فهرست مطالب

  • Volume:7 Issue: 4, 2018
  • تاریخ انتشار: 1397/09/02
  • تعداد عناوین: 8
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  • Abdollah Dargahi , Mohammadreza Samaghandi*, Yaser Vaziri , Ghobad Ahmadidoost Pages 242-250
    Background & Aims of the Study: Discharge of industrial wastewater to the environment has harmful effects. Textile industry is one of the industries that burdens pollutants to the environment. So the wastewater of these industries must be treated before discharging into the environment. Various methods for removing industrial pollutants have been investigated. Among them, AOPs have attracted much attention due to their ease of use, economic efficiency, and high performance. Therefore, the purpose of this study was to investigate the photocatalytic role of ZnO nanoparticles coated on activated carbon made from mango seed as an advanced oxidation process in removal of Acid Black 1 from aqueous solutions.
    Materials & Methods
    This experimental research was performed in a 1000 cc batch reactor. In this process, effect of initial pH (3-9), initial dose of Acid Black (20-200 mg/L), modified photocatalyst concentration (20-100 mg/L) and reaction time (5-30 min) were investigated. The reactor contained of a 55-watt low-pressure mercury lamp inside a steel chamber.
    Results
    The results showed that in this reserch the max removal efficiency of Acid Black 1 at pH=3, contact time of 30 min, initial dose of “Acid Black 1” 100 mg/L and modified photocatalyst dose of 0.1 g/L, was equal to 95%.
    Conclusion
    This process had a high efficiency for Acid Black 1 Removal and it can be used to reduce the dye concentrations in textile wastewater before final discharge to the environment. Due to the lack of sludge and waste production, this environmental friendly process showed a remarkable potential for the purification of industrial effluents.
    Keywords: Photocatalytic Degradation, Acid Black 1, Synthetic Activated Carbon, Zinc Oxide, Aqueous Solutions, Iran
  • Samar Mortazavi * Pages 251-263
    Background & Aims of the Study: The present research aims to use sediment quality indices in the assessment of toxicity and ecological risk factors of heavy metals Pb, Cu and Zn in Anzali, Meighan, Shadegan and Hashilan wetlands. Material & Methods: Given the environmental conditions, surface sediments in 71 diverse stations were sampled in three replications. Having preparation and subjected to acid digestion of sediment samples, 0.5 g of each sample was digested with a mixture of nitric acid and super-pure ratio of 4 to 1 perchloric acid. Finally the concentration of these metals was determined using the contrAA 700 Analytic Jena Atomic absorption spectroscopy.
    Results
    The results of the potential acute toxicity and the ecological risk of the considered metals indicated low toxicity and risk. Also, the outcomes of Modified Hazard Quotient (mHQ) indicated a low to moderate pollution risk in Anzali wetland, very low pollution in Shadegan wetland, and in Meighan wetland for Pb and Cu, low pollution to very low and for Zn metal it showed low to high pollution. In Hashilan wetland Modified Hazard Quotient for Pb and Zn showed very low pollution and for Cu it was negligible to moderate among others.
    Conclusion
    However, the growth of urbanization and the increase of various anthropogenic activities such as agriculture, urban, industrial ... within the wetland basin (draining area) and entry of untreated urban and rural sewage requires urgently continuous monitoring of wetlands as well as the assessment of their health risks and ecological risk among others.
    Keywords: Heavy Metals, Sediment Quality Index, Ecological Risk, Acute Toxicity, Wetland, Iran
  • Elaheh Asadi, Ghalhari , Mahdi Asadi, Ghalhari , Mohsen Zargar * Pages 264-272
    Background and objective
    Tetracyclines are the second most used group of antibiotics in the world. This type of antibiotic has a weak attraction in the body and enters wastewater through urine and feces. This study investigated the effectiveness of tetracycline removal from wastewater by air-cathode microbial fuel cells.
    Materials and methods
    The current study was bench-scale experimental research as a batch mode. The anode was made of flat graphite and the air cathode was a carbon cloth with four PTFE diffusion layers with platinum cover (0.3 mg/cm2). Two similar reactors were used. The influent wastewater (500 mg/L) was injected into two reactors (one with tetracycline and the other without tetracycline). Both reactors were used in a batch mode with 1000 Ohm external impedance in 25±2 Cº via artificial wastewater.
