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Aim and Introduction
Today, the environment is considered as one of the most important pillars of sustainable development, and the development of other economic and social sectors depends on its sustainability and proper functioning. Environmental pollution has become one of the main challenges of countries. Environmental health is currently one of the most critical concerns of people and officials round the world. Almost all managers and decision makers believe that this national wealth should be protected not only for the current generation but also for future generations, since the pollutants caused by industries are highly costly and detrimental to health.
Active industries are one of the main sources of environmental pollution. One of the necessary conditions for economic progress and the introduction of extensive structural changes in economic and technological fields is industrialization and industrial development. In the production process, using production inputs whose main source is the environment, in addition to desirable outputs such as consumer goods, undesirable outputs such as environmental pollutants are also produced. If the number of outputs is not controlled and disproportionate, the losses from undesirable outputs will be greater than the benefits of desirable products in such a way that damages to the environment would be irreparable and sustainable development less likely to be achieved.
One of the most important concerns related to industrialization is the effects and environmental consequences of industrial activities. Therefore, achieving the necessary solutions to control such consequences is vitally important. Minerals are essential for human survival, but their extraction and processing are not environmentally friendly practices which contribute to problems such as soil erosion, air and water pollution. On the other hand, mineral sector is one of the largest energy consumers which has active contribution to air pollution and global warming. The main purpose of this study is to investigate the economic effects of Gol Gohar mine in Sirjan. For this purpose, it is intended to determine the type and amount of pollutants released from this complex, and also to determine the amount of the green tax of the complex as a solution to reduce pollution and examine the social welfare resulting from reducing pollution.
Methodology
In this study, the economic effects of environmental pollutants of Gol Gohar Iron Mine in Sirjan (Southeastern Iran), is investigated using the input distance function model from 2001 to 2022. Through calculating the shadow price of pollutants, a criterion for determining the green tax is determined, and then the amount of social cost resulting from the emission of pollutants is calculated.
The shadow price of the undesirable output is the cost that the producer must bear if they plan to reduce the production of the undesirable output. In fact, it can be interpreted as the marginal cost of reducing pollution for each producer. Therefore, the shadow price of the desirable output is considered positive and equal to the market price of that output, but the shadow price of the undesirable output must be estimated to be less than zero.
Findings
The products of Gol Gohar Iron Ore Complex in Sirjan, include granulated iron ore, iron ore concentrate and pelletized in the production process. The most greenhouse gases and air pollutants are related to carbon dioxide (CO2), sulfur oxides (Sox), nitrogen oxides (Nox) and particulate matter (SPM). According to the obtained results, the average shadow price for air pollutants in Gol Gohar complex for CO2, Sox Nox, and SPM was calculated as 11.15, 3,074.5, 5,529.62, and 1,875.62 rials per kilogram respectively. Moreover, the average total social costs resulting from the production of Gol Gohar Sirjan Complex was calculated as 92,710 billion Rials according to the amount of pollution produced over the period.
Discussion and Conclusion
The estimation of environmental costs is actually an introduction to providing solutions for internalizing and reducing environmental costs, using the input distance function model and the shadow price of environmental pollutants in the industrial and mineral complex of Gol Gohar, Sirjan. The title of the largest producer of iron ore in the country was calculated, and the social cost resulting from the emission of pollutants was also evaluated. Finally, in this study, solutions and mechanisms for reducing environmental costs have been proposed.
Considering that the ability to absorb pollutants by the environment is limited, the shadow price of pollutants, which represents their real social cost, should be taken into consideration. The damages should also be determined based on the shadow price of the pollutants. In other words, the amounts of pollutant emission should be calculated and while taking into account the allowed limit of pollutant emission and shadow prices, based on a legal plan, the environmental costs should be reimbursed. Taking such measures would surely require more studies and capable executive management system

