20 research outputs found
Survey the Effect of Natural gas Consmption on the air Pollutants Reduction in Yazd- Province Brick-Making Kilns
Introduction: Replacingfuel oil with natural gas in brick kilns is one of the effective ways to reduce air pollution as well as the cost of the furnaces maintenance. The aim of this study isto estimate reduction of air pollutants resulting from brick kilns functioning with natural gasin Yazdprovince.
Methods: In this descriptive-survey research, we estimated consumption of the fuel oil in the brick kilns with considering the usage of fuel oil instead ofnatural gas at the studied time usingthe heating value of the fuel oil and natural gas consumption of46 gas-makingbrick kilnsin the Yazd province from 2008 to 2012.Then the produced air pollutants from the natural gasconsumption andproduced air pollutants by assuming consumption of the fuel oil instead of natural gasin the brick kilnsat this timewere compared and the rate and value of reduction in each one of pollutants weredetected. Finally, the value of budget savings and social costs of the environmental damage resulting from the usage of natural gas instead of fuel oil were calculated on the basis ofusing the price per liter of fuel oil and natural gas per cubic meter as well as the studies by the World Bank and the Environmental Protection Agency of Iran.
Results: The results indicated that emission of air pollutants is reduced up to130485.71 ton in CO2 and 8695.63 ton in other pollutants by run-by-gas brick kilns in the studied area since 2008 – 2011 (end of September). In addition,the amount of budget saving is estimated as 187.578 billion Rials by replacing the gas fuel inthe brick kilns and 129.380 billion Rials in the social and environmental costs from emission of pollutantin the years studied.
Conclusion: For positive economic, environmental and health-related effects resulting from this program, planning and financial support for running-by-gas of other brick kilnsseems to be urgent
Performance of Olive pit Ash\'s In Nitrate Removal from the Aqueous Solutions
introduction: Nitrate ion in drinking water has been found to have a significant effect against health human. Nitrate is an acute toxic it can be reduced to nitrite in the stomach when it can lead to have blue baby diseases in infants. This research is directed towards to elucidate the nitrate removal efficiency by kernel ashes of olive in water supply.
Methods: This experimental study was conducted in a batch laboratory scale. The batch flow experiments for nitrate removal were undertaken to investigate the effects of the different parameters such as: initial concentrations of nitrate solution (50, 100, 150 mg/l), initial pH (3,5,7,9), detention time (15,30,60,120,180 min), and weight of adsorbent( .04, .06. .08 gr). Nitrate concentrations were measured by standard method using a spectrophotometer at two wavelengths 220 and 275 nm.
Results: The Results obtained showed that the removal efficiency increases when the time and adsorbent dose is increased. By decreasing of pH value and the initial concentration of nitrate, the removal efficiency would be increased significantly.
Investigation of the effect of nitrate initial concentration showed that increasing initial concentration of nitrate from 50 to 150 mg/l and without changing absorbent dose would lead to decrease in the absorption efficiency from 88% to 48% but the absorption capacity (qe) increased from 8.31 to 14.3. Moreover the maximum absorption took Place at 60 min of the first reaction.
Conclusion: Nitrate removal by olive kernel ashes are considered as effective and appropriate method compared with other absorbents and the process is more efficient at acidic pH
Application of the Photocatalytic Process of Ag-ZnO / UV-C for the Degradation of 2,4-Dichlorophenoxyacetic acid In Aqueous Aolutions
Introduction: A variety of pesticides is used to combat weeds. Check-resistant residues of contaminants in drinking water resources have detrimental effects on human health and on environment. In recent years, advanced oxidation methods o remove toxins from the environment, particularly the aquatic environment is further considered.
Methods: In this study, samples adding different concentrations (mg/L10, 20, 30) of pesticides were prepared in deionized water. Specimens of the individual phases in a batch reactor with the catalyst (g / L 1 ,2, 3 and, 4), pH (3,5, 7, 9, 11) and contact time (60, 120, 180, 240 min) exposure contacts coupled Ag / ZnO and UV-c was performed.
Results: The results showed a reduction in pesticide concentrations (2, 4-D) and increasing the reaction time, the degradation efficiency increases. The highest degradation efficiency was for 240 minutes and the initial concentration of toxin was (2, 4-D) 10 mg/L to 96 percent. The kinetics of the elimination of toxins (2, 4-D) by the process of photocatalytic Ag / ZnO in the presence of UV-C light corresponded to the pseudo first.
CONCLUSION: The most effective degradation of toxins (2, 4-D) by the process of photocatalytic Ag / ZnO under conditions of neutral pH and with increasing reaction time and reduce toxin concentrations (2, 4-D) is the result
Evaluation of synthesized iron oxide nanoparticles in removal of copper ions from aqueous solution
Abstract
Introduction: water source pollutant, result of direct releasing of metal ions to environment, is one of the most important problems in the world. In this study, efficiency of synthesized iron oxide nanoparticles in presence of extract tangerine Peel was investigated for removal of copper ions in the solution.
