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ORIGINAL ARTICLES
Knowledge attitude and practice study on biomedical waste management among health care professionals and paramedical students in a Tertiary Care Government Hospital in South India
Vetrivel Chezian Sengodan, KH Amruth
2014, 3:11 (23 May 2014)
Aims: The aim of our study was to analyze the knowledge attitude and practice (KAP) of biomedical waste management among medical, paramedical students and health care professionals in Coimbatore Medical College Hospital in South India. Materials and Methods: Study was conducted among 400 health care professionals including doctors, nurses, nursing students, and laboratory technician course students. The results were evaluated. Results: It was found that the doctors had the maximum knowledge and practice among health care professionals. The results also indicate that knowledge is not uniform among individual group, and there exists considerable variation within the group. Conclusion: The results of our study revealed that the project for upgrading safety in health care initiative taken by the Government of Tamil Nadu to create awareness of biomedical waste management among health-care professionals have certainly improved the KAP on biomedical waste management. Hence, such a program is mandatory to improve the biomedical waste management in health-care centers.
  11,416 1,006 -
Occupational health problems of municipal solid waste management workers in India
Thayyil Jayakrishnan, Mathummal Cherumanalil Jeeja, Rao Bhaskar
2013, 2:42 (29 November 2013)
DOI:10.4103/2277-9183.122430  
Aims: The present study aimed to assess the occupational health problems of municipal solid waste management workers. Material and Methods: Cross-sectional descriptive study was conducted among solid waste management workers of Kerala, India. All workers (408) were included the study of which 313 (77%) participated. Data were collected by direct interview and clinical examination using a structured questionnaire. The observed morbidity like respiratory diseases, eye diseases, dermatological problems and nail infections were elicited by clinical examination. The point prevalence of other occupational related health events present either during the study time or during 1 month recall period and that occurred ever after entry in present occupation was collected by self-reported complaints and doctors diagnoses. Results: The mean age was 42.5 ± 7.2 years. The observed morbidity like respiratory diseases, eye diseases, dermatological problems, nail infections were high ranged from 21% to 47%. The reported prevalence of occupation related morbidities like falls (63.6%), accidents (22%), injuries (73.2%), and water-vector borne disease (7.1%) were high. The current prevalence of musculoskeletal morbidities showing that all major joints are involved (17-39%). Conclusions: The work related health-problems were reported to be high. The prevalence of Respiratory, dermatological, eye problems and injury, musculoskeletal problems were reported to be high among municipal solid work handlers. Measures are needed to improve the work environment of waste handlers by ensuring availability protective gears based on ergonomic principles, clean drinking water and washing and sanitation facilities during working hours.
  10,679 1,630 4
Oxalic acid degradation from aqueous solution using ozonation process in the presence of magnesium oxide nanoparticles catalyst stabilized on activated carbon
Sara Haidari, Bahram Kamarehie, Ali Jafari, Mahdi Birjandi, Sohila Afrasyabi
2016, 5:23 (26 December 2016)
DOI:10.4103/2277-9183.196665  
Aims: In this work, activated carbon, magnesium oxide (MgO), and MgO stabilized on activated carbon derived from sweet corn were applied as catalysts for oxalic acid degradation from aqueous. Materials and Methods: Sweet corn pile was used for the production of activated carbon, and magnesium nitrate applied for the production of MgO. Ozone concentration determined using iodometry method, and oxalic acid concentration was determined by a spectrophotometer at 210 nm. Moreover, the effect of MgO, activated carbon and oxalic acid concentration, pH, contact time, and oxalic acid mineralization were investigated. Results: The results showed that ozonation in the presence of activated carbon or MgO and/or MgO stabilized on activated carbon, increased the decomposition rate of oxalic acid. Removal efficiency of oxalic acid with increasing catalysts dose of 0.05–1 g, pH of 3–11, and time of 1–30 min have increased from 72% to 85%, 72% to 85%, and 92% to 95% respectively. Furthermore with increasing of oxalic acid from 40 to 100 mg/L, the removal efficiency decreased from 96% to 88%. Conclusion: According to this study, catalytic ozonation processes have shorter time and more removal efficiently than the single ozonation process. Moreover, the results showed that oxalic acid was mineralized significantly and interfering factors have negligible effect on the catalytic ozonation process than the single ozonation.