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Background: Airborne biological agentsmaterials in hospitals, such as fungal i micro-colonies, play a significant role in life-threatening airborne infections in immunocompromised individuals. Thus, it is crucial to reduce airborne contamination and address the related several of its influencing factors. This study aimeds to evaluate indoor air quality (IAQ) in terms ofrelated to fungal contamination, the fungal genera contaminating the  hospital rooms' air, and several factors that could influence IAQ in hospital rooms.
Materials & Methods: This environmental surveillance study was conducted in two rooms for onea year, andwith 288 air specimens were collected using thean active air sampling method equipped with chloramphenicol-supplemented Sabouraud Ddextrose Aagar. In addition to air samples, tTemperature, relative humidity, and occupants’ number were also recorded. The fFungal colony counts wereas recorded and converted using the Feller table. Furthermore, the fungi were identified based on macroscopic and microscopic characteristics.
Findings: The mean difference of isolated fungi between the twoboth rooms was statistically significant (p< 0.0001). Yeast, Penicillium spp, and Aspergillus spp. were the most predominant fungi. Both rooms hadwere observed to have room temperature and relative humidity above the national recommended levels (above 23 ˚C and 60%). However, the number of oOccupants' number in the room without HEPA filter was significantly correlated with airborne fungal contamination level in the room without a HEPA filter.
Conclusion: The level of airborne fungal contamination wasis significantly higher in the room without a HEPA filter. Yeast, Aspergillus spp., and Penicillium spp. were the most predominant fungi isolated fromin both rooms. Room temperature and relative humidity haddid not effect oninfluence the level of airborne fungal contamination level. The oOccupants' number in the room without a HEPA filter influenced airborne fungal contamination level.

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In present paper, the effect of combined cooling, heating and power generation systems(CCHP) in the reduction of pollutants emission have been investigated and a hotel with 80 rooms in Zahedan have been selected as case study , also gas engine (With part-load operation) as prime mover for design CCHP system. In this work is assumed that sell electricity to grid is possible. At the first phase, optimization for access to maximum reduce Pollutants emission have been done, at the other phase, a multi-criteria function has been introduced and the optimization process, with Percentage of Relative Annual Benefit (PRAB) has been investigated and the results of these two phases, have been compared together. Results show, CCHP systems have a high effect in reduce environmental pollutants emission CO, CO2 and NOx, as the percent reduce pollutants emission is positive in an extensive range of nominal power of gas engine. Also results show for access to maximum reduce pollutants emissions , CO2, CO and NOx, annual benefit as multi-ceritria objective function a gas engine with nominal power 2050kW is needed; in this case in addition to the most annual benefit also have a good effect for reducing Pollutants emission. In the end, the effect of the number of prime mover as designing parameter assessed with increase from one into two and three numbers. Results show increasing prime mover, cause decrease Relative Annual Benefit and pollutants emission.

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Air staging is defined as the supply of inadequate air from the primary stage to the reaction zone, and the completion of the air supply through the next stage or stages. This study is concerned with the optimization of the air staging system of a burner with two air inlets and one fuel (natural gas) inlet with the help of numerical modeling. The equivalence ratio of the primary air (with the assumption of a fixed total air mass flow rate), and the distance between the two air inlets constitute the design variables of the problem. In the previous research works, the air staging technology has been mainly employed as a method to reduce the emission of NO. However, in the current study, in addition to the emission of NO, the emissions of CO and soot, and radiative heat transfer from the flame are considered as the objective functions. The results show that increasing the level of air staging (or the equivalence ratio of the primary air) has contradictory effects on the objective functions so that, as positive influences, it increases the radiative heat transfer from the flame and decreases the emission of NO, and as negative effects, it increases the emission of both CO and soot. The results also indicate that when all the previously mentioned objectives are considered simultaneously, the optimal case, which is selected based on the Pareto front concept, is the case in which the primary air is about 20% of the theoretical air.

