Nowadays, underground water is the main source of drinking water that contamination to organic pollutants such as MTBE is an important issue. One of the suitable methods for these types of pollutants is the advanced oxidation methods. Advanced oxidation processes (AOPs) are involved in the production of highly reactive hydroxyl radicals that oxidize organic matter such as MTBE and even lead to its full mineralization. The use of light in the presence of catalysts is one of the methods of advanced oxidation processes. Photocatalytic methods widely used for a wide range of toxic and none degradable pollutants. Recent advances in the fabrication and characterization of Nano scale materials have extensively developed research into methods for the preparation of highly effective Nano-sized catalysts for the removal of chemical contaminants. This review article discusses the work on the photo catalysis of MTBE in water using different types of photo catalysts.

Background: Gas stations are one of the most well-known risky potentials in cities. Attitude and culture are underlying reasons for unsafe behaviors, which can lead to accidents. This study aimed to evaluate safety culture among workers of gas stations in the city of Zanjan. Methods: In this descriptive analytical study, a valid safety culture questionnaire consisting of five dimensions was used. The study population included all workers in gas stations in the city of Zanjan. The questionnaires were completed, after getting consent from the subjects. Then, the data were introduced into SPSS 9 for analysis. Statistical tests such as t-test, Spearman and Pearson correlation were used with the significance level of 0.95. Results: The studied individuals enjoyed good attitude about safety culture, and the mean safety culture score of them (151.1) was assessed as acceptable. The relationship between work experience (Pvalue=0.015), age of subjects (Pvalue=0.020) with safety culture were significant. Conclusion: The results of this study indicate that training is considered an important dimension among safety culture dimensions.  As the score obtained for this dimension is lower than other dimensions, it can be promoted through different solutions including the organization of briefing classes and installment of safety signs.

Background: This research aims to measure and study spatial changes, and the reason behind the increasing nitrate content in water wells in the Central District of Khodabandeh County in the Zanjan Province. Methods: The nitrate and nitrite content, electrical conductivity, dissolved oxygen, temperature, total hardness and pH were measured at 40 sampling stations in the study area. The obtained features were categorized into four classes by principal component analysis. The kriging and cokriging methods along with electrical conductivity and total hardness covariates were used to study the spatial changes. By using the cross validation method, the linear model for cokriging method with electrical conductivity covariate was selected as the best model for nitrate zoning in ArcGIS 10.2 software. Results: The principal component analysis indicated that nitrate feature was in the same classification as that of electrical conductivity and total hardness. The comparison of surface digital elevation model, geology and land use maps with nitrate zoning indicated that nitrate pollution in the south and south west regions was due to geological content, agricultural activities, and the discharge of human sewage into absorbing wells. Conclusion: The findings of the present research revealed that lowlands with agricultural use had more nitrate content than other uses, and the most important reason could be attributed to the excessive use of nitrate containing chemical fertilizers.  

Background: Although the expansion of innovation in the industry has led to an increase in the fast of works, production and productivity, it has also imposed an increase in the incidence of musculoskeletal disorders. So, the aim of this study was determination the risk level of work posture by REBA and RULA method among workers of assembly line of a cosmetic manufacturing factory. Methods: This study descriptive was carried out among the assembly line workers of a cosmetic manufacturing factory in 2016. Six tasks (including 28 work postures) were selected due to the most risk of inappropriate work posture factor. 18 postures were evaluated by REBA method and 10 postures by RULA method. Results: The results showed that the highest REBA score (score10) in the hair color manufacturing section and the highest RULA score (score 7) related to the oxidant and powder parts. The minimum score obtained by the REBA and RULA method was 5 and 4 (minimum 2 corrective action level), respectively. Conclusion: To prevent musculoskeletal disorders and reduce the staff posture score in pouring materials into the mixer or reservoir of manufacturing hair color, oxidant and powder sections, corrective actions such as the use of a pump system for transferring materials to the reservoir and the use of an footrest to avoid lifting the load to a height above the shoulder are recommended.  

