mostafa hadei

Assessing the health effects of air pollution can provide useful information for health policy . AirQ + software is a tool for determining and modeling the health effects attributed to air pollutants such as O3, NO2, PM10 and PM2.5. The aim of this study was to quantify the health effects of PM2.5 pollutants in the air of Mashhad.

In order to present this analytical study, air quality data were obtained in 2019 from the General Department of Environment of the province and the Environmental Pollutants Monitoring Center of Mashhad Municipality. Hourly data of each validated station and stations that less than 75% of the data were not registered or were not valid were eliminate. Demographic and meteorological information were also obtained from relevant organizations. AirQ + software was used to quantify the health effects of suspended particles. The desired cut-off concentration was 10 μg / m3 according to WHO guidelines.

The results show that the total death rate attributed to PM2.5 in 2019 was about 1069 cases, which is about 9.5% of the total deaths in Mashhad. In the long term exposure, the rate of premature death attributed to PM2.5 due to COPD in that year was about 14%, due to cancer about 12%, due to IHD about 6% and due to stroke about 8% of the total deaths in Mashhad in the upper25 years old population.

Among air pollutants, PM2.5 due to its special structure composition can be one of the risk factors for public health. This study does not consider the synergistic effects of air pollutants, which is due to the lack of studies worldwide. If the synergistic effects of pollutants are taken into account, the rate of deaths attributed to air pollution could be much higher than currently estimated.

Air pollution is one of the main causes for the significant increase of respiratory infections in Tehran. In the present study, we investigated the associations between short-term exposure to ambient air pollutants with the hospital admissions and deaths.

Health data from 39915 hospital admissions and 2459 registered deaths associated with these hospital admissions for respiratory infections were obtained from the Ministry of Health and Medical Education during 2014-2017. We used the distributed lag non-linear model (DLNM) for the analyses.

There was a statistically positive association between PM2.5 and AURI in the age group of 16 years and younger at lags 6 (RR 1.31; 1.05-1.64) and 7 (RR 1.50; 1.09-2.06). AURI admissions was associated with O3 in the age group of 16 and 65 years at lag 7 with RR 1.13 (1.00-1.27). ALRI admissions was associated with CO in the age group of 65 years and older at lag 0 with RR 1.12 (1.02-1.23). PM10 was associated with ALRI daily hospital admissions at lag 0 for males. ALRI admissions were associated with NO2 for females at lag 0. There was a positive association between ALRI deaths and SO2 in the age group of 65 years and older at lags 4 and 5 with RR 1.04 (1.00-1.09) and 1.03 (1.00-1.07), respectively.

Exposure to outdoor air pollutiants including PM10, PM2.5, SO2, NO2, O3, and CO was associated with hospital admissions for AURI and ALRI at different lags. Moreover, exposure to SO2 was associated with deaths for ALRI.

The novel coronavirus disease 2019, namely COVID-19, has been known as a global pandemic by the World Health Organization (WHO). To prevent of COVID-19 spread, most countries including Iran have implemented many preventive measures. This study aimed to evaluate the effect of implementation /non- implementation of the traffic plan on confirmed cases, suspected cases, and mortality cases by COVID-19 as well as on air quality in Tehran.

Daily data of confirmed COVID-19 cases, suspected COVID-19 cases, mortality COVID-19 cases, air pollutants concentration and meteorological variables were obtained from 26 February, 2020 to 5August, 2020 in Tehran megacity and data were compared during the period’s implementation / non-implementation of traffic plan in Tehran.

Our results showed that the non-implementation of traffic plan has been effective in reducing the number of daily confirmed cases, suspected cases and mortality by COVID-19. Also, the average concentration of PM10, PM2.5, NO2, O3, SO2 and CO have reduced significantly during non-implementation traffic plan phase

Our findings indicate that there is a significant association between non-implementation traffic plan and reduce risk of COVID-19 infection.

Estimating air pollution levels in areas with no measurements is a major concern in health-related studies. Therefore, the aim of this study was to investigate the amount of exposure to particulate matter below 2.5 μ (PM2.5) in the metropolis of Tehran.

