PM2.5 in China: Measurements, sources, visibility and health effects, and mitigation

http://www.users.abo.fi/jwerkeli/OOK%20I%202010/Jaworek%3B%20Modern%20electrostatic%20devices%20and%20methods%20for%20exhaust%20gas%20cleaning.pdf

Modern electrostatic devices and methods for exhaust gas cleaning: A brief review

Air pollution control systems in WtE units: An overview

Porous membranes/filters that can remove airborne fine particulates, for example, PM2.5, with high efficiency at low energy consumption are of significant interest. Herein, we report on the fabrication of a new class of unusual superior air filters with ultrahigh efficiency and an interesting antibacterial functionality. We use atomic layer deposition (ALD) to uniformly seed ZnO on the surface of expanded polytetrafluoroethylene (ePTFE) matrix, and then synthesize well-aligned ZnO nanorods with tunable widths and lengths from the seeds under hydrothermal conditions. The presence of ZnO nanorods reduces the effective pore sizes of the ePTFE filters at little expense of energy consumption. As a consequence, the filters exhibit exceptional dust removal efficiencies greater than 99.9999% with much lower energy consumption than conventional filters. Significantly, the presence of ZnO nanorods strongly inhibits the propagation of both Gram positive and negative bacteria on the filters. Therefore, the functional...

Unusual Air Filters with Ultrahigh Efficiency and Antibacterial Functionality Enabled by ZnO Nanorods.

This paper presents the extension of the Regional Air Pollution Information and Simulation (RAINS) model that addresses present and future emissions of fine particulates in Europe, the potential for controlling these emissions and the costs of such emission reductions. Together with the existing modules dealing with the emissions of the precursor emissions of secondary aerosols such as sulphur dioxide (SO2), nitrogen oxides (NOx), ammonia (NH3) and volatile organic compounds (VOC), this extension enables the comparison of the potentials and costs for controlling primary emissions of fine particles with those of secondary aerosols and to find cost-minimal approaches for reducing ambient levels of particulate matter. 

The emissions of particulate matter (PM) in the RAINS model are calculated for three different size classes: the fine fraction (PM2.5), the coarse fraction (PM10 - PM2.5) and large particles (PM_>10 5m). Summed up, these three fractions represent total suspended particles (TSP). 

Fine particles are emitted from a large number of sources with large differences in their technical and economic properties. The methodology distinguishes 392 source categories for stationary energy combustion, industrial processes, mobile sources and agriculture. For each of these sectors, the study explores the applicable options for reducing PM emissions, their efficiency and their costs. 

Emissions characteristics of the individual sectors are strongly determined by country-specific conditions. The methodology estimates emission control costs of standard technologies under the specific conditions characteristic for the various European countries. Based on the assumption of the general availability of control technologies with equal technical properties and costs, a number of country-specific circumstances (level of technological advancement, installation size distribution, labor costs, etc.) are used to estimate the costs for the actual operation of pollution control equipment. 

For the individual source sectors, emissions are estimated based on statistical information on economic activity and emission factors that reflect hypothetical emissions if no control measures were applied. These emission factors were taken from the literature and were, to the maximum possible extent, adapted to the country-specific conditions. Actual emissions are calculated taking into account the application of emission control measures in a given sector, for which also costs are estimated. 

The methodology was implemented for all European countries, covering the period from 1990 to 2010. At an aggregated level, estimates for past years (1990, 1995) correspond well with other national and international inventories. However, discrepancies are found for some detailed results for individual sectors and activities, and more work will be necessary to clarify them. 

This preliminary implementation suggests for Europe a 50 percent decline of primary emissions of fine particles between 1990 and 1995, mainly due to the economic restructuring in central and eastern European countries. The recently tightened regulations on large combustion plants and mobile sources will further reduce PM emissions, so that for 2010 European PM emissions are expected to be 60 percent below the level of 1990. However, less improvement is expected for the health-relevant fraction of fine particles (PM2.5). 

It needs to be emphasized that these preliminary estimates are still associated with considerable uncertainties, and more work, involving national experts, will be necessary to obtain a verified and generally accepted European data base to estimate the potential for further reductions of fine particles in Europe. 

The present implementation (version 2.00) of the RAINS PM module on the Internet (www.iiasa.ac.at/rains/Rains-online.html) provides free access to the input data and results to facilitate interaction with national experts.

C.E. Capes

Papers

Developments in the control of fine particulate air emissions

The application of dynamic clustering data to the sedimentation rates of concentrated suspensions

Coal rank and surface properties of oil agglomerates