Sharif Digital Repository

The aim of this study was to investigate the possible reduction of air and noise pollution due to the substituent of motorcycles and personal vehicles with bicycles by the theoretical phase and to compare the exposure of a cyclist to noise pollution in using different modes of transportation in the field phase. In the theoretical phase, different scenarios were designed based on a 25% and 50% reduction in the volume of motorcycles and personal vehicles separately, as well as a simultaneous reduction of 50% for motorcycles and personal vehicles. The effect of running these scenarios on reducing air pollution was investigated using emission inventory model and on noise pollution by CadnaA... 

In this paper, controlling microbial degradation of water based metalworking system fluid, emulsion oil, is investigated using glutaraldehyde as biocide. Microbial population was determined through colony counting method. Evaluation and results demonstrate that a 15 day treatment by glutaraldehyde results in higher resistance to microbial deterioration. Analysis of variance through multiple comparison tests was conducted and Least Significant Difference (LSD) was determined. An overall observed paired difference between the first and second treatment is significant; therefore, the first treatment, with an addition of glutaraldehyde every 15 days is suggested  

Hydrocarbon contaminations due to their volatility, solubility and biodegradability properties can enter the vadose zone and adversely influence the soil properties. Recently, some deep and superficial signs of oil pollution have emerged in the soils around the refinery of Sarkhoun. In order to assess the exact type and behavior of pollutants, evaluate the environmental attributes and measure some important factors of oil contamination in this region, and also to see how pollution transfer in the underground environment, this study has been done. Materials & methods Sarkhoun refinery is located 50 kilometers away from ar Abbas in the northeast direction. The area is mostly composed of Marne... 

The city of Tehran, the capital of Iran, has been facing severe air quality problems. The air quality of Tehran has been stated as unhealthy over one-third of year during the last two decades. According to the last emission inventory of Tehran for the base year of 2013 mobile sources contribute by about 6, 46, 98, 87, and 70% of total primary SOx, NOx, CO, VOC and PM emission. A number of policies have been implemented in Tehran during the last two decades to tackle the air quality issue. Concentrated mostly on transportation sector, these policies aimed to improve fuel quality and emission performance of vehicles. Nevertheless, there is no quantified evaluation regarding the effectiveness... 

Air pollution in urban centers has become a key public concern around the world. Apart from its adverse health effects, air pollution could impact less visible outcomes like cognitive performance. Standardized tests are a fixture of all education settings that are susceptible to pollution shocks because they require high cognitive function. Given that test scores are widely used as signals by parents, employers, and education institutions, pollution shocks could render tests unfair and unreliable. In this paper, we combine pollution data with test scores from a large testing institution in Iran between 2012 and 2017 to quantify the impact of short-term exposure to air pollution on test... 

Heterogeneous photocatalytic reactions have experienced many efforts in developing new materials to tackle environmental and energy crises through utilizing appropriate photocatalysts in wastewater treatment, H2 generation, organic transformations, CO2 reduction, N2 photofixation, and biomass conversion. While these processes are addressed in the literature separately, a recent innovative viewpoint is to employ a photocatalytic system to achieve simultaneously two or more functions. The challenging point is that the combination of two functions in one photocatalytic system requires a novel design and engineering of an appropriate semiconductor photocatalyst with special characteristics for... 

Chlorobenzoic acids (CBAs) are recalcitrant and toxic materials which enter the environment directly using pesticides and herbicides, or indirectly through the biodegradation of polychlorinated biphenyl (PCB) compounds. In the conducted study, biodegradation of 4-chlrobenzoic acid was investigated by Lysinibacillus macrolides DSM54T, which had previously been isolated from PCB-polluted soils. Environmental factors including pH, temperature, 4-CBA concentration and inoculation percentage were optimized using response surface methodology (RSM). 58 experiments were designed according to Historical Data, because of the arbitrary selection of experiments, and the combined effects of the... 

A model to predict air pollutants' concentrations was developed by implementing spectral decomposition of time series data, obtained by Kolmogorov-Zurbenko filter, in Artificial Neural Networks (ANN). This model was utilized to separate and individually predict three spectral components of air pollutants' time series of short, seasonal, and long-term. The best set of input variable was selected by evaluating the significance of different input variables while modeling different time series components. Moreover, different possible approaches for constructing such models were examined. Performance of the constructed model to predict air pollutants' level at a central location in Tehran, Iran,... 

Urban transportation is one of the main sources of air pollution in mega cities, and urban job related trips can effectively influence the state of air quality. Tehran, the capital of Iran, with a population of 7.3 million, was selected for this study. The present model is designed to investigate the effect on traffic of the business working hours of different occupations and, as a result, on the status of air pollution. Daily job, non-job and recreational trips using the present vehicle fleet is a major factor affecting air pollution in Tehran. In the context of the present study, the necessary information was utilized to define some relations between job trips and pollutant emissions. The... 

