Impact of international lobby groups on international environmental agreements

Environmental Economics and Policy Studies - Economists have long argued over the political economy of tradable emission permits, especially the political pressure of lobby groups on international...     

Simultaneous Cr (VI) reduction and diazinon oxidation with organometallic sludge formation under photolysis: kinetics,degradation pathways,and mechanism

Environmental Science and Pollution Research - In this study, simultaneous removal of an organic matter (diazinon, DIZ) and an inorganic substance (chromium, Cr) was used. Breaking down of organic...     

A stochastic conflict resolution model for trading pollutant discharge permits in river systems

This paper presents an efficient methodology for developing pollutant discharge permit trading in river systems considering the conflict of interests of involving decision-makers and the stakeholders. In this methodology, a trade-off curve between objectives is developed using a powerful and recently developed multi-objective genetic algorithm technique known as the Nondominated Sorting Genetic Algorithm-II (NSGA-II). The best non-dominated solution on the trade-off curve is defined using the Young conflict resolution theory, which considers the utility functions of decision makers and stakeholders of the system. These utility functions are related to the total treatment cost and a fuzzy risk of violating the water quality standards. The fuzzy risk is evaluated using the Monte Carlo analysis. Finally, an optimization model provides the trading discharge permit policies. The practical utility of the proposed methodology in decision-making is illustrated through a realistic example of the Zarjub River in the northern part of Iran.     

Use of plastic waste (poly-ethylene terephthalate) in asphalt concrete mixture as aggregate replacement.

One of the environmental issues in most regions of Iran is the large number of bottles made from poly-ethylene terephthalate (PET) deposited in domestic wastes and landfills. Due to the high volume of these bottles, more than 1 million m3 landfill space is needed for disposal every year. The purpose of this experimental study was to investigate the possibility of using PET waste in asphalt concrete mixes as aggregate replacement (Plastiphalt) to reduce the environmental effects of PET disposal. For this purpose the mechanical properties of plastiphalt mixes were compared with control samples. This study focused on the parameters of Marshall stability, flow, Marshall quotient (stability-to-flow ratio) and density. The waste PET used in this study was in the form of granules of about 3 mm diameter which would replace (by volume) a portion of the mineral coarse aggregates of an equal size (2.36-4.75 mm). In all prepared mixes the determined 6.6% optimum bitumen content was used. In this investigation, five different percentages of coarse aggregate replacement were used. The results showed that the aggregate replacement of 20% by volume with PET granules would result in a reduction of 2.8% in bulk compacted mix density. The value of flow in the plastiphalt mix was lower than that of the control samples. The results also showed that when PET was used as partial aggregate replacement, the corresponding Marshall stability and Marshall quotient were almost the same as for the control samples. According to most of specification requirement, these results introduce an asphalt mix that has properties that makes it suitable for practical use and furthermore, the recycling of PET for asphalt concrete roads helps alleviate an environmental problem and saves energy.     

Evaluation of workers' exposure to methylene diphenyl diisocyanate (MDI) in an automobile manufacturing company, Iran.

Evaluation of personal inhalation exposure to methylene diphenyl diisocyanate (MDI) among 39 employees, working in the window fixation and window glue processes in an automobile manufacturing company was performed. This study was conducted for both case and control groups. After sampling and sample preparation processes, MDI was determined with a UV-VIS spectrophotometer at 590 nm; the lung function was assessed with a digital spirometer, too. The average concentration of MDI in the window fixation, and window glue workplaces were 34.53 and 27.37 micro g/m3, respectively, which was lower than the threshold limit value (TLV) recommended by the American Conference of Governmental Industrial Hygienists (ACGIH) (51 micro g/m3). Respiratory symptoms in the exposed group were significantly different compared to the unexposed group (p < .05). Lung capacities in the case group were lower than in the control group (p < .05). Therefore, MDI can be easily measured making it possible to evaluate the adverse effects caused by occupational exposure.     

