Showing 27 results for Naddafi
K Naddafi, S Rezaei, R Nabizadeh, M Younesian, H Jabbari,
Volume 1, Issue 2 (10 2009)
Abstract
Background and Objectives: Atmospheric transport is a key mode of microbial dispersal and the transmission of airborne microbe can have significant impacts on human health. The main objective of this study was to determine the concentrations of airborne bacteria in a children.s hospital.
Materials and methods: Three sampling points were selected. Airborne bacteria were collected with 6 days interval at each location using Quick take 30® sampler at an sampling rate of 28.3 l min-1 from November 2007 to March2008.
Results: The results showed that the highest indoor density of bacteria was 429 CFU/m3 that founded in oncology ward. Bacteria identified were representative of normal flora of the skin, respiratory and gastrointestinal tracts.
Conclusion:Our analysis revealed that colony of bacteria in 14% in patient room exceeded available guideline value for indoor air quality. That 11% cases was found in the oncology ward.
H Jabbari, N Mansouri, A Abdollahi, M Chehrehei, K Naddafi,
Volume 2, Issue 1 (16 2009)
Abstract
Background and Objectives :Microorganisms including Fungi, are among air-transmitted infectious agents at hospitals and patient care settings, which in addition to patients, can afflict Health Care Workers (HCWs) and visitors, and may results in extravagant economic burden and impact on human health. Use of nanotechnology and especially nanosilver particles is one of the methods which are used in infection control. This article is the result of a research project investigating nanosilver painting effect on bioburden of indoor hospital air.
Materials and Methods: The study was aimed to assess antifungal effects of nanosilver painting. Three rooms were selected at the infectious diseases ward of Imam Khomeini hospital complex. Two of the rooms were painted with two brands of nanosilver paints provided from two separate companies (as cases), and the third room with non-nanosilver paint brand(as control).
Results: Air sampling was carried out using a portable air pump (Quick Take 30) at pre-planned schedule Each Sampling was done in two minutes with the rate of 28.3 Liter per minute. Samples were transferred on Sabourauds Dextrose Agar culture, to count the colonies of fungal based on Colony Forming Unite (CFU/m3). Results were analyzed by ANOVA method.
Conclusion: Active sampling method was not able to show statistically significant reduction in the total fungal bioburden between the control and case rooms. In evaluating the time trend of the nanosilver paints effect, sampling measures revealed that nanosilver paints had statistically significant effect in fungal bioburden reduction in the first third( i.e. first month) of the study period.
K Naddafi, R Nabizadeh, M.s Hassanvand, A.r Mesdaghinia, K Yaghmaeian, F Momeniha,
Volume 2, Issue 3 (25 2009)
Abstract
Backgrounds and Objectives: Due to having features such as toxicity, corrosiveness, ignitability, reactivity or other similar characteristics, hazardous wastes refer to the wastes that jeopardize man's health and environment. A study was required to identify the hazardous wastes in Tehran University of Medical Sciences (TUMS), since it plays an important role in the development of the country's education. The objective of this research was to provide a review of hazardous wastes production and its management at Tehran University of Medical Sciences.
Materials and Methods: In this study, four schools that were in the central campus of Tehran University of Medical Sciences, Iran, were selected and the necessary data were gathered using a sampling, questionnaire, interviewing those in charge of the units, and referring to the available documents. The information includes the type and amount of waste, method of temporary storage, frequency of waste discharge, and method of final disposal of wastes.
Results: The obtained results indicate that approximately 2072 Kg of hazardous wastes are produced each year, excluding the uncontrolled wastewater. Moreover, schools of dental, pharmacy, medicine, and public health produced approximately 993, 606, 256, 217 Kg/year, respectively, of hazardous wastes in the central campus. Also, the results show that, of total amount of annual hazardous waste that was 2.72 tons, 954, 848, 475, 427, 245, 49 Kg were wastes that the features infectious, toxicity, ignitability, carcinogenesis, corrosiveness, and reactivity, respectively.