The hourly concentrations of PM2.5 during 2017-2018 period were acquired from the Department of Environment (DOE) and Air Quality Control Company of Tehran (AQCC). The hourly concentrations were validated and 24-h concentrations were calculated. Inverse distance weighting (IDW), Universal Kriging, and Ordinary Kriging were used to spatially model the PM2.5 over Tehran metropolis area. Root Mean Square Error (RMSE) and Mean Error (ME) were used to measure and control for the accuracy of the methods.

The results of this study showed that RMSE and MENA values in Kriging method was less than the IDW, which indicates that the Kriging was the best method to estimate PM2.5 concentrations. According to the final map, the highest annual concentrations of PM2.5 were observed in the southern and southwestern areas of Tehran (districts 10, 15, 16, 17, and 18). The lowest exposure to PM2.5 was found to be in districts 1, 2, 3, 6, and 8.

It can be concluded that Kriging method can predict spatial variations of PM2.5 more accurately than IDW method.

Attributable health impacts of air pollution result in economic costs to societies. In this study, the WHO AirQ+ model was used to estimate the health impacts and health-related economic costs of PM2.5 and O3 in Karaj, the fourth largest city in Iran, from March 2015 to March 2016.

For PM2.5, long-term mortality due to ischemic heart disease (IHD), lung cancer, chronic obstructive pulmonary disease (COPD), and morbidity such as acute lower respiratory infection (ALRI), and short-term cardiovascular and respiratory hospitalizations were calculated. For ozone, short-term mortality and hospitalizations due to cardiovascular and respiratory diseases were estimated. The human capital method (HCM) was used to monetize the mortality impact attributed to selected air pollutants. Direct and indirect costs of morbidity were estimated using available local data on the costs related to cardiovascular and respiratory diseases.

The total number of IHD, COPD, LC and ALRI deaths attributed to PM2.5 in selected age groups was 576. The total number of cardiovascular and respiratory deaths attributed to O3 was 46 cases. For hospitalization, the aggregate cardiovascular and respiratory hospital admissions for both pollutants were 552. The total economic loss due to mortality and morbidity from selected health endpoints was approximately 44 million USD.

Despite the limitations, such methodologies can be useful for policy-makers. Therefore, there is a compelling need to conduct cost of illness’s studies in other areas.

BTEX refers to a volatile compound with single aromatic ring in petroleum including benzene, toluene, ethyl benzene, and xylenes. Due to its flammability, toxicity and carcinogenicity properties, BTEX has many adverse effects on human health. This study aimed to evaluate the efficiency of multi-walled carbon nanotube (MWCNT) modified with an ultrasonic homogenizer (UH) to remove BTEX from aqueous solutions.

MWCNT was modified in different concentrations, times and intensities. Then, the best condition was selected. After modification based on the design of experiments (DOE), 16 experiments were arranged at 4 levels with 4 factors. Samples required for simulation were built according to the standard methods and then analyzed by gas chromatography mass.

The results revealed that the optimum conditions for modified carbon nanotubes were obtained at concentration of 30% sodium hypochlorite, time of 5 seconds, and intensity of 50 dB. The optimum conditions for initial BTEX concentration, MWCNT dose, contact time, and pH were 100 mg/L, 2000 mg/L, 20 min and 7 respectively.

The results indicated that carbon nanotubes modified with homogenizer are a simple and effective technique to remove BTEX from the environment.

This study aimed to calculate and evaluate air quality index (AQI) in Tehran according to the EPA’s instruction, and evaluate the obtained values.

The study period included three years of 2013, 2015, and 2017 within the six-year period of 2013-2017. The concentrations of six studied pollutants were acquired from Department of Environment (DE) and Air Quality Control Company of Tehran (AQCC). EPA’s method was applied to calculate AQI values during the study period, selecting the highest AQI value among all of the pollutants and monitors.

