فصلنامه سلامت و محیط زیست
سال نهم شماره 1 (پیاپی 31، بهار 1395)

Phenol is a toxic and persistent substance in the environment. The aim of this study was to evaluate the performance of silica aerogel synthesized using sodium silicate in the adsorption of phenol from aqueous solutions.
Material and Silica aerogel was prepared by Sol-Gel process. The influence of effective variables such contact time, initial pH of the solution, adsorbent dose, and initial phenol concentration on the adsorption efficiency was investigated. The characterization of prepared silica aerogel and confirmation of phenol adsorption was determined through SEM, XRD analysis and NMR, FTIR spectra respectively. The adsorption data was evaluated via Langmuir and Freundlich isotherms and pseudo-first and pseudo-second-order kinetics.
This research found that the phenol adsorption efficiency increased by increasing pH from 3 to 11, so that after 60 min, the absorption efficiency at the 100 mg/L initial phenol concentration and 0.5 g adsorbent obtained 84 and 96.4 % at pH 3 and 11, respectively. The SEM image and XRD patternof synthesized silica aerogel confirmed the creation of porous and amorphous structure. After the phenol absorption, the NMR and FTIR spectra of silica aerogel, confirmed the creation of new bands because of phenol molecule at the adsorbent structure. The absorption of phenol was compatible with Freundlich isotherm and pseudo-second-order kinetic. The maximum absorption capacity (qm) obtained was 47.39 mg/g.
Silica aerogel as an adsorbent, due to special characteristics in the structure and usage, can be a promising treatment process for adsorption of toxic and persistent substances.

Swimming is one of the most popular sport fields and entertainments that has considerable benefits for human health, but on the other hand microbial water contamination in swimming pools through transmission and spread of infectious diseases is a significant threat against public health. In this study, microbial water quality of all public swimming pools in Tehran were assessed and effective factors on microbial water quality were analyzed.
This cross-sectional study with the analytical approach was performed in 2013. The whole public swimming pools in Tehran were inspected and water samples were taken for measurement of microbial indicators including thermotolerant coliforms, heterotrophic plate count (HPC), and physicochemical parameters affecting the microbial water quality including turbidity, free residual chlorine and pH and an integrated swimming pool microbial water quality index were used to describe the overall situation. Operational parameters with probable effects on microbial water quality were checked through inspection using a checklist.
The assessment of the swimming pool microbial water quality indicated that the compliance rates of thermotolerant coliforms and HPC were 91.4 and 84.5%, respectively. Compliance rates of free residual chlorine, turbidity, Ph, and temperature were also obtained to be 82.7, 45.5, 85.6, and 65.4% respectively. Based on the integrated swimming pool microbial water quality index, the proportions of swimming pools with excellent and good microbial water quality were 39.6 and 50.4% respectively and the others had not proper microbial water quality. The parameters of water free residual chlorine and turbidity, swimmer density, water recirculation period, dilution amount, cleaning, usage rates of shower and disinfection basin and operation of water treatment systems had significant effects on the microbial indicators (P The study showed that the overall microbial water quality status of public swimming pools in Tehran was acceptable and analysis of the results determined the most efficient interventions for improvement of the microbial water quality of the pools.

Chemical hair color are one of the most widely used cosmetics. The presence of heavy metals in these products can affect the health of consumers. Unlike other cosmetics, no study has been conducted on the heavy metal levels in the synthetic chemical hair colors. This study determined the concentration of heavy metals in these products and the risk assessment of non-carcinogenic effects by these elements were calculated.
Material and 32 samples of chemical hair color from eight brands (3 local and 5 imported ones) and four most used colors were collected from the markets in Tehran. The concentration of cadmium, lead, and barium was determined using ICP-MS. The information required to assess exposure risk was gathered through a questionnaire distributed among citizens of Tehran. The assessment of exposure was conducted using Mont Carlo method and non-carcinogenic risk was determined using the index of Hazard Quotient. .
Barium concentration measured was 0.86 mg/kg and concentrations of Cadmium and Lead were 0.45 and 185.34 µg/kg respectively. Among the elements, Pb with Hazard Quotient equals to 7.46×10-4 had the most risk and cadmium with Hazard Quotient equals to 3.57×10-5 had the lowest risk. Moreover, the Iranian brand and blond had the highest risk among the samples.
Based on the index of Hazard Quotient, heavy metals in the studied samples had no risk for consumers of these products.