Conclusion: It is to be mentioned that hazardous solid wastes were manage with household solid waste and hazardous liquid waste were discharged into sink without any kind of control. Improper practice is evident from the point of waste production to final disposal.
R Nabizadeh, Sh Salehi, M Younesian, K Naddafi,
Volume 2, Issue 4 (9 2010)
Abstract
Backgrounds and Objectives:Skin cancer is the most frequent malignancy in Iran. Exposure to the excessive ultraviolet radiation is an important factor in creating skin tumors. The purpose of this study is to determine how the ultraviolet index has been distributed in all townships throughout the country, to determine different kinds of skin cancer and to evaluate a geographical distribution of skin cancers with regard to the UV geographical distribution.
Materials and Methods: This study is ecologic, descriptive and analytical in nature. A total number of 6921 skin cancer cases registered at the Center for Disease Control of Iran in 2004 were thoroughly analyzed and UV data were collected from the world wide web. With the help of ArcGIS software and SPSS, the statistical analysis was done.
Results:The incidence rates were 10.13 for the total skin cancer, 7.53 for basal cell carcinoma, 1.79 for squamous cell carcinoma and 0.39 for malignant melanoma per 100000 population of Iran. The mean ultraviolet index differed from 9 in July to 3 in January. The correlation between the skin cancer incidence at the level of districts and ultraviolet index was not significantly observed.
Conclusion:Skin cancer is a public health problem in Iran. Further research in this regard would lead to skin cancer registration improvement and more understanding of different climatic, cultural and behavioral factors in developing skin tumors. With this knowledge the possibility of more effective prevention of the most prevalent cancer in Iran can be created.
A Ghanavati Hormozi, K. Naddafi, R. Nabizadeh Nodehi, N. Jaafarzadeh,
Volume 3, Issue 1 (3 2010)
Abstract
Background and Objectives:Fanavaran petrochemical company is located on the shore of Persian Gulf on west south of Iran, Imam Khomeini Bandar, petrochemical special economic zone with of 25 hectares area. Two units of this company, methanol unit with production capacity 1000000 tons/years and monoxide carbon unit with 140000 tons/years were studied for determination and emission factories of SO2, CO2, CO, NO, NO2, NOx Gases.
Materials and methods: With attention to project goals, for implementation of this project 14 months took into from April 2008 till June2009.For goals provide of mentioned research on this basis,case sampling were done from 3 emission sources by using of direct reading device of gas concentration according to standard methods of United State Environmental Protection Agency.
Results: Results of the study indicate that concentration of issued pollutant gases from these units is in the level lower than Iran department of environment standard level. The total amount of emission Factory of SO2, CO2, CO, NO, NO2, NOx gases diffused from these units are11.7×10-6 , 81/8×10-6, 0.14×10-6, 431.5×10-6, 19.2×10-6 , 681.2×10-6kg /tons million production in a year respectively.
Conclusion:Parameters which optimization is performed in accordance with them, include of additional air percentage, exit air temperature from pre heater, and fuel type, in fact with regarding these 3 factors. effects, the work is done in a manner that the amount of pollutants diffusion is near to minimum and the selected best fuel.
K Naddafi, R Nabizadeh Nodehi, M Jahangiri Rad,
Volume 3, Issue 4 (8 2011)
Abstract
Backgrounds and Objectives: Anthraquinone dyes such as reactive blue29 in water resources and industrial wastewater effluents are one of the most environmental setbacks in many countries. Various methods have been considered to remove these dyes One of which is adsorption.
Materials and Methods: All adsorption experiments were conducted in different pHs and various concentrations of adsorbents. The initial concentration of reactive blue 29 chosen in this study was 30mg/L.Adsorption isotherms were determined and correlated with Longmuir, Freundlich and BET models.
Results: The maximum adsorption capacity of reactive blue 29 onto single wall carbon nanotubes was 496mg/g.Results showed that the best pH for adsorption was 5 followed by pH3 and 8. Kinetic study showed that the equilibrium time for adsorption of RB 29 to SWCNT is 4 hr.
