Samaneh Ghodrati; Seyyed Gholamreza Mosavi; ahmad Allahabadi
Volume 22, Issue 3 , May and June 2015, , Pages 270-281
Abstract
Background: Removal of humic acids during water treatment is important because it can react readily with chlorine and produce carcinogen compounds. In this study, performance, kinetic and isotherm of humic acid (HA) adsorption onto NH4Cl-induced activated carbon (NAC) has been investigated and compared ...
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Background: Removal of humic acids during water treatment is important because it can react readily with chlorine and produce carcinogen compounds. In this study, performance, kinetic and isotherm of humic acid (HA) adsorption onto NH4Cl-induced activated carbon (NAC) has been investigated and compared to the standard activated carbon (SAC).
Materials and Methods: NAC and SAC were used as the adsorbent in the present work and adsorption experiments were performed in batch mode. Adsorption of humic acid (HA) on SAC and NAC as a function of solution initial pH (2-10), adsorbent dosage (0.1-0.4 g/L), contact time (5-70 min), and adsorbate concentration (5-20 mg/L) was investigated.
Results: NAC exhibited higher HA adsorption capacity than that of SAC and HA adsorption capacities for both decreased with increasing solution initial pH in range of 2 to 10. The HA removal efficiencies of SAC and NAC were found to increase with increasing the adsorbent dosage. The adsorption kinetics data were well fitted by pseudo-second-order equation. The mechanisms of the adsorption of HA on SAC and NAC at pH 7 may include electrostatic attraction and hydrogen bonding. The adsorption isotherm data showed that adsorption behavior of HA well fitted by Langmuir adsorption isotherm for both NAC and SAC. The maximum adsorption capacity was 93.45 and 67.57 mg/g for NAC and SAC, respectively.
Conclusion: The results revealed that NAC has significantly removed HA from aqueous solutions compared to SAC and even many other adsorbents. Thus NAC as a cheap and more appropriate adsorbent can be used for removal of humic substances from polluted waters.
Ayyob Rastegar; Zahra Rezaee Gezal Abad; Ahmad Allahabadi; Abolfazl Rahmani Sani; RamezanAli Khamirchi
Volume 21, Issue 6 , January and February 2015, , Pages 1090-1102
Abstract
Background: Aniline is an important chemical compound which has wide applications in several industries such as dyestuffs, rubbers, pesticides and plastics. It is highly toxic and has injurious influences on human physical conditions and aquatic life. Therefore the purpose of this study is to investigate ...
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Background: Aniline is an important chemical compound which has wide applications in several industries such as dyestuffs, rubbers, pesticides and plastics. It is highly toxic and has injurious influences on human physical conditions and aquatic life. Therefore the purpose of this study is to investigate the effects of NH4Cl-induced activated carbon (NAC) and standard activated carbon (SAC) in aniline removal from aqueous solutions were investigated. Material & method: This study is of experimental–intervention type. An UV-Visible spectrophotometer (CECIL CE7400) used For determination of remaining aniline concentrations. The effect of various parameters like adsorbent dose, pH, contact time and initial aniline concentration were studied for optimization.
Results: The results showed that the prepared NAC had a higher absorption capacity than standard activated one. The maximum adsorption capacity of aniline onto SAC and NAC was 1666 and 1000 mg/g, respectively, and the rate removal was dependended to pH, contact time, aniline concentration and absorption type. Results of equilibrium experiments indicated that the adsorption process of aniline onto SAC and NAC follows Langmuir model (R 2> 0.99.47 and 0.99,776 ). Also, kinetics of adsorption process follows pseudo second-order model with correlation R2> 0.99.97 and 0.99,30 respectively for SAC and NAC.
Conclusion: These consequences show that the developed NAC was a more competent adsorbent than SAS for removal aniline in water.
Mehran Eyvazzadeh; MohammadHasan Rakhshani; Ayyob Rastegar; Ahmad Allahabadi; Ebrahim Manochehriyan; Fatemeh Dareyni; Abolfazl Rahmanisani
Volume 21, Issue 5 , September and October 2014, , Pages 934-941
Abstract
Background: In recent years, crisis of water shortage has become a serious problem in many countries. In this regard, the use of treated wastewater in natural or artificial method in agriculture and the like, has been proposed as an important and practical solution. The natural purification method by ...