  11,121 371 1
Study of the coagulation process in wastewater treatment of dairy industries
Mahshid Loloei, Hosein Alidadi, Gholamabbas Nekonam, Yousef Kor
2014, 3:12 (23 May 2014)
DOI:10.4103/2277-9183.132684  
Aims: In this study, the effect of the coagulation process on treatment of simulated dairy wastewater (SDW) was investigated using the mineral and organic coagulants. Materials and Methods: Different types of coagulants such as inorganic (Alum and ferrous sulphate) and polymeric coagulants (polyacrylamide [PAA] and polyferric sulphate [PFS]) were investigated. Inorganic coagulants dosages were varied from 100 to 1000 mg/L and the polymers dosage was 20 mg/L. Turbidity, chemical oxygen demand (COD), electrical conductivity (EC) and chloride of samples were investigated in optimum pH. Results: Both two coagulants had an optimum dose and pH of 1000 mg/L and 5 respectively. According to the findings, Alum with 95% turbidity removal and 68% COD removal had more high efficiency than ferrous sulphate (95% and 62% efficiency for turbidity and COD removal respectively). When Alum via PFS and PAA as a coagulants aid were used, 82% decrease in COD was obtained using low dose of Alum (100 mg/L). Conclusion: In studied dairy wastewater, Alum was more effective than ferrous sulphate. Addition of 20 mg/L of both two coagulants aid (PFS and PAA) effectively reduced the use of Alum and it was effective in COD removal.
  9,186 1,330 5
Measurement of used oil rancidity indexes in the confectioneries and food shops
Hossein Farrokhzadeh, Ebrahim Ghorbani, Hassan Hashemi, Leili Mohebat, Akbar Hassanzadeh, Mahmoud Yahay, Fatemeh Samadanian, Hossein Jaberi
2013, 2:28 (29 June 2013)
DOI:10.4103/2277-9183.114188  
Aims: The aim of this study was to determine the peroxide value, acid value and rancidity of edible oil which are used in sweet pancake, samosa, confectionery and sandwich shop. Materials and Methods: This descriptive study was carried out on all sandwich shops and sweet pancake at north region of Isfahan city. The peroxide value, acid value and rancidity were determined based on national standard procedure number 4179, on thirty samples. Results: The average of peroxide and acid value was 5.2 and 0.5, respectively. Around 7.4 percent of tested oil has a non permissible rancidity value. Also, 87 percent of samples were healthy. In general, 98.1 percent of oil samples were unusable. Conclusion: The acid and peroxide numbers was in acceptable range, however, the rancidity or oil chemicals corruption caused by inappropriate conservation conditions. This type of fast food, have adverse effects on consumers' health.
  9,543 479 -
Catalytic oxidation of hydrogen peroxide and the adsorption combinatory process in leachate waste pretreatment from composting factory
Behrooze Karimi, Mohammad Hassan Ehrampoush, Asghar Ebrahimi, Mehdi Mokhtari, Mohammad Mehdi Amin
2012, 1:15 (28 March 2012)
Aims: The purpose of this study was to use a combinational process of catalytic oxidation of hydrogen peroxide (CWPO) and activated carbon for improving the removal efficiency of organic matter. Materials and Methods: The effect of the operational parameters such as residence time (30 - 90 minutes), reaction temperature (100-300°C) in the pressure 10 bar, and catalytic iron concentration were investigated. The effect of the catalytic method, catalytic wet peroxide oxidation (CWPO), along with the absorption process, on granular activated carbon (GAC), powdered activated carbon (PAC), PAC/Cl 2 , and GAC/Fe were considered; oxygen is used to supply pressure and H 2 O 2 is applied as the main oxidant in various concentrations. Results: The removal efficiency of the chemical oxygen demand (COD) was over 35%, obtained in one hour of retention time, with the wet air oxidation (WAO) process, and the removal efficiencies of GAC, PAC, and PAC/Cl 2 , at a temperature of 300°C, and activated carbon concentration of 2 g/l, were 43.4, 38.9, and 33.6%, respectively. Conclusion: These results indicate that the reaction temperature, residence time, and H2O2 dose are the most important factors affecting the degradation of organic matter. The GAC/Fe catalyst process had a higher efficiency than other absorbents for organic matter oxidation.
  7,810 627 -
Noise pollution of air compressor and its noise reduction procedures by using an enclosure
Farhad Forouharmajd, Parvin Nassiri, Mohammad Reza Monazzam
2012, 1:20 (15 May 2012)
DOI:10.4103/2277-9183.96143  
Aims: The aim of this study is to find manners of noise abatement to reach to its allowable values by which the noise caused by compressors can be reduced, and if use of enclosure is an effective alternative. Materials and Methods: In the study, analysis of noise caused by the compressor and how distribution of sound frequencies with and without the use of enclosure was done, and then compared with standard values to help choose the best absorber material. This method is in accordance with the in situ assessment techniques for noise generated by different sources. A second order analyzer was use to study the recorded sound pressure level (SPL) values, and to demonstrate which frequencies can be more important in designing the enclosure. A sheet metal was used for enclosing the compressor, and this was lined with an absorber material to achieve a better sound reduction. SPL levels, before and after the enclosure of the compressor with the sheet material, were measured and compared. Results: There was a reduction in the level of noise produced for all frequencies due to use of the enclosure, a difference of 10 to 50 dB of reduction was recorded for all the frequencies. For higher frequencies in the range of 500 Hz to 4000 H, the SPL showed a similar reduction. A reduction of 50 dB in the produced noise below the standard was seen for the frequency of 63.5 Hz in octave band frequencies. There was also a permissible limit for higher frequencies of noise produced by the compressor, but with a gap of 10 dB of its standard limit at the frequency of 500 Hz. Conclusions: An overall noise reduction by 25 dB with the use of mineral wool as an extra liner on the inside of the enclosure, suggests that the effectiveness of the enclosure can be increased by using such absorber materials.