Discovering and characterizing farm households’ resilience under water scarcity

Water scarcity at an alarming rate has been a limiting factor for sustainable agriculture in arid and semi-arid environments of the world. It has resulted in a number of problems such as poverty and food insecurity among farm households. Therefore, building and improving resilience, as a way to mitigate the impacts of water scarcity, is important for farm households. But one of the significant steps for planning to improve farm households’ resilience under water scarcity is investigation of the current level of resilience of these households and understanding their variances. Therefore, this study offers a classification of farm households’ diversity based on resilience. Primary data were collected from 260 randomly selected farm households in 21 villages around Parishan wetland, Iran. Farm Household Resilience Scale was used to measure resilience. Cluster analysis suggested three groups: highly, medium-, and low-resilient farm households. The results of comparing three groups revealed that highly resilient farm households characterize with higher risk management, more agricultural water security, more positive psychological traits, and better knowledge management. Also, they had better water quality, attended more agricultural extension activities, and used modern irrigation systems. Farm households’ resilience map using GIS software illustrated that there is a relationship between resilience and farm location from the wetland. The findings of this study could be used by planner and policy-makers to improve farm households’ resilience in arid and semi-arid environments. Improvement in knowledge management system is recommended as one of the most effective policy instruments in building resilience.     

A comprehensive systematic review of photocatalytic degradation of pesticides using nano TiO2

Environmental Science and Pollution Research - This study has systematically reviewed all of the research articles about the photocatalytic degradation of pesticides using titanium dioxide (TiO2)...     

Comparative cancer risk assessment of THMs in drinking water from well water sources and surface water sources

This research evaluates the lifetime cancer risks from trihalomethanes in Tehran's drinking water. The Trihalomethanes were measured in seven different water districts. Sixty-three samples were taken from tap water across the city for 7 months. The samples were analyzed for trihalomethanes using US EPA method 524.2. The average concentration of total trihalomethanes in different districts were between 0.81 and 9.0 μg/L, and the highest concentrations were detected in district 2 at 19.5 μg/L. Total lifetime cancer risks assessment from exposure to trihalomethanes in drinking water (ingestion, inhalation, and skin routes) were performed for people living in different districts in Tehran. The lifetime cancer risk was 7.19 × 10(-5) in district 2 (a more affluent neighborhood) where mostly surface water sources is used to supply drinking water and 9.38 × 10(-6) in district 7 (a less affluent neighborhood) which is mainly supplied with well water sources. Based on the population data, the total expected lifetime cancer cases from exposure to trihalomethanes are 104, 108, 81, 81, 41, 27, and three for districts 1 through 7, respectively. The average lifetime cancer risk was 4.33 × 10(-5) which means a total of 606 lifetime cancer cases for the entire province of Tehran. The highest risk from THMs seems to be from the inhalation route followed by ingestion and dermal contacts.     

Examination of the operator and compensator tank role in urban wastewater treatment using activated sludge method

No doubt, operator is one of the main fundaments in wastewater treatment plants. By identifying the inadequacies, the operator could be considered as an important key in treatment plant. Several methods are used for wastewater treatment that requires spending a lot of cost. However, all investments of treatment facilities are useable when the expected efficiency of the treatment plant was obtained. Using experienced operator, this goal is more easily accessible. In this research, the wastewater of an urban community contaminated with moderated, diluted and highly concentrated pollution has been treated using surface and deep aeration treatment method. Sampling of these pilots was performed during winter 2008 to summer 2009. The results indicate that all analyzed parameters were eliminated using activated sludge and surface aeration methods. However, in activated sludge and deep aeration methods in combination with suitable function of operator, more pollutants could be eliminated. Hence, existence of operator in wastewater treatment plants is the basic principle to achieve considered efficiency. Wastewater treatment system is not intelligent itself and that is the operator who can organize even an inefficient system by its continuous presence. The converse of this fact is also real. Despite the various units and appropriate design of wastewater treatment plant, without an operator, the studied process cannot be expected highly efficient. In places frequently affected by the shock of organic and hydraulic loads, the compensator tank is important to offset the wastewater treatment process. Finally, in regard to microbial parameters, existence of disinfection unit is very useful.