فهرست مطالب

  • Volume:5 Issue:4, 2018
  • تاریخ انتشار: 1397/08/01
  • تعداد عناوین: 9
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  • Reza Shokoohi, Hassan Zolghadranasab, Samane Shanesaz Pages 1082-1090
    Pentachlorophenol is one of the resistant phenol compounds has classified in the group of the primary pollutants due to its high toxicity and carcinogenic potential. The aim of this study is determining the efficiency of advanced oxidation process method using O3/H2O2 in the presence of TiO2 and ZrO2 nano-particles stabilized on pumice for the removal of PCP from aquatic solutions. This experimental study was performed in a batch reactor at laboratory scale. In this study, the effects of reaction time, initial concentration of PCP, pH, concentration of catalysts and H2O2 and also the amount of decline in chemical oxygen demand (COD) after the process were investigated. The concentration of PCP in the sample was determined using spectrophotometer at wavelength of 500 nm and, in the end, the results were analyzed using SPSS software and according to repeated measures analysis and statistical test of comparative ordered pairs with confidence interval of 95%. Scanning electron microscope (SEM), fourier transform infrared spectroscopy (FTIR) and x-ray diffraction (XRD) images of modified pumice were taken and the kinetic degree of the processes was also determined. The results indicated that the PCP removal by the both processes increased with increasing reaction time, catalyst concentration, H2O2 concentration and pH and reduced with decreasing initial PCP concentration. The maximum removal efficiencies by the two processes: O3/nZrO2/H2O2 and O3/nTiO2/H2O2 were 100 and 95%, respectively, in the optimum conditions. The results illustrated that the two studied processes followed the pseudo-second -order kinetic model. Further, the findings revealed that the both processes mentioned in this study were of high capability in removing PCP and they could be used as an appropriate process in removing this organic material.
    Keywords: Pentachlorophenol, Advanced Oxidation, Zirconium Dioxide Nano Particles, Titanium Dioxide Nano Particles, Pumice
  • Shima Rezaei, Hooshyar Hossini, Majid Hashemi Pages 1091-1098
    Chlorophenols as priority pollutants are toxic. These acidic organic compounds cause digestive disorders, liver damage, and cancers. The aim of this study is Ortho- chlorophenol removal using zero-valent iron nanoparticles modified clay. In this experimental study, the clay soil was sampled from the mountains of Shah Murad, Rafsanjan, Iran. Then it was treated with hydrochloric acid. In the next step, the clay was modified with ferrous sulfate in the presence of the N2 gas to prepare magnetic clay. Then, the prepared adsorbent was used to remove o-chlorophenol as a function of pH, adsorbent dose and contact time. In addition, adsorption isotherms and kinetics were determined. The findings of the present study showed that the removal efficiency obtained by the iron nanoparticles carrying clay was higher than that of the raw clay. The highest removal efficiency (91.3 %.) was obtained for pH 4. The o-CP removal efficiency by the modified clay increased from 35.9 to 82.7 as the adsorbent dosage is increased from 0.05 to 1 g after 120min contact time. The Langmuir isotherm model and the second-order kinetic model provided the best fit to the experimental data compared to other studied models. The results showed that the modified adsorbent could be used an effective and readily available low-cost adsorbent for the removal of chlorophenols in industrial applications
    Keywords: Chlorophenols, Adsorption, Clay, Iron nanoparticle
  • Hamid Boleydei, Zahra Razavi Pages 1099-1106
    In the present study, the efficiency of date palm trunk fibers (DPTFs) to remove crude oil from aqueous solution was evaluated. The sorbent were characterized by Fourier transform infrared (FT-IR) spectroscopy. The effect of various parameters including contact time, pH of oil solution, particle size, initial oil concentration and adsorbent dose on oil adsorption were investigated. The results showed that the adsorption kinetic was described by pseudo-second-order model. The change in the pH of oil solution from 2–10 had no effect on the oil adsorption. The decrease of particle size of DPTFs reduced oil sorption percent. The crude oil adsorption on DPTFs was well fitted by the Langmuir model. Maximum capacity of adsorption of crude oil by DPTFs was 2500 mg g-1. The results obtained revealed that crude oil adsorption onto the date palm wastes as the abundantly available low cost and readily biodegradable material is feasible and can successfully be used as an effective adsorbent to oil spill cleanup in water basins.
