Mansur Zarrabi; Mohammad Noori Sepehr; Mohammad Shakak; Gholamreza Ebrahimzadeh; Mahmoud Taghavi
Volume 24, Issue 4 , July and August 2017, , Pages 239-248
Abstract
Background & Objectives: Phosphorus is a common ion in wastewater treatment effluents, but excess amount of phosphate concentration in the effluent discharge accelerates eutrophication that affects many natural water bodies. Eutrophication of the water bodies is one of the most important environmental ...
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Background & Objectives: Phosphorus is a common ion in wastewater treatment effluents, but excess amount of phosphate concentration in the effluent discharge accelerates eutrophication that affects many natural water bodies. Eutrophication of the water bodies is one of the most important environmental problems. Eutrophication can lead to abundant development of aquatic plants, growth of algae and disturbance to the balance of organisms present in the water. Therefore, in present work, natural and modified yellow and red soil with EDTA was used for removal of phosphorous from aqueous solution.
Materials & Methods: All experiments were conducted in a batch system. Natural yellow and red soil and its modified one with EDTA were used as adsorbent for removal of phosphorous from aqueous solutions. Effect of various experimental parameters such as pH, initial phosphorus concentration, contact time and adsorbent mass were investigated.
Results: Results showed that the removal efficiency was increased by increasing in contact time, adsorbent mass and initial phosphorus concentration. Higher removal efficiency was observed at 150 min contact time, 10 g/L adsorbent mass, 50 mg/L phosphorus concentration and pH 5. At these conditions, about 65% of phosphorus were removed by natural soils, while 78% was removed by modified adsorbents.
Conclusion: The results of present work well demonstrate that, due to higher content of calcium, red and yellow soil is capable for adsorption of phosphorus and if they be modified with EDTA, their efficiency will be improved remarkably.
Gholamreza Godarzi; Kambiz Ahmadi Angali; Javad Salimi; Farrokh Ghaffarizadeh; Farzad Kadkhodaee; Gholamreza Ebrahimzadeh; Ameneh Eskandari; Fatemeh Barjasteh Askari
Volume 22, Issue 5 , November and December 2015, , Pages 832-841
Abstract
Backgrounds: Today, the different consequences of air pollution especially on health effects caused to evaluate, monitor and control air quality as the most important national issues. The aim of this study was to determine the health quality of air in Zabol city based on AQI index and mortality rate ...
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Backgrounds: Today, the different consequences of air pollution especially on health effects caused to evaluate, monitor and control air quality as the most important national issues. The aim of this study was to determine the health quality of air in Zabol city based on AQI index and mortality rate caused by dust.
Materials and Methods: This is a descriptive-cross sectional study. The concentration of air pollutants, including carbon monoxide, sulfur dioxide, nitrogen dioxide, suspended particles were measured by Zabol environmental department using BAM 1020 device in 2011.Air quality index was calculated by interpolation between four concentrations of criteria pollutants. In addition, AirQ2.2.3 computer model was used to determine the mortality rate caused by dust.
Results: The results showed that air qualities in 68 percent of the days were exceeded from standard limit in 2011. According to AQI index, the air qualities in 27% and 6% of days in Zabol city were classified into unhealthy and very unhealthy categories, respectively. PM10 as pollutant was responsible for the pollutant of Zabol city. Furthermore, the number of admission rate in hospitals were 575, respiratory diseases 41 and cardiovascular diseases 227.
Conclusions: A survey on air quality index (AQI) in July, August and September showed that the highest level of PM10 which classified in "very hazardous" (401 <AQI <500) category which was related to a hundred and twenty days winds of Sistan. Although in Zabol city, there are not problems of big cities such as industries and traffic jam, but due to number one in the occurrence and severity of storms in the country and experiencing 107 days in very dangerous condition and regarding to high number of deaths caused by exposure to dust, required special attentions to improve environmental conditions, proper planning and reducing exposure of sensitive groups in dusty days.