Air Pollution Control Technologies Research Articles

Mercury Air Emission from Coal-Fired Public Power Sector: Uncertainty and Its Monthly Distribution. Case Study from Poland

The paper presents two aspects concerned with the mercury air emission inventory from coal-fired public power and energy plants: an uncertainty analysis, using Monte Carlo simulation (Journal of the American Statistical Association, 44(247), 335–341 1949) and the monthly distributions applying the Denton-Cholette approach (Dagum & Cholette 2006). The analysis determines uncertainty about the estimates mercury air emission from 1990 to 2012 including the development of air pollution control (APC) technologies in the Polish public power and energy sector, also the monthly distributions in comparison with previously obtained results (Hławiczka 2008). The uncertainty of mercury (Hg) content in fuel is 31.6% for hard coal and 42.4% for brown coal. The confidence interval for the estimated emission changed from [kg] (16,082.2; 16,242.2) in 1990 to (10,525.9;10,671.1) in 2012. However, the Denton-Cholette approach overestimates the emissions for the warmer periods of the year, but it could, however, in our view, be applied to attain the monthly distributions.

Analysis of emission reduction strategies for power boilers in the US pulp and paper industry

The US pulp and paper (PNP) industry utilizes a variety of fuels to provide energy for process needs, resulting in air emissions of sulfur dioxide (SO2), nitrogen oxides (NOX), particulate matter (PM), and greenhouse gases such as carbon dioxide (CO2). Emissions from this sector have largely declined and continue to decline steadily since the mid-1990s, reflecting changes in fuel types used and their sulfur content, fluctuation in PNP production, increase in the volume of recycling, efficiency gains throughout the sector, and capital investments for compliance with regulations. Because of the above factors, recent market trends favoring the use of natural gas over coal, and more demanding regulatory limits, it is reasonable to expect that air emissions from the sector will continue to decline in the near future. Boilers have been the dominant source of SO2, NOX, PM, and CO2 emissions for the sector. It would, therefore, be of interest to understand how air pollution controls have been applied to date on new, existing, and replaced units, as well as the cost and emission reductions associated with expanding their use throughout the sector. In the work described here, the Universal Industrial Sectors Integrated Solutions (UISIS) model developed by the U.S. Environmental Protection Agency is used to examine the emission reduction potential and cost of controls. This paper briefly characterizes air emissions from boilers operating in the PNP sector and reviews the menu of air pollution control technologies applicable to the sector. Then, after describing the UISIS PNP model, modeling results are presented, in which several illustrative air emission reduction strategies are assessed, including fuel switching, installation of air pollution control equipment, and implementation of energy efficiency measures.

Substantial air quality and climate co-benefits achievable now with sectoral mitigation strategies in China

China is the world's top carbon emitter and suffers from severe air pollution. We examine near-term air quality and CO2 co-benefits of various current sector-based policies in China. Using a 2015 base case, we evaluate the potential benefits of four sectoral mitigation strategies. All scenarios include a 20% increase in conventional air pollution controls as well as the following sector-specific fuel switching or technology upgrade strategies. Power sector (POW): 80% replacement of small coal power plants with larger more efficient ones; Industry sector (IND): 10% improvement in energy efficiency; Transport sector (TRA): replacement of high emitters with average vehicle fleet emissions; and Residential sector (RES): replacement of 20% of coal-based stoves with stoves using liquefied petroleum gas (LPG). Conducting an integrated assessment using the regional air pollution model WRF-Chem, we find that the IND scenario reduces national air-pollution-related deaths the most of the four scenarios examined (27,000, 24,000, 13,000 and 23,000 deaths reduced annually in IND, POW, TRA and RES, respectively). In addition, the IND scenario reduces CO2 emissions more than 8times as much as any other scenario (440, 53, 0 and 52Mt CO2 reduced in IND, POW, TRA and RES, respectively). We also examine the benefits of an industrial efficiency improvement of just 5%. We find the resulting air quality and health benefits are still among the largest of the sectoral scenarios, while the carbon mitigation benefits remain more than 3 times larger than any other scenario. Our analysis hence highlights the importance of even modest industrial energy efficiency improvements and air pollution control technology upgrades for air quality, health and climate benefits in China.