The three-year average of AQI was about 147. During all the three years, the air quality had never been in a “good” condition (AQI<50). About 92%, 91%, 87% of AQIs indicated the conditions unhealthy for sensitive groups (100<AQI<150) or unhealthy for all groups (150<AQI<200). PM2.5 accounted for most of the AQI values in Tehran, followed by NO2 and O3. Evaluating the histogram of AQI values indicated a strange form of distribution, showing a decline in the 100-150 range and a sudden increase just after AQIs higher than 150.

This study indicated that governmental organizations should follow EPA’s instruction for AQI calculations to avoid underestimation of air pollution, and broadcast accurate and reliable AQIs to public. To determine the reason for the abnormal distribution of AQI, further studies with longer study periods are required.

The wide range of studies on air pollution requires accurate and reliable datasets. However, due to many reasons, the measured concentrations may be incomplete or biased. The development of an easy-to-use and reproducible exposure assessment method is required for researchers. Therefore, in this article, we describe and present a series of codes written in R Programming Language for data handling, validating and averaging of PM10, PM2.5, and O3 datasets. These codes can be used in any types of air pollution studies that seek for PM and ozone concentrations that are indicator of real concentrations. We used and combined criteria from several guidelines proposed by US EPA and APHEKOM project to obtain an acceptable methodology. Separate .csv files for PM10, PM2.5 and O3 should be prepared as input file. After the file was imported to the R Programming software, first, negative and zero values of concentrations within all the dataset will be removed. Then, only monitors will be selected that have at least 75% of hourly concentrations. Then, 24-h averages and daily maximum of 8-h moving averages will be calculated for PM and ozone, respectively. For output, the codes create two different sets of data. One contains the hourly concentrations of the interest pollutant (PM10, PM2.5, or O3) in valid stations and their average at city level. Another is the final 24-h averages of city for PM10 and PM2.5 or the final daily maximum 8-h averages of city for O3. These validated codes use a reliable and valid methodology, and eliminate the possibility of wrong or mistaken data handling and averaging. The use of these codes are free and without any limitation, only after the citation to this article.

The aim of this study was to investigate the concentrations of PM10, PM2.5, O3, NO2, SO2, and CO in Tehran during March 2014-March 2018, and evaluate the effects of holidays and meteorological parameters on the air pollution levels. Hourly concentrations of PM10, PM2.5, O3, NO2, SO2, and CO in different air quality monitors of Tehran were acquired. The data from each air quality monitored were validated, and only high-quality monitors were included in this study. The 4-year averages of PM10, PM2.5, O3, NO2, SO2, and CO concentrations were 88.74 (μg/m3), 31.02 (μg/m3), 34.87 (ppb), 71.01 (ppb), 20.04 (ppb), and 3.78 (ppm), respectively. Higher concentrations of PM10 and O3 were observed during summer. In case of PM2.5 and CO, autumn and winter concentrations were higher than those in springer and summer. Lower concentrations of PM10 and NO2 in Fridays were observed comparing to other days of week. Ozone had high concentrations in Fridays as the weekend in Iran. Except for O3, all of the pollutants had higher concentrations in the working days, comparing to those in any type of vacation days. Concentrations of all pollutants rather that SO2 and O3 in Nowruz holidays were statistically lower than those in the working days. By controlling for the effects of meteorological variables, our results showed that the air pollution control policies and actions have been not effective for particulate matter. These results determines the time periods in which the concentrations of criteria air pollutants are high. This can be very useful for announcing alarms for citizens, and designing the air pollution control plans. In addition, more effective actions should be designed and implemented for reducing ambient levels of particulate matter.