  6,464 656 -
Assessment of physical risk factors among artisans using occupational repetitive actions and Nordic questionnaire
Ehsanollah Habibi, Mohsen Zare, Azam Haghi, Peymaneh Habibi, Akbar Hassanzadeh
2013, 2:14 (6 April 2013)
DOI:10.4103/2277-9183.110158  
Aims: The aims of present study is to determine the level of exposure to physical risk factors of work related repetitive movements in the upper limbs among the artisans in Isfahan, using occupational repetitive actions index and the Nordic Questionnaire. Material and Methods: In this cross-sectional study, the study population consisted of 94 males employed in Artisan production. The tools that be used for assessing physical ergonomic risk factors among artisans was Nordic Questionnaire and OCRA index. The different handicraft tasks and work activities included: Simple etching, embossing, reticular embossing, enameling, tiling, illumination, inlay, copper smithing and, miniature painting have been chosen for the study. The Study was carried out on the both left and right hands. The results were analyzed by statistical tests included Chi square, Kruskal Wallis and one-way variance analysis. Results: The highest OCRA index score was related to simple etching job, and the other tasks such as embossing, copper smithing, reticular embossing, tiling, miniature painting, and illumination were in lower risk category. Our finding showed that there are a significant difference between OCRA scores of the various jobs (P value < 0.001), and also the relationship between OCRA index and the type of jobs was statistically significant (P value < 0.001). Risk level in the right hand was significantly higher than the left hand (P value < 0.001). Moreover, in both right and left hands, OCRA index was different among several types of jobs (P value < 0.001). Conclusion: Our assessment showed that in overall there are different physical risk factors among artisans which make them susceptible to musculoskeletal disorders.
  6,463 537 3
Microbial quality and prevalence of Salmonella and Listeria in eggs
Manijeh Mahdavi, Mohammad Jalali, Hjieh Ghasemian Safaei, Ehsan Shamloo
2012, 1:48 (31 December 2012)
DOI:10.4103/2277-9183.105347  
Aims: This study was undertaken to determine the microbial quality and the prevalence of Salmonella and Listeria in table eggs in Isfahan, Iran. Materials and Methods: A total of 525 samples were randomly collected from various shops in Isfahan, Iran. Microbial quality of eggs evaluated by coliform count and total bacterial viable counts. Also, detection of Listeria and Salmonella in egg contents and on eggs shells was performed. Results: The mean of total viable bacteria and coliform counts in the egg contents were 3.95 × 10 4 CFU/g and 4.94 × 10 3 CFU/g, respectively. Salmonella and Listeria were not found on the shell or content of eggs. Enterobacteriaceae families were found in 357 of 525 (68.28%) and 276 of 525 (52.44%) of egg shell and egg content samples, respectively. Moreover, Pseudomonas aeruginosa was isolated from 175 (33.41%) and 144 (25.37%) of egg shell and egg content, respectively. The isolated Enterobacteriaceae were included: Enterobacter aerogenes, Escherichia coli, Klebsiella pneumoniae, Buttiauxella agrestis, Cedecea lapagei, Cedecea davisae and Erwinia herbicola. Conclusion: The findings of the present study indicate although Salmonella and Listeria were not found in egg samples; however, there is an urgent need to improve the hygienic level of consumed eggs.