Selection of optimized air pollutant filtration technologies for petrochemical industries through multiple-attribute decision-making

Selecting cost-effective and efficient air filtration technologies that ensure sustainable development is a challenge to national, regional and local policy makers. Various factors such as efficiency, maintainability, and design of the developed devices can affect the selection of optimized technologies. The present study aimed to select optimal technologies for air filtration devices in petrochemical industries through a multi-criteria decision-making (MADM) method based on a fuzzy model of Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). Five criteria (filtration efficiency, cost, maintainability, designability, and size) were used to rank air pollution control technologies designed to eliminate particulate matter (PM), volatile organic compounds (VOCs), and ammonia (NH3). According to the results, the research criteria had different weights for different air pollutants. High-efficiency particulate air (HEPA + pre collector) filters, plasma chemistry, and chemical absorption were identified as the most appropriate filtration methods for PM, VOCs, and NH3, respectively (coefficients = 0.923, 0.9586, and 0.867, respectively).

Environmental Generation Scheduling Considering Air Pollution Control Technologies and Weather Effects

Because the power industry makes a significant contribution to air pollution, a variety of air pollution control technologies have been adopted to reduce emissions of nitrogen oxides, sulfur dioxide, and particulate matters. However, the deployment of these technologies affects the operation of the power plants and of the power system. This paper first discusses the emissions of multiple pollutants by coal- and gas-fired generators equipped with different emission control devices. It then presents the formulation of an environmental power generation scheduling (EnPGS) model, which coordinates the operating cost and the emissions of these pollutants, including the emissions during the startup and shutdown processes. This model considers the air quality index and how this index is affected by the weather, and optimizes the spatial distribution of generation between regions. It also takes into account the operating characteristics of various emission control devices, such as the deactivation of selective catalytic reduction at low output, and the burn mode switching of combined cycle gas turbines. A case study covering several Chinese provinces demonstrates the potential effectiveness of the EnPGS at reducing multiple air pollutants.

廃棄物焼却における排ガス処理技術の解説

Several types of air pollution control technologies about waste combustion system were developed on the last quarter century. If those new technologies have come into wide use, we ought to explain several new technology convincingly to customers or users. Therefore I will take a few examples of explanations about those new technologies.

Air Pollution Monitoring Changes to Accompany the Transition from a Control to a Systems Focus

During the 20th century, air pollution control technologies grew at an amazingly rapid rate. Air quality in much of the industrialized world greatly improved as the efficiencies of these technologies improved. This continued improvement in pollution control has more recently been complemented with measures to prevent the emission of air pollutants. The previous, exclusive focus on treatment requires systems thinking. This review provides a framework for this Special Issue of Sustainability by describing the new tools that are needed to support this new, broader focus, including life cycle assessments, exposure models, and sustainable design.

Impact of photocatalytic remediation of pollutants on urban air quality

In the recent years, photocatalytic self-cleaning and “depolluting” materials have been suggested as a remediation technology mainly for NOx and aromatic VOCs in urban areas. A number of products incorporating the aforementioned technology have been made commercially available with the aim to improve urban air quality. These commercial products are based on the photocatalytic properties of a thin layer of TiO2 at the surface of the material (such as glass, pavement, etc.) or embedded in paints or concrete. The use of TiO2 photocatalysts as an emerging air pollution control technology has been reported in many locations worldwide. However, up to now, the effectiveness measured in situ and the expected positive impact on air quality of this relatively new technology has only been demonstrated in a limited manner. Assessing and demonstrating the effectiveness of these depolluting techniques in real scale applications aims to create a real added value, in terms of policy making (i.e., implementing air quality strategies) and economics (by providing a demonstration of the actual performance of a new technique).

Brominated flame retardant emissions from the open burning of five plastic wastes and implications for environmental exposure in China

