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Background and Objective: In recent years, management and disposal of municipal solid waste has become a global problem and the most important environmental concern. Anaerobic digestion is a cost-effective solution for treatment of both solid waste and wastewater. The aim of this study was to investigate the positive or negative effects of calcium chloride content in anaerobic digestion process of municipal solid waste and leachate on biogas production. Materials and Methods: Experiments with 8 levels of calcium chloride on co-digestion of municipal solid waste and leachate were investigated in 500 ml digesters under mesophilic conditions in a completely randomized design with three replications. Reactors with a ratio of substrate to inoculum of 2 (on VS basis) were operated and the volume of the biogas was measured daily. Volatile and total solids, carbon/nitrogen of waste, COD, BOD and heavy metals were measured by following APHA. Results: The results of the experiment showed that the pH was decreased with increasing calcium chloride concentration. The highest amount of cumulative biogas production was obtained in CaCl2 of 2 g/L with the highest VS and TS reduction. Higher concentrations of CaCl2 (≥3 g/L) caused a reduction in the degradability of volatile and total solids and, as a result, a decreased performance of the digester. Conclusion: The results clearly confirmed that the addition of calcium chloride was an effective solution to improve biodegradability in co-digestion of the MSW and leachate and consequently to reduce the total and volatile solids and to increase the amount of‌ biogas.

Background and Objectives: Cadmium can enter water resources through the industrial wastewater. It could cause intensivly damages to the liver and kidney of humans. Magnetic iron nanoparticles are used to control and eliminate heavy metals from industrial effluents through the mechanisms of adsorption, ion exchange and electrostatic forces. The aim of this study was to evaluate the efficiency of magnetic nanoparticles for adsorption of cadmium. Methods: The magnetite nanoparticles were prepared by co-precipitation method through the addition of bivalent and trivalent iron chloride under alkaline conditions. Characteristics of nanoparticles including particles structure, composition and size were determined using analytical devices such as XRD, SEM, and FT-IR. For optimization of adsorption process of cadmium, some parameters such as pH, contact time, initial concentration of cadmium, nanoparticles concentration, and temperature were studied under different conditions. Results: It was found that 95% of cadmium could be removedAt pH ≥ 5.6, 10 mg/L initial cadmium concentration, a dose of 1 mg synthesized magnetite nanoparticles, 10 minutes contact time, and 200 rpm mixing rate at 25 °C. The isotherm of adsorption follows the Langmuir model (R2 < 0.995). Maximum capacity of cadmium adsorption was found to be 20.41 mg/g. Conclusion: Magnetite nanoparticles exhibit high capability for removal of cadmium. The nanoparticles synthesized could be used at industrial scale because of having the magnetic property, which make them easily recovered from aqueous solution through applying a magnetic field.

Background and aims: Inappropriate solid waste management industry in recent years has created a lot of risks. As a result, the health, safety and the humans environment is at risk for it. main objective of this study is solid waste management assessment of 10 large food industries in Tehran. Methods: This study is descriptive and sectional based on field visits, questionnaires, preparation of the database and the analysis of the results. The selected units were categorized based on ISWMI scale. The questionnaire consisted of 47 questions related with key elements of industrial solid waste management. This questions consist of 10 separate areas. 10 large industrial units of the food industry in Tehran were randomly selected. Results: The results showed that the index of selected industrial units based on ISWMI scale (based on100) is: 96 for J company (very good), 49 for A company (week), 85 for H and I company (very good), 72 for E, 77 for F and 80 for G (good), 57 for B, 63 for C and 64 for D company (moderate). Conclusion: According to the results of this study, industrial waste management situation in most of the selected units are above average. However it seems that factors such as a lack of senior management commitment and belief to implementation of the waste management system, the lack of requirement industrial units to employ an expert in environmental or environmental health and the lack of a comprehensive at the national level plan for waste management of the most effective factors to determine ISWMI values in industries.

Introduction and purpose: Groundwaters provide the main source of drinking water in Mazandaran province; however, the high concentration of soluble salts and hardness in these waters result in probable sedimentation and corrosion in water distribution systems of these areas. Therefore, the aim of this study was to determine the sedimentation and corrosion potential in the drinking water resources in Amol, Babol, Ghaemshahr, Sari, and Neka in the second and first halves of 2015 and 2016, respectively. Methods: A total of 192 water samples from selected cities of Mazandaran province were tested using determining parameters of sedimentation and corrosion indices by a standard method. The indices, such as Langelier saturation, Ryznar stability, Puckorius scaling, Aggressive, and Larson-Skold were determined using relevant data. Results: The results of the study showed that out of 192 analyzed samples in the surveyed cities, 76 and 81.3 % of them had the sedimentation propertiesand potentials considering Ryznar stability and Langelier saturation indices, respectively. With regard to Puckorius scaling index, sedimentation potential was observed in 68.8 % of water samples. Aggressive and Larson-Skold indices have also showed sedimentation properties of water. Conclusion: It can be concluded that the drinking water in the water distribution systems of these cities has relatively sedimentation properties.