    Results
    The results of the study showed that the voltage production time in the tetracycline reactor was considerably longer than the tetracycline-free reactor. The amount of COD reduction was almost similar in both reactors. Although the effectiveness of COD reduction was similar in both reactors, because the operation time for the tetracycline reactor was longer, the rate of COD removal was considerably higher in the tetracycline-free reactor.
    Conclusion
    The air-cathode microbial fuel cell reactor could remove about 50% of tetracycline antibiotic from the wastewater.
    Keywords: Tetracycline, Antibiotic, Air-cathode, Microbial Fuel Cell, Wastewater treatment, Iran
  • Mohammad Khandan , Somayeh Momenyan , Zhaleh Abbaspour , Alireza Koohpaei * Pages 273-281
    Background & Aims of the Study: Investigating and recognizing effective internal factors of organizations has always been one of the concerns in pursuit of organizational goals and to raise level of personnel’s safety, welfare and job performance. This study was aimed to evaluate psychometric characteristics of Organizational Diagnosis Questionnaire (ODQ) in small-scale industries in Hamedan province in Iran, 2016.
    Materials and Methods
    This analytical study was conducted among 397 employees who were selected by simple random sampling. The ODQ questionnaire contains 35 questions, which consists of seven factors. A demographic questionnaire and Paterson's job performance questionnaire were used too. Confirmatory factor analysis (CFA), convergent, and face validity, internal reliability, and test-retest were used to analyze data through SPSS V20 and LISREL V8.5.
    Results
    The mean of total questionnaire was 3.1±1.08. Cronbach's alpha was 0.96. Results of CFA supported seven dimensions model. Pearson's analysis also showed a correlation between ODQ’s factors and job performance (p<0.001). Rewards as a motivational factor was inferior to the other factors. However, relationships, supervisory and purposes were acceptable.
    Conclusion
    The Persian version of ODQ is appropriate for assessing internal conditions in Persian language organizations and it was related to job performance.
    Keywords: Macroergonomics, Occupational accidents, Safety, Organizational Diagnosis, Small-scale Industry, Iran
  • Saeed Shams , Mahdi Ghorbanalizadgan*, Saedeh Minoii , Sarallah Shojaei Pages 282-287
    Background & Aims of the Study: In spite remarkable progress in the anti-microbial treatment in the last 60 years and despite all the care in the health system, infectious diseases especially burn wound infection is a major problem and one of the most important causes of morbidity and mortality for burn patients. Certainly, the identification, review and updating of bacterial infections and their antibiotic resistances have an important role in the control, prevention, and correct treatment of burn patients. This study aimed to determine burn wounds and antibiotic resistance in patients hospitalized at the Nekoei Burn Center, Qom, Iran. Material & Methods: A cross-sectional study was performed on patients referred to a Burn Center in Qom, Iran, for a three-year period (from May 2012 to November 2014). After sampling, the identification of the isolates was done by conventional biochemical tests. Disk diffusion method was performed for testing antibiotic resistance according to CLSI guideline.
    Results
    Among a total of 793 patients, 45 patients (19.82%) were positive culture. Pseudomonas aeruginosa was the most dominant microorganism in patients (66%), followed by coagulase-negative staphylococci (16%) and Staphylococcus aureus (12%). In the evaluation of antibiotic resistance, Pseudomonas aeruginosa showed the most resistant to ciprofloxacin (93.3%) and ceftriaxone (86.6%). Among the used antibiotics, meropenem and cephalexin had a better effect than other antibiotics.
    Conclusion
    Based on the obtained results, Pseudomonas aeruginosa was the most isolated common microorganism of burn wounds at our hospital and it seems that treatment of common antibiotics in this center has not enough effectiveness. Thus, it is essential to use effective antibiotics correctly and to prevent the extension of resistant bacteria.
    Keywords: Burn Wound, Infection, Pseudomonas Aeruginosa, Antibiotic Resistance, Iran
  • Reza Moradi*, Amin Ganjali , Ahmad Reza Yari , Mohammad Hassan Mahmoudian Pages 288-294
    Background & Aims of the Study: Pharmaceutical compounds have a variety of forms and applications. Specific amounts of toxic organic compounds in the process of their manufacturing and utilization cause environmental pollution problems. So, degradation and removal these compounds are necessary. The aim of this paper is the study photocatalytic degradation of ciprofloxacin drug in aqueous solution using photo-Fenton process in a batch photoreactor.