Based on the most widely used plastics in China, five plastic wastes were selected for investigation of brominated flame retardant (BFR) emission behaviors during open burning. Considerable variations were observed in the emission factors (EF) of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) from the combustion of different plastic wastes. Distribution of BFR output mass showed that ΣPBDE was emitted mainly by the airborne particle (51%), followed by residual ash (44%) and the gas phase (5.1%); these values for ΣHBCD were 62%, 24%, and 14%, respectively. A lack of mass balance after the burning of the plastic wastes for some congeners (output/input mass ratios>1) suggested that formation and survival exceeded PBDE decomposition during the burns. However, that was not the case for HBCD. A comparison with literature data showed that the open burning of plastic waste is major source of PBDE compared to regulated combustion activities. Even for state-of-the-art waste incinerators equipped with sophisticated complex air pollution control technologies, BFRs are released on a small scale to the environment. According to our estimate, ΣPBDE release to the air and land from municipal solid waste (MSW) incineration plants in China in 2015 were 105 kg/year and 7124 kg/year. These data for ΣHBCD were 25.5 and 71.7 kg/year, respectively. Considering the fact that a growing number of cities in China are switching to incineration as the preferred method for MSW treatment, our estimate is especially important. This study provides the first data on the environmental exposure of BFRs emitted from MSW incineration in China.

Observed decrease in atmospheric mercury explained by global decline in anthropogenic emissions

Observations of elemental mercury (Hg(0)) at sites in North America and Europe show large decreases (∼ 1-2% y(-1)) from 1990 to present. Observations in background northern hemisphere air, including Mauna Loa Observatory (Hawaii) and CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) aircraft flights, show weaker decreases (<1% y(-1)). These decreases are inconsistent with current global emission inventories indicating flat or increasing emissions over that period. However, the inventories have three major flaws: (i) they do not account for the decline in atmospheric release of Hg from commercial products; (ii) they are biased in their estimate of artisanal and small-scale gold mining emissions; and (iii) they do not properly account for the change in Hg(0)/Hg(II) speciation of emissions from coal-fired utilities after implementation of emission controls targeted at SO2 and NOx. We construct an improved global emission inventory for the period 1990 to 2010 accounting for the above factors and find a 20% decrease in total Hg emissions and a 30% decrease in anthropogenic Hg(0) emissions, with much larger decreases in North America and Europe offsetting the effect of increasing emissions in Asia. Implementation of our inventory in a global 3D atmospheric Hg simulation [GEOS-Chem (Goddard Earth Observing System-Chemistry)] coupled to land and ocean reservoirs reproduces the observed large-scale trends in atmospheric Hg(0) concentrations and in Hg(II) wet deposition. The large trends observed in North America and Europe reflect the phase-out of Hg from commercial products as well as the cobenefit from SO2 and NOx emission controls on coal-fired utilities.

Biological Sulfur-Oxidizing Potential of Primary and Biological Sludge in a Tannery Wastewater Treatment Plant

Hydrogen sulfide (H2S) is one of the major tannery wastewater pollutants. Up today, chemical scrubbing is the most established technology for H2S removal in wastewater treatment plants. However, this procedure increases both the operating costs and the carbon footprint of the treatment. On the other hand, biological treatment is an emerging and sustainable technology for air pollution control. Our study focuses on the biological sulfur-oxidizing potential of autochthonous sludge of a plant treating tannery wastewater, located in Santa Croce (Tuscany, Italy). We propose a multidisciplinary approach to investigate two aspects: first, the composition of the microbial community both in the biological sludge and in the primary sludge and second, the sulfur-oxidizing potential of these native matrices. In order to do that, biological and primary sludge were used as inoculum in a reactor fed with sulfides. Then, traditional cultivation techniques were combined with several molecular approaches for analyzing the microbial community structure with a special focus on sulfur-oxidizing bacteria (SOB). Our study demonstrated that the use of different techniques was fundamental in order to detect the largest number of sulfur-oxidizing bacterial components; in particular, the detection of less represented components was guaranteed only by the performed multidisciplinary approach. Our study demonstrated the optimal performances of the reactor in selecting a sulfur-oxidizing biomass from autochthonous matrices. In addition, the importance of the primary sludge as inoculum for sulfur-oxidizing reactors was proved.

Biological technologies for the removal of sulfur containing compounds from waste streams: bioreactors and microbial characteristics.

Waste gases containing sulfur compounds, such as hydrogen sulfide, sulfur dioxide, thioethers, and mercaptan, produced and emitted from industrial processes, wastewater treatment, and landfill waste may cause undesirable issues in adjacent areas and contribute to atmospheric pollution. Their control has been an area of concern and research for many years. As alternative to conventional physicochemical air pollution control technologies, biological treatment processes which can transform sulfur compounds to harmless products by microbial activity, have gained in popularity due to their efficiency, cost-effectiveness and environmental acceptability. This paper provides an overview of the current biological techniques used for the treatment of air streams contaminated with sulfur compounds as well as the advances made in the past year. The discussion focuses on bioreactor configuration and design, mechanism of operation, insights into the overall biological treatment process, and the characterization of the microbial species present in bioreactors, their populations and their interactions with the environment. Some bioreactor case studies are also introduced. Finally, the perspectives on future research and development needs in this research area were also highlighted.