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Background: In recent years, crisis of water shortage has become a serious problem in many countries. In this regard, the use of treated wastewater in natural or artificial method in agriculture and the like, has been proposed as an important and practical solution. The natural purification method by the use of artificial canebrakes, compared with other methods of treatment is an appropriate method because of its low cost, and also, because of easy navigation, the requirements of low technology and low energy consumption. Several herbs have been used to increase the efficiency canebrakes which including special plants to purify such wastewater is Vetiveria that has unique genetic, morphological and physiological characteristics. Due to the limited knowledge of the plant's industrial wastewater treatment, in this study, a comparison of filterablity of hospital wastewater was done between Vetivaria and bulrush in tropical areas.
Methods: This experimental study was done in 2013 in the hot season, summer. In this study, was made two pilot glass with dimensions of 50*60*100 Cm. A mixture of soil, sand, gravel, clay soil was selected. The irrigation method in this study was subsurface and continuous. First, hospital wastewater via a 220 liter tank as the primary sedimentation retention time and with time of 2 hours entered into bed with a hydraulic retention time of 4 days to discharge 85/0 liters per hour. To evaluate the efficiency of each plant in the treatment of hospital wastewater, chemical parameters including (PH, TP, TN , TSS, BOD5, COD)were measured according to standard methods of measuring. . Analysis of the data was done by the use of t-test and Mann-Whitney and SPSS software.
Results :Based on the finding of this study, percentage of removal parameter(Bod5,Tss,Tn,Tp) by plant Vetiveria was (88.54,95.71,93.93,99.80) and for bulrush was (82.54,91.13,86.64,99.28).
Conclusion: Due to the unique characteristics of Vetiveria, such as high resistance against unfavorable environmental conditions and its higher efficiency than bulrush, this plant is recommended for the treatment of hospital wastewater.
Akram Mahmoudi Baghkheyrati; MohammadHasan Rakhshani; Ahmad Allahabadi; Reza Hekmat shoar
Volume 20, Issue 4 , January and February 2014, , Pages 457-463
Abstract
Background and Purpose :Cost-benefit equations is one of the most important by of GNP and a training a Sustainable development as designated by professionals of occupational health .Therefore ‚ drivers as a forgotten index in sustainable development and its effect on community health.
Methods & ...
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Background and Purpose :Cost-benefit equations is one of the most important by of GNP and a training a Sustainable development as designated by professionals of occupational health .Therefore ‚ drivers as a forgotten index in sustainable development and its effect on community health.
Methods & Material : This descriptive analytical study involved the statistical community of 55000 vehicles in Sabzenar ‚Iran ‚from which 380 cases were splected by systematic sampling during six months from 17:00 to 20:00‚winter and spring 2011 with a traffic load peak ‚where right – trun violations were recorded at two major crossroads The obtained data were analyzed in SPSS 10.5 using normal Kolmogroff-smironoff and chi-square.
Results: significant relationship was observed between .occupation type and attitude (P=0.013) ‚ occupational history and attitude (P=0.03)‚ as well as residential area and attitude (P=0.011)‚ however‚ no significant relationship was found between age and attitude (P=0.0149)‚ education and attitude (P=0.0118) ‚ at a confidence interval of 95%. Total wasted time per year at a crossroad with three outlets was 1/123/260 hours per year. Given a 4 – cross road typical city in Iran with 340 cities ‚ an estimated 1/527/633/600 hours per year will be wasted. As far as the cost is concerned ‚ the total amount of gas wasted (7000 Rials/litre)will amount to 1/226/534/400 Rials per year in one single cross road in Sabzevar ‚Iran .The same equation applies here to produce a cost estimation of 167/280/000/000 Rials/year nationwide.
Conclusion: Immediate action for geometric correction of crossroads is required for preventing wastage of national resources and imposing economic costs on community members and the wasted time due to abnormal traffic behavior‚ increased GNP and moving toward Sustainable development will follow as a Consequence.
Kamyar Yaghmaiyan; Gholamreza Mousavi; Hamidreza Karimi; Ahmad Allahabadi
Volume 20, Issue 4 , January and February 2014, , Pages 573-582
Abstract
Background: Antibiotics are important pollutants of water resources, and because of hard biodegradability, they can be filtered through adsorption method. Activated carbon is one of the best adsorbents. The aim of this study was to investigate the amoxicillin removal rate of a standard granular activated ...
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Background: Antibiotics are important pollutants of water resources, and because of hard biodegradability, they can be filtered through adsorption method. Activated carbon is one of the best adsorbents. The aim of this study was to investigate the amoxicillin removal rate of a standard granular activated carbon.