    Keywords: Adsorption Kinetic, Isotherm, Agricultural byproduct, Crude Oil, Date Palm Trunk Fibers (DPTFs)
  • Mohammad Amin Mououdi, Seyed Nouraddin Mousavinasab, Jafar Akbari Pages 1107-1114
    This study assessed the status of health, safety and environment (HSE) in all public schools (n=188) in Iran using a new tool (HSE-S) based on audit system.
    The first part of HSE-S tool was about general specifications and environment conditions. The second consists of the physical conditions and school management. The HSE-S was validated using CVI and CVR, Cronbach's alpha and Kappa coefficient.
    The CVI, CVR, Cronbach's alpha coefficient and Kappa index were 0.75,> 0.7, 0.99 and 0.736 respectively. Ten schools were ranked as one-star, 149 as two-star and 29 as three-star. The top priorities for achieving an acceptable HSE status in schools were establishing a HSE unit, improving ergonomics and having a risk management system in each school.
    The HSE-S is an effective tool to evaluate and promote health, safety and environment in schools. Its application can help in implementing the “health promoting school” program of WHO
    Keywords: Health, Safety, Environment, Audit System, School
  • Kamyar yaghmaiean, Hoda Amiri, Sadegh Hassanvand, Farzad Mohammadi, Heshmatollah Nourmoradi, Ali Amarloei, Sajad Mazloomi Pages 1115-1121
    Although the numbers of death related to air pollution appear to be low, the incidence of related disease to air pollution would be too high that is because of exposure of the large population to air pollutants and also the existence of certain sensitive groups. The aim of this study was to quantification health impacts of two pollutants PM10 and O3 in Karaj city during 2012- 2013. In this study, the air quality data were obtained from Karaj Department of Environment Protection. Quantification the health impacts of air pollutants were assessed using AirQ2.2.3 model which is a proposed method for assessing the health impact of air pollutants by World Health Organization. The annual, warm, and cold average concentrations of PM10 were 77.48, 87.86, and 62µg/m3, respectively. O3 average concentration in the warm semester was 63.5µg/m3 and it is more than a cold season which was 60µg/m3. Total mortality rate related to PM10 and O3 were assessed 282 and 164, respectively, which are 3.9 and 1.53 percent of all deaths, respectively. The Average cases of obstructive lung disease related to O3 were 58 people and average cases of hospitalization due to cardiovascular diseases related to PM10 were 492 people. This study was the first attempt to reveal the health outcome of air pollutants on a human in Karaj as one of the crowded city of Iran. Totally we found that the average concentration of 8-hours O3 and 24-hours PM10 were higher than the national standard of Iran and WHO guideline.
    Keywords: Air Pollution, Cardiovascular Diseases, Hospitalization, Karaj City, Related Death
  • Javid Manzoor, Manoj Sharma Pages 1122-1127
    We investigated general working conditions in the hospitals and nursing homes in Gwalior and assessed the health risk factors of employs in these hospitals April 2016 to August 2016. Sound Intensity Level (SIL) and light intensity was measured with sound and lux meter respectively. The temperature and humidity in hospitals and nursing homes was measured by thermo hygrometer. A pretested questionnaire was used to evaluate the health problems among the employs. Results indicated that employs in these hospitals were exposed to poor environmental conditions. The majority of these employs were suffering from musculoskeletal disorders, allergic reactions, respiratory disorders and other physical disorders.