Economic analysis of atmospheric mercury emission control for coal-fired power plants in China

Coal combustion and mercury pollution are closely linked, and this relationship is particularly relevant in China, the world's largest coal consumer. This paper begins with a summary of recent China-specific studies on mercury removal by air pollution control technologies and then provides an economic analysis of mercury abatement from these emission control technologies at coal-fired power plants in China. This includes a cost-effectiveness analysis at the enterprise and sector level in China using 2010 as a baseline and projecting out to 2020 and 2030. Of the control technologies evaluated, the most cost-effective is a fabric filter installed upstream of the wet flue gas desulfurization system (FF+WFGD). Halogen injection (HI) is also a cost-effective mercury-specific control strategy, although it has not yet reached commercial maturity. The sector-level analysis shows that 193tons of mercury was removed in 2010 in China's coal-fired power sector, with annualized mercury emission control costs of 2.7 billion Chinese Yuan. Under a projected 2030 Emission Control (EC) scenario with stringent mercury limits compared to Business As Usual (BAU) scenario, the increase of selective catalytic reduction systems (SCR) and the use of HI could contribute to 39tons of mercury removal at a cost of 3.8 billion CNY. The economic analysis presented in this paper offers insights on air pollution control technologies and practices for enhancing atmospheric mercury control that can aid decision-making in policy design and private-sector investments.

Editorial: advanced catalytic materials for environmental application

Environmental protection is directly related to the sustainable development of the economy and society. Controlling the release of major air and water pollutants remains a daunting challenge in China. The removal of major air pollutants [PM, SO2, NOx, volatile organic compounds (VOCs), and Hg] from stationary and mobile sources is becoming increasingly urgent to improve air quality. Additionally, the removal of numerous industrial and natural chemical compounds from contaminated water systems is essential to maintaining the availability of clean water. Therefore, cost-effective and appropriate air pollution control and water treatment technologies must be explored and implemented. Regarding air pollution control, the selective catalytic reduction of NOx (SCR) by ammonia and hydrocarbons over metal oxide and zeolite catalysts is discussed; non-toxic transition metal oxides supported on titania and zeolite matrices are emerging new catalysts. The removal of Hg from flue gas using catalysis is also a new research direction in this field. The oxidation of VOCs using photoand thermal catalysis for indoor air quality improvement is reviewed based on recent research progress achieved worldwide. Regarding wastewater treatment, the catalytic elimination of inorganic and organic pollutants from wastewater is presented. Additionally, mechanisms for the abatement of air and water pollutants using catalysis are discussed in detail. Finally, several aspects should be aimed in future research of environmental catalysis for the abatement of major pollutants in air and water. For instance, the development of environment-friendly catalysts that have attracted much attention in both the academic and industrial fields should be enhanced. Significant efforts should be made towards the development of highly active and durable catalysts, and anti-fouling catalysts for long-term successful treatments. For the selectivity of pollutants transformation to harmfulness should be more concerned by adjusting heterogeneous catalytic processes. Further efforts should be made to gradually improve material or reactor design for pilot and demonstration purposes. Moreover, much work is required to combine catalytic processes with other remediation technologies.

Reduction of Pm10 Emissions under Scenarios of Regulation and Availability of Natural Gas in the Bio Bio Region, Chile

The high level of industrial activity in the Bio Bio Region has led to local air pollution problems, due to the high emission levels of particulate matter. The feasibility of bringing liquefied natural gas to the region is under study. This paper compares a system of tradable emissions permits and command and control type regulation for industrial sources considering two alternatives for reducing PM10 emissions: Changing the fuel used to natural gas and incorporating air pollution control technologies. It was found that given certain fuel prices, the industries will likely change to natural gas without the need for regulation. Moreover, it was found the maximum price that could be paid whilst retaining the economic attractiveness of this alternative as a cost-effective option for emissions reductions.

