Saeed Akbari; Mohammad Hadi Dehghani; Mehdi Salari
Abstract
Background and objective: Due to its high concentration on the surface and its pathogenic function, fluoride is noticeable. Fluoride at high concentrations can be dangerous. The World Health Organization's allowable concentration is 1.5milligrams per liter. The aim of this study was to take chitosan ...
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Background and objective: Due to its high concentration on the surface and its pathogenic function, fluoride is noticeable. Fluoride at high concentrations can be dangerous. The World Health Organization's allowable concentration is 1.5milligrams per liter. The aim of this study was to take chitosan from shrimp shells and evaluate its performance in the removal of fluoride in aqueous solutions. The purpose of this study was to isolate chitosan from shrimp shells native Persian Gulf and evaluate its performance in the removal of fluoride in aqueous solutions. Materials & Methods: Chitosan from shells native Persian Gulf shrimps in three stages, protein , minerals and de-acetylation separation. The isotherms and adsorption kinetics were evaluated in optimal conditions. Results: The results showed with 100 ml of 4 Results: milligrams per liter of fluoride, the fluoride removal at pH = 7, 60 minutes contact time and adsorbent concentration of 2 grams per liter respectively. The result of the absorption curve obeys a second-order. Freundlich adsorption isotherm data were more consistent. Maximum capacities of 0.157 milligrams per gram was with the removal of fluoride with chitosan. Conclusion:The extracted chitosan can be an effective adsorbent for the removal of fluoride from contaminated water so that the amount of fluoride in drinking water is reduced to below the allowable level of fluoride.
Amin Ahmaditabar; Mohammad Hadi Dehghani; Faezeh Izadpanah
Abstract
Background & Objective: Textile effluents contain significant amounts of toxic and organic pollutants. Due to health risks such as carcinogenic and mutagenic effects, discharge of this kind wastewater to water resources can lead to health impacts. The aim of this study was to survey the efficiency ...
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Background & Objective: Textile effluents contain significant amounts of toxic and organic pollutants. Due to health risks such as carcinogenic and mutagenic effects, discharge of this kind wastewater to water resources can lead to health impacts. The aim of this study was to survey the efficiency of Chitosan derivative in removal of basic dyes violet16 from aqueous solutions. Materials & Methods: In this study the influence of different parameters including contact time, initial dye concentration, adsorbent concentration, and PH, was studied. Residual of dye concentration was measured using a spectrophotometer set in 545 nm wavelength. Adsorption data was described by Langmuir and Freundlich isotherms and kinetic reactions. Results: The results showed that increasing contact time and adsorbent dose enhances dye removal rates for this adsorbent. By decreasing initial concentration of dye, removal rates increased. In optimal conditions, Chitosan derivatives were able to remove dye 68 percent respectively. For this adsorbents optimum pH was obtained 10. According to the results, adsorption process for both adsorbents was determined by Freundlich isotherm by R2>0.98. Dye absorption kinetic of both adsorbents followed pseudo second degree by R2>0.98. Conclusion: the results showed that Chitosan derivative can be applied as an efficient adsorbent for removal basic violet 16 dye from aqueous solutions.
Nasrin Abdollahi; Mohammad Hadi Dehghani; Kazem Nadafi; Fazlollah Changani; Amir Hossein Mahvi; Niaz Mahdi Esfahani
Abstract
Background and objective: Oil and grease causes damages for aquatic organisms, soil ecosystem, and mutagenic and carcinogenic for human. The aim of this research was to study the reduction of pollution of oil and grease of steel mill wastewater with Air Flotation system. Materials and Method: At first ...
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Background and objective: Oil and grease causes damages for aquatic organisms, soil ecosystem, and mutagenic and carcinogenic for human. The aim of this research was to study the reduction of pollution of oil and grease of steel mill wastewater with Air Flotation system. Materials and Method: At first phase of this examination the sampling performed of raw wastewater for determine amount of oil and grease, COD, TS, TDS, TSS, Turbidity and Alkalinity. The second phase flotation with dispersed air performed at pilot vessel and the second sampling performed for determinationof removal efficiency of oil and grease in 3 different concentration and 4 different retention time and measured for other parameters in best concentration and retention time. Results: The retention time were selected 30, 45, 60 and 90 min and concentrations were 591 mg/l, 386 mg/l and 277 mg/l. removal efficiency for parameters of oil and grease, COD, TS, TDS, TSS, Turbidity, Alkalinity, obtained %48, %46, %37, %36, %82, %89, %6. Conclusion: This study showed with increases of retention time from 30minute to 90minute removal efficiency for all of parameters gently increased but between 60 and 90 minute retention time removal efficiency was almost stable. Removal efficiency in high concentration of oil and grease(591mg/l) was more than removal efficiency in low concentration of oil and grease (277mg/l). Paper type: Research article
Negar Ordooei; Mohammad Hadi Dehghani; Aida Bayati; Kambiz Larijani; Niaz Mahdi Esfahani
Abstract
Background and objective: Laboratory wastes are produced in small, but varied quantities. These wastes need to be managed correctly. Consequently, this research has undertaken a quantitative and qualitative assessment and management of the laboratory wastes of Zakaria Razi Laboratory Complex in TehranScience ...
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Background and objective: Laboratory wastes are produced in small, but varied quantities. These wastes need to be managed correctly. Consequently, this research has undertaken a quantitative and qualitative assessment and management of the laboratory wastes of Zakaria Razi Laboratory Complex in TehranScience Research Branch Islamic Azad University. Materials and Method: This study, primarily with the help of interviews, determined the most productive laboratories of the Complex, which then led to the selection of two educational laboratories and two research laboratories for qualitative and quantitative sampling. After sampling which the samples werecatalogued according to the four categories of corrosive, toxic, flammable and reactive. Results: The findings of this research show that 54% of the hazardous waste of the research laboratories is flammable and in the educational laboratories 56% of the waste produced is corrosive. Conclusion: In most of the laboratories in this complex (88%), a list of the hazardous waste produced is not compiled and stored, and in all but 16% of the laboratories where hazardous waste is disposed after being secured in appropriate containers, this waste is poured into the drain without any proper management. A list of produced wastes in each laboratory is required to be prepared, using the laboratory operator’s assistance.