Background: Water pollution is an important environmental problem, undoubtedly, the presence of toxic heavy metals forms the main source of water contamination. Sorption characteristics of polyurethane foams modified with bis (2-ethylhexyl)phosphoric acid (DEHPA) for the removal of zinc, lead and cadmium ions from contaminated solutions were investigated. Methods: Operating variables, such as initial pH of the aqueous solution (1-6), ion concentrations (5-100 mg/l), sorbent dosage (1-8 g) and contact time (0-60 min), were studied. Results: A value of 98 ± 3% of initial amount of studied ions (20 mg/l) was eliminated using 5 g of polyurethane sorbent modified with DEHPA (0.01 M in methanol) at pH 5. The selectivity order for metal ions toward the sorbent is Zn> Pb> Cd. Analysis of the equilibrium sorption data using Langmuir, Freundlich and Temkin models revealed that the Langmuir model was well suited to describe the zinc, lead and cadmium ions sorption. Power function, simple Elovich, pseudo ?rst-order and pseudo second-order kinetics were applied for kinetic study in batch sorption and it was found that experimental data can be suitably described by pseudo second-order model. Conclusion: Removal of studied metal ions from real samples shows that the modified polyurethane foam is useful for the treatment of polluted waters.

Background: Being a cameraman is one of those occupations that expose people to musculoskeletal disorders (MSDs). Therefore, control measures should be taken to protect cameramen’s health. To solve the given problem, a vest was designed for cameramen to prevent MSDs by reducing the pressure and contact stress while carrying the camera on their shoulder. However, the usability of vest had to be considered. The aim of this study was to determine the usability of the proposed vest using the spirometry parameters indicator. Methods: In this experimental study, 120 spirometry experiments were conducted with 40 male volunteer subjects with and without designed vest. Data were analyzed using SPSS-16 with dependent t-test, at 0.05 significance level. Results: Based on the spirometry results, there is a significant difference between Forced Vital Capacity (FVC), Forced Expiratory Volume (FEV1) and heart rate in activity with and without vest (p<0.001). Conclusion: The results suggest that the promising impact of this invention on the health of cameramen makes this domestically designed camera vest a good option for mass production.  

Background: Butter is one of the oldest dairy products known in the world and plays an important role in human nutrition. The aim of this study was evaluating of the microbial quality of traditional   and industrial butter marketed in Zanjan. Methods: In this descriptive cross-sectional study, a total of 29 samples of butter were investigated in 2 groups which 24 samples were of traditionally producedl butter and 5 industrially produced butter samples, randomly collected from the market in Zanjan, Iran. All samples were evaluated for total bacterial count, Staphylococci, coliform, fungi and mold. Results: Fourteen samples of traditional butter had higher coliform load than allowed in standards. Eighteen samples were contaminated with Staphylococcus, and mold was found in 8 samples. Also, fifteen samples were contaminated with Escherichia coli. Among the industrial samples, one was contaminated with Staphylococcus aureus but no contamination by coliform, Escherichia coli and mold and mold was observed. Conclusion: 58.33%, 75%, 33.33% and 62.5% of the traditional butter samples had higher coliform, Staphylococcus, mold and E. coli contamination, respectively than standard limit.  One of the industrial samples was contaminated with Staphylococcus. It is recommended that higher supervision on the production and distribution of these products is applied.  

Background: Providing safe drinking water has critical importance to human societies. The aim of this study was to investigate microbiological quality of drinking water in distribution system of urban and rural regions of Ijroud, in Zanjan province. Methods: In present descriptive study, the microbiological examination of drinking water was conducted in 15 facilities with 401 samples. Transportation and test procedures were according to standard methods for the examination of water and wastewater. Results: Total number of microbial samples were 401 and 66.66% of them were positive for total and fecal coliforms. Also, water of 10 villages were not suitable for drinking with respecting to national standards. In addition, samples of only 5 villages were suitable for human consumption. The range of fecal coliforms in distribution networks samples were from 4 to 75 MPN/100 ml. This study showed that as microbiological aspect, drinking water is not potable in some rural communities. The consumption of drinking water in this distribution networks can threaten the health of consumers, thus, the water supply organizations have to improve operation and maintenance measurements due to prevent the spread of water-borne diseases. Conclusion:This study showed that as microbiological aspect, drinking water is not potable in some rural communities. The consumption of drinking water in this distribution networks can threaten the health of consumers, thus, the water supply organizations have to improve operation and maintenance measurements due to prevent the spread of water-borne diseases.