Materials and methods: The adsorption experiments were conducted in the stirred (100 rpm) glass reactor. In each test, 50 ml of aqueous solution contaminated by amoxicillin was transferred into the reactor, and the influence of adsorbent dose, adsorbent type, amoxicillin concentration, reaction time, solution pH and temperature was tested on the amoxicillin adsorption. At the end of each of adsorption tests, the suspension was filtered using a cellulose acetate filter with 0.45µm pore size and the filtrate was analyzed for residual amoxicillin using HPLC.
Results: The obtained data showed that the best conditions for removal of amoxicillin from contaminated water using granular activated carbon were as follow: pH: 6, adsorbent concentration: 1.6 g/l, reaction time: 60 min, temperature: 25oc. In these conditions up to 86% of amoxicillin (concentration: 50 mg/l) could be adsorb by a granular 16-20 activated carbon.
Conclusion: Adsorption onto activated carbon is an efficient method for the removal of non-degradable water pollutants such as antibiotics and toxins.
Yosef Pour Eshgh; Ayyob Rastegar; Ahmad Allahabadi; Zahra Rezaee Gazal abad; Abdolmajid Gholizadeh
Volume 20, Issue 1 , March and April 2013, , Pages 72-83
Abstract
Background: The effluent of textile industries is high dyefully and this is one of most problems for environmental health engineers. Two Azo dyes biosorption, direct black 19 and direct red 23, on Cystoseira indica, an invasive macroalga in Iran, has been investigated using visible absorption spectroscopy. ...
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Background: The effluent of textile industries is high dyefully and this is one of most problems for environmental health engineers. Two Azo dyes biosorption, direct black 19 and direct red 23, on Cystoseira indica, an invasive macroalga in Iran, has been investigated using visible absorption spectroscopy.
Materials and methods: Pre-treatment and chemical cross-linking with CaCl2, have been conducted in order to improve the stability as well as the biosorption capacity of the algal biomass. All measurements were conducted by UV-Visible Spectrophotometer. The effects of operating parameters such as contact time, pH, initial dye concentration and amount of biosorbent on the dye removal efficiency were investigated. The biosorption has been described in terms of isotherm and kinetic models; from the maximum adsorption capacity values, an estimation of the algal specific surface area was made.
Results: It has been found that biosorption kinetics can be described according to the pseudo second order model and biosorption equilibrated for 120 min (89.3% of direct red 23 and 69.02% of direct black 19 removed). Maximum biosorption found at pH 5 (2.4mg/g). It also observed increasing initial dye concentration and decreasing biomass dosage would reduce dye removal. Isotherm studies also revealed the dye biosorption on algal biomass followed from Freundlich model. Conclusion: Biosorption of selected Azo dyes onto algal biomass, Cystoseira indica was fast and more dye is eliminated in the first hour. So, by determining the optimum conditions of contact time, pH, initial dye concentration and biosorbent dosage, Cystoseira indica can be used as an inexpensive sorbent for removal of Azo dyes from aqueous solutions.
Akbar AhmadiAsoor; yaser Tabaraee; Ahmad Allahabadi
Volume 19, Issue 4 , January and February 2013, , Pages 390-394
Abstract
Background: Many diseases are triggered depending on the condition of the building environment. Purpose of this study was to investigate the incidence of sick building symptoms in office staff of Sabzevar University of Medical Sciences . Materials and Methods: In this cross-sectional study, all the office ...
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Background: Many diseases are triggered depending on the condition of the building environment. Purpose of this study was to investigate the incidence of sick building symptoms in office staff of Sabzevar University of Medical Sciences . Materials and Methods: In this cross-sectional study, all the office staff of Sabzevar University of Medical Sciences building condition surveyed by using a standard questionnaire for signs of disease. Results: The results showed that during the last year of the 69 people surveyed, about 62.7% at work feeling tired and 27.1% with vertigo and 24.28% felt sleepy, while approximately 95% of people stated that after leaving Work the symptoms disappeared. Average concentration of Carbon monoxide has been 3.4 ppm and sulfur dioxide with an average 0.027 ppm . Conclusion: Note that the measured concentrations of carbon monoxide , sulfur dioxide increasingly been far too low and Prevalence rate of illness among staff in the building haven't been of a high percentage, Therefore it can be concluded that the building was not sick building and prevalence symptoms of sick Building in the headquarters staff of Medical Sciences of Sabzevar is not significant.
Roshanak Rezaei Kalantary; Ahmad Allah-Abadi; Mehdi Farzadkia; Ayyob Rastgar; Ahmad Joneidi Jafari; Abdolmajid Gholizadeh
Volume 19, Issue 3 , September and October 2012, , Pages 277-286
Abstract
Background: Leaching of nutrients and heavy metals from municipal solid waste compost leads to accumulation of certain elements in soil layers, causing underground water pollution. The objective of this study was to investigate the effect of compost on leaching and adsorption of heavy metals and nutrients ...