This study aimed to investigate the adsorption of CH4, CO2, H2S at a temperature of 298.15 K and pressurerange of 0.1 to 30 atm, and compare the results with experimental data for MIL-47 using GCMC. Themaximum CH4, CO2 and H2S adsorptions were 3.6, 10.45, and 12.57 mol.kg-1, respectively. In addition, theselectivity for binary mixtures of CH4/CO2 and CH4/H2S was calculated. The results for CH4/CO2 mixturesat 10 atm showed that: 1) MIL-47 only adsorbed CO2 in a 0.05 CH4/ 0.95 CO2 mixture, and 2) by increasingthe mole fraction of CH4, the selectivity toward CO2 decreased. The results for H2S/CH4 mixture at 10atm showed that: 1) H2S was adsorbed only in mole fractions of 0.95, 0.75, and 0.50 of H2S, and 2)the observed selectivity was about 132.7 and 63.2 at H2S mole fractions of 0.25 and 0.05, respectively.The MD simulations and RDF analyses were used to investigate 0.5 CH4/0.5 CO2 and 0.75 CH4/0.25 H2Smixtures. The results showed that the adsorption mostly occurs on the metallic part of MIL-47. Wefound that V and O atoms were the active adsorption sites in MIL-47. H2S and CH4 showed to have thehighest and lowest levels of self-diffusions, respectively. The MD simulations were used to study the selfdiffusionfor mixtures across all mole fractions. In the binary mixture of 0.95 CO2/0.05 CH4, the maximumself-diffusion was 1.49×10-12 m2s-1 for CO2. The maximum self-diffusion for H2S in the mixture of 0.05CH4/0.95 H2S was 2.62×10-10 m2s-1.

This study aimed to determine the number of all causes such as lung cancer, chronic obstructive pulmonary disease (COPD), ischemic heart disease (IHD), and stroke deaths due to exposure to PM2.5 in Mashhad during March 2013-March 2017 using the AirQ+ model. Hourly concentrations of fine particulate matter were obtained from Department of Environment (DOE) of Iran, and validated according to APHEKOM study and WHO's criteria. Baseline incidence (BI) values for all-cause, COPD, lung cancer, IHD and stroke mortality was obtained from Ministry of Health and Medical Education. The annual average of (±SD) was determined for all four years and the average four- year were 36.07 (± 26.93), 27.29 (± 13.24), 30.53 (± 13.82), 30.14 (± 15.94), and 31.01 (± 10.22) µg / m3, respectively. The averages of PM2.5 concentrations during the cold months of years was higher than those in the warm months. Calculating the daily air quality index (AQI) indicated that only few days (48 days) during this period of time ( 4 years ) had a "standard" air quality and a concentration lower that 12.5 µg / m3. The total number of deaths in all the four years was 4457 cases. Furthermore, the total number of COPD, lung cancer, IHD, and stroke mortality was 146, 142, 5263, and 2608 cases, respectively. The trend of death numbers did not follow a specific direction, and some fluctuations can be observed. Due to the considerable health effects of the poor air quality in Mashhad, controlling actions should be implemented to reduce the levels of air pollution.

Background and Airports are proved to have adverse effects on the air quality of neighboring areas. This study aimed at determining the concentrations of air pollutants including PM10, PM2.5, O3, NO2, SO2, CO, benzene, toluene, ethylbenzene, and xylene (BTEX) in Mehrabad International Airport.
The samples were taken from two sites (runway and passengers waiting hall) in Mehrabad in December 2015. The concentrations of BTEX, particulate matter, and other gaseous pollutants were measured using gas chromatography-flame ionization detector (GC-FID), MetOne aerocet 531s, and Aeroqual Series 500, respectively. The effect of meteorological parameters (temperature, wind speed, and relative humidity) on the concentrations of air pollutants were analyzed using nonparametric correlation test.
In runway, the temperature was found to have a significant correlation with all the pollutants except PM2.5 (p Prevention of air pollution in neighboring areas of Mehrabad airport could be done using appropriate management system and flight schedule planning according to current findings, especially the effect of meteorological parameters.