Energy and Environment: Challenges and Achievements in Rapid Urbanization

Energy and Environment: Challenges and Achievements in Rapid Urbanization

Strength and Elasticity of Mortar with Municipal Solid Waste Incineration Ash

Energetic and metallurgic wastes are widely used as Supplementary Cementitious Materials (SCM) and aggregates in order to reduce the concrete price and/or enhance its durability and mechanical properties. Ashes generated in process of Municipal Solid Waste Incineration (MSWI) feature certain similarity with conventional SCMs and thus there is a potential to utilize MSWI ashes as concrete admixtures. Unfortunately high variety of MSWI ashes is observed as consequence of differences in incinerated waste composition and also variability of applied combustion and air pollution control technology. Therefore it is necessary to evaluate the applicability of MSWI ashes individually. The present paper deals with influence of MSWI bottom ash from a Czech incineration facility on strength and Young’s modulus of cementitious mortars where the MSWI bottom ash was used as aggregates. Even though the content of ash was as high as 40 % of aggregates dosage the influence on mechanical properties was found to be not very significant. The strength was not lost by MSWI admixing, the Young’s modulus decreased somewhat.

Development of a modified differential biofiltration reactor with online sample and carbon dioxide monitoring system

ABSTRACTBiofiltration is one of the air pollution control technologies (APCTs) used widely in treating the odorous and volatile organic compounds (VOCs). Reliability and robustness in measuring the pollutant degradation rate and carbon dioxide production is considered most important in a biofiltration system. In this current work, a gas chromatography (GC) system and carbon dioxide analyser were introduced online to a lab scale differential biofiltration reactor with water content control. Toluene, one of the potential VOCs, was used as a model pollutant in our current study. The feasibility and limitations of online GC and CO2 analyzer was evaluated by measuring the inlet and outlet toluene concentrations along with CO2 concentrations and compared with the regular offline measurements. Furthermore, a simple diffusion system was proposed and used in the current work to improve the robustness of toluene vapour production. The results indicate that the modifications carried out in the lab scale biofiltration reactor and in the diffusion system improved the data collection and stability. This improved system can be used effectively in the lab scale biofiltration research. © 2012 Curtin University of Technology and John Wiley &amp; Sons, Ltd.

Biofiltration for treating VOCs: an overview

In this paper we present a review of Biofiltration, one of the air pollution control technologies (APCT) used to treat volatile organic compounds (VOCs) effectively. It also talks about the history of biofiltration, and also proposes few ideas for the future developments in the biofiltration research pertaining to VOC control. Moreover, the paper also discusses about various important physical, chemical and biological factors which affect the performance of a biofilter both directly and indirectly. This paper will be handier for those who are new to the field of biofiltration research for VOC treatment.

Removal of VOCs in waste gas by the photo‐Fenton reaction: effects of dosage of Fenton reagents on degradation of toluene gas in a bubble column

AbstractBACKGROUNDVolatile organic compounds (VOCs) are major pollutants in the atmosphere of all urban and industrial areas, and the development of an effective treatment process for VOCs is highly desirable. Advanced oxidation processes (AOPs) are a promising technology for air pollution control. In this study, the AOP photo‐Fenton oxidative reaction in the liquid phase was applied to chemical absorption and degradation of toluene in waste gas.RESULTSFor toluene levels of 0.25 mg L−1 in waste gas flowing at 5.0 Lmin−1 the maximum removal and mineralization of toluene in the waste gas were more than 90% with H2O2 dosage above 150 mg L−1 and Fe dosage above 10 mg L−1. The Toluene photodegradation efficiency increased with increasing dosages of Fenton reagents, however, beyond a certain dosage further improvements were insignificant. The photo‐Fenton reaction in the liquid‐phase could improve the overall toluene absorption rate by increasing the driving force for mass transfer and as a result enhance the removal of toluene from exhaust gas.CONCLUSIONToluene in waste gas was successfully removed and mineralized by the photo‐Fenton process. The mineralization of toluene was strongly linked with the iron redox cycle and H2O2 decomposition driven by the Fenton reagents and UV light. The proposed chemical absorption process based on photo‐Fenton photocatalytic oxidation in the liquid phase was shown to be very effective for the degradation of VOCs in waste gas. Copyright © 2012 Society of Chemical Industry