Conclusion:According to the results obtained BET isotherm fitted well the experiment. It shows the adsorption of reactive blue 29 onto single wall carbon nanotubes is multilayers and the mechanism of SWCNTs adsorption toward RB29 is based on weak van der waals forces.
K Naddafi, M.r Zare, M Younesian, M Alimohammadi, N Rastkari, N Mousavi,
Volume 4, Issue 2 (9 2011)
Abstract
Background and Objectives: This study was conducted to investigate the toxicity of Titanium Oxide (TiO2) and Zinc Oxide (ZnO) nanoparticles as two of most widely used nanoparticles. The result of this study can help to designing environmental standard and legislations for nanoparticles.
Materials and Methods: Different concentrations of nano ZnO and TiO2 nanoparticles were added to nutrient Agar culture media. Then, definite numbers of Escherichia coli and Staphylococcus aureus bacteria were added to culture media and inhibition of these bacteria growth was measured in comparison to controls. Obtained data were analyzed to determine nanoparticles' EC50 and NOEC (No Observed Effect Concentration) using SPSS ver.16 and Probit standard test.
Results: 24-hours EC50 of nano ZnO using E. coli and S. aureus determined to be 5.47 mg/L and 2.38 mg/L respectively. In addition, 24-hours EC50 of nano TiO2 using E. coli and S. aureus determined to be 5366 mg/L and 3471 mg/L respectively. In the case of ZnO nanoparticles, no observed effect concentration determined to be 1.15 and 3.28 mg/L for E. coli and S. aureus respectively and in the case of TiO2 nanoparticles no observed effect level determined to be 1937 and 1184 mg/L for E. coli and S. aureus respectively.
Conclusion: This study showed that acute toxicity of nano ZnO is by far more than that of nano TiO2. Regarding the EPA acute toxicity criteria, nano ZnO is categorized as moderately toxic and nano TiO2 is categorized as practically non toxic. Hence, regarding the acute toxicity, in recommending exposure criteria and environmental disposal standards, compared to nano TiO2, nano ZnO requires more attention.
Ramin Nabizadeh Nodehi, Hassan Aslani, Mahmood Alomohammadi, Reza Nemati, Kazem Naddafi, Maryam Ghany,
Volume 5, Issue 2 (13 2012)
Abstract
MicrosoftInternetExplorer4
Background and Objectives: Irrigation of agricultural crops using wastewater will
increase, in some cases, their growth by 40 to 60 percent. However, this has a
high risks for human health because of the presence of higher number of
pathogenic organisms. The main purpose of this study was to investigate the
feasibility use of Fenton and modified Fenton with copper for the disinfection
of raw wastewater.
Materials and Methods: After primarily laboratory physicochemical and biological analysis, the
disinfection process was performed in three different phases in each process.
First, the disinfectants were injected separately, then we performed
disinfection using Fe++ and cu++ ions combined with hydrogen peroxide in order
to determine synergistic effect of each catalyst. Direct method was used for
fecal coliforms counting.
Results: Hydrogen
peroxide maximum efficiency for inactivation of fecal coliforms was only
0.66log inactivation. Fenton and modified Fenton with copper ions showed a
remarkable effect on the bacterial inactivation so that Fenton and modified
Fenton with 1 and 2 mg/l of Cu++ inactivated coliforms by 4.73, 3.28, and 4.88
log respectively.
Conclusion: Application of HP alone for the disinfection of raw wastewater is not
practicable due to low observed efficiency. However, its combination with ions
such as Fe++ and Cu++ increases HP performance in disinfection and has a
notable synergistic effect on HP
disinfection power, where, in the presence of each catalyst, hydrogen
peroxide can reduce the fecal coliforms of raw wastewater to meet the Iranian
Environmental Protection Agency Standards.