Traffic and mobile sources are possibly responsible to the most of the ambient volatile organic compounds (VOCs) in urban areas. This study aimed to measure and determine the traffic - related concentrations of benzene, toluene, ethylbenzene, xylenes, formaldehyde, and acetaldehyde at the main streets of Tehran, Iran.
The samples were taken from highly populated streets or main roads with heavy traffic in Central, Northern, Eastern, Southern, and Western areas of Tehran. In total, 33 points for BTEX and 23 points for formaldehyde and acetaldehyde were selected for sampling. The sampling and analysis were performed according to NIOSH methods 1501 and 2016.
The averages (± SD) of benzene, toluene, ethylbenzene, xylenes, formaldehyde and acetaldehyde concentrations in Tehran were 15.04 (± 9.18), 23.42 (± 8.73), 4.97 (± 2.55), 11.81 (± 4.46), 107.11 (± 30.58) and 57.10 (± 18.28) ppbv, respectively. Benzene concentrations were 3.30 to 26.00 times higher than air quality standard of European Union (5 μg / m3). High concentrations of BTEX and formaldehyde / acetaldehyde were found in central and eastern areas, respectively. High correlation coefficients were found between BTEX species (r = 0.77-0.95) and also formaldehyde and acetaldehyde (r = 0.98). The highest coefficient of variation (CoV) as a measure of spatial variability was observed for benzene (54.5 %).
The high outdoor concentrations observed in this study needs to be decreased immediately, especially in case of benzene.

Various epidemiological studies have related fine particles (PM2.5) to incidence of lung cancer. In addition, particulate air pollution has been classified as Group 1 carcinogen by international agency for research on cancer (IARC) in 2013.

The aim of this study was to quantify the number of gender-specific lung cancer deaths due to exposure to PM2.5 among individuals aged over 30 years using WHO AirQ model in 10 cities of Iran during March 2013-March 2016.

Hourly concentrations of PM2.5 were obtained from department of environment (DOE) of Iran and Tehran air quality control company (TAQCC). Demographic information and baseline incidence (BI) were acquired from statistical center of Iran, ministry of health and medical education, respectively. AirQ model was used to quantify the lung cancer deaths among males and females aged over 30 years.

The highest lung cancer deaths were in Tehran with approximately 407 cases of death during the whole three-year period. The total deaths among men and women in the whole period were 433 and 431 cases, respectively. The sum of lung cancer deaths due to PM2.5 exposure in all the 10 cities during these 3 years were estimated 864 cases. In addition, the attributable proportion of lung cancer due to PM2.5 exposure in each city was estimated. Despite the high number of lung cancer deaths in Tehran, higher AP values were observed in cities such as Isfahan, Ahvaz, Khoram Abad and Arak, reflecting the higher risk of death per unit of population.

The results of this study could be used by authorities for making air pollution reduction strategies and plans. Furthermore, any reduction in attributed mortality and hospitalization reduces financial burden in health organizations.

Particulate air pollution is known as a major risk factors of ischemic heart disease (IHD) and stroke. The aim of this study was to estimate the premature IHD and stroke deaths attributed to long-term exposure to PM2.5 in 10 cities of Iran during March 2013 to March 2015 using AirQ model.
Ten cities of Iran including Tehran, Mashhad, Isfahan, Shiraz, Tabriz, Ahvaz, Arak, Sanandaj, Khoram Abad, and Ilam were chosen, and their air quality data were acquired from Department of Environment (DoE) and Tehran Air Quality Control Company (AQCC). Validation of monitoring stations were accomplished according to WHO and APHEKOM criteria for health impact assessment of air pollution. The number of deaths due to IHD and stroke was estimated using AirQ , which is developed by WHO.
The total number of IHD and stroke deaths in the March 2013- March 2014 and March 2014 - March 2015 periods were 15479 and 15321 deaths, respectively. In case of both IHD and stroke mortality, the highest number of IHD and stroke deaths was estimated to be in Tehran, Mashhad and Isfahan, respectively. The highest number of attributable deaths per 100,000 population were estimated to be in Ahvaz and Isfahan. The average of excess IHD and stroke deaths due to exposure to PM2.5 in all cities were 84 and 41 per 100,000 population, respectively.
The results of this study indicated the necessity of urgent actions to improve the outdoor air quality in Iranian cities.