In the present research work, an environmental policy procedure for setting a cap on emissions, as a crucial step in any total emission control system, has been provided and evaluated. It is shown that general regulations on emission intensities and rates do not guarantee that ambient air quality standards are met in intense industrial zones. Local emission limits are necessary to meet ambient air quality standards in these zones. To that end, we used dispersion simulators to back-calculate pollutant concentration thresholds for a large and intense energy system in the Assaluyeh region of southern Iran. Verified modeling results indicate 218 d of pollutant concentration threshold exceedance... 

Network pricing is an effective transportation demand management scheme to reduce traffic and control air pollution, particularly in CBDs. In this study, congested area cordon entry and Park-and-Ride (P/R) facility use are priced for automobiles. Increase in these prices may reduce private auto demand by impelling some of the auto passengers to use public transport from the origin of their trips, or encouraging them to park their cars at the P/R facilities and use buses, or pay the entrance fee and drive inside the cordon. A Markov decision process has been devised to find an optimal policy for pricing the P/R facilities and cordon entry in a city within a variable demand context. This... 

Tehran with a population of 8.2 million urban residents, suffers from rapid urbanization in recent years resulting in severe air pollution. The aim of this study is to develop a high resolution emission inventory of primary air pollutants for Tehran. Tehran pollution sources are classified into two major categories. Mobile sources, including vehicles such as passenger car, taxi, motorcycle, pickup, minibus, bus and truck, and stationary sources; consisting of industries, general service and household, energy conversion, terminals and gas stations. The emission of SOx, NOx, CO, VOCs and PM in the year of 2013 were estimated as 37.411 kt, 85.524 kt, 506.690 kt, 83.640 kt and 8.496 kt,... 

The goal of this work is separation and recovery of catalyst residue in wastewater and byproducts of PTA (poly terephetalic acid) unit. Catalyst recovery consists in separating the maximum amount of catalyst and changing the same into valuable compounds. The PTA unit uses cobalt catalyst for oxidation reactions. The byproducts, which contain catalyst, were burned. In the case of metal oxide recovery in the ashes of waste materials, we could solve the problem of the Petrochemical Company. This new method may help us to recover catalyst from wastewater in PTA unit, after which small amounts of ions may be absorbed on a column filled with special absorbent, in such a way that the wastewater... 

Economic development and population growth in Tehran has increased demand for goods movement and road transportation. This trend has increased mobile source emissions and citizens’ exposure, imposing severe health risks. We used the framework of Land-Use Regression models to quantify the effect of real-time traffic, within buffer distance, on hourly exposure of CO, NO2, and PM2.5. Effect of residential, industrial, and governmental land-use in addition to the effect of pollution sources, such as construction sites and airport were assessed on air pollution. Meteorological variables were also employed to adjust between day variations. R-squared of the models were 38, 27, and 38% for CO, NO2,... 

Mixture of sandy soil and bentonite clay can be used to seal the sanitary landfills and prevent the spread of leachate. Over time, this mixture may be subjected to different landfill contaminants, including acidic pollutants and shear strength variations. The objective of this research was to study the effects of sulphuric acid pollutant with pH values of 7, 3 and 1 on the shear behaviour and strength of clean sand and sand mixed with bentonite clay using common consolidated undrained triaxial tests. The tests results showed that the presence of acid in the soil pore water changes the shear behaviour pattern of the soil. Acid pollutant decreases the clean sand shear strength. In... 

Vegetation acts as a momentum and thermal sink, affecting the mixing of species and temperature-dependent constants of reaction rates. Numerical simulations were performed to investigate the effects of vegetation on the dispersion of reactive pollutants using a computational fluid dynamic (CFD) model coupled with NO-NO2-O3 photochemistry. Moreover, characteristics of temperature and flow fields were analyzed for different aspect ratios and leaf area densities. The results showed that flow is reversed in the presence of trees, and it enhances as leaf area density (LAD) increases; additionally, vegetation creates downward and vortex flows. The results also revealed that the dispersion of... 

Environmental degradation due to economic activities is a key challenge facing sustainable development. The fossil fuel production sector is a very polluting industry. In this research, the future trends of pollution accumulation in the region due to direct/indirect oily discharge into the semi-enclosed area of the Persian Gulf are studied. The purpose of the study was not only to alert policy-makers about potential future threats in the region but also to conduct a trial to develop potential solutions to these problems. Four different environmental cases were studied via the principle of system dynamic modeling simulation. The cases consisted of three situations: relaxed, simple policy, and... 

Noise population is one of the most important environmental pollution cases that cause some troubles for inhabitants and employees in city limit and it is seriously considered as a hygienic risky case and even immunity in the world (Abaspour, 1992).The population of khoramabad city as Lorestan state capital has been 305590, on the basis of population estimate in 2003. It has three-city area and it is located at north-southern corridor of country (management and planning organization of Lorestan province 2004).The matter lead to great bulk of jam that pass through the passageway and linking line that cross through khoramabad city and caused diffusion of many kinds of pollution specially noise...