Kazem Naddafi, Mehran Mohammadian Fazli, Ali Reza Mesdaghinia, Simin Nasseri, Mahnaz Mazaheri Assadi, Masoud Yunesian,
Volume 5, Issue 2 (13 2012)
Abstract
MicrosoftInternetExplorer4
Background and Objectives: Environmental pollution and health risks of dyestuffs
extensively are caused by many industries. Nonbiodegradability of dyes is
important so that different methods are studied for removing them. The use of
white rot fungi is promising technique in this regard. Therefore, objective of
this work is to investigate Rimazol Brilliant Blue Royal decolorization by
immobilized Ganoderma sp. in sodium alginate from aqueous solution.
Material and Methods: This is an experimental study. First, the nutritional, environmental, and
operational conditions of decolorization process were optimized. Then,
efficiency of immobilized fungal cells was investigated. Experimental designs
were provided using fractional factorial methods and quadratic model was fitted
on decolorization data by MiniTab software.
Results: Our findings
showed that type and concentration of carbon source, temperature, and pH were
the most important factors affecting decolorization and statistically
significant. Optimal conditions to 95.3 percent color removal were: glycerol as
carbon source at 19.14 g/L temperature, 27 oC and initial pH, 6.26. Moreover,
decolorization efficiency increased from 75 percent up to 95 percent by improving
process and fungal immobilization.
Conclusion: Ganoderma
fungus has suitable potential to decolorization. Besides, optimization and cell
immobilization can improve its capability. Application of experimental design
to research methodology is important because of decreasing in experiments and
saving resources. It is suggested to use these potentials in environmental
pollution control.
Fatemeh Momeniha, Ramin Nabizadeh Nodehi, Mohammad Sadegh Hassanvand, Amir Hossein Mahvi, Kazem Naddafi,
Volume 5, Issue 2 (13 2012)
Abstract
MicrosoftInternetExplorer4 Background and Objective: Dioxins and Furans are dangerous and highly toxic compounds entering to the environment from natural and manmade sources. Having high stability and half-life, these compounds remain for a long period in the medium and bring about severe effects on human beings and the environment. The aim of this study was to identify dioxins and furans emission sources in Iran and to estimate their contribution in emission rate.
Materials and Methods: First, we identified the emission sources of dioxins and furans and then necessary data was gathered by referring to the authorized organizations and filling the prepared UNEP questionnaires. We used Excel software to analyze the data collected.
Results: According to the results obtained, total dioxins and furan emission in Iran in 2010, was 1957 g TEQ/yr out of this amount, 705.8 g TEQ is emitted to the atmosphere and 643.2 g TEQ is residual ash. Therefore, dioxins and furans emission rate was 26.4 µg TEQ/capita in Iran. The most rates of emissions were associated with uncontrolled open burning (732.8 g TEQ/yr) and ferrous and nonferrous metal production (635.7 g TEQ/yr) such as cupper, iron, and steel.
Conclusion: Our findings showed that the emission rate of Dioxins and Furans is much higher in Iran compared with other countries and appropriate management strategies are required to control these dangerous pollutants.
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Mohammad Sadegh Hassanvand, Ayoub Torkian, Mohammad Reza Sahebnasagh, Kazem Naddafi, Mohammad Kazem Moayyedi,
Volume 5, Issue 3 (21 2012)
Abstract
MicrosoftInternetExplorer4
Background and
Objectives: Wind-induced particulate air pollution from iron ore piles can
causes environmental and economic problems for steel industries. In this
experimental study, the effectiveness of various additives in reducing
particulate air pollution from iron ore piles was investigated in a laboratory
wind tunnel.
Materials and Methods: The experimental set up consisted of a
prismatic pile and a wind tunnel. Four different wind speeds of 4.3, 5, 7 and
11 m/s was used in the study Municipal
water, quick lime (2%), seawater, treated industrial wastewater and Polylatice
(0.25%) were used as additives to stabilize the upper layer of the pile.