Understanding public attitudes for planning policies and actions to control air pollution is important. Attitude is partially socially constructed and thus must be studied in each area separately, rather than inferred from other settings. This study was aimed to evaluate the knowledge and attitudes of university students about the air pollution sources and solutions in Tehran.
Material and 200 students of Shahid Beheshti University of Medical Sciences (SBMU) during 2015 - 2016 years were selected by random sampling. The questionnaires were used to collect data consisted of four parts: demographic information, knowledge, attitude, and solutions for reducing air pollution.
Most of the participants were 18 - 22 years old, male, single, studying in bachelor degree, and from Tehran. Significant correlations were found between attitude on one side and age, gender, marital status, and education level on the other side. The most approved solutions for air pollution by students were improvement of the quality of fuel (84.7%) and vehicles (79.7%), and development of green space (76.2%).
Educational programs must be designed to raise the level of public attitude about air pollution. Citizens should be a part of any solution for environmental problems.

Long-term exposure to particulate matter with an aerodynamic diameter less than 2.5 μm is associated with lung cancer incidence. This study aimed to estimate the number of lung cancer deaths attributed to lung-term exposure to PM2.5 among people older than 30 years in 15 cities of Iran during 2015- 2016 using AirQ modelling approach.
Validation of monitoring stations was done according to WHO’s criteria for health impact assessment of air pollution. As AirQ needs, 24-h concentrations of PM2.5 during a year, total population and at-risk population, baseline incidence of lung cancer, and cut-off value of 10 μg/m3 for PM2.5 concentration were prepared and entered into the model.
Annual concentrations of particulate matter in all cities were 1.8 to 6.7 times higher than WHO’s guideline. The most and least cases of lung cancer deaths due to PM2.5 were estimated to be in Karaj and Birjand, respectively. Total mortality of lung cancer attributed to PM2.5 in these 15 cities were 120 cases.
Since air pollution’s health impacts impose financial losses to countries, results of this study can be useful for decision-makers to highlight areas requiring urgent action.

Moving bed biofilm reactor (MBBR) is a process in which attached growth is utilized for wastewater treatment. This process does not require sludge recycling or backwash. Activated sludge processes can be promoted to an MBBR by adding media to an aeration tank. Rapid sand filter is a physical method for the removal of total suspended solids (TSS) in advanced wastewater treatment. The purpose of this study was the evaluation of effluent reuse feasibility of MBBR and rapid sand filter in agricultural irrigation. Results showed TSS, biochemical oxygen demand (BOD5), and chemical oxygen demand (COD) concentrations in effluent were 10, 7.7, and 85.75 mg/l, respectively. Removal efficiency of TSS, BOD5, and COD was 98%, 98.8%, and 94.6%, respectively. Furthermore, the value of chemical parameters was less than the standard limitations. Average removal efficiency of total coliform, fecal coliform, and nematode was 100%. Total dissolved solids (TDS) and electrical conductivity (EC) in effluent were 960.5 mg/l and 1200.63 μs/cm, respectively. The Wilcox diagram showed that effluent was in the C3-S1 class, which means effluent quality was appropriate for irrigation. The results showed that effluent quality was completely compatible with the national standards in agricultural irrigation.

Background & Aims of the Study: Ethylbenzene (EB) is a dangerously organic compound, which the presence of this pollutant in water solutions can be considered as an environmental and public health hazard. In this study, nano magnetic particles (Fe3O4) were used as an adsorbent to remove ethylbenzene from aqueous solutions.
The specification of the adsorbent was investigated by transmission electronic microscope (TEM) and X-ray diffraction (XRD) pattern. A 4×4 factorial design including initial concentration of ethylbenzene, nano magnetic particles dose, contact time and pH were studied.
The results showed that the maximum ethylbenzene removal by nano magnetic particles was achieved in the following conditions; 100 mg.L-1, 2000 mg.L-1, 20 minutes and 8, in initial concentration, nano magnetic concentration, contact time and pH respectively. The most amounts of ethylbenzene adsorption and distribution ratio in optimum condition was 49.9 mg.g-1 and 261.9 l.g-1 respectively. The results demonstrated that the removal rate of ethylbenzene was higher in batch (99.8 %) rather than continuous (97.4%) condition.
The removal rate of ethylbenzene was higher in batch rather than continuous condition. The study of isotherm showed that adsorption data follow up linear isotherm. Comparing adsorption rate of NM particles and other adsorbents proved that Fe3O4, as a material with high capacity of adsorption can apply for removing ethylbenzene as an efficient and also cheap adsorbent.