  5,827 492 -
Treatment of hospital wastewater by electrocoagulation using aluminum and iron electrodes
Mansooreh Dehghani, Someih Shiebani Seresht, Hassan Hashemi
2014, 3:15 (23 May 2014)
DOI:10.4103/2277-9183.132687  
Aims: The main goal of this study was to determine of the removal efficiency of chemical oxygen demand (COD) from educational hospital waste-water using electrocoagulation process by using iron and aluminum electrodes. Materials and Methods: A laboratory-scale batch reactor was conducted to determine the removal efficiency by the electrocoagulation method. Fifty-five samples of Shahid Mohammadi Hospital waste-water in Bandar Abbas were collected for the periods of 6 months according to standard methods. The removal of COD from the waste-water was determined at pH 3, 7, and 11 in the voltage range of 10, 20, and 30 V at the operation time of 30, 45, and 60 min. Data were analyzed in SPSS (version 16) using Pearson's correlation coefficient to analyze the relationship between these parameters. Results: The removal efficiency is increased by 6.2% with decreasing pH from 11 to 3 at the optimal condition of 30 V and 60 min operation time. By increasing the reaction time from 30 min to 60 min at voltages (10, 20, and 30 V), the removal efficiency was increased from 32.3% to 87.1%. The maximum COD removal efficiency was observed at pH 3 and voltage of 30 V and 60 min reaction time using four iron electrodes. Pearson correlation analysis showed a significant relationship between voltage and the reaction time with the removal efficiencies (P < 0.01). Conclusion: Due to the high efficiency of the electrocoagulation process and also the simplicity and relatively low-cost, it can be used for removing COD from hospital waste-water.
  5,423 886 1
REVIEW ARTICLES
A review on wastewater disinfection
Mohammad Mehdi Amin, Hassan Hashemi, Amir Mohammadi Bovini, Yung Tse Hung
2013, 2:22 (10 June 2013)
DOI:10.4103/2277-9183.113209  
Changes in regulations and development of new technologies have affected the selection of alternative for treated wastewater disinfection. Disinfection is the last barrier of wastewater reclamation process to protect ecosystem safety and human health. Driving forces include water scarcity and drinking water supply, irrigation, rapid industrialization, using reclaimed water, source protection, overpopulation, and environmental protection. The safe operation of water reuse depends on effluent disinfection. Understanding the differences in inactivation mechanisms is critical to identify rate-limiting steps involved in the inactivation process as well as to develop more effective disinfection strategies. Disinfection byproducts discharged from wastewater treatment plants may impair aquatic ecosystems and downstream drinking-water quality. Numerous inorganic and organic micropollutants can undergo reactions with disinfectants. Therefore, to mitigate the adverse effects and also to enhance that efficiency, the use of alternative oxidation/disinfection systems should be evaluated as possible alternative to chlorine. This review gives a summary of the traditional, innovative, and combined disinfection alternatives and also disinfection byproducts for effluent of municipal wastewater treatment plants.
  5,216 596 4
ORIGINAL ARTICLES
Heavy metal content in edible salts in Isfahan and estimation of their daily intake via salt consumption
Hajar Pourgheysari, Malihe Moazeni, Afshin Ebrahimi
2012, 1:8 (28 March 2012)
Aims: In this study, the heavy metal contamination of consumable table salt, both unrefined and refined, was investigated. The provisional tolerable weekly intake (PTWI) of heavy metals just by edible salt, of the Isfahan population, was also estimated. Materials and Methods: Twenty samples of salt, including 15 refined and five unrefined were analyzed. Precision of the analysis was assured through repeated analysis of the five samples, which had a great demand in the city. The heavy metal content in the samples was analyzed with Flame Atomic Absorption Spectrometry (AAS) and Inductively Coupled Plasma (ICP). The PTWI of the metals was calculated by a formula and by using the Iranian average body weight. Results: The mean and standard deviations of cadmium (Cd), lead (Pb), arsenic (As), mercury (Hg), copper (Cu), and zinc (Zn), in refined table salts were 0.15 ± 0.02, 0.57 ± 0.1, 0.69 ± 0.09, 0.061 ± 0.008, 0.87 ± 0.11, and 6.34 ± 1.08 μg/g, and those in the unrefined ones were 0.16 ± 0.02, 0.61 ± 0.13, 0.63 ± 0.07, 0.058 ± 0.004, 0.86 ± 0.06, and 7.53 ± 2.93 μg/g, respectively. A PTWI via salt consumption was in the range of 0.8 - 3.1 percent. Conclusions: There was a significant difference between the heavy metal concentrations and their guideline values. Estimation of the health risk due to heavy metals was not possible as PTWI showed total intake of a metal by total food consumption during a week. Therefore, it was important to assess the public health risks arising from the presence of these toxic contaminants in the foods consumed by the population of Iran.