Results: Emission factors for
non-stabilized (without additive) piles at 4.3, 5, 7 and 11 m /s wind speeds
were 46.7, 73.2, 1025.4 and 13768.7 g/m
2, respectively. Stabilized
piles with 2.6, 2.7, 2.8, 2.7 and 2.8 percent additive (moisture content of the
upper layer of the pile) for municipal water, Polylattice (0.25%), treated
industrial wastewater, seawater and quick lime (2%) indicated a decrease of
99.4%, 100%, 99.3%, 99.5% and 99.5% particulate emission reduction,
respectively.
Conclusions: Proper selection and use
of additives on iron piles has the potential for decreasing more than 99% of the wind-induced particulate
emissions. Operational factors such as covered area, spray frequency, pile
geometry, seasonal adjustments related to ambient temperature and humidity,
wind speed and operator training need to be an integral part of the pollutant
reduction program.
Soheila Rezaei, Kazem Naddafi, Hossain Jabbari, Masoud Yonesian, Arsalan Jamshidi, Abdolmohamad Sadat, Alireza Raygan Shirazinejad,
Volume 6, Issue 1 (5-2013)
Abstract
Background and Objectives: In recent years exposure to fine airborne particles has been identified as an important factor affecting human health. Epidemiological studies have showed that the aerosol laden air can be an agent for microorganisms’ dispersion. Ignoring internal sources, ambient air quality significantly affects indoor air quality. Since people spend most of their times in the indoor spaces and little data are available on the general understanding of the indoor air quality, therefore, the aim of this study is to determine the particulate matter concentrations in indoor and ambient air of Tehran Children Medical Center Hospital.
Materials and Method: PM10/PM2.5 samples were collected in the indoor environment of the Tehran Children Medical Center Hospital and its adjacent outdoor environment by a portable GRIMM dust monitor model 1.108 from November 26 to March 10, 2007. The places of sampling for indoor and ambient air were in the patient room and the roof of the hospital respectively.
Results: The results showed that indoor PM10 level was higher than WHO standards in 80% cases in patient room, whereas, for indoor PM2.5 level, this value was 42 and 64% more than the EPA standards and WHO standards respectively. The relationship between outdoor and indoor particulate matters was examined by linear regression analysis. The indoor particulate matter levels were correlated with the corresponding ambient air ones.
Conclusion: Our analysis revealed that infiltration of ambient air could substantially increased indoor pollutants and thereby influences the indoor air quality.
Mohammad Reza Mehrasebi, Mansour Baziar, Kazem Naddafi, Mehran Mohammadianfazli, Ali Assadi,
Volume 6, Issue 2 (9-2013)
Abstract
Background and Objectives: Soil pollution by oil compounds is a serious environmental and ground water problem throughout the world. Total petroleum hydrocarbons (TPH) are a combination of many distinctive compounds. Some of these compounds in exposure with human and animal can cause cancer, disorder central nervous system, liver and lungs affects. The objective of this research was to investigate gasoline removal (C10 – C 28) using Brij 35 and Tween 80 from polluted soil. Materials and Methods: In this experimental study, the efficiency of soil washing with nonionic surfactants (Brij 35, Tween 80) for remediation of gasoline polluted soils was studied. The effects of soil washing time, agitation, surfactant concentration, and pH on the removal efficiency were studied. Results: The results showed that gasoline removal efficiency increased with increasing agitation speed and washing time. In addition, it was found that removal efficiency of gasoline was decreased by increasing surfactant concentration. But, increasing pH did not have remarkable effect on removal efficiency of gasoline. The efficiencies of Tween 80 and Brij 35 for removal of gasoline under optimal condition were 70 -80 and 60- 65% respectively. Conclusion: The results showed that soil washing with non ionic surfactants was effective in removal of gasoline from polluted soil and it can be recommended for treating surface soil polluted.
Farin Fatemi, Hamed Mohammadi, Ali Ardalan, Kazem Naddafi,
Volume 6, Issue 2 (9-2013)
Abstract
Background and Objectives: On August 2012, two earthquakes measured 6 and 6.2 on the Richter scale took place in Eastern Azerbaijan province. Environmental Health Department is accounted as one of the main units for providing and supervising environmental sanitation services at the emergencies, therefore, the objective of this study was allocated to assess environmental health response performance in recent earthquake.
