21 research outputs found
A Comprehensive Review on Risk Factors Affecting the Crash Severity
As a matter of growing machinery life, traffic crashes are considered an inevitable source of injuries and costs around the world. Regarding to increasing traffic accident outcomes, controlling the current status is necessary. In this way, identifying risk factors affecting the crash severity is an essential step toward initiating a convincing solution. The core objective of this study was to categorize the risk factors affecting the severity of crashes. Data needed for this study were gathered through searching Web of Science, Google Scholar, and Science Direct databases using the keywords included fatal and crash, injuries and crash, fatal and traffic accident, and injuries and traffic accident. Based on 83 selected studies for review, factors affecting the crash severity divided into five factors and forty-seven sub-factors. The most prevalent sub-factors were age, sex, safety belts, alcohol and drug use, speed, weather conditions, lighting conditions, time of the day and week, vehicle kind, road condition, collision type and crash location. Many risk factors affect crash severity and determination of the most important ones can be a prelude in reducing the effects. Therefore, the conclusion of this review can assist to traffic safety experts, police and contribute to distinguishing and monitoring the risk factors affecting crash severity transportation agencies
Pesticides Residue in Drinking Groundwater Resources of Rural Areas in the Northwest of Iran
Background:The majority of rural population in Iran depends on groundwater resources for drinking purposes. In recent years, pesticide contamination of limited water resources has become a serious challenge worldwide. This study quantified the pesticides residue in rural groundwater resources in the northwest of Iran.
Methods: A total of 78 groundwater samples were collected in June and September 2011 from all 39 drinking water wells. Liquid-liquid extraction (LLE) followed by Gas Chroma9tography/Mass Spectrometry (GC/MS) was used to determine the selected pesticides.
Results: Detection frequencies of profenofos, malathion, diazinon, endosulfan, trifluralin, deltamethrin, methyl parathion, and fenitrothion were determined with the concentrations exceeded 0.1 μg/L in 2.6, 17.9, 15.4, 10.3, 2.6, 2.6, 7.7, and 44.9% of the samples, respectively. Total pesticides residue was also observed in 26.9% of the samples with concentrations exceeded 0.5 μg/L. Among them, profenofos, malathion and diazinon were detected as the most frequently observed pesticides with the maximum concentrations of 0.542, 0.456 and 0.614 μg/L, respectively.
Conclusion: Higher pesticides residue than European Economic Commission (EEC) guidelines occurred in a number of monitored resources
Optimized coupling of a submerged membrane electro-bioreactor with pre-anaerobic reactors containing anode electrodes for wastewater treatment and fouling reduction
In this paper, the performance of a submerged membrane electro-bioreactor with pre-anaerobic reactors containing anode electrodes (SMEBR+) was compared with that of a membrane bioreactor (MBR) in municipal wastewater treatment. The new design idea of the SMEBR+ was based on applications of direct current (DC) on the anode and cathode electrodes. The pilot study was divided into 2 stages and operated for 48 days. In Stage I, the MBR was continuously operated for 24 days without the application of electrodes. In Stage II, the SMEBR+ was continuously operated for 24 days, while aluminum electrodes and an intermittent DC were working with an operational mode of 2 min ON/4 min OFF at a constant voltage of 1.4 V. The results indicated that membrane fouling was reduced by nearly 22.02% in the SMEBR+ compared to the MBR. The results also showed that the SMEBR+ increased the quality of effluent to the extent that high removals of NH3+-N, PO43−-P, and chemical oxygen demand (COD) were 98%, 76%, and 90%, respectively. This system, in comparison with those proposed in other studies, showed a suitable improvement in biological treatments, considering the high removal of NH3+-N. Therefore, SMEBR+ can be considered as a promising treatment alternative to the conventional MBR
Natural Arsenic Pollution and Hydrochemistry of Drinking Water of an Urban Part of Iran
Natural contamination of surface and groundwater resources with arsenic is a worldwide problem. The present study aimed to investigate and report on the quality of drinking water resources with special focus on arsenic presence in an urban part of Iran. Arsenic concentrations were measured by graphite furnace atomic absorption spectroscopy (GFAAS). In both surface and groundwater samples, arsenic concentrations ranged from 6 - 61 µg/L with an average value of 39 ± 20 µg/L. Concentration of arsenic, which was up to six times greater than guideline values (10 µg/L) indicates the presence of arsenic bearing materials in the geological structure of the region. It was found that the quality of treated surface water produced by the water treatment facility was good in respect to arsenic (9 µg/L) and solid content (EC = µs/cm). However, in drinking water samples of wells, total solids (mean EC = 1580 ± 150 µs/cm), total hardness (mean = 479 + 94 mg/L as CaCO3) and arsenic (mean = 42 + 16 µg/L) were significantly higher. Correspondingly, there was a significant correlation between arsenic concentration and EC, Na+, K+ and Cl- values. The type of water in most of groundwater samples (70%) was determined as HCO3-Na+. Considering the population of the city and probable health effects due to exposure to arsenic through drinking water, comprehensive measures as well as application of arsenic removal processes in water treatment facilities and replacement of contaminated wells with safe wells are required
Performance of on-site Medical waste disinfection equipment in hospitals of Tabriz, Iran
Background: The number of studies available on the performance of on-site medical waste treatment facilities is rare, to date. The aim of this study was to evaluate the performance of onsite medical waste treatment equipment in hospitals of Tabriz, Iran. Methods: A various range of the on-site medical waste disinfection equipment (autoclave, chemical disinfection, hydroclave, and dry thermal treatment) was considered to select 10 out of 22 hospitals in Tabriz to be included in the survey. The apparatus were monitored mechanically, chemically, and biologically for a six months period in all of the selected hospitals. Results: The results of the chemical monitoring (Bowie-Dick tests) indicated that 38.9% of the inspected autoclaves had operational problems in pre-vacuum, air leaks, inadequate steam penetration into the waste, and/or vacuum pump. The biological indicators revealed that about 55.55% of the samples were positive. The most of applied devices were not suitable for treating anatomical, pharmaceutical, cytotoxic, and chemical waste. Conclusion: Although on-site medical waste treating facilities have been installed in all the hospitals, the most of infectious-hazardous medical waste generated in the hospitals were deposited into a municipal solid waste landfill, without enough disinfection. The responsible authorities should stringently inspect and evaluate the operation of on-site medical waste treating equipment. An advanced off-site central facility with multi-treatment and disinfection equipment and enough capacity is recommended as an alternative