 The present study was carried out to determine biokinetic coefficients of a pilot-scale adsorption-bio-oxidation process. 

 The pilot plant was simulated North wastewater treatment plant, Isfahan, Iran. The pilot plant was operated 135 days under different mixed liquor suspended solids (MLSS) concentrations in aeration tank. In each phase, MLSS value was kept constant to reach a steady state condition. B-stage has a higher hydraulic retention time and SRT than A-stage. Also, in order to determine influence of biokinetic parameters on the effluent substrate concentration, a sensitivity analysis was performed. 

 The coefficients Y, K d , K S , and μmax of A-stage were 1.34 mg VSS/mg sCOD, 0.17 d−1 , 8.61 mg/L, and 2.78 d−1 , respectively. Also, Y, K d , K S , and μmax of B-stage were 0.74 mg VSS/mg sCOD, 0.12 d−1 , 3.34 mg/L, and 71.94 d−1 , respectively. Sensitivity analysis showed that in the A-stage, all coefficients are directly proportional to the effluent sCOD concentration. In the B-stage, K d and K S are directly proportional, but μmax was inversely proportional to the effluent sCOD concentration. 

 All coefficients were in the range of activated sludge coefficients that are mentioned in the literature, except μmax and K S of B-stage. However, K S value of B-stage was close to the desired range. Sensitivity analysis showed that μmax and K S have the most influence on effluent substrate concentration (sCOD).

Since hospitals give their services to a huge number of people most of whom are sick and disabled and also because they have many expensive and modern equipment and facilities, any negligence regarding the standards of safety management leads to severe damages including financial ones. This may even result in irrecoverable consequences such as their clients’ Death. So, this investigation was conducted to assess the condition of safety management in Isfahan’s AL Zahra hospital. This cross-sectional and descriptive-analytical project was conducted in different wards of AL Zahra hospital. In this study, the hospital''s units under the investigation were determined and no sampling method was used. The data collection was done by a checklist and questionnaire. They had content validity which was confirmed by the viewpoints of psychiatric and behavioral sciences specialists. The data were analyzed through SPSS (version 16) using Kruskal Wallis statistical tests. In this study, the level of significance was 0.05. After assessing safety management in Safety and Accidents Committee and calculating the score average of the studied factors, safety management organization and also hospital’s organizational constructs sectors were 74.43±13.47 and 65.48±12.25, respectively. Their safety management condition was assessed appropriate. Surgery ward was also assessed appropriate regarding the principles of safety management with a mean score of 77.36±13.84. No significant difference was found among the studied standards in these units according to Kruskal Wallis statistical test. (P-value>0.05) The results showed that the condition of safety management in this hospital was acceptable, in general. However, it is necessary to do the following interventions to improve safety condition; training managers and staff, setting and observing the rules and disciplines of safety, regular monitoring of safety issues and considering safety principles implementation as an important factor in evaluating and ranking of hospitals.

 This study investigates the potential of chitin shrimp shells for the removal of arsenic (V) and zinc (II) ions from aqueous solutions. 

 In this study, the chitin was extracted from shrimp shells for arsenate and zinc ions removal from aqueous solutions. The effects of pH, adsorbent dosage, contact time and initial metal ion concentration on As (V) and Zn (II) removal were investigated in a batch system. 

 The equilibrium data were described using the Langmuir and Freundlich isotherm models. The Langmuir equation was used to find the maximum adsorption capacity for arsenate (11.574 mg/g) and Zn (270.27 mg/g). Biosorption was found to depend significantly on the pH of the solution and is optimal at pH values of 4 and 7. To determine the rate-controlling mechanism for metallic ion adsorption, pseudo-first-order and pseudo-second-order equation kinetic models were tested with experimental adsorption kinetic data. Modeling results revealed that As (V) and Zn (II) kinetics data were successfully described using pseudo-first and second-order models, respectively. FTIR analyses showed that hydroxyl and carboxyl groups could be very effective for capturing these metals. 

 Results showed that the chitin is a good adsorbent for the removal of arsenate and zinc ions from aqueous solutions.