oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 54 )

2019 ( 728 )

2018 ( 821 )

2017 ( 758 )

Custom range...

Search Results: 1 - 10 of 462631 matches for " A Jonidi jafari "
All listed articles are free for downloading (OA Articles)
Page 1 /462631
Display every page Item
Treatment of Synthetic Wastewater Containing Reactive Red 198 by Electrocoagulation Process
A Dalvand,A Jonidi jafari,M Gholami,A Ameri
Iranian Journal of Health and Environment , 2011,
Abstract: "nBackground and Objectives: Discharge of textile colored wastewater industries without providing enough treatment in water bodies, is harmful for human and aquatic organisms and poses serious damages to the environment. Most of conventional wastewater treatment methods don't have enough efficiency to remove textile dyes from colored wastewater; thus in this research the efficiency of electrocoagulation treatment process with aluminum electrodes for treatment of a synthetic wastewater containing C.I. Reactive Red 198 in batch reactor was studied."nMaterial and Methods: The experiment conducted in a Plexiglas reactor with a working volume of 2L that equipped with 4 aluminum electrodes. The effects of operating parameters such as voltage, time of reaction, initial dye concentration and interelectrode distance on the color removal efficiency, electrical energy consumption and electrode consumption were investigated."nResults: in the optimum operational condition electrocoagulation, is able to remove color and COD as high as 99.1 and 84.3% in aluminum electrode in 75 minutes at 20 volt and 2 cm interelectrode distance, respectively. Under this condition, operating cost was 2986 rails per cubic meter of treated wastewater. Increase in the interelectrode distance and initial dye concentration,lead to the decrease in efficiency of dye and COD removal.While as the voltage and time of reaction increased, energy consumption, electrode consumption, final pH and color removal, increased too."nConclusion: electrocoagulation process by aluminum electrode is an efficient and suitable method for reactive dye removal from colored wastewater.
Evaluation of dental solid waste in Hamedan
Nabizadeh R.,Kulivand A.,Jonidi Jafari A.,Younesian M.
Journal of Dental Medicine , 2009,
Abstract: "nBackground and Aim: Today, one of the most important environmental issues is dental solid wastes which are of great importance because of the presence of hazardous, toxic and pathogen agents. In this survey, solid waste produced in Hamedan general dental offices is evaluated. "nMaterials and Methods: In this descriptive study, from 104 general dental offices in Hamedan , 10 offices were selected in simple random way. From each offices, 3 sample at the end of successive working day (Sunday, Monday and Tuesday) were analyzed. Samples were manually sorted into different 74 components and measured by means of laboratory scale. Then, measured components were classified in the basis of characteristic and hazardous potential as well as material type. "nResults: Total annual waste produced in general dental offices in Hamadan is 14662.67 Kg (9315.45>95.0% Confidence Interval>20009.88). Production percentages of infectious, domestic type, chemical and pharmaceutical and toxic wastes were 51.93, 38.16, 9.47, 0.44 respectively. Main components of produced dental waste were 14 components that consist of more than 80 percents of total dental solid waste. So, waste reduction, separation and recycling plans in the offices must be concentrated on these main components. "nConclusion: In order to dental waste proper management, it is suggested that in addition to educate dentists for waste reduction, separation and recycling in the offices, each section of dental waste(toxic,chemical and pharmaceutical, infectious and domestic type wastes) separately and according to related criteria should be managed.
Survey of Ability of Activated Sludge Isolated Bacteria in Removal of RB-B Dyestuff from Aqueous Medium
P Bahmani,R Rezaei Kalantary,M Gholami,A Jonidi Jafari
Iranian Journal of Health and Environment , 2011,
Abstract: "n "n "nBackgrounds and Objectives: Reactive dyestuff has potential of toxicity, carcinogenesis and mutagenesis for mammals and aquatic organisms. The current physical and chemical methods such as adsorption, coagulation, precipitation, filtration and ... can been used for removing of dyestuff. Biological treatment which is effective and economic for decontamination of dyestuff wastewaters was preferred because of limitation and difficulty of physicochemical methods. In order to investigate the trend of pollution reduction of color compounds, ability of Remazol Black-B dyestuff removal from aqueous medium by bacterial consortium under anoxic conditions was studied."nMaterials and Methods: The mix culture of bacteria from textile industries activated sludge was enriched in luria broth medium containing RB-B dyestuff as a carbon source. Then biodegradation was assessed in 4 batch reactors. Microbial population of bacterial and decolorization quantities of samples were detected by MPN and UV-Vis spectrophotometer."nResults: Decolorization efficiency by the bacterial consortium was obtained more than 99% for 50 and 250 mg/L concentrations in 72 and 144 h (3 and 6 days) respectively, while for the initial concentration of 500 mg/L was 98.1in 240 h (10 days) of biodegradation period. Dyestuff reduction rate after completed removal was about 0.69, 1.74,2 mg/L/h for initial concentration of 50, 250, 500 mg/L respectively."nConclusion: Results showed that Alcaligenes denitrificans and Alcaligenes xylosoxidans bacteria"nwhich were isolated from activated sludge have good potential of RB-B dyestuff removal and this removal is depending on primary concentration of dye. Removal efficiency increased as primary concentration went up.