  4,951 581 -
An ergonomic study in building demolition: Assessment of musculoskeletal disorders risk factors by PATH method
Mohammad Hajaghazadeh, Yosef Mohammadian, Mohammad Normohammadi, Mehdi Zare
2012, 1:43 (13 October 2012)
DOI:10.4103/2277-9183.102386  
Aims: The aim of this study was the investigation of musculoskeletal disorders risk factors among building demolition workers. Materials and Methods: Posture, activity, tools, and handling (PATH) method as a work sampling method was applied to record the postures, activities, and handling of building demolition workers in four tasks. The percentage of working time is reported for each item to compare the risk factors in tasks. Nordic musculoskeletal questionnaire also was used to study the prevalence of musculoskeletal disorders over 12 months. Results: Trunk, leg(s), and arm(s) postures differed significantly among tasks. Neutral arm posture and non-neutral leg(s) and trunk postures were observed frequently. Manual materials handling (MMH) activities are distributed differently among tasks. Moving was the most observed (35%) and carrying was the less observed (11.8%) MMH activity. Gross grasp was the most observed (78.5%) hand activity in building demolition workers. The most observed weight category was 0 kg≤load<5 kg. Low back had the highest prevalence of MSDs symptoms (91.1%) and hip had the lowest prevalence of symptoms (6.7%). Conclusions: PATH is applicable to building demolition process. Ergonomic intervention is necessary in high prevalence body regions such as lower back and wrist to decrease the symptoms. With respect to the results of PATH method, ergonomic interventions for trunk and leg(s) are necessary in all tasks, but only task #3 is in the priority of arm(s) intervention.
  4,617 633 1
Comparison of conventional activated sludge system and stabilization pond in removal of chemical and biological parameters
Kiomars Sharafi, Mehdi Fazlzadeh Davil, Mohsen Heidari, Ali Almasi, Hossein Taheri
2012, 1:38 (13 October 2012)
DOI:10.4103/2277-9183.102360  
Aims: The aims of this study were to determine the efficiency of Kermanshah wastewater treatment plant (conventional activated sludge) and Gilan-e-Gharb wastewater treatment plant (stabilization ponds) in removal of organic matters (BOD 5 and COD), suspended solids, total coliform, protozoan cyst, and parasitic eggs in order to reuse their effluent for agriculture. Materials and Methods: In this study, the samples were taken every five days from both inlet and outlet of wastewater treatment plants (WWTPs) for five months. Identification and counting of the protozoa cysts and parasitic eggs was carried out using McMaster slide according to Bailenger method. Other parameters were determined according to standard methods. Appropriate statistical techniques (T-test, Kolmogorov Smirnov test, and Mann-Whitney U test, Using SPSS ver. 16) were applied to interpret data. Results: The efficiencies of Kermanshah wastewater treatment plant in removing BOD 5 , COD, TSS, total coliform, parasitic eggs, and protozoan cyst were 82 ± 4%, 83 ± 2%, 78 ± 5%, 66.2 ± 4.2%, 97-99%, and 99-100%, respectively. The respective efficiencies for Gilan-e-Gharb stabilization ponds were determined as % 84 ± 3, %82 ± 8, %84 ± 5.3, %75 ± 6, %100, and %100. Conclusions: According to the results, the removal efficiencies of all parameters except COD in stabilization ponds are higher than those in the activated sludge. Effluent quality in both plants met agricultural effluent reuse standards in view of all studied parameters except total coliform.
  4,774 443 1
The effect of the waste separation policy in municipal solid waste management using the system dynamic approach
Ahmad Jamshidi Zanjani, Mohsen Saeedi, Behdad kiani, Ali Vosoogh
2012, 1:5 (28 March 2012)
Aims: In the present study, Vensim was used to simulate waste management system of Tehran, the capital of Iran, with the system dynamic approach. Materials and Methods: The environmental system dynamic modeling is one of the comprehensive simulation tools capable of simulating and analyzing complex systems. In this approach, the model is developed based on the existing realities and userâ€'comments. User participation to develop the model could increase the reliability of the results. Results: The simulation results revealed good conformity with the statistical data. Waste production prediction in the model with real data was more than 95%. Moreover, the effect of applying an encouraging policy for people to separate their waste was considered. The result indicated that applying a new policy, and the economic benefit through this policy would prevent getting a loan from the government after 20 years. Conclusions: It could be concluded that public participation in waste separation was an effective policy to help in the financial independence of the municipality in terms of urban waste management. Moreover, conformity between the simulation results and real data revealed an appropriate capability of the simulated model to predict Tehran waste generation.
  4,420 692 -
Ability of phytoremediation for absorption of strontium and cesium from soils using Cannabis sativa
Parisa Seyed Hoseini, Parinaz Poursafa, Faramarz Moattar, Mohammad Mehdi Amin, Amir Hossein Rezaei
2012, 1:17 (15 May 2012)
DOI:10.4103/2277-9183.96004  
Aims: This study is aimed at assessing the effectiveness of Cannabis sativa in the absorption of cesium and strontium elements from the soil. Materials and Methods: This study was conducted in 2011, in Tehran, Iran. We employed the phytoremediation technology to refine the contamination of soil with radioactive material such as cesium and strontium. Cannabis sativa was selected because of its capability for potential radioactive absorption. It was planted in various soils with different concentrations of cesium and strontium (20 ppm, 40 ppm, 60 ppm, and 80 ppm), and after sufficient growth for about six months, it was separated into root, stem, and leaves for measuring the absorption of these elements in the main parts of the plant. The samples were measured by using the Inductively Coupled Plasma (ICP) method. Results: Strontium absorption and the main parts of the plant showed a significant relationship. The percentage of strontium absorption was 45% in the root, 40% in the stem, and the minimum absorption was found in the leaves (15%), but the corresponding figure was not significant for the cesium element. A strontium concentration of 60 ppm was possibly the maximum absorption concentration by Cannabis. Conclusion: Our findings suggest that strontium can be absorbed by Cannabis sativa, with the highest absorption by the roots, stems, and leaves. However, cesium does not reach the plant because of its single capacity and inactive complex formation.