    Keywords: Health Risk, Hospitals, Environment, Employs
  • Jamal Mehralipour, Mohammd Reza Samarghandi, Razzagh Rahimpoor Pages 1128-1131
    To investigate the demographic characteristics, concentration of Benzene, Toluene, Ethyl benzene and Xylenes (BTEX) in output smoke and health risk assessment in hookah smokers in hookah cafés, Iran. We checked hookah cafés in the different parts of Hamadan city and analyzed location and social station of each cafés in 2016. Finally, 20 cafés selected and five samples on each cafés (total of 100 samples). BTEX compounds were sampled in output smoke from mouth smokers using charcoal and analyzed by GC- MS according to NIOSH1501 method. The quantitative risk assessment of exposure to BTEX as recommended by the United State Environmental Protection Agency method was used. The smokers' demographic characteristics collected using a self-designed questionnaire. The average concentrations of benzene, toluene, ethyl benzene, o, m-Xylene and p- Xylene were 6.45, 7.02, 10.07, 7.21 and 8.36 mg/m3, respectively. The mean cancer risk for benzene was estimated as 529 × 10-5 and mean non-carcinogenic risks for toluene, ethyl benzene and o, m-Xylene and p–Xylene (TEXs) were 17.57, 5.03, 24.03 and 27.88, respectively. Hookah smoking is prevalent among youths and smokers are exposed to benzene level higher than the threshold limit value recommended by ACGIH. Cancer risk for benzene and non-carcinogenic risk for TEXs were much higher than recommended limits. Thus, in order to prevent diseases stemming from hookah smoking, urgent and increased notification about its adverse health effects and intensified regulatory laws are needed to decrease hookah smoking in hookah cafés.
    Keywords: BTEX Compounds, Hookah Smoke, Risk Assessment, Addiction.
  • Alireza Dehdashti, Mahdieh Ghainy, Ghasem Askari, Gholamreza Ghaeiny Pages 1132-1137
    Ultraviolet emission from sun considered as a hazardous parts of optical waves. This study aimed at determining exposure to ultraviolet radiation among taxi drivers in Damghan. A cross-sectional survey was conducted on a sample of taxi drivers. Individual exposure to solar ultraviolet-A was assessed during day light working hours. Exposure was determined on the basis of radiation intensity and biologically cumulated standard erythema dose. Our findings showed that exposure was varied in terms of time and geographical sites. The exposure intensity ranged from 0.01 to 15.36W/m2 and from 1.42 to 28.7W/m2 inside and outside the vehicles, respectively. Drivers had the highest exposure from June till August (17.54W/m2). Results showed lower exposure in April, May, and September (12.34W/m2). Cumulative exposure based on erythema dose showed the highest value (41.0 SED) inside vehicle at 9-10 am intervals. Taxi drivers are exposed to significant ultraviolet radiation. Geographical situation and time caused variations in exposure. Future studies should focus on the health effects so that determine the risk of exposure more accurately.
    Keywords: Solar Ultraviolet, Occupational Exposure, Drivers
  • Zahra Moradpour, Sajjad Farhadi, Mohsen Mohsenabadi, Mahdi Jalali, Ghasem Hesam Pages 1138-1143
    Air conditioning systems are the main source of background low frequency noise in administrative buildings, restaurants, classrooms, and hotels. There are different ways to reduce the low frequency noise. Silencers are generic tools which are utilized for controlling noise produced by air conditioning systems. Sound assessment and frequency analysis were performed in accordance with standard methods to evaluate the exposure of workers in separate work stations. In the next step, an absorptive- dissipative silencer which its inner side was covered by convoluted acoustical foam was implemented in the ventilation system. The exposure of employees was re-evaluated. Moreover, Preferred Noise Criterion (PNC) and Speech Interference Level (SIL) were two acoustic indices used for assessing the effectiveness of the silencer. Before implementing the silencer, the sound pressure level in the rooms was between 57.8 and 61.1dBA with a peak frequency at 125Hz. The implemented silencer with dimensions of 1.4 ×1×1m, and inlet and outlet area of 0.45×0.45m was able to reduce the sound pressure level of about 13 to 14.2dB. Further, the PNC and the SIL indices were reduced to 14.33 and 15.31dB, respectively. The implemented absorptive- dissipative silencer reduced the sound pressure level of about 13.6dBA. Moreover, PNC and SIL indices are two important indices which can be used for assessing the level of comfort in office buildings.
    Keywords: Noise Pollution, Silencer, Air Conditioning System, Acoustic Comfort