فهرست مطالب

Advances in Environmental Health Research - Volume:5 Issue: 2, 2017
  • Volume:5 Issue: 2, 2017
  • تاریخ انتشار: 1396/08/13
  • تعداد عناوین: 8
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  • Hamed Fathi Dokht *, Esmaeil Dordipour, Seyedalireza Movahedinaeini Pages 59-69
    The effective management of sewage sludge materials in an environmentally and economically acceptable way is through the pyrolytic conversion of the sludge to biochar and its use for agricultural purposes. The aims of this work were: (1) to assess the effect of biochar prepared from sewage sludge at two different temperatures (350 ºC and 650 ºC) on the adsorption/desorption capacity of Pb (II) in two different Iranian soils (acidic and alkaline soils), and (2) to investigate the adsorption/desorption isotherm. The results indicated that with increasing pyrolysis temperature, the soil pH, ash content, aromaticity, BET, and total heavy metal concentration increased. On the other hand, the pyrolysis yield, percentages of H, N and O, atomic ratios, CEC and polarity of biochar decreased. The adsorption and desorption of Pb was more accurately described by the Langmuir isotherm than the Freundlich isotherm The maximum adsorption capacity of biochars increased for alkaline and acidic soils when pyrolysis temperatures increased, suggesting that high temperature pyrolysis led to the biochars having high Pb adsorption capacity. The desorption of pre-adsorbed Pb (II) by NaNO3 decreased in soils incorporated with biochars.
    Keywords: soils, sewage sludge, environmentally
  • Majideh Babaei, Mansoor Anbia *, Maryam Kazemipour Pages 70-77
    In this work, a new synthesized Y-type zeolite with an Si/Al molar ratio of 2.5 (NaY) was modified with amines, in order to probe the influence of the modification of the adsorbent’s surface on CO2 adsorption. The three selected amines were diethanolamine, tetraethylenepentamine, and 2- methylaminoethanol. The surface nature of NaY was changed after amine modification, which causes a significant increase in the CO2 adsorption capacity. The CO2 adsorption capacity of the amine- modified NaY increased with temperature. The mechanism of CO2 adsorption on NaY is usually a physical interaction, but it seems that after amine modification, chemical mechanism is the dominant mechanism for the chemical interaction between CO2 and amine groups. The adsorbents were characterized by surface area and porosity analysis, X-ray diffraction, Fourier transform infrared spectroscopy, thermal gravimetric analysis, and scanning electron microscopy. The CO2 adsorption capacity was measured by the volumetric method at 298 and 348 K. The CO2 adsorption capacity of TEPA-NaY, DEA-NaY, and 2-MAE-NaY at 298 K was 60.63. The CO2 adsorption capacity of TEPA- NaY, DEA-NaY, and 2-MAE-NaY at 348 K were 92.9, 78, and 85.42, respectively. These results showed that amine-functionalized NaY zeolites have excellent adsorption potential for CO2 adsorption at high temperatures.
    Keywords: CO2 Adsorption, Y-Type Zeolite, amine modification, chemisorption, physisorption
  • Hamed Aghdasi, Rahim Aali, Nabiollah Mansouri, Heresh Amini * Pages 78-84
    One of the pillars of epidemiologic research on the long-term health effects of air pollution is to estimate the chronic exposures over space and time. In this study, we aimed to measure the intra-urban ambient carbon monoxide (CO) concentrations within Urmia city in Iran, and to build a model within the geographic information system (GIS) to estimate the annual and seasonal means anywhere within the city. We collected more than 5,000 measurements from 53 locations during July 2010 to July 2011 in four seasons to calculate the annual and seasonal means in Urmia. The Universal Kriging was used to predict the spatial and seasonal concentrations of CO. The annual mean and annual peak CO concentrations were respectively 2.5 and 4.4 ppm. The results of the spatial analysis showed that the north-eastern parts of the city were more polluted than the other areas. The mean and peak seasonal spatial patterns were consistent over time. This is the first study that monitored and predicted the long-term CO concentrations with a dense measurement network in Urmia, providing a foundation for future epidemiological studies on the health effects of air pollution. The spatial estimates can also be used for a variety of other purposes, such as evidence-based air quality management and urban planning. Overall, the CO levels in Urmia were lower than the values recommended by the World Health Organization. However, further research is required on other important pollutants, such as particulate matter, nitrogen dioxide, air toxics and so forth.
    Keywords: Air pollution, carbon monoxide variability, intra-urban, Iran, long-term, Urmia, spatial
  • Reza Rezaee, Mahdi Safari *, Reza Ghanbari, Esmael Ghahremani, Mehdi Hosseini, Yahya Zansalimi Pages 85-92
    This study aimed to investigate the efficiency of the enhanced coagulation (EC) process for the simultaneous removal of turbidity and humic substances (HS) from raw water from the Sanandaj Water Treatment Plant (SWTP). This study was conducted on a laboratory scale using a jar test device and ferric chloride (FeCL3) as the coagulant. Accordingly, the effects of pH and coagulant dosage variations on the simultaneous removal efficiency of turbidity and humic substances in the enhanced coagulation process were investigated. Furthermore, certain parameters including the total organic carbon (TOC), dissolved organic carbon (DOC), ultraviolet absorbance (UV254), and chemical oxygen demand (COD) were determined as the indices of the humic substances and turbidity in the water samples. The results of the raw water analysis showed that the mean values of TOC, DOC, UV254, COD, and turbidity parameters were 4.41 mg/L, 4.11 mg/L, 16.47 1/cm, 15 mg/L, and 4.37 NTU, respectively. Moreover, the results of the present study showed that the average efficiency of the enhanced coagulation process in the removal of TOC, DOC, UV254, COD, and turbidity was 65%, 62%, 70%, 69%, and 93%, respectively. Accordingly, the EC process using FeCL3 coagulant is a suitable, cost-effective, and highly efficient method for the simultaneous removal of turbidity and humic substances from water. Furthermore, this process can be used as an applicable method in SWTP as well as in other similar water treatment plants.