  4,441 667 1
The evaluation of heat stress through monitoring environmental factors and physiological responses in melting and casting industries workers
Habibollah Dehghan, Seyed Bagher Mortazavi, Mohammad Javad Jafari, Mohammad Reza Maracy, Mahdi Jahangiri
2012, 1:21 (15 May 2012)
DOI:10.4103/2277-9183.96144  
Aims: Evaluation of heat stress in workers exposed to hot/dry conditions of melting and casting industry is imperative for management of heat stress. This study aims to compare results of heat strain evaluation by monitoring environmental factors and physiological responses. Materials and Methods: This is a cross-sectional study that was conducted on 51 workers of a large melting and casting company in 2010. Wet Bulb Globe Temperature (WBGT) index, heart rate and ear canal temperature were measured by WBGT meter, heart rate monitor and personal heat stress monitor, respectively. Physical activity intensity was assessed based on the ratings of perceived exertion (RPE). Data were analyzed using descriptive statistics and Pearson correlation test. Results: WBGT index in 64.7% of workstations exceeded 30°C and in 41.2% was over 32°C. The value of WBGT index in 69% of work stations exceeded the threshold limit of the ACGIH standard. The physiological strain index (PSI) in 31% of worker was higher than 5, although its mean measured at 3.8 (1.8). Increase in the ear canal temperature in 64.7% of cases (33 persons) was over 1°C. Correlation between WBGT index with ear canal temperature and PSI index, adjusted body mass index and age, was 0.67 and 0.69 (P < 0.0001). Conclusion: In hot/dry conditions of melting and casting processes, despite moderate correlation between WBGT index with ear canal temperature and PSI index, work-rest cycles of WBGT index is not applicable for many of the workstations. Therefore, heat stress evaluation based on physiological variables probably has higher validity and is more appropriate.
  4,021 707 10
An investigation on the lead and cadmium content in vegetables and irrigating water in some farms in Gorgan, Iran
Ali Shahryari, Yousef Dadban Shehamat
2012, 1:12 (28 March 2012)
Aims: The objective of this study is to investigate the levels of lead (Pb) and cadmium (Cd) in the vegetables from the farms of Gorgan, Iran, and compare them with the permissible levels proposed by the Food and Agriculture Organization (FAO) and World Health Organization (WHO) standard. Materials and Methods: In this descriptive study, 40 samples of irrigating water and vegetables were collected, between the periods of August and December 2008. The Polarography apparatus was used to determine the amount of cadmium and lead after sample preparation. The level of significance was set at 5% for all the tests Result: The cadmium concentrations in spinach, garden cress, and radish were 0, 0.085, and 1.56 μg.kg -1 , respectively. The lead concentrations in spinach, garden cress, and Radish were 51.21, 40.13, and 87.27 μg.kg -1 , respectively. The cadmium concentration in irrigating water was not detectable with the Polarography apparatus. However, the lead concentration in water was 26.75 μg.kg -1. There was no significant variation between the cadmium levels in spinach and garden cress (P<0.05), while there was a significant difference between the amount of cadmium in radish and spinach and garden cress (P<0.05). Conclusion: All the vegetables and water contained Pb, although Cd was lower than the permissible levels proposed by FAO/WHO and might not cause health hazards to consumers.
