Health and environment
Ali Esrafili; Maryam Izanloo; Mahdi Farzadkia; Ahmad Joneidi Jafari; Mina Yousefi
Volume 26, Issue 4 , November and December 2019, , Pages 535-546
Abstract
Nowadays,due to the irreparable effects imposed on aquatic ecosystems,organisms and humans,the removal of heavy metals and herbicides from water sources has extremely become vital.In recent years, the process of adsorbing contaminants with magnetic nanoparticles has gained lots of attention.Therefore, ...
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Nowadays,due to the irreparable effects imposed on aquatic ecosystems,organisms and humans,the removal of heavy metals and herbicides from water sources has extremely become vital.In recent years, the process of adsorbing contaminants with magnetic nanoparticles has gained lots of attention.Therefore, the present study aimed to synthesize nanoparticles as an adsorbent for adsorption of the contaminants of Pb and 2,4-D from water. Materials and methods:To evaluate the effect of independent variables such as pH(3-11),contact time(0-150min),adsorbent dose(0.2-1.2g/L) and adsorbate concentration(5-50mg/L) on the contaminant removal and determine the optimal conditions, the method of one factor at the time was used by design expert software. Nanoparticles were synthesized via a co-precipitation method and their morphology were characterized by TEM,XRD,FT-IR and SEM. Finally, the experiments were performed on aqueous solution. Results: Structural analysis revealed that adsorbent has a spherical structure with a Fe3O4 core and SiO2 shell, modified by both amine and thiol functional groups.The results of experiments showed that the maximum adsorption efficiency of single system occurred at pH 5 and contact time 40 min for lead and at pH6 and contact time 90min for 2,4-D.Also the optimal values of adsorbent dose and initial concentration obtained 0.8 g/L and 10 mg/L. In the binary adsorption system,the maximum adsorption efficiency determined at pH 6 and contact time 40 min for lead and contact time 60 min for 2,4-D and adsorbent dose 1.2 g/L. Conclusion:According to the results,the bi-functional nanoadsorbent could be effectively used for the simultaneous removal of inorganic and organic pollutants from various aqueous solutions.
Roshanak Rezaei Kalantary; Ahmad Allah-Abadi; Mehdi Farzadkia; Ayyob Rastgar; Ahmad Joneidi Jafari; Abdolmajid Gholizadeh
Volume 19, Issue 3 , September and October 2012, , Pages 277-286
Abstract
Background: Leaching of nutrients and heavy metals from municipal solid waste compost leads to accumulation of certain elements in soil layers, causing underground water pollution. The objective of this study was to investigate the effect of compost on leaching and adsorption of heavy metals and nutrients ...
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Background: Leaching of nutrients and heavy metals from municipal solid waste compost leads to accumulation of certain elements in soil layers, causing underground water pollution. The objective of this study was to investigate the effect of compost on leaching and adsorption of heavy metals and nutrients (sodium, potassium, and sulfate) from silt-loamy soils. Materials and Methods: In this empirical, applied study, three polyethylene columns (height 50 cm, inner diameter 10 cm), filled with sandy clay loam soil, were randomly selected. Then, 10 kg of compost per square meter were sprayed onto the columns, and leachates exiting the columns were routinely analyzed for pH, electrical conductivity, sulfate, sodium, potassium, lead, chromium, and cadmium. Data analysis was performed with Excel and SPSS software using Kruskall-Wallis test. Results: The data showed that the use of enriched and unenriched compost leachate decreased pH (from 7.43±17.0 to 6.7±0.25 and 7.07±0.11, respectively) and increased the electrical conductivity (EC) (from 1.8±0.3 mSiemens/m to 3.7±0.12 and 12.87±0.41 mSiemens/m respectively). Leakage of metals in the unenriched treatments was not significantly different from the control (p>0.78), but leakage with three metal-enriched compost applications was significant compared with control (p