    Materials and methods
    This is an experimental study on a laboratory scale. Fe2+ ions as a homogeneous catalyst applied for the degradation of ciprofloxacin in aqueous solution. The study was performed on synthetic wastewaters that contain ciprofloxacin as a pollutant. The effect of operational parameters such as pH, Fe2+ concentration and H2O2 concentration on reaction kinetics were studied and the optimum conditions were determined for the photocatalytic degradation of ciprofloxacin using one factor at the time (OFAT) experimental design method.
    Results
    The optimal conditions were obtained at pH =3, Fe2+ concentration at 35 ppm and H2O2 concentration at 25 ppm. A first order reaction with rate constant (k=0.0291 min−1) was observed for the photocatalytic degradation reaction. The chemical oxygen demand (COD) analysis of the ciprofloxacin under optimum conditions showed 92% reduction COD in a 49 min period.
    Conclusions
    The results showed that the photo-Fenton process can be a suitable alternative method to degradation of pharmaceutical compounds from synthesis wastewaters.
    Keywords: Photo-Fenton process, Ciprofloxacin, Pollutant, Batch reactor, Iran
  • Mohsen Mohammadi galangash*, Pedram Hedayat , Ali Fazlollahi Pages 295-302
    Background & Aims of the Study: Jamalabad district of Lowshan is one of the ancient industrial zones of the country with regard to having Lowshan industrial estate, Shahid Beheshti power plant, and the locality of two cement production factories. Hence, the study of some persistent pollutants such as heavy can be extremely valuable in terms of public health and environmental issues.
    Materials & Methods
    In this survey, 30 samples of surface soils were collected around Lowshan industrial estate and Shahid Beheshti power plant. After sample preparation the specimens were analyzed using ICP-OES. In the next, according to the results of statistical analyzes, Pollution Loading Index (PLI) and Contamination Factor (CF), the qualitative status of the soils in the region was evaluated.
    Results
    The distribution of metals was obtained according to pattern of Si>Pb>V>Co>Ni> Cd, respectively. The mean soil concentrations ranged within 1.33-2.08 for Cd, 32.55-49.33 for Ni, 80.12-124.76 for Pb, 45.51-66.36 for Co, 59.58-106.76 for V and 140.61-304.36 mg/kg for Si. According to the results of PLI, the soil of the area was classified as inappropriate quality.
    Conclusions
    The main components of cobalt, cadmium and nickel were more effective on contamination levels than other metals. According to cluster analysis, these grouping of metals can illustrate the industrial origins of pollutants. Surface soil pollution in the area, demonstrate the long-term effects of various industrial units activities in the industrial estate, power plant activities, and road transport, operation of various mines activities and the existence of cement industries, can also be effective in discharging of pollutants in the region.
    Keywords: Heavy metals, Soil pollution, Jamalabad, Lowshan, Guilan
  • Parvin Sabet Aghlidi , Mehrdad Cheraghi*, Bahareh Lorestani , Soheil Sobhan Ardakani , Hajar Merrikhpour Pages 303-311
    Background & Aims of the Study: The aim of this study is spatial distribution of arsenic (As) under the influence of chemical fertilizers using geostatistics in city of Eghlid, Iran.
    Materials & Methods
    In this descriptive study, spatial distribution of arsenic was randomly investigated in 100 soil samples and its content was measured by ICP-OES. Spatial distribution of As and geostatistics were studied by ArcGIS software. Data distribution normality was performed by Kolmogorov-Smirnov test; and then Pearson correlation coefficient was used for correlation analysis.
    Results
    The mean concentration of As was 1.85 mg/kg in the studied area and its change range was 2.08 mg/kg with the minimum and maximum concentration of 0.90 and 2.98 mg/kg respectively. Since the mean concentration of this element was estimated equal to 5 mg/kg in the world's soil, the mean concentration of As was lower than its global value and higher than the qualitative standard in the studied area. Also, the correlation of As with lead (Pb) was 0.406 which was significant at the level of 99%. Therefore, lead was used as the auxiliary data for As zoning. The results of the geostatistics, cokriging method showed that the highest precision due to the lower error of RMSE and RMSS (RMSE = 0.001, RMSS = 1.052), and thus map of spatial distribution of As was provided on this basis.
    Conclusions
    Results indicated that the dense agricultural soils located in the center of studied area had the highest concentration of As, but the northwestern poor agricultural soils had the highest concentration of As in studied area.
    Keywords: Cokriging, Geostatistics, Agricultural fertilizers, Arsenic, Eqlid, Iran