Background and aims: Fossil fuels Emission and their limited resources make to use renewable energy with more sustainable energy sources and less minimal environmental impacts. One of the most appropriate renewable energies considered lots of advantages including being renewable and environmentally friendly and containing social and economical interests, is Biomass. “Biomass” means a power source that is comprised of, but not limited to, combustible residues or gases from forest products manufacturing, waste, byproducts, or products from agricultural and orchard crops, waste or co-products products from livestock and poultry operations, waste or byproducts from and food processing, urban wood waste, municipal solid waste, municipal liquid waste treatment operations, and landfill gas. Due to the wide availability of biomass worldwide, mainly because it can be obtained as a by-product of many industrial and agricultural processes, biomass represents a growing renewable energy source with high growth potential. Biomass helps reduce the amount of GHG that give more impact to global warming and climate change. The biomass emissions level is far smaller compared to fossil fuels. The basic difference between biomass and fossil fuels when it comes to amount of carbon emissions is: all the CO2 which has been absorbed by plant for its growth is going back in the atmosphere during its burning for the production of biomass energy. While the CO2 produced from fossil fuels is going to atmosphere where it increases greenhouse effect. Another great advantage of biomass energy is that it is an indigenous fuel. The fuels from biomass materials can be produced locally and no high technology is required. Producing fuel from biomass materials reduces the dependence of a country on foreign resources for their fuel requirements. Moreover, since this indigenous fuel is labor intensive, it can contribute to the generation of new jobs, particularly in rural and farming communities. The number of employed workers required is 3-6 times greater than the fossil energy production in the associated processes. This study was aimed to identification and green grading of environmental management in that’s jobs. Some other socio-economic benefits can be counted such as slowing down the migration from the rural areas to cities, decreasing the issues associated with rapid urbanization, and developing a biodiesel production industry. Among its great benefits is the forest use of the territory, which would also serve to clean the forest and thus prevent forest fires, and the ability to generate jobs. Biomass generates continuous employment such as the extraction of raw materials from the countryside and the bush. This study was aimed to identification and green grading of environmental management in that’s jobs. The research questions are: 1. What are green job indicators? and 2. has renewable energy biomass business indicators of green jobs? Methods: This study was qualitative – quantitative, first according to the grounded theory qualitative method semi-deep interviewed with 50 environmental experts in the Environmental Protection Agency, the municipality, faculty members of the universities, the natural resources and watershed management, agriculture ministry and NGOs active in the environment conducted a with purposeful sampling (snowball). Regarding qualitative data validation were used constant data comparison, reviewing the observers and handwriting by participants and use of foreign and expert researchers familiar with qualitative research as an observer. Then, data was analyzed using the grounded theory of open, axial and selective coding analyzed in MAXQDA software. Once coding categories emerge, the next step is to link them together in theoretical models around a central category that hold everything together. In order to explain the grounded theory, green jobs are considered as the central variable, and the main line of research is defined using reminders and diagrams around it, and finally the green indicators derived from it are developed. Based on them, researcher-made questionnaire was designed in a combination, closed response with 5-rate likert scale. In order to determine the validity of the questionnaire, the content validity was used with the lawshe model and with reviewing previous studies was determined, the scope of the questionnaire in greenness of the job, and the reliability of the questionnaire was obtained using Cronbachchr('39')s alpha coefficient for internal consistency. Cronbachchr('39')s alpha value for each research question was more than 0.7, the reliability of the questionnaire was approved. Also, the Cronbachchr('39')s alpha coefficient of the questionnaire was 0.890. In order to estimate the repeatability, the retest method and the ICC index were used that index was 0.996 (p <0.001), indicating its high repeatability. For estimating the results of greenness and its degree in the jobs of renewable energy biomass, were used statistical analysis of Kolmogrov-Smirnov test, single-sample t-test and Friedman test in SPSS software. Result: Findings of the qualitative research on the structure of green job identification and prioritization were discussed in six categories including establishment in accordance with the legal and technological infrastructure of the green job as