Environmental Exposure to Xylenes in Drivers and Petrol Station Workers by Urinary Methylhippuric Acid
AR Bahrami,A Jonidi-Jafari,H Mahjub
Journal of Research in Health Sciences , 2011,
Abstract: Background: The aims of this study were evaluation of exposed to xylenes in low concentration and compare urinary level of methyl hippuric acid in taxi drivers and petrol stations workers in West of Iran. Methods: This observation study was carried out on samples of the exposed men to xylenes in two occupational groups in Hamadan City (west of Iran) from March 2003 to March 2004. Subjects included 45 taxi drivers and 25 petrol station workers. The study group was selected from 54 workers at petrol stations and 300 drivers by simple random sampling. Xylenes was analyzed using gas chromatography equipped with a Flame Ionization Detector (FID). The urinary methyl hippuric acid (MHA) was analyzed with High performance Liquid Chromatography (HPLC) equipped with an ultraviolet (UV) detector. Results: Total xylene exposure was 1.05 ±0.55 ppm (mean ±SD) with a range of 0.20-2.55 ppm that was about 4 times more than taxi drivers' exposure. The poor correlation coefficient was seen between xylenes concentration and urinary MHA for drivers (r2= 0.09 to 0.42) but significant associations were noted between urinary MHA and xylene in the breathing zone of petrol station workers (r2= 0.69 to 0.77; P< 0.05). Conclusion: High xylenes levels are emitted in petrol stations at Iran. Urinary MHA level has a poor correlation with exposure to xylenes in drivers but has good correlation in petrol station workers.
The effect of hydrogen peroxide and solvent on photolysis of PCBs to reduce occupational exposure
Hasan Asilian,Reza Gholamnia,Abbas Rezaee,Ahmad Jonidi Jafari
Behbood , 2010,
Abstract: Background: Polychlorinated biphenyls (PCBs) are toxic bio-accumulate components and may increase risk of adverse effects on human health and the environment. For different social, technical and economic reasons, significant quantities of PCBs contaminated transformer oil are still in use or storied. The study aimed to determine the effect of hydrogen peroxide and solvent on photolysis of PCBs to reduce occupational exposure. Methods: The photochemical annular geometry (500 ml volume) reactor was designed with a cylindrical low-pressure mercury lamp (UV-C Cathodeon TUV 6WE) with emission at 254 nm. The radiant power emitted by the lamp was 6w. The whole lamp was immersed in a reactor thermostat controlling of temperature at 32 ± 2 oC. The PCBs was determined using GC/ECD and data was analyzed by SPSS. Results: Degradation of total PCBs in terms of %10 and %20 of volume of H2O2 were 41%, 75% and 94%, respectively. The degradation of total PCBs in terms of ratio to solvent with oil transformer in 1:1, 2:1 and 3:1 was 61%, 75% and 94%, respectively. Conclusion: Our study show that UV-C photolysis of H2O2 leads to a degradation efficiency of PCBs only in the presence of isooctane, therefore indicating that the intermediates formation after ethanol oxidation are able to initiate PCBs degradation.
Comparison of Urinary o-Cresol and Hippuric Acid in Drivers, Gasoline Station Workers and Painters Exposed to Toluene in West of Iran
Abdulrahman Bahrami,Ahmad Jonidi-Jafari,Behzad Folladi,Hossien Mahjub
Pakistan Journal of Biological Sciences , 2005,
Abstract: The aim of this study was evaluation of exposed to toluene and compare levels of hippuric acid and o-Cresol in taxi drivers, petrol station workers, car painters with a control group in West of Iran. The urinary o-creasol and toluene in air were analyzed by a gas chromatography and hippuric acid was extracted from urine and analyzed by high performance liquid chromatography. The significant differences in the levels of urinary o-Cresol were found in painters and petrol station workers compared to the control group (p<0.005). There was no significant correlation between toluene in air and biomarkers for taxi drivers. The lowest toluene concentration at which urinary hippuric acid increased to a measurable level was approximately 25 to 35 ppm and for o-Cresol was 2 ppm. In conclusion our results was showed that o-Cresol and hippuric acid could separate the exposed to toluene from the non-exposed when toluene in breathing zone of subjects was greater than 3 and 35 ppm, respectively. Hippuric acid and o-Cresol are not suitable biomarkers for occupations such as drivers that exposure to toluene in low concentration.
Investigation of Water Disinfection by Electrolysis
Ali Reza Rahmani,Ahmad Jonidi Jafari,Amir Hossein Mahvi
Pakistan Journal of Biological Sciences , 2005,
Abstract: The main purpose of this study was to conduct experimental investigation of water disinfection by using the electrolysis method. Inactivation and killing Coliform in polluted waters are investigated by different voltage, electrodes (Al, St and Cu) and 5 min electrolyze time. The experimental results showed that the removal efficiency depends on the voltage and electrode materials. From the experiments carried out at 10 V and at current intensity of 135 mA, it was found that 5 min period was sufficient for disinfecting water by Stainless steel electrodes.
Survey of Modified Clinoptilolite Zeolite and Cooper Oxide Nanoparticles-Containing Modified Clinoptilolite Efficiency for Polluted Air BTX Removal
Ruhollah Rostami,Ahmad Jonidi Jafari,Roshanak Rezaee Kalantari,Mitra Gholami
Iranian Journal of Health and Environment , 2012,