The contamination of soils and plants with heavy metals is a serious and growing problem. The present study aimed to determine the concentration of heavy metals in soil and some agricultural products and the probability of risks due to their consumption.
This cross-sectional descriptive study was performed using random sampling at harvest time in 2014 on 205 samples of vegetable crops (Leek, chard, parsley, watermelon, melon, tomatoes, cucumber, potatoes, onion, garlic, radish, green peas, and broad bean) and 129 samples of soils under cultivation. Concentrations of Cu, Zn, Cd, and Pb in soil and plant samples were determined by an atomic absorption instrument and the data was analyzed using SPSS software.
There were significant differences between the mean concentrations of Pb, Cu, and Zn for different vegetables (P The results of this study indicated that major accumulation of heavy metals was obtained in leafy vegetables. Therefore, much attention should be paid to consumption of leafy vegetables, especially vegetables grown in the surrounding industrial areas.

Predicting municipal solid waste generation has an important role in solid waste management. The aim of this study was to predict municipal solid waste generation in Isfahan through time series method and system dynamics modeling.
Verified data of solid waste generation was collected from Waste Management Organization and population information was collected from the National Statistics Center, Iran for the period 1996-2011. Next, the effect of factors on solid waste generation such as population, urbanization, gross domestic product was investigated. Moreover, the relationship between each of these factors was identified using generalized estimating equation model. Finally, the quantity of the solid waste generated in Isfahan city was predicted using system dynamics modeling by Vensim software and time series method by ARMA technique.
It was found that population and gross domestic product have a significant relationship with the amount of solid waste with P value 0.026 and 0 respectively. The annual average of municipal solid waste generation would be 1501.4 ton/day in 2021 estimated by the time series method and 1436 ton/day estimated by the system dynamics modeling. In addition, average annual growth rate achieved was 3.44%.
According to the results obtained, population and gross domestic product have a significant effect on MSW generation. Municipal solid waste generation will increase in future. Increasing solid waste is not the same in different areas and methods. The prediction of the time series method by ARMA technique gives precise results compared with other methods.

In order to optimize wastewater nitrogen removal and to reduce the problems of entering nutrients in final receptors, for example, a lake, partial nitrification, as a novel nitrogen removal method, was studied.
The efficiency of simultaneous nitrification and denitrification (SND) in partial nitrification through nitrification/denitrification in fixed-film reactor was surveyed. In this process, ammonium was converted to nitrite by ammonium oxidizing bacteria (AOB) but the activity of nitrite oxidizing bacteria (NOB) was limited at low dissolved oxygen (DO) level. The inflection points of oxidation-reduction potential (ORP) profile were used as the indicators of process optimization.
This research showed that in period 2 at fixed DO level of 0.5 mg/L, nitrite accumulation rate (NAR) was higher than period 1 in which DO was declined from 1 to 0.5 mg/L. In contrast to period 1, SND efficiency was reduced in period 2. In period 3, by increment of the carbon to nitrogen ratio (C/N) to 12.5, NAR increased to 71.4 % and SND efficiency increased to 96.7%. In the long term analysis of proposed method, SND efficiency was, at least, 90%.
Proper C/N ratio and minimum DO level resulted in higher nitrogen removal efficiencies than the operation in which DO was decreased during aerobic phase. By using a fixed-film reactor and without considering an anoxic step, at DO level of 0.5 mg/L, maximum SND efficiency and maximum NAR would be achieved.