Methods: Iron oxide nanoparticles were prepared by co-perception method using Tangerine Peel extract. The Tangerine Peel extract used to decrease of nanoparticle size and to prevent of particles coagulation. The effect of different parameter includes initial copper concentration, adsorbent dose, contact time and solution pH was investigated on removal of copper. The experimental data were fitted to Langmuir and Freundlich isotherm models.
Results: The results showed that the removal efficiency was increased by increasing of pH and decreased from 88% to 81% by increasing of initial copper concentration from 5 mg/l to 10 mg/l. The most removal percent was 92% when copper concentration was 5 mg/l and adsorbent doze was 0.6 g in 100 ml suspension.
Conclusion: The results showed the removal efficiency is depended on to pH. The increase of copper concentration decreased the removal efficiency. Adsorption experimental data were in good accordance with Langmuir isotherm model. The synthesized iron oxide nanoparticles with extract Tangerine Peel is a good adsorbent for removing of heavy metals from aqueous solution
The Efficiency of Inactive Saccharomyces Cerevisiae Biomass on Removing Arsenic from Aqueous Solutions
Introduction:Arsenic is a common toxic element that is mainly transported in the environment by water. Arsenic in drinking water is of major concern to many of the water utilities in the world. Therefore, the objective of this study was selected biosorption of arsenic by inactive Saccharomyces cerevisiae as low-cost biological adsorbent from aqueous solution.
Methods:This experimental study was performed in laboratory scale and was performed on 243 synthetic samples in a batch system. In this study the effect of parameters such as contact time (5,15,30,60,120,min and 24 h), pH (5,7,9), fluoride concentration (100, 250, 500, 750,1000 µg/l) and absorbent dosages (0.5,1,2/5,5g/l) was evaluated. Finally biosorption kinetic and equilibrium isotherms of adsorbent was investigated.
Results: The removal efficiency of inactive Saccharomyces cerevisiae was 89.49% at pH 5, adsorbent dose of 1g/L and initial metal concentration of 100 mg/L. Maximum uptake was observed after the Contact time of 60 minutes. In addition absorption isotherm followed pseudo-second order model with a maximum R2 = 0.999.
Conclusion:The results of study showed that biosorption efficiency decreases with increase in pH of solution. Optimum pH of biosorption was 5. The Removal efficiency of arsenic enhanced with increase in mass of Saccharomyces cerevisiae up to 1 g/L, but The Removal efficiency decreased with increase in initial concentration of arsenic. Maximum absorption was observed in 15 minutes
Evaluation of Microbial Quality of Sausage Slicers at Food Retail Food Stores in Shiraz, Iran
Introduction: The purpose of this study was to evaluate the microbial quality of sausage slicers in Shiraz retail food stores.
Methods: A total of 60 slicer samples from retail food stores were collected according to ISO protocols. Then microbial condition of the samples was examined using selective media. Data were then analyzed with SPSS software using descriptive statistical indices and ANOVA test.
Results: The total bacterial, total coliforms and Staphylococcus aureus counts exceeded the satisfactory limit in 23%, 4% and 6% of the samples respectively. Only 2 samples were found to be contaminated with Staphylococcus aureus coagulase positive. Microbial analysis showed an absence of Salmonella and Escherichia coli. The lowest total bacterial counts, total coliforms and Staphylococcus aureuswere detected in samples from North,WestandSouth of the city respectively.
Conclusion:Our finding shows that bacterial contamination of some slicers is higher than the standards level. The results suggest that more effort is needed in the application of personal and environmental hygiene principles in food supplies
A Survey of Knowledge, Attitude and Practice of Planting Greenhouse Operators in Yazd in Regard with Health Hazards Associated with Pesticide use in 2012-2013
Introduction: Pesticides used in agriculture in order to protect crops and plants from pests, diseases and weeds are regarded as one of the major sources of environmental pollution, with produce a negative effect on the health of living organisms, including humans.Therefore this study aimed to evaluate knowledge, attitude and practice of planting greenhouse operators in Yazd in regard with health hazards associated with pesticide use in 2012-2013.
Methods: This study was a cross-sectional study, which its population consisted of active nursery operators in Yazd. In this randomized study, 250 samples were selected out of 2233 greenhouse operators and then knowledge, attitudes and behavior of workers were measured using a questionnaire. After the study data were collected and codified, they ere entered into SPSS software. Moreover T-test and ANOVA tests were utilized to compare the average.
Results: The results of the present study revealed that out of all greenhouse operators, 134 (6/53%) had received pesticideuse training were trained. Education of 74 (29%) of the operaters were reported at the initial level. Experience of 104 operaters (9/41%) was revealed 6-10 years. 73 (2/29%) of operaters aged between 25 and 35 years. Moreover, the results showed, none of the officers receive the full credit(Maximum knowledge score is 13). Attitudes of 243 operaters towards the use of pesticides in greenhouses was reported at a high level. Performance of 138 operaters were moderate.