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The ecosystem is a fundamental pillar of human life, which has been changed due to the progress and development of the world. The emission of air pollutants is a key factor in environmental degradation. Air pollutants impose the so-called "degradation costs" on different sectors, which these costs are not included in official calculations. Consumption of energy carriers is the main cause of air pollutants emissions in Iran. Therefore, this research seeks to examine the degradation costs of air pollutants emitted by the use of energy carriers in Iran. One way to reduce the emissions of air pollutants and their degradation costs is to impose tax on the consumption of energy carriers. This study considers a scenario for raising the price of energy carriers to the level of FOB price of Persian Gulf. For this purpose, the standard computable general equilibrium model of Lofgren et al () is used. The statistical basis of the CGE model is the 2006 social accounting matrix (SAM). The statistical data on energy consumption and emissions of air pollutants are derived from the energy balance sheets over the period 2006-2012. In addition, economic sectors are divided into 25 sections according to the ISIC classification. Degradation cost in the baseline scenario is equivalent of 14.43% of GDP (at constant prices) in 2006, which by applying the scenario for increasing the price of energy carriers, this cost declines by 23% and amounts to 10 percent of GDP. Results also reveal that the road transportation and electricity sectors experience the greatest reductions in degradation cost.

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Now a days gas turbines are widely used in the transportation and energy industry. According to Combustion of fossil fuels in these engine, environmental concerns have increased due to production of nitrogen oxides and carbon monoxide. Various methods have been offered to reduce the emission of pollutants. One of these methods is adding steam or water to the combustion chamber to reduce the flame temperature. Different methods can be applied to add steam to the combustion chamber, in this study, the steam is added to the diffuser and premixed with air into the combustion chamber. Steam addition influences the combustion process inside the combustion chamber, which should be considered during the combustion chamber design process. Therefore, a model for the conceptual design of the chamber geometry and the effect of adding steam on it will be presented. For this purpose, the data from an actual combustion chamber will be used to compare results of geometry design by using this model and to study the influence of steam on the chamber geometry. To investigate the combustion chamber performance, the chemical reactor network method for combustion modeling will be used. First, with this procedure an annular conventional combustion chamber will be modeled without steam addition and the results of this method will be compared with the actual data of this combustor. Then the effect of adding steam on the performance will be investigated. The study will show adding steam is an effective way to reduce the flame temperature and emission of pollutants.

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Waste heat recovery systems, which make use of waste sources for their input energy, have considerable importance in industry since they utilize streams, which will be disposed to nature if not employed. Ship’s engines are one of the places, where a large amount of energy is wasted in different forms. In the present article, the idea of making use of these loss streams and consequently producing useful power in the outlet is proposed in the form of two systems. In the first system, the only stream of exhaust gases is utilized, while in the second system, the jacket cooling water is used together with the engine exhaust gases. Screening in the working fluids is conducted in order to select appropriate fluids, which have suitable characteristics in the physical, safety, and environmental aspects. The analyses indicate that using R600a presents the highest net power output, which reaches to the value of about 575 kW at the most. Comparison of the two introduced systems shows that preheating the working fluid by the jacket cooling water makes the better operation of the system and the power output is increased up to about 31-58% in different fluids. The lowest payback period in the systems is achieved through the use of R600a as the working fluid, which is about 3.48 year in the second system.
 

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Co-firing of biomass and fossil fuels in industrial furnaces is a suitable way to reduce the environmental impact from human activities, with acceptable investment. In this paper, the results of numerical simulation co-firing of sulfide concentrates and three auxiliary fuels including gasoil, kerosene and sawdust biomass are compared in the flash furnace copper smelting. For modeling of turbulent flow and combustion, RNG, k-ε model and probability density function model (pdf) have been used, respectively. This study has been carried out to investigate the furnace temperature and combustion pollutants distribution. The numerical simulation results show that the flame temperature resulting from the combustion of diesel fuel and sawdust as auxiliary fuel is the highest and lowest, respectively. In biomass combustion, despite that the flame temperature is low, but the NOx mass fraction increases because there is nitrogen in the sawdust chemical composition. Also in sawdust combustion that the oxygen content is high, the SO2 and SO3 sulfur pollutants increase in the high temperatures regions of the furnace and the lower temperature of the auxiliary fuel burner, respectively. Because SO2 is formed at high temperatures (> 1273K) and oxygen-rich and SO3 species is produced at relatively low temperatures with excess oxygen. The amount of CO emissions in sawdust combustion is much lower than the amount of combustion of diesel and oil.