  4,293 373 -
Prevalence of antibiotic residues in commercial milk and its variation by season and thermal processing methods
Fathollah Aalipour, Maryam Mirlohi, Mohammd Jalali
2013, 2:41 (29 November 2013)
DOI:10.4103/2277-9183.122429  
Aims: In this study, the prevalence of antibiotic residues in pasteurized and sterilized commercial milk available in Shahre-kourd, Iran, was investigated. In addition, the influence of seasonal temperature changes on the prevalence of contamination was studied. Materials and Methods: Commercial milk samples of 187, including 154 pasteurized and 33 sterilized, milk samples were collected from the market between early January 2012 and late July of the same year. The presence of antibiotic residues was detected using the microbiological detection test kit, Eclipse 100, as a semi-quantitative method. Results: The results showed that 37 of the samples (19.8%) have contained antibiotic residues above the European Union Maximum Residues Limits (EU-MRLs), of which 28 samples (14.97%) were found to be contaminated but at the concentrations below the EU-MRLs. There was no significant difference between the contamination rate of pasteurized and Ultra High Temperature (UHT)-sterilized samples. Similarly, variation of weather temperature with seasons had no effect on the contamination prevalence of milk samples ( P > 0.05). Conclusion: Based on the result of this study, antibiotics residues were present in the majority of milk samples. Neither the season nor the type of thermal processing of the commercial milks had noticeable impact on the prevalence level of the milk samples. However, an increasing trend of prevalence level for antibiotic residues was observed with increasing the temperature through the warm season.
  4,086 489 6
Implementation of hazard analysis and critical control points in the drinking water supply system
Asghar Tavasolifar, Bijan Bina, Mohammad Mehdi Amin, Afshin Ebrahimi, Mohammad Jalali
2012, 1:32 (3 August 2012)
DOI:10.4103/2277-9183.99334  
Aims: This study was aimed to design comprehensive risk management based on hazard analysis and critical control points (HACCP) in the Isfahan drinking water system. Materials and Methods: Data obtained from field inspections and through related organizations of Isfahan, Iran. The most important risks and risky events of water quality in all sources of raw water in the study area including the Zayanderoud river, the water treatment plant, and the distribution system were identified and analyzed. Practical measures for the protection, control, and limitation of the risks in different phases, from water supply to consumption point, were presented in the form of seven principles of the HACCP system. Results: It was found that there was a potential of hazards during the treatment process of water because of seasonal changes and discharge of various pollutants. Water contamination could occur in eight identified critical control points (CCP). River water could be contaminated by rural communities on the banks of the river, by natural and sudden accidents, by subversive accidents, by incomplete operation, by lack of proportionate of the current treatment process, and by the high extent of antiquity of the Isfahan water distribution system. Conclusions: In order to provide safe drinking water, it is necessary to implement a modern risk management system such as the HACCP approach. The increasing trend of the Zayandehroud river pollution needs urgent attention. Therefore, the role of the government in developing and mandating the HACCP system in water industries is essential.
  3,961 611 -
Predicted sound absorption coefficients of absorber materials lined in a chamber
Farhad Forouharmajd, Parvin Nassiri, Mohammad Reza Monazzam, Mohammadreza Yazdchi
2014, 3:13 (23 May 2014)
DOI:10.4103/2277-9183.132685  
Aims: The present study was aimed to measurement of sound absorption coefficient of mineral wool and determination of their absorption ability. Materials and Methods: Mineral wool was used to find noise absorption coefficient. Random and normal sound absorption coefficient values were predicted. Then, the measures of transmission loss calculated as an overall value, for applied absorbent material and bare sheet metal. Results: The measured values of noise with one octave band frequency demonstrated an attenuation of 5.5-7 dB for these frequencies. The absorption coefficients of materials showed that mineral wool had more normal sound coefficients than its random sound absorption coefficient values. Conclusion: It can be concluded that predicted normal sound absorption coefficients of used mineral wool materials were near to the areas of standard line. It seems that the amount or thickness of absorbent lining was a main reason of noise reduction in low band frequencies. Mineral wool has a higher density and can provide better acoustical and insulating results than fiberglass. Besides, mineral wool doesn't lose its insulating value when wet and has an outstanding resistance to fire.
  4,110 428 -
Kinetic and isotherm studies of humic acid adsorption onto iron oxide magnetic nanoparticles in aqueous solutions
Hamzeh Esmaeili, Afshin Ebrahimi, Mehdi Hajian, Hamid Reza Pourzamani
2012, 1:33 (27 August 2012)
DOI:10.4103/2277-9183.100133  
Aims: In this study, humic acid (HA) removal by iron oxide magnetic nanoparticles (IOMNPs) was surveyed in aqueous solutions. Materials and Methods: Batch adsorption technique was used to determine kinetic and isotherm parameters. The effects of pH value, agitation rate, adsorbent dose, contact times and the adsorbate concentrations on the adsorption efficiency were studied as critical parameters. The IOMNPs was characterized by X-ray diffraction. Results: HA adsorption on the IOMNPs was fitted with Freundlich isotherm model and followed the pseudo-second-order kinetics. Results revealed that at HA concentration of 10 mg/L, pH 4.5, adsorbent dose of 2.7 g/L, agitation rate of 250 rpm and contact time of 90 min at presence of 0.1 M NaCl as an ionic strength agent, the HA removal reached to about 98%. Also, the turbidity of treated samples was increased with increasing of HA loading. Conclusions: With increasing HA concentrations, adsorption capacity of IOMNPs was increased and HA removal efficiency was decreased. By adding ionic strength, HA removal was improved and turbidity of treated samples was reduced.
