Membrane-Based Technology for Air Pollution Treatment

Rapid growth in environmental awareness raised the strict regulations on air pollution control and led to great developments in air filtration or cleaning technologies. The membrane is one of the promising technologies for air filtration due to its high efficiency, low cost, and easy to scale-up. Two types of air filtration membranes have been used to provide high efficiencies in contaminant removal, namely electro-spun fibrous and microporous polymeric membranes. The fibrous membranes composed of randomly oriented fibers, either micro-or nano-fiber, and have been widely used to remove fine particles, such as aerosols. Meanwhile, the microporous membranes have a pore size that can remove both particulate and molecular, such as toxic gases. This paper reviews the role of membrane technologies in air pollution control. The performances of the membranes are presented comprehensively. Besides, the developments of the membranes to improve the filtration efficiency and reduce air-flow resistance are also discussed.

Electrospun fibrous membrane with controlled hierarchical structure and wettability for effective emulsion separation

Transformation of Fibrous Membranes from Opaque to Transparent under Mechanical Pressing

Aligned porous fibrous membrane with a biomimetic surface to accelerate cartilage regeneration

This paper focuses on the study of the most recent ultra-filtration techniques, based on porous polymer membranes, used for the treatment of wastewater from oil, mine and hydrometallurgical industries. The performance of porous membranes used in separation and recovery of oil and heavy metals from wastewater, was evaluated by the polymer composition and by the membrane characteristics, as it follows: hydrophobicity or hydrophilicity, porosity, carrier (composition and concentration), selectivity, fouling, durability, separation efficiency and operating conditions. The oil/water efficient separation was observed on ultra-filtration (UF) techniques, with porous membranes, whereas heavy metals recovery from wastewater was observed using porous membranes with carrier. It can be concluded, that in the ultra-filtration wastewater treatments, a hybrid system, with porous polymer membranes with or without carrier, can be used for these two applications: oil/water separation and heavy metals recovery.

China has been suffering from serious air pollution for years due to rapid industrialization. However, the relationship between China’s air pollution and pollution control schemes remains understudied in the Chinese air pollution literature. Using the Environmental Theory Model, this paper studies the relationship between air pollution and control investment in China for the period 2005–2014 and applies the inverse distance weighted interpolation (IDW) and Pearson correlation methods. As a result, this paper puts forward some policy suggestions for the governance of air pollution in China. The results are as follows: (1) The Pearson correlation coefficient between China’s air pollution index (API) and control investment is 0.466 (p < 0.01). This shows that the phenomenon of ‘Treatment after Pollution’ still exists in China’s economy; (2) there is an inverted U-shaped relationship that is in accordance with the environmental Kuznets curve between China’s air pollution control investment and air pollution; (3) the high-effectiveness of governmental air pollution control is reflected in the 2013–2014 period, where the API of year 2014 decreased by 10.45 from 2013. This shows a one-year lag between exposure to air pollution and the start of control investment. Future research is warranted to concentrate on establishing a model of the relationship between air pollution and control investment or an air pollution risk assessment based on the proportional hazards model (COX) model.

Self-Healing Hydrophilic Porous Photothermal Membranes for Durable and Highly Efficient Solar-Driven Interfacial Water Evaporation

Wrinkled silica doped electrospun nano-fiber membranes with engineered roughness for advanced aerosol air filtration

For a number of years the oil and gas fields of West Texas have supplied Texas and the nation with large amounts of fossil fuel. In recent years the Texas Air Control Board has adopted regulations which directly affect the exploration, production, and processing of these energy sources. The purpose of this paper is to show how adopted air pollution control regulations affect the various pollution control regulations affect the various phases of development of these fuel sources phases of development of these fuel sources in this age where concern for both a clean environment and abundant energy supplies is paramount. paramount Introduction In 1967, the 60th Texas Legislature passed the Texas Clean Air Act. The stated purpose of the Act was to "…safeguard the air resources of the state from pollution by controlling or abating air pollution and, emissions of air contaminants, consistent with the protection of health, general welfare, and physical property of the people, including the esthetic enjoyment of the air resources by the people and the maintenance of adequate visibility." The Act establishes the Texas Air Control Board as the state air pollution control agency, and names the Board as the "principal authority in the state on matters relating to the quality of the air resources in the state and for setting standards, criteria, levels, and emission limits for air contaminants and pollution control." The Act also provides for an Executive Director to be administrator of air control activities for the Board. His responsibilities include any and all things necessary to achieve the purposes and objectives of the Act and to purposes and objectives of the Act and to provide general supervision over all personnel provide general supervision over all personnel employed by the Board. The Executive Director has established 12 Air Quality Control Regions in the state. Within each region the Executive Director has established a regional office at a convenient location. These regions and their corresponding regional offices are designated in Figure 1. The Regional Supervisor is responsible for the operations of the regional office as well as all air pollution control activities within his assigned region. In January 1972 a regional office of the Texas Air Control Board, Air Quality Control Region 6, was established in Odessa, Texas. From the time of establishment of the Odessa regional office it became apparent that the largest number of air pollution problems in the region were those directly related to the production and/or processing of oil and gas from the rich deposits in West Texas. This paper is concerned with the air pollution problems encountered by the oil and gas industry in West Texas, and how that industry might operate in compliance with the Regulations established by the Board.