Abstract: Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 Background and Objectives:Benzene, toluene and Xylenes (BTX) are organic pollutants, which are mainly associated with oil and its derivatives. BTX is environmental contaminants and considered harmful to human health. Application of surface absorbents such as zeolite is one of several methods for the removal of these compounds. In this study, BTX compounds' removal efficiencies were investigated and compared by using clinoptilolite type zeolite and zeolite with copper oxide nanoparticles.Materials and Methods: In this study, the modified zeolite by hydrochloric acid in the grain size 1-2 mm and modified zeolite with nano particle of copper oxide were used. Artificially- Contaminated Air flow was used continuously .To determine BTX concentrations, samplings were done by charcoal tube in current input and output. The concentrations of contaminants were determined by gas chromatography with FID detector.Results: Removal efficiency of benzene, toluene, p-xylene, m-xylene and o-xylene by clinoptilolite were 78.3%, 62.1%, 32.2% 32.15% and 18.8%, respectively. For the clinoptilolite containing copper oxide nano particles efficiency were 25.42%, 35.65%, 36.33%, 33.24% and 29.39%, respectively. Average removal efficiency of BTX compounds observed when the zeolite without nanoparticles used (43.31%) was more than zeolite with nanoparticles (32%). The results showed that the concentration of CO2 in the outlet air of the zeolite-containing nanoparticle (550 ppm) was more than the zeolite without nanoparticle (525 ppm).Conclusion: Results showed that adding nanoparticles to the zeolite, although the removal efficiency of benzene and toluene can be reduced. The results showed that adding nanoparticles to the zeolite, although can be reduced removal efficiency of benzene and toluene, which may be due to occupying or blocking of the pollution absorption sites by the nanoparticles on the zeolite, but It cause promote more catalytic effect of zeolite in the decomposition process of contaminants by breaking the molecules of pollutants and their further degradation progress is done for conversion to carbon dioxide /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; m
A survey on Bacterial Contamination of Food Supply in the West of Tehran
Tehereh Faramarzi,Ahmad Jonidi Jafari,Somayyeh Dehghani,Maryam Mirzabeygi
Journal of Fasa University of Medical Sciences , 2012,
Abstract: Background & Objective: Transfer of food born diseases is a common problem in hygiene and public health. The bacteria are the most important factors of food contamination and intoxications. The aim of this study is to determine the bacterial contamination of food supply in the west of Tehran supermarkets. Materials & Methods: In this descriptive cross-sectional study, 642 samples of foods were taken randomly from west of Tehran supermarkets. The levels of bacterial contamination of the foods were assessed in the department of food and drug microbiology of lab, affiliated to Iran University of medical science. Results: Salads were the most (50%) and protein products (6.36%) the least rate in terms of mesophilic bacteria contamination. Also, sweets (13.46%) and protein products (1.73%) in terms of Coliforms. Salads (58.33%) and dairy products (9.84%) with respect to Escherichia coli, sweets (4.81%) and salads (0%) in terms of Staphylococcus aureus, sweets (4.81%) and dairy products (0.39%) with respect to Bacillus cereus, were the most and least contaminated foods, respectively. Conclusion: In overall, salads had the most contamination percentage with respect to mesophilic bacteria, Escherichia coli and Enterococcus (P . According to our study, we conclude that training of dealers and food suppliers are necessary and healthy principals should be followed. Also supervision on food packing and storage should be considered to prevent food microbial contamination.
Hospital Solid Waste Management in Qom Hospitals
A Jonidi,A R Jafaripour,M Farzadkia
Journal of School of Public Health and Institute of Public Health Research , 2010,
Abstract: Background and Aim: Inadequate management of biomedical waste can be associated with risks to healthcare workers, patients, communities and their environment. In this study a comprehensive survey was conducted to obtain information on the management of solid wastes in Qom hospitals.Materials and Methods: Field visits were made to 2 private and 4 governmental hospitals to collect the required information and weighing the solid wastes generated. In addition, supplementary information was collected using a modified World Health Organization questionnaire. Results: The results showed total the average generation rate of solid waste in Qom hospitals was 3057.55 kg/day. The shares of general, infectious, sharp, and pharmaceutical and chemical solid wastes were 1523.6, 1520.6, 12.72 and 0.93 kg/day, respectively. The results on various aspects of solid waste management indicate that practices in the hospitals do not comply with the principles stated in the respective Iranian regulations. Similarly, the segregation process was inefficient. No information was available concerning the quantity and quality of solid wastes. Conclusion: Development of suitable waste management schemes and plans are strongly recommended. In addition, establishing training programs on proper waste management for all the personnel involved (managers, physicians, nurses, workers) are essential. These actions, plus effective supervision, will result in considerable reductions in hospital solid waste disposal cost
Page 1 /462631
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.