Material and Methods: Through multi-stages stratified sampling, we selected 8 and 4 villages from the earthquake zones of Heris and Varzaghan respectively. The collecting data tools in this research were the WHO checklist in 7 categories, 14 subcategories, and 37 environmental health activities and also the minimum standards of Sphere Project checklist. The status of environmental health in each village was assessed using the mentioned checklists. This study was carried out with attendance of research team in earthquake zones 21 days after the occurrence of earthquake.
Results: Among the 37 environmental health activities, 7 activities were the joint ones, which Environmental Health Department had to carry it out with the coordination of other related organizations. In other words, the environmental health has the supervising role in these activities. Totally, such activities had more nonconformities compared with the activities in which environmental health was administered as the main responder. The details of results have been expressed in the full text.
Conclusion: Providing intra-sector coordination, prioritizing the needs of the affected population and considering the principles of community based management in the natural disaster are proposed as the recommendations of this study.
Mahdi Sadeghi, Kazem Naddafi, Ramin Nabizadeh,
Volume 7, Issue 2 (10-2014)
Abstract
Background and objective: Perchloroethylene is a chlorinated hydrocarbon used as a solvent in many industries and services activities such as dry cleaning and auto industry as degreasing. We carried out a bioassay using Daphnia Magna in order to determine the ecological effects of wastewater treatment through applying advanced oxidation processes (ultrasonic, ultraviolet irradiation and hydrogen peroxide processes) for removal of perchloroethylene. Materials and Methods: Due to the sensitivity of Daphnia and reports indicating this species is the most sensitive aquatic invertebrate to a variety of organic compounds, toxicity of perchloroethylene and its intermediate degradation products during applying different processes was tested using Daphnia. Lethal concentration (LC50) and toxic units (TU) were determined. In to determine toxicity of perchloroethylene, its stock solution was prepared at a concentration of 100 mg/L. Then, nine samples each containing 0 (control), 5, 10, 20, 30, 40, 50, 75, and 100% by volume of the primary stock solution were prepared. To determine the toxicity of the intermediate products of perchloroethylene by ultrasonic, photolysis, photolysis with hydrogen peroxide and photosonic processes, an initial concentration of perchloroethylene for each reactor (100 mg/L) was taken. All experiments were carried out at the Laboratory of Microbiology, Faculty of Health, Tehran University of Medical Sciences, Iran. Results: It was found that the 24 h LC50 for perchloroethylene on Daphnia Magna was 35.51 mg /L. The 48 h, 72 h and 96 h LC50 of perchloroethylene were 28.058, 21.033, and 19.27 mg/L respectively. Toxicity of perchloroethylene was decreased after oxidation processes. Conclusion: The toxicity after hybrid processes was lower than the single processes. The toxicity reduction was the same during all time period. Hence, the hypothesis of reducing toxicity of the intermediate products of perchloroethylene degradation after the abovementioned processes is acceptable. It is noteworthy that although there are different intermediate compounds in the effluent of various chemical oxidation processes, , but they are less toxic compared with the original perchloroethylene this may be due to the partially concentration of intermediate products that will decrease toxicity.