Due to rapid urbanization, industrialization and motorization, a large number of Chinese cities are affected by heavy air pollution. In order to explore progress, remaining challenges, and sustainability of air pollution control in the Beijing-Tianjin-Hebei (BTH) region after 2013, a mixed method analysis was undertaken. The quantitative analysis comprised an overview of air quality management in the BTH region. Semi-structured expert interviews were conducted with 12 stakeholders from various levels of government and research institutions who played substantial roles either in decision-making or in research and advising on air pollution control in the BTH region. The results indicated that with the stringent air pollution control policies, the air quality in BTH meets the targets of the Air Pollution Prevention and Control Action Plan. However, improvements vary across the region and for different pollutants. Although implementation has been decisive and was at least in parts effectively enforced, significant challenges remained with regard to industrial and traffic emission control, and national air quality limits continued to be significantly exceeded and competing development interests remained mainly unsolved. There were also concerns about the sustainability of the current air pollution control measures especially for industries due to the top-down enforcement, and the associated large burden of social cost including unemployment and social inequity resulting industrial restructuring. Better mechanisms for ensuring cross-sectoral coordination and for improved central-local government communication were suggested. Further suggestions were provided to improve the conceptual design and effective implementation of respective air pollution control strategies in BTH. Our study highlights some of the major hurdles that need to be addressed to succeed with a comprehensive air pollution control management for the Chinese mega-urban agglomerations.

Microporous fibrous membranes were prepared from poly(vinylidenefluoride-co-hexafluoropropylene) P(VdF-HFP) solutions in an acetone/N,N-dimethylacetamide mixture using the electrospinning method. Varying the P(VdF-HFP) polymer concentration in electrospinning can easily control the pore size and the porosity of the electrospun fibrous membranes (ES-FMs). The usefulness of the ES-FMs as a matrix of polymer electrolyte for a lithium-ion polymer battery with high performance was evaluated. Electrospun fibrous polymer electrolyte membranes (ES-FPEMs) showed excellent electrochemical properties of ionic conductivity, higher than S/cm at room temperature, and the electrochemical stability window, up to 4.5 V vs. At a C/2 rate, the prototype cell using the ES-FPEM showed a good charge/discharge property, with little capacity fade under constant current and constant voltage conditions at 20 and 60°C. © 2004 The Electrochemical Society. All rights reserved.

Electrospinning ultrathin continuous cellulose acetate fibers for high-flux water filtration

In this study, capture of CO2 and H2S from natural gas mixture using porous polymeric membranes has been investigated numerically to assess the capacity of a novel absorbent, di‐isopropanol amine (DIPA), in CO2 removal. Diffusion of acid gases through porous polymeric membranes was simulated by employing CFD techniques and considering a gas feed stream, a porous membrane and a reaction medium. For solving conservation equations, finite element method was applied to calculate the rate of CO2 and H2S absorption in the membrane. The type of membrane in this work is a hollow‐fiber module. According to the modeling results, a high H2S removal can be achieved by DIPA absorber. Moreover, CO2 was captured from natural gas in an efficient manner in low gas/liquid flow rates. POLYM. ENG. SCI., 55:598–603, 2015. © 2014 Society of Plastics Engineers

본 연구의 목적은 대표적 점오염원인 석탄화력발전소의 대기오염방지시설을 개선했을 때 최대 착지 농도 및 주변지역의 대기오염도 변화를 파악하는데 있다. 대기오염방지시설 개선 전 후의 대기질을 예측 비교하여 시설의 개선 효과가 어느 정도인지를 분석하였다. 대기질 예측에는 바람장의 변화를 Puff의 이동으로 나타낼 수 있고, 비정상 상태를 구현 할 수 있는 대기오염확산모델인 CALPUFF 모델을 이용하였다. 화력발전소의 주요 대기오염배출 물질인 아황산가스( $SO_2$ ), 이산화질소( $NO_2$ ), 먼지( $PM_{10}$ ) 항목을 예측 항목으로 선정하였다. 연구결과 $SO_2$ , $NO_2$ 항목은 대기오염방지시설 개선으로 인하여 최대 착지지점 및 주변지역의 대기질 오염도 감소에 상당히 효과가 있는 것으로 분석되었다. $PM_{10}$ 항목의 경우에는 최대 착지지점에서는 오염도 감소 효과가 높으나, 석탄 화력발전소 주변지역의 대기오염도 감소 효과는 다소 낮게 분석되었다. 【The object of this study is to identify changes in air pollution in the maximum ground level concentration and the surrounding area when air pollution control facilities are improved in the thermal power plants. The effects of improved facilities are analyzed by comparing air quality after applying improved air pollution control facilities. For prediction of air quality, the change of wind field can be represented with movement of Puff and CALPUFF Model, air pollution diffusion models which can implement abnormal conditions. Major air pollutants of thermal power plants such as $SO_2$ , $NO_2$ , and $PM_{10}$ are selected as prediction items. That results show that improvement of air pollution control facilities is significantly effective in reduction of air pollution of $SO_2$ and $NO_2$ in the maximum ground level concentration and areas around of thermal power plants. In the case of $PM_{10}$ , it is found that the effect of reduction in pollution is high in the maximum ground level concentration, but the effect of reduction in air pollution is somewhat low in the area around of the thermal power plant.】

Air pollution control and enterprise competitiveness – A re-examination based on China's Clean Air Action