Qualitative evaluation of sewage sludge before any kind of application is essential. The present study was aimed to investigate Total coliform, Fecal coliform and Salmonella in sewage sludge produced at wastewater treatment plants in Azerbaijan Province, Iran.
Nine wastewater treatment plants were chosen in East Azerbaijan Province, and their sludge from drying bed was studied. Total coliforms, thermo-tolerant coliforms, and Salmonella spp., were surveyed during winter time, 2015. Total and thermos-tolerant coliforms were enumerated by EPA method 1680 and salmonella was counted using EPA method 1682.
In the case of total coliform, sludge sample from Jolfa with 1.82×106 MPN/g showed the highest contamination, while Sarab showed lowest fecal coliform count with 2.02×103 MPN/g. As in the case for fecal coliform, the bacteria count for thermo-tolerant coliforms was higher in Jolfa than other cities; on the other hand, Ahar with no fecal coliform count or less than 2.2 showed the minimum contamination rate to fecal coliforms. In case of Salmonella spp., sludge samples from Ahar and Bostan Abad did not show any salmonella. While sludge sample from Tabriz wastewater treatment plant was determined as the most contaminant sludge with bacteria count equal to 84 per g. Moreover, sludge sample from Sarab wastewater treatment plant showed the least contamination rate, and bacteria count was 6 per g.
From the stand point of microbial quality, all sludge samples met class B standards set by USEPA, while none of them could provide class A standards. Thus, special precautions must be taken in case of soil amendments by the sludge produced from wastewater treatment plants.

The aim of noise control in a community is to improve its management in the community, because the traffic noise can affect neighboring residential areas. Well-planned noise management can eliminate this major and harmful component issue, which is one of the stresses of urban life on human health. However, before planning to decrease urban noise, it is necessary to determine the very noisy areas in a given city. Therefore, the objective of this study was to measure the main noise indices at the noisy areas of Zanjan City, Iran.
This study was performed in the central area of Zanjan City, with heavy traffic. For this purpose, the equivalent sound level (Leq), the day-night sound level (Ldn), the day-evening-night sound level (Lden), the noise pollution level (NP) and the traffic noise index (TNI) were measured in 19 stations in the first half (winter and spring) of 2012. The measurements were conducted in the main streets of this area as recommended by EPA guidelines and finally the results obtained were mapped using the ArcGIS (Ver. 10.2) software.
the noise maps in GIS showed clearly the variations of Leq, Ldn, and Lden indices in the study field area. Moreover, it was found that the hourly variations of Leq, Ldn and Lden in stations are completely function of population movements and therefore traffic loads in the Zanjan city center. In addition, the extent of violation of traffic noise level from the ambient noise standard was estimated by Lden at 100% stations (greater than 55 dB). The TNI values at 67 and 100% stations were more than 74 dB (A), but in the evenings the TNI values at 100% of stations were more than 74 dB (A). The NP values at 78% sampling stations were more than 80 dB implying traffic noise was annoying in the most stations and times.
Using noise maps, NP and TNI indices can help intelligent traffic control planning, because the noise maps can be used to represent the movement of people in different times and parts of a city.

In this study, WQI was estimated using an Iranian software called IWQIS to assess drinking water quality in Ray Township distribution systems.
The assessment of 73 samples of drinking water during 2013 and the comparison of 18 physicochemical parameters with the standard Code of 1053 (Iran National Standard) was done.
The results showed that the concentration of 7 parameters is out of normal range in special percentage of the samples. Those parameters are as follow: total hardness (31.5%), Mg (46.6%), nitrate (50.68%), Na (45.2%), F (42.46%), Cl (2.7%), Sulfate (28.76%) of samples. The medium concentration of theses parameters was: total hardness (375 mg/L), Mg (32 mg/L), Nitrate (47.43 mg/L), Na (187 mg/L), F (0.5 mg/L), Cl (169 mg/L), and Sulfate (263 mg/L). It is estimated that 5.6% of the population of this township are highly exposed to nitrate, 79.1% to fluoride and 13.5% are exposed to sodium. The average WQI in Rey Township in a good spectrum is 71.22.
17 samples (23.2%) were assessed in excellent spectrum, 54 samples (74%) in good and 1 sample (1.4%) in very poor spectrum and 1 sample in unsuitable condition were assessed. No sample was assessed in poor situation. The samples of the autumn showed the worst quality.