context, green job as a phenomenon, environmental pollution elimination and the health risks reduction of the community as causal conditions, green management as operational strategies, environmental empowerment of jobs as an intermediary conditions and economic and environmental benefits as a consequence. The results of quantitative to showed that jobs studied are considered green jobs and their green grading are as follows: 1. Maintenance (mean=5/61), 2. System Design (mean=4/83), 3. Training (mean=4/22), 4. Quality Monitoring and Quality (mean=4/03), 5. Collection (mean=3/64), 6. Manufacturer (mean=3/61) and 7. Worker and System Administrator (mean=2/06). According to the results, components of green jobs are defined including: (1. explaining Green Jobs, Productivity of Occupations, 2. environmental Protection and Health, 3. Green potentials and incentives, 4. environmental Standards and Indices of Health and Green Management, 5. environmental and health challenges and solving energy crisis with the help of green jobs, 6. environmental education and green culture, 7.environmental empowerment through a variety of environmental and health education, informing and accompanying NGOs, 8. economic-ecological profitability and the optimistic approach to economic interests (green economy) and impact of economic issues, profitability, financial support, market regulation, and return on investment in the process of greening and green expanding businesses). Results show that green indices of occupations are 1- environmental and health of profile occupational, 2- strengths and weaknesses, threats and opportunities green jobs, 3- green supply chain management of businesses, 4- impact of green jobs on sustainable development and community health, 5- effect of environmental education on the green performance of occupations, the impact of environmental advertising on green performance and 6- reduce employee costs and increase business profits through environmental management. These green jobs literature extols the virtues of generating energy using “wood waste and other byproducts, including agricultural byproducts, ethanol, paper pellets, used railroad ties, sludge wood, solid byproducts, and old utility poles. Several waste products are also used in biomass, including landfill gas, digester gas, municipal solid waste, and methane. Conclusion: The green features of the biomass business are included solving the problem of fossil fuels, caused by fossil energy and renewable energy sources. identification and green grading jobs diversifying energy sources, sustainable development, securing energy, removing environmental and health problems would help to managers and policy makers for identifying and providing executive solutions and identifying multifaceted priorities for green management. Despite the high potential of bio-economy in renewable energy (biomass) and high amounts of raw materials in the agricultural waste and sewage has not been fully realized. To achieve of developing a competitive economy, low-carbon resources with efficient resources, global economic markets have shifted strategy towards renewable energies, so as to create green jobs in order to reduce environmental problems (waste and climate change). For performance of macroeconomic policy in notification Supreme Leader on the restructuring of the countrychr('39')s economic structure has proposed policies to change reducing dependencies on fossil fuels and external resources towards the creation and development of green jobs in the field of renewable energy, especially biomass, because there are a lot of raw materials in the country, especially in the villages and without necessary to high technologies. Biomass development increase energy efficiency, the use of renewable energy resources and the creation of a favourable environment for investment in energy efficiency measures and the generation of ‘green’ jobs. The rural development prospects for green job growth are mixed. Rural areas contain biomass feedstocks which will be increasingly relied upon to offset fossil fuel dependencies. The distribution of those feedstocks, however, is not uniform across rural areas. Furthermore, the technologies to convert those feedstocks into fuels and other uses are yet to be demonstrated at commercially successful scales. Both policy development and research activities should be focused on the efficient utilization of rural natural resources, human capital, and rural infrastructure in achieving national green policies. The green economy appears to be fertile ground for unbiased, academic research to examine some of the regional consequences of green jobs growth and green jobs policies, to include an examination of rural opportunities, but going well beyond that dimension to include the integration of statewide and multi-state regional development opportunities as well as consequences. This study was not about raw materials (waste and sewage) to produce renewable energy biomass, and it is possible that this section may also be effective in the creation and development of green jobs, then there may be restrictions on the generalized findings, interpretations, and attributes of the causation of variables. Therefore, it is suggested that future research into this part of the process of producing renewable energy biomass should be considered.