R Nabizadeh, K Naddafi, A Jonidi Jafari, M Yunesian, A Koolivand,
Volume 7, Issue 3 (5-2014)
Abstract
Background & Objectives: Remaining crude oil in storage tanks lead to accumulation of oily sludge at the bottom of the tank, which should be treated and disposed of in a suitable manner. The aim of the present study was to investigate the efficiency of chemical oxidation using H2O2 and Fenton’s reagent in removal of Total Petroleum Hydrocarbons (TPH) from bottom sludge of crude oil storage tanks. Materials & methods: In this experimental study, hydrogen peroxide and Fenton’s reagent were added to the sludge in six concentrations including 2, 5, 10, 15, 20, and 30% (w w-1) and TPH was measured for a period of 24 and 48 h of reaction time. The oxidants were added in a single and stepwise addition way, both to the pristine and saturated sludge. The elemental analysis of sludge and TPH measurement were carried out using ICP and TNRCC methods respectively. Results: The mean TPH removal of 2, 5, 10, 15, 20, and 30% oxidant concentrations were 1.55, 9.03, 23.85, 33.97, 41.23, and 53.03%, respectively. The highest removal efficiency was achieved in stepwise addition to the saturated sludge. Increasing oxidation time from 24 to 48 h had a little effect on increase in TPH removal. Moreover, the removal efficiency of H2O2 and Fenton was nearly similar. Conclusions: Mere application of chemical oxidation is not capable of complete treatment of the sludge but it is an effective process as a pre-treatment step for decreasing toxicity and increasing its biodegradability.
K. Naddafi, M. Gholami,
Volume 7, Issue 3 (5-2014)
Abstract
Background & objective: Synthetic dyes are extensively used in various industries such as textile, leather tanning, plastic, pulp and paper. Since dyes are toxic and even carcinogenic, discharging dye-containing wastewater into the environment poses serious environmental and health problems. Therefore, the purpose of this paper was to evaluate the removal of Reactive Red 120 from aqueous solutions using surface modified natural zeolite. Materials &Methods: The Semnan zeolite was sieved using standard sieves in size of 0.2 - 0.3 mm and then was modified by cationic surfactant. Batch adsorption studies carried out to study various parameters included contact time, initial concentration of Reactive Red 120, pH, and adsorbent dosage. The concentration of dye was measured using a UV-vis Spectrophotometer at the wavelength of 537 nm. Freundlich and Langmuir isotherms and Pseudo-first order and pseudo-second order kinetics were used to analyze the isotherm and kinetic data respectively. Results: The adsorption studies indicated that increasing of the contact time, initial concentration of Reactive Red 120, decreasing pH and adsorbent dosage leads to increasing dye adsorption. Equilibration of Reactive Red 120 adsorption was reached at lapse of 90 min. Moreover, it was found that Langmuir isotherm (R2=0.9814) and pseudo second-order kinetic (R2=0.9814) are well fitted with our data. Conclusion: The results of the study show that Iranian modified zeolite can be used effectively for removal of Reactive Red 120 in comparison with other parts of the world. Considering the cost, availability and ease of modification, it can be used to remove dye in industrial wastewater.
M Abtahi, K Naddafi, A.r Mesdaghinia, K Yaghmaeian, R Nabizadeh, N Jaafarzadeh, N Rastkari, R Saeedi, Sh Nazmara,
Volume 7, Issue 4 (1-2015)
Abstract
Background and objectives: Dichloromethane (DCM) is one of the hazardous contaminants of the environment, especially ambient air that threatens human health at both acute and chronic exposures. In this study, the performance of a pilot-scale hybrid bubble column/biofilter (HBCB) bioreactor was studied for the removal of DCM from waste gas streams at steady state. Materials and methods: The experiments were conducted in four stages with relatively constant concentrations of DCM (approximately 240 ppm) and variable empty bed residence time (EBRT) of 50, 100, 150 and 200 s. In addition to determining DCM removal rate and efficiency, quality parameters of mixed liquor of the bubble column bioreactor were studied and kinetic of biofiltration was analyzed. Results: The average DCM removal efficiency of the HBCB bioreactor at EBRT of 200 and 150 s were 79 and 71% respectively. However, further reduction of EBRT resulted in significantly decreased DCM removal efficiency, so that at EBRT of 50 s, the DCM removal efficiency decreased to 32%. In addition, the EBRT reduction from 200 s to 50 s through increasing DCM loading rate resulted in increasing DCM removal rate from 12.1 to 19.6 g/m3.h. The results of kinetic analysis showed that the kinetic data of biofiltration were in the best fitness with the first order rate equation (R2>0.99 and &epsilon%<2.2) and the DCM removal rate constant was determined 0.0114 s-1. The mixed liquor characterization indicated that the daily adjustment of pH and EC was sufficient to prevent any limitation in the performance of the HBCB bioreactor. Conclusion: This study indicated that the DCM removal rate and efficiency of the HBCB bioreactor were relatively high and the HBCB bioreactor had reliable performance during the variable operational conditions.