The presence of fungal bioaerosols in hospitals indoor environments have affected the health of patients with the defect in immunity system. Therefore, determination of the rate and species of these agents is essential. This study aimed to investigate association between fungi contamination and particulate matter (PM10, PM2.5 and PM1) concentrations in the main indoor wards and outdoor environment and to determine I/O ratio in two educational-medical hospitals of Khorramabad City.
In this description-analytical study, the concentration of fungal bioaerosols and particulate matter was measured in 10 indoor parts and 2 outdoor stations over 6 mounts. The sampling was conducted using Quick Take-30 at an airflow rate of 28.3 L/min and sampling period of 2.5 min onto Sabouraud dextrose agar medium containing chloramphenicol. The particulate matters were measured using Monitor Dust-Trak 8520. Moreover, the relative humidity and temperature were recorded using digital TES-1360.
Analysis of 288 fungi samples and 864 particulate matter samples showed that the average of fungi accumulation was 59.75 CFU/m3 and the mean concentrations of PM10, PM2.5 and PM1 in the indoor environment was 27.3, 23, and 20.2 µg/m3 respectively. In addition, in ambient air the mean concentration was 135.3 CFU/m3 for fungal bioaerosols and 40.2, 35.7, and 29.8 µg/m3 for PM10, PM2.5 and PM1 respectively. At the total of fungi samples, 12.5% were negative and 87.5% were positive. Having 101.7%, Infection ward was the most contaminated ward. The operation ward in both hospitals showed the minimum fungal contamination.
The results of the present study showed that at all of the samplings the ratio of I/O was lower than one. It was noticed the dominancy of fungal bioaerosols and particulate matter of outdoor source on the indoor environment. In addition, a significant correlation (P

The presence of industrial workshops has increased urban pollution. This study aimed to investigate the heavy metal pollutants of Yazd battery repairing workshops and to identify the ecological and environmental effects resulted.
This descriptive cross-sectional study was carried out in Yazd. In this regard, the city was divided into three parts on the basis of geographical features. Then, 30 workshops were selected from each part through stratified random sampling method. Heavy metals (Pb, Cd, Cr, Zn, Cu, Fe, Mn) in the floor were measured using atomic absorption spectrophotometry (AAS). The impacts assessment of heavy metals was evaluated using environmental potential risk index (RI), cumulative pollution index (IPI), pollution coefficient factor (Cf), and the degree of modified contamination (mCd) and Pearson’s correlation statistical test.
The trend of heavy metals concentrations in floor dust particles of workshops was as Fe>Cu>Pb>Zn>Mn>Cr>Cd. Therefore, the average concentrations of Fe and Cd in the samples were 27011.52 ±4721.05 and 78.25±21.07 mg/kg respectively. The results of the RI showed that heavy metal of floor dust had very high danger (2816.29). The mCd value was as 63.35 indicating these workshops were at severe contamination class. The value of Cf was as 304.17 revealing that these workshops were at very severe contamination class.
This research showed that the high concentration of heavy metals in battery repairing workshops is due to the interaction of heavy metals of industrial wastes components, including electrical wastes and battery with the dust having mankind origin.

Formaldehyde is a toxic volatile organic compound, which its removal from polluted air is essential. One of the techniques available for removing such compounds is photocatalytic degradation. The aim of this study was to investigate the photocatalytic degradation of gaseous formaldehyde on TiO2 nanoparticles coated on reduced graphene oxide
The synthesized reduced graphene oxide- TiO2 nanocomposite was characterized using SEM, EDS, and FTIR spectra. The photocatalytic activity of prepared reduced graphene oxide- TiO2 nanocomposite was investigated for degradation of gaseous toluene under different operational conditions such as different initial concentration, flow rate, and time.
The photocatalytic degradation efficiency of the RGO-TiO2 nanocomposite was much higher than P25 TiO2. The photocatalytic degradation efficiency of the RGO-TiO2 nanocomposite decreased by increasing the flow rate so the flow rate is a key factor for the use of RGO-TiO2 nanocomposite as a photocatalyst. The results showed that the photocatalytic degradation rates decreased from 89 to 30% with increasing formaldehyde initial concentration from 0.1 to 1 ppm.
This research indicated that RGO-TiO2 nanocomposite can be effectively used as suitable photocatalyst to remove gaseous pollutants. One of the advantages of the as-prepared composite was using visible light instead of UV to activate the oxidation process.