Conclusions: Although operaters nformation in such fields as precautions when working with pesticides lies relatively at a good level in some other contexts such as respiratory masks for spraying and special work uniform, lack of sufficient information was reported for indicating the need to develop and implement specialized training programs
The Survey of Melia Azaderach L. ash in Removal of Hexavalent Chromium from Synthetic Electroplating Industry Wastewater
Introduction: One of the heavy metals is chromium which is used in trivalent and Hexavalent oxidation state in industries such as, glass, ceramic, tannery, leather especially in electroplating industries. Hexavalent Chromium has proven several health hazards such as a carcinogen. The aim of this study was to investigate the efficiency of Melia azedarach ash in the removal of hexavalent chromium from synthetic electroplating industry wastewater.
Methods: This is an experimental study which investigates the effect of initial chromium concentration, adsorbent dose and reaction time on removal of chromium by Melia azedarach ash. The adsorbent was prepared in experimental conditions using electric oven in 550 0C at 2 hours and pulverized using ASTM standard sieves with a particle size range of 40–60 mesh. The study was performed on the synthetic samples containing 5and 10 mg/l concentration of chromium. The unknown concentration of Hexavalent chromium was detected by spectrophotometer set (UV/VisibleSP-3000 Plus-Japan) at 540 nm.
Results: According to the results, removal efficiency increases by increasing adsorbent dose and reaction time and decreases with increasing initial concentration of chromium. Results of this study showed that Hexavalent chromium adsorption by Melia azedarach ash reaches equilibrium at 180 minutes.
Conclusion: Melia azedarach ash is an effective adsorbent in removal of hexavalent chromium from synthetic electroplating industries wastewater. In addition, the use of this biosorbent in preparation and application aspects is simple and cheap compared to many other natural and man-made adsorbent
The Investigation of Electron Beam Catalytical Oxidation Process Efficiency with Potassium Persulfate in Removal Humic Acid from Aqueous Solutions
Introduction: The most important affect of natural organic matters in water is their reaction with chlorine and producing of disinfection byproducts that are carcinogenic. Humic acid is most common natural organic materials of surface water. Advanced oxidation processes (AOPs) are methods for the removal of organics from aqueous solutions. Application of electron beam radiation is one of these methods for water treatment. The aim of this study was to evaluate the efficiency of catalytic oxidation process of electron beam radiation with potassium persulfate in removal of humic acid from aqueous solutions.
Methods: This experimental study was performed in laboratory scale. In this study, effect of pH (4 -10), initial concentration of potassium persulfate (0.1- 0.5 mmol/100cc), different radiation doses of electron beam (1-15 kGy) and the initial concentration of Humic acid (10-50 mg/l) in removal of humic acid were studied. Electron irradiation performed using an electron accelerator model TT200. Residual concentrations of humic acid in the samples determined by spectrophotometer UV/Vis at a wavelength of 254 nm.
Results: Based on the results, changes in pH had little effect on the Humic acid removal efficiency. The average, with increasing of pH from 4 to 10, the removal efficiency of humic acid from 72.59% to 73.36% increased, respectively. The results showed that increasing of the dose from 1 to 15 kGy, humic acid removal efficiency increases. Based on results by increasing of persulfate concentration, the removal efficiency increased so that with increasing of concentration of potassium persulfate from 0.1 to 0.5 mmol/100cc, removal efficiency from 69.43% to 83.82% was increased. Kinetic experiments showed that the decomposition of humic acid by electron beam radiation followed the second-order kinetic.
Conclusion: The data from this study showed that the aqueous solution containing acid Humic is decomposed effectively by electron beams irradiation. Addition of potassium persulfate can be have significant improvements in removal efficiency of humic acid in the presence of electron beam
Performance Assessment of Chemical Coagulation Together with Advanced Oxidation Peroxone Regarding Dye Wastewater Treatment of Appliance Factories
Abstract
Introduction: Considering the important role of industry in polluting the environment, the present study aimed to evaluate the performance of chemical coagulation together with advanced oxidation (peroxone) regarding dye wastewater treatment of appliance factories.
Methods: This study was experimental, which it’s pilot-scale was conducted on the wastewater of the painting appliance Factory. The sample was selected via the combined sampling procedure. The processes used in the present study consisted of chemical coagulation and advanced oxidation (peroxone) processes and 250 samples were analyzed. MgCl2, PAC and FeCl3, Bentonite, Cationic Polymer were used for chemical coagulation. The used equipments consisted of Spectrophotometer DR 2000, Jar taste and a ozonation reactor. COD and dye of samples were measured according to standard method.
Results: The results revealed that each of the coagulants in its optimal pH were able to arrange the magnesium chloride 86.85%, poly aluminum chloride 88.47% and ferric chloride 85.41% in removal of COD. Poly aluminum chloride achieved the highest dye removal 90.92%. Furthermore, the highest COD removal efficiency was related to the combination of magnesium chloride (1.4 mg/l), poly aluminum chloride (0.6 mg/l) and cationic polymers (0.4 mg/l) with an efficiency of 89.11%, which managed to remove the dye up to 93.38%. COD removal efficiency reached to 99.67% using advanced oxidation process by peroxone method on pretreated wastewater (with chemical coagulation).
Conclusions: For better performance of peroxone treatment, the wastewater should be pretreated for removal of dissolved solids. As a result, due to its suspension status of using peroxone method together chemical coagulation has a high capability to remove COD and dye from appliance Factore ,s wastewater