K Naddafi, A Beiki , R Saeedi, G Ghanbari, A Niati, L Sori,
Volume 8, Issue 3 (12-2015)
Abstract
Background and objectives: In the outbreak of infectious diseases, the on time epidemiological, environmental, and laboratorial investigations result in rapid diagnosis of cause and source of the outbreaks and decrease the diseases spread and public health loss. Following the outbreak of gastroenteritis in Pardis Town in January 2014, this research was conducted to identify the cause, source, and route of transmission of the outbreak.
Materials and methods: First, the descriptive epidemiological study was conducted using checklist and the stool samples were prepared and analyzed. The drinking water quality in Pardis during and before the outbreak was obtained from National Environmental Health Network. The community water supply system consisting of watershed, water resources, pipelines, storage reservoirs, disinfection systems, and distribution network were inspected and sampling and detection of thermotolerant coliforms and norovirus in water samples were performed according to the Standard Methods.
Results: There were 6,027 patients with symptoms of nausea, vomiting, cramps, mild diarrhea, and mild fever. The distribution of the disease in all age groups, gender, ethnicity, and location was uniform. Out of nine stool specimens, molecular testing of norovirus in six samples was positive. Hazards identified in the water supply system consisted of a water pipe fracture occurred two days before the outbreak, illegal connection of landscape irrigation system to the drinking water supply network, the use of unprotected Fellman wells as the resource of water supply, and discharge of domestic wastewater into the water resource upstream of the Fellman wells. The water samples taken from the Fellman wells had fecal contamination (11 out of 12 samples), but because of weakness and limited experience in identifying norovirus in water samples, norovirus was not detected in the raw water samples.
Conclusion: This study showed that the pathogen came from a single source. Clinical symptoms, epidemiological evidence, the results of analysis of human stool samples, fecal contamination of raw water samples and norovirus resistance to the standard amounts of free residual chlorine in water indicated that the outbreak caused by consumption of contaminated drinking water (discharge of domestic wastewater to water supply system). In order to prevent similar outbreak, resolving the observed bugs in the water supply system and implementation of water safety plan is recommended.
K Naddafi, R Nabizadeh, S Nasseri, K Yaghmaeian, A Koolivand,
Volume 8, Issue 3 (12-2015)
Abstract
Background and Objectives: Remaining of crude oil in storage tanks usually results in accumulating oily sludge at the bottom of the tank, which should be treated and disposed of in a suitable manner. The efficiency of in-vessel composting process in removing total petroleum hydrocarbons (TPH) from bottom sludge of crude oil storage tanks was investigated in the present study.
Material and methods: The sludge was mixed with immature compost at the ratios of 1:0 (as control), 1:2, 1:4, 1:6, 1:8, and 1:10 (as dry basis) with the initial C:N:P and moisture content of 100:5:1 and 55% respectively for a period of 10 weeks. The moisture adjustment and mixing process were done 3 times a day during the composting period. Sampling and analysis of TPH and pH were done every week and every two days, respectively.
Results: TPH removal in the 1:2, 1:4, 1:6, 1:8, and 1:10 composting reactors was 66.59, 73.19, 74.81, 80.20, and 79.91%, respectively. Thus, initial adjustment of sludge to immature compost ratios plays a great role in reduction of TPH. The results of the control reactors indicated that the main mechanism of TPH removal in the composting reactors was biological process.
Conclusions: In-vessel composting by addition of immature compost as amendment is a viable choice for bioremediation of the bottom sludge of crude oil storage tanks.