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Background: Leaching of nutrients and heavy metals from municipal solid waste compost leads to accumulation of certain elements in soil layers, causing underground water pollution. The objective of this study was to investigate the effect of compost on leaching and adsorption of heavy metals and nutrients (sodium, potassium, and sulfate) from silt-loamy soils. Materials and Methods: In this empirical, applied study, three polyethylene columns (height 50 cm, inner diameter 10 cm), filled with sandy clay loam soil, were randomly selected. Then, 10 kg of compost per square meter were sprayed onto the columns, and leachates exiting the columns were routinely analyzed for pH, electrical conductivity, sulfate, sodium, potassium, lead, chromium, and cadmium. Data analysis was performed with Excel and SPSS software using Kruskall-Wallis test. Results: The data showed that the use of enriched and unenriched compost leachate decreased pH (from 7.43±17.0 to 6.7±0.25 and 7.07±0.11, respectively) and increased the electrical conductivity (EC) (from 1.8±0.3 mSiemens/m to 3.7±0.12 and 12.87±0.41 mSiemens/m respectively). Leakage of metals in the unenriched treatments was not significantly different from the control (p>0.78), but leakage with three metal-enriched compost applications was significant compared with control (p
Tahereh Vazeiri; Abolfaz Rahmani Sani; Ahmad Allahabadi; MohammadHossein Saghi; Reza Hekmatshoar
Volume 19, Issue 2 , May and June 2012, , Pages 127-135
Abstract
Background: The biosorption process has found numerous applications due to low cost, availability, biosorbent reuse, and utilization of excess sludge from wastewater treatment facilities. The aim of the present study was to evaluate the efficiency of dried activated sludge in removing Reactive Orange ...
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Background: The biosorption process has found numerous applications due to low cost, availability, biosorbent reuse, and utilization of excess sludge from wastewater treatment facilities. The aim of the present study was to evaluate the efficiency of dried activated sludge in removing Reactive Orange 3R dye. Materials and methods: For this experimental, laboratory study, dye solutions were prepared in three concentrations: 50, 100, and 150 mg/L. The solutions were then subjected to adsorbent in weights 0.2, 0.4, 0.6, 0.8, and 1.0 g for various durations (0.5, 1, 1.5, 2, 2.5, and 3 hours) in different pH levels (4, 7, and 12). Data was analyzed using Excel software. Results: Increasing contact time from 0.5h to 3h, the dye removal efficiency increased from 56% to 76%. When the weight of the biomass increased from 0.2g to 0.8g, the dye removal efficiency increased from 58% to 72%. High initial iron concentration had an adverse effect on iron removal efficiency. Increasing initial dye concentration from 50 to 150 mg/L decreased iron removal efficiency from 71% to 62%. Freundlich isotherm models could describe the adsorption equilibrium of the dye onto the activated sludge. Freundlich isotherm represented a better correlation compared to other isotherms (R2>0.952). Also, second-order models fit well with experimental data (R2>0.979). Conclusion: This technology for dye removal from industrial wastewater, in addition to the optimal use of biomass from wastewater, can help resolve the environmental problem of wastewater dye excretion.
Ahmad Allahabadi; Akbar Ahmadi Asoor
Volume 18, Issue 2 , July and August 2011, , Pages 140-147
Abstract
Background and Purpose: Photochemical smogs، CO، NO2 and SO2 are among the major air pollutants with known effects and complications. The present study was designed to investigate the density of these pollutants in Sabzevar، Iran.
Methods and Materials: this descriptive cross-sectional study intended ...
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Background and Purpose: Photochemical smogs، CO، NO2 and SO2 are among the major air pollutants with known effects and complications. The present study was designed to investigate the density of these pollutants in Sabzevar، Iran.
Methods and Materials: this descriptive cross-sectional study intended to measure the air pollutants in different parts of Sazbevar، Iran. Sampling was done with stratified time sampling based on NIOSH 4800 and 6004 methods for SO2 and NO2، and method 6604 for CO. Sampling instruments included pump (debi 5 L/min)، impinger، detector tube and ratameter. Based on traffic intensity، four points in the city were located and observe for 12 months، three day a month and three times per day; total sample swere 324. Data analyssi was done in SPSS 16 usingdescriptive measures as well as Pearson correlation coefficient ad one-sample t-test.
Results: Significantly highest rate of CO intensity was observed in Mordad (August) (64.1 mg/m3) and Esfand (March) (63.11 mg/m3) (P