Background and Objectives: Given that no comprehensive studies have yet been conducted on treatment of infectious wastes in hospitals of Qom City, this research was performed with the purpose of investigating the treatment methods used in these hospitals and monitoring the performance of waste elimination devices. Methods: Required information was obtained through in-person visit and observing the current situation, and the variables affecting waste treatment were extracted based on the type of treatment systems, and were collected, and accordingly, biological monitoring tests were designed for the studied hospitals. The data were analyzed using Fisher's exact test. Results: In this study, from 9 active hospitals in Qom Province, only 3 hospitals were equipped with waste treatment system. In hospital A, growth of Bacillus stearothermophilus spore were observed in 6.25% of the samples, while no microbial growth was recorded in hospital B. The initial investment to buy the machine in hospital A was about four times than that of hospital B. Conclusion: The findings of this study showed that treatment device of hospital B is more appropriate compared to the devices of hospital A due to complete destruction of spores, lower cost (for purchase), and maintenance. .

Background and Aim: Among the medical wastes, dental wastes have a high diversity and due to its high contents of hazardous, toxic, and pathogenic agents, therefore these wastes are of great importance. The aim of this study was to investigate and analyze the amount of waste produced in dentistry offices in Birjand. Materials and Methods: In this descriptive cross-sectional study, 48 dental offices in the city of Birjand were studied. Sampling was carried out by environmental health experts in three consecutive working days (Monday, Tuesday, and Wednesday) from every center. The Samples were divided into 5 categories such as semi-domestic, infectious, chemical-pharmaceutical, toxic and sharp material, Separated and weighed using a laboratory scale. Information was expressed as percentage by weight. Results: Based on the results, the total amount of waste produced in dental offices in Birjand was 7848.02 kg / year. percentages of semi-domestic, infectious, chemical-pharmaceutical, sharp material, and toxic wastes were 54.3%, 29.7%, 11.8%, 3.9% and 0.11% respectively. Conclusion: Considering the high volume of dental waste, especially infectious and hazardous materials, the need for separation and recycling in the office is evident. It is necessary to manage the wastes and their separation and recycling in source place.

The energy management of ships to improve the efficiency of ships and reduce greenhouse gas emissions is among the most important issues that have been considered as a milestone in designing and constructing of vessels in recent years. The study of energy trends and attention to technological changes and the importance of more stringent environmental standards in recent years have led to a major challenge in relation to air pollution, energy management, and exposure to end-of-life sources of fossil fuels. In recent years, focus on current fuels and technologies in vehicles has led to a major challenge regarding air pollution, greenhouse gas emissions, energy security, and also exposure to exhausting sources of fossil fuels. Now days, Hybrid propulsion systems are one of the solutions that are being followed in many countries to solve this problem. In this paper, after introducing the hybrid system; conceptual design and determination of a suitable hybrid system for vessels have been investigated. Then the calculations and relations dominating the hybrid parallel system of vessel are presented. The modeling is also done using the ADVISOR software run in the Simulink platform of the MATLAB for both conventional and hybrid systems. The results show that parallel hybrid vessel has improved by 7% in total efficiency and 7.1% for consumption. In addition, HC and CO emissions have been decreased by 0.44% and 0.39%, respectively.

Introduction: Identification of degrading microorganisms of toxic materials is regarded as an important step to complete air treatment systems. Effective microorganisms in treatment and elimination of pollutants seems to be different depending on the type of pollutants as well as environmental conditions. Identification of these microorganisms can determine optimum conditions for the system performance and the maximum efficiency can be reached. Moreover, biotechnological methods can strengthen the microorganisms to treat the pollutants. This study aimed to identify the predominant microorganisms at two biotrickiling filters that formaldehyde was used in one and ethanol in another as the sole carbon source. Methods: In this study, two biotrickling filter pilots were made at the laboratory scale. These microorganisms were inoculated and adapted within three months. Then biotrickling filters were studies for a long time. At the end of experiments, biofilm samples were taken from biotrickling filters and predominant microorganisms were identified via microbiology studies. Results: The results of the present study managed to identify such microorganisms as Salmonella Bongori, Pneumonia, Subspecies Pneumonia, Klebsiella Terrigena, etc. at different parts of both biotrickling filters. Conclusion: Microbial species can be widely changed with operating of biotrickling filters at different conditions. Identifying active microorganisms in each biotrickling filter can lead to detecting optimum conditions as well as the risks caused by transfer of the filters' available microorganisms to the human body .

Background and Objective: Water is one of the most valuable environmental factors that has become one of the greatest challenges of human society today. The purpose of this study was to investigate the relationship between religious attitudes toward water saving in high school students in Yazd. Materials and Methods: This cross-sectional descriptive study was conducted in 2018. 600 subjects (300 girls and 300 boys) were selected by random sampling method. The data collection tool was a questionnaire on water saving tendency including 21 questions and Religious attitude questionnaire including 60 questions. The score range for the religious attitude and the tendency to save water was 60-300 and 21-105, respectively. Data were entered into SPSS18 software and analyzed using Chi-square, Pearson correlation coefficient and descriptive statistics. Results: The mean and standard deviation of the religious attitude score and the tendency to save water consumption were 180.11 ± 14.31 and 65.27 ± 10.21, respectively. The religious attitude of students with age and gender, and the tendency toward water saving with gender variables and number of family members was significant (p<0.05). Correlation between religious attitude and tendency to water saving was statistically significant (r=0.69, p=0.01) Conclusion: Considering the positive correlation between religious attitude and tendency towards water saving, efforts to strengthen religious and moral inputs related to water consumption in students can lead to the development of an optimal water consumption attitude in this influential community of a society.