution was determined spectrophotometrically.
Statistical analyses were performed on data using SPSS16 software by applying
Kruskal-Wallis tests using Excel software. The results showed that the adsorption
of nitrate was influenced by counterions. Finally, experimental data were analyzed
using adsorption isotherm. The results show that nitrate removal efficiency
increases with an increase in the initial nitrate concentration and contact
time and decreases in the presence of other ions. |
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Ramin Nabizadeh
and
Mahsa Jahangiri Rad
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PAN-oxime-nano Fe2O3 prepared and used as adsorbents for the adsorption studies of nitrate in aqueous solution. The main and interactive effects of two various experimentally controlled environmental factors namely, initial nitrate concentration and time of reaction were investigated through the model equations designed by a two-level full factorial design in a shake-flask system. The results predicted using factorial regression model showed high values of regression coefficients (R2 = 0.959) showing good agreement with experimental data. Main and interacting effects of different process parameters on the response (amount of nitrate removal adsorbed) were found. The maximum adsorption of 24 mg g–1 achieved at initial concentration of 200 mg L–1 and reaction time of 50 min. |
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