Design and demonstration of a next-generation air quality attainment assessment system for PM2.5 and O3

Due to the increasingly stringent standards, it is important to assess whether the proposed emission reduction will result in ambient concentrations that meet the standards. The Software for Model Attainment Test—Community Edition (SMAT-CE) is developed for demonstrating attainment of air quality standards of O₃ and PM_2.5. SMAT-CE improves computational efficiency and provides a number of advanced visualization and analytical functionalities on an integrated GIS platform. SMAT-CE incorporates historical measurements of air quality parameters and simulated air pollutant concentrations under a number of emission inventory scenarios to project the level of compliance to air quality standards in a targeted future year. An application case study of the software based on the U.S. National Ambient Air Quality Standards (NAAQS) shows that SMAT-CE is capable of demonstrating the air quality attainment of annual PM_2.5 and 8-hour O₃ for a proposed emission control policy.     

Development and case study of a science-based software platform to support policy making on air quality

This article describes the development and implementations of a novel software platform that supports real-time, science-based policy making on air quality through a user-friendly interface. The software, RSM-VAT, uses a response surface modeling (RSM) methodology and serves as a visualization and analysis tool (VAT) for three-dimensional air quality data obtained by atmospheric models. The software features a number of powerful and intuitive data visualization functions for illustrating the complex nonlinear relationship between emission reductions and air quality benefits. The case study of contiguous U.S. demonstrates that the enhanced RSM-VAT is capable of reproducing the air quality model results with Normalized Mean Bias < 2% and assisting in air quality policy making in near real time.     

Synthesis of mesoporous magnesium oxide: Its application to CO2 chemisorption

Mesoporous magnesium oxide (MgO) was synthesized using mesoporous carbon CMK-3 obtained from mesoporous SBA-15 as exotemplate. P123 was used as the structure-directing template and rice husk ash (RHA) as the silica source for the synthesis of SBA-15, which was subsequently treated with sucrose and sulphuric acid to obtain mesoporous carbon (CMK-3). X-ray powder diffraction (XRD) results and the type-IV adsorption isotherm with H1 hysteresis obtained by N₂ adsorption/desorption study for SBA-15, CMK-3 and mesoporous MgO suggests its resemblance with materials synthesized using conventional silica sources. Mesoporous MgO was subjected for CO₂ adsorption study in TGA; adsorption was 8 and 10 wt% at 25 and 100 °C, respectively. Finally, mesoporous MgO is selective to CO₂ gas, thermally stable and regenerable. Thus, this study contributes a better route to enhance CO₂ gas adsorption and use ecological waste rice husk for the synthesis of such efficient mesoporous materials.     

Efforts to develop regulations in Korea similar to the US maximum achievable control technology (MACT) regulations for hazardous waste incinerators

The development of regulations patterned after the United States’ requirement for maximum achievable control technology (MACT) to control hazardous air pollutants from major industrial sources in Korea is in progress. Current management practices and installed air pollution control devices were surveyed; emission tests and continuous emission data collected from facilities under operation were assessed considering other MACT requirements such as reporting, report keeping requirements. Emission sampling and air pollutant analysis were carried out at representative hazardous waste incinerators installed with wet-type and dry-type air pollution control devices. Korean and United States Environmental Protection Agency methods were used for sampling and analysis. The major heavy metals emitted were Zn, Ni, Pb, and Cr. The heavy metal removal efficiency of existing air pollution control devices was greater than 99%. The average mercury removal efficiency was more than 30%. Toluene; m,p-xylene; o-xylene; benzene; dichloromethane; styrene; ethylbenzene; 1,3-dichlorobenzene; and 1,2,4-trimethylbenzene were the major volatile organic compounds emitted. The emissions from field tests were compared, reviewed, and analyzed with respect to MACT regulations to check applicability. Finally, draft guidelines were suggested for effective hazardous air pollutant management in Korea.     

Spatiotemporal distribution of arsineic species of oysters (Crassostrea gigas) in the coastal area of southwestern Taiwan

This study investigated total arsenic (As) and As species contents of oysters (Crassostrea gigas) in different production areas, seasons and sea locations on the southwestern coast of Taiwan. Analytical results indicate that contents of total As, arsenite, arsenate, dimethylarsinic acid, monomethylarsonic acid and arsenobetaine in oysters are 9.90 ± 3.68, 0.091 ± 0.104, 0.033 ± 0.038, 0.529 ± 0.284, 0.037 ± 0.046 and 3.94 ± 1.33 mg/g (dry wt), respectively. A ratio of inorganic As concentrations to total As concentrations is 1.26%. Total As contents of oysters cultured in the outer sea are statistically significantly lower than those of oysters cultured in the inner sea. The total As contents of oysters is the highest in Putai, where the blackfoot disease prevails. The low As contents in oysters is attributed to the low temperature in winter, which slows the metabolism of oysters. A maximum value is 33.37 μg/g (dry) in Putai in spring, because a considerable amount of aquacultural waste water with high As contents is discharged into adjacent drainage channels and rivers there during that season.     

南水北调中线工程对陆生植物的影响及其对策初步研究

介绍了南水北调中线工程丹江口水库库区及输水总干渠沿线所经地区的自然环境状况和植物资源特征；分析了工程所造成的淹没，占地，移民和迁建用材等方面对库区和干渠沿线地段的陆生植物和植物物种资源各方面所可能造成的损失，以及有益的影响，并针对库区和干渠沿线的植物资源保护，环境恢复和地区经济重建等问题提出对策。     

高速公路小煤窑采空区路基综合勘察与评价

采空区是公路建设中一种特殊的地质病害，特别是小煤窑采空区，由于无规划、无序、反复地开挖，故小煤窑采空区勘察与评价有较多不确定性。在公路工程地质勘察中采用综合勘察方法，查明采空区分布范围并评价其对公路工程危害程度及稳定性，对高速公路建设非常重要。本文结合安徽省铜陵至汤口高速公路具体工程实例，探讨小煤窑采空区综合勘察与评价。     

Pilot-scale tests to optimize the treatment of net-alkaline mine drainage

A pilot-scale plant consisting of an oxidation basin (OB), a neutralization basin (NB), a reaction basin (RB), and a settling basin (SB) was designed and built to conduct pilot-scale experiments. With this system, the effects of aeration and pH on ferrous oxidation and on precipitation of the oxidized products were studied systemically. The results of pilot-scale tests showed that aeration at 300 L/min was optimum for oxidation of Fe(II) in the OB, and the efficiency of oxidation of Fe(II) increased linearly with increasing retention time. However, Fe(II) was still present in the subsequent basins-NB, RB, and SB. Results from pilot-scale tests in which neutralization was excluded were used to obtain rate constants for heterogeneous and homogeneous oxidation. Oxidation of Fe(II) reached almost 100% when the pH of the mine drainage was increased to more than 7.5, and there was a linear relationship between total rate constant, log (K(total)), and pH. Absorbance changes for samples from the NB under different pH conditions were measured to determine the precipitation properties of suspended solids in the SB. Because ferrous remained in the inflow to the SB, oxidation of Fe(II) was dominant initially, resulting in increased absorbance, and the rate of precipitation was slow. However, the absorbance of the suspension in the SB rapidly dropped when pH was higher than 7.5.