    Keywords: Humic substances, Enhanced coagulation, Ferric chloride, Turbidity
  • Mostafa Leili *, Hosseinali Norouzi, Mahdi Khodabakhshi, Afsaneh Naghibi Pages 93-100
    Swimming is considered one of the most conventional recreational activities for both leisure and exercising. Swimming pools have either public or private usage. Nevertheless, if the water of the swimming pools is polluted and is not identified on time, it could result in the transmission of various diseases to the people who use them. Therefore, the main objective of this study was to assess the health situation of swimming pools in the Hamadan province during the period of 2012–2014.This research was a descriptive-analytical (cross-sectional) study on the 19 active pools in the 8 cities of Hamadan province. A total of 120 samples were randomly taken from different parts of the swimming pools during the three-year study period. The sampling and testing procedures were performed according to standard methods. The SPSS software (IBMÒ) and the linear correlation test were used for data analysis. The results showed that the physicochemical parameters, such as pH and residual chlorine for 76% and 86% of the total samples, respectively, showed good compliance in pool water during the study period. In terms of microbiological parameters, the lowest and highest numbers of positive samples were observed in the years 2012 and 2014, respectively. According to the results and the unfavorable trend observed mainly in terms of microbial contamination, appropriate measures, such as through strict enforcement of sanitary standards and provision of required equipment like turbidity meter, should be undertaken in order to increase the hygiene level of swimming pools in the Hamadan province.
    Keywords: Swimming pools, physico-chemical parameters, biological parameters, Hamadan
  • Mitra Mohammadi, Khadije Shamsi, Abdollah Dargahi *, Pegah Sekhavat Pages 101-107
    Mercury is a carcinogenic and teratogenic compound that tends to accumulate in water solutions. In this research, the removal of mercury from an aqueous solution was evaluated by using palm leaves. Experiments were performed to study the adsorption efficiency, the effect of the adsorbent amount, the balance time, the adsorbate concentration, and the pH on mercury removal. The experimental apparatus used was a batch stirred reactor (volume: 1m3). The study was conducted under almost isothermal conditions. The test results showed that the optimum adsorbate concentration was 2 g/l, the balance time was three hours, the optimum adsorbent concentration was 15 mg/l, and the pH was 6. The maximum efficiency obtained was 99.24%. The chemical compounds with the highest presence in the palm leaves were LoI (93.76%), and SiO2 (4.1%), whereas the compound with the lowest presence was Na2O (0.08%). The mercury removal efficiency increased with an increase in the adsorbent dose and the contact time, and reduced with an increase in the initial mercury concentration. The Freundlich model, using the variables provided in the study, predicted the change in the adsorption kinetics.
    Keywords: Palm leaves, Adsorption, Mercury, Isotherm
  • Saeid Fallahizadeh*, Bahador Neamati, Abdalmajid Fadaei, Nezamaddin Mengelizadeh Pages 108-113
    This work assesses the efficiency of integrated enhanced coagulation and direct filtration processes for the removal of color, turbidity, and natural organic matter (NOM) from surface water. The processes were conducted in a simulated pilot. The operating conditions of the treatment process, including pH, FeCl3 dose, and influent flow, were investigated. Following that, its efficiency was evaluated by measuring specific water quality parameters in the output stream including NOM, turbidity, and color. The results showed that under optimum conditions (pH, FeCl3 dose, and influent flow of 6.2, 95 L/h, and 40 mg/l, respectively), the color and turbidity were removed 96% and 95% respectively. According to factors analysis by the Taguchi method, the influence of these factors on the removal of pollutants decreased as follows: pH → FeCl3 dose → influent flow. The results revealed that the integrated enhanced coagulation process and direct filtration can improve the efficiency of colors, turbidity, and NOM removal in water treatment plants.
    Keywords: Enhanced coagulation, Color, NOM, Turbidity, FeCl3
  • Fariba Mohsenzadeh*, Sanaz Safaie Pages 114-122
    Discharging industrial wastes into the soil causes accumulation of pollutants, especially petroleum hydrocarbons and used engine oil, in the environment. This study was done to find some bacterial strains capable of removing the engine oil from contaminated soils. Soil samples contaminated by engine oil were collected from some polluted area of Hamadan City, and then their bacterial strains were isolated and classified on the basis of morphological keys and biochemical tests. The efficiency of these bacterial strains in removing the pollutant was evaluated in minimal salt medium (MSM) containing 1% engine oil. The optical density (OD) of the media was measured as an indicator of bacterial growth and degradation of the engine oil during day 0, 5, 10, and 15 at 600 nm wavelength. The bacterial strain responsible for the highest OD was chosen as the effective one, and the efficiency of oil removing was evaluated for this bacterial strain. In this study, eight bacterial strains called EODB1-8 were isolated. The results of the OD determination showed that the four bacterial strains caused more turbidity in the samples. The effects of time, type of bacteria, and their interaction effects were also significant in all samples. The turbidity of the samples was increased with increasing exposure time. The maximum turbidity was caused by the bacterial strain EODB4 and it was introduced as the best engine oil degrading bacterial strain. Its engine oil removal efficiency was evaluated to be 62.85% and it was identified as Pseudomonas alcaligenes using morphological keys and biochemical identification methods.
    Keywords: Bioremediation, Engine oil, Pseudomonas alcaligenes, Soil pollution