  3,723 575 2
Effects of oxytetracycline, tylosin, and amoxicillin antibiotics on specific methanogenic activity of anaerobic biomass
Mohammad Mehdi Amin, Hassan Hashemi, Afshin Ebrahimi, Asghar Ebrahimi
2012, 1:37 (13 October 2012)
DOI:10.4103/2277-9183.102356  
Aims: The purpose of this study was to survey the antibiotics effects of oxytetracycline, tylosin, and amoxicillin on anerobic wastewater treatment process. Materials and Methods: To evaluate the inhibitory antibiotics amoxicillin, tetracycline, and tylosin on biomass activity, specific methanogenic activity (SMA) using anerobic biomass batch; into 120 ml vials: 30 ml biomass and 70 ml substrate including volatile fatty acids, mainly acetic acid and various concentrations of antibiotics were added. Methane gas production replacement through solution of KOH (2 N) as an absorber of CO 2 and bromine thymol blue as indicator was measured. Each batch was tested for 10 days. Results: Based on the findings, inhibitory concentration of oxytetracycline, amoxicillin, and tylosin were 8000, 9000, and 9000 mg/L, respectively. Conclusions: This study showed that with increasing concentrations of antibiotics, the produced biogas volume from biomass per unit weight is decreased. COD removal was 42-82 % due to long retention time and adsorption to flocks.
  3,911 342 1
Effectiveness of nanozeolite modified by cationic surfactant in the removal of disinfection by-product precursors from water solution
Amir Mohammadi, Bijan Bina, Afshin Ebrahimi, Yaghoub Hajizadeh, Mohammad Mehdi Amin, Hamidreza Pourzamani
2012, 1:3 (28 March 2012)
Aim: In this study the performance of a natural nanozeolite, modified with a cationic surfactant, on the adsorption of humic acid from water was investigated in a batch system. Materials and Methods: Clinoptilolite as a natural nanozeolite was modified with different doses of a cationic surfactant solution, hexadecyltrimethylammonium bromide (HDTMA-Br), at dosages from 0.5 to 10 g/l. The modified adsorbents were individually added to synthetic water samples containing a known amount of humic acid and put on the shaker for two hours, at room temperature. Humic acid (HA) concentrations, turbidity, and pH were measured before and after the adsorption process. Results: According to the results obtained, and based on the statistical analysis (Pearson correlation statistical test), there was a clear correlation between the cationic surfactant dosage and HA removal (Pvalue <0.001, r=0.87). By increasing the HDTMA-Br dosage, the ratios of turbidity/turbidity initial and UV 254 /UV 254-initial adsorbance by HA (after/before adsorption process) were decreased. In HDTMA-Br dosages of 7 and 10 g/l, the maximum removal efficiency for HA was 96 and 86%, respectively, with a slight variation in the pH value and turbidity unit. Conclusions: This study showed that modification of nanozeolite by cationic surfactants, to reduce its negative surface charge, could markedly improve its efficiency in the adsorption of disinfection by-product precursors from an aqueous solution. The HDTMA-Br/Clinoptilolite nanozeolite (CNZ) ratio of 0.07, pH have to coincide in iso-electric point, can be an optimum ratio for the modification.
  3,663 531 -
Determination of design parameters of urban wastewater treatment plants in the cold regions of Iran
Mehraban Sadeghi, Hassan Hashemi, Fahimeh Teimouri
2012, 1:13 (28 March 2012)
Aims: This study has been conducted to focus on the localization of the design parameters used for the design of wastewater treatment plants in a region of Iran. Materials and Methods: Three wastewater treatment plants were selected (as models) in a cold weather region of Iran. The main characteristics of the wastewater, such as, flow rate and its fluctuations, total solids, and the organic and nutrient contents, which play an important role in the design and operation of the wastewater treatment facilities, were measured for the selected plants during a year. Results: The averages of the design parameters for the investigated plants, including, biochemical oxygen demand (BOD 5 ), chemical oxygen demand (COD), total suspended solids (TSS), volatile suspended solids (VSS), total Kjeldahl nitrogen (TKN), and total phosphorous (TP) were, 41, 60, 65, 47, 8.3, and 0.93 g/capita, respectively. Wastewater production was 177 lit/cap-day with a maximum and minimum coefficient of 1.76 and 0.29, respectively. Conclusions: Using design parameters based on the local characteristics and the real-world conditions of the wastewater, can result in more+operational efficiency in the wastewater plants. It is suggested that the results of this study can be applied to the design of wastewater facilities throughout Iran, with the same local conditions.
  3,749 414 -
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