Sahand Jorfi; Nematallah Jafarzadeh Haghighifard; Mohammad Javad Ahmadi; Narjes Shaheidar; Hakimeh Purhoseini
Volume 24, Issue 1 , March and April 2017, , Pages 55-62
Abstract
Background & Objectives: Cr(IV) is a toxic heavy metal with dangerous effects on health and environment and is discharged through industrial effluents. The main aim of the current study was to determine the efficiency of natural zeolite on removal Cr(IV) from aqueous solutions. Materials & Methods: ...
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Background & Objectives: Cr(IV) is a toxic heavy metal with dangerous effects on health and environment and is discharged through industrial effluents. The main aim of the current study was to determine the efficiency of natural zeolite on removal Cr(IV) from aqueous solutions. Materials & Methods: Following the chemical modification of Zeolite, the study variables including pH (2-10), adsorbent dosage (2-20 g/L), reaction time (5-150 min) and Cr(IV) concentration (10-50) were optimized according to the one at the time experimental design. The correlation of obtained data with conventional isotherms and kinetics were also studied. Results: In optimum pH 2, reaction time of 30 min and adsorbent dosages of 8 g/L, the most removal efficiency of 99.53% was observed for initial Cr(IV) concentration of 10 mg/L. The Freundlich isotherm and pseudo –second order kinetics were better fitted to the findings. Conclusions:According to findings of current study in lab scale, it can be concluded that natural Zeoliite can be considered as an efficient and cost effective alternative on treatment of effluents containing Cr(IV).
Afshin Takdastan; Mehdi Jolanejad; Abdolkazem Neisi; Mehrnosh Abtahi; Sahand Jorfi
Volume 23, Issue 4 , September and October 2016, , Pages 698-705
Abstract
Background Chromium and cadmium are two heavy metals having adverse effects on the health and environment, which are released to environment by waste streams. Because of high solubility, they are absorbed by living organisms and through food chain accumulate in human body. This study aimed to determine ...
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Background Chromium and cadmium are two heavy metals having adverse effects on the health and environment, which are released to environment by waste streams. Because of high solubility, they are absorbed by living organisms and through food chain accumulate in human body. This study aimed to determine the efficiency of the polyferric sulfate (PFS) in removing of Cr6+ and Cd2+ from aqueous solutions.Methods & Materials This study was investigated in bench scale using a jar test apparatus. The effect of pH (4-11), dose of coagulants (10-200 mg/l), initial amount of metals (1-100 mg/l) and settling time (15-9 min) were investigated. Cr and Cd concentration were determined by atomic absorption spectroscopy.Results The result showed that the maximum removal efficiency was 52.82% for Cr and 93.13% for Cd, at pH values of 6 and 9, coagulant dosage of 100 and 50 mg/l, respectively, and settling time for 30 min. Conclusion Coagulation and sedimentation by use of polyferric sulfate can be considered as an efficient process for removal of Cd and pretreatment of Cr.