• ROGER J. CHENG, ASRC SUNY UALBANY

• ATMOSPHERIC SCIENCES RESEARCH CENTER
• STATE UNIVERSITY of NEW YORK

环境中的微观世界  工业污染、酸雨形成及生态环境影响   ● 通过开展显微镜测量，具体形象的揭示了工业污染排放的二氧化硫及其界面氧化反应       ● 在酸雨形成过程中的主要特征以及它们在建筑腐蚀、植被灼烧等方面的生态环境影响。 纽约州立大学，大气科学研究中心郑均华研究员主持的科研项目  INDUSTRIAL EMISSION, ACID RAIN FORMATION and their EFFECT on OUR ENVIRONMENT ● Microscopically Examination, by Atmospheric Scientist- Roger J. CHENG of ASRC (Atmospheric Sciences Research Center) SUNYA,(State University of New York at Albany) illustrated ● the characterization of industrial emission, catalytic oxidation of SO/2 in the formation of acid rain drop, and their ecological effects ----( building erosion & leaf damage) on our environment.

POWER PLANT EMISSION	ACID RAIN FORMATION	ECOLOGICAL EFFECT	ALBEDO of CLOUDS	BUILDING EROSION	ATMOSPHERIC PTS	CARBONACEOUS PTS	AIR POLLUTION CONTROL

• DETERIORATION of MARBLE STRUCTURES-
• THE ROLE of ACID RAIN
• 

Microscopical investigation reveals that industrial emissions play a major role in the deterioration of marble structures and historic monuments (References 1, 2).  Chemical analysis indicates that the serious damage is primarily due to a constant direct attack by sulfuric acid (H/₂SO/₄). Industrial particulate is always observed on the damaged surfaces.

 Cross sections of samples examined by both optic and scanning electron microscopy show detailed interior structure of the damaged area. The formation of gypsum crystals (CaSO/₄ · 2H/₂O) on the marble surface, by reaction of sulfuric acid with calcite (CaCO/₃), is positively identified by dispersion staining microscopy and by energy dispersive x-ray spectroscopy.  Several parallel layers of numerous atmospheric particulates were embedded within gypsum crystals.  Elemental mapping and line profile analysis yield definite penetration by sulfuric acid 20 mm below the surface for a 50-year-old marble building.  The most damaged region is always found to be in a shady area where moisture surface is usually formed by condensation of water vapor.The concentration of [SO/₄⁼] and [NO/₃^-] extracted from damaged surfaces was analyzed by the technique of liquid ion chromatography.  The extremely high ratio of [SO_/4⁼] / [NO_/3^-]  obtained in marble samples, compared to the ratio generally measured from acid precipitations (rain and snow) suggests that the contribution of sulfuric acid from precipitation and from deposited industrial particulate is limited and insufficient for serious damage to the marble structure.  We hypothesize that the majority of sulfuric acid is being produced continuously on wet surfaces by heterogeneous oxidation of absorbed SO_/2, in the presence of any necessary active catalysts.  Heterogeneous catalysts such as:  carbon, iron, vanadium and manganese associated with particulate which are generated by electric power plants burning fossil fuels, especially coal, and by combustion engines of automobiles (Reference 3), contribute to the complex surface chemical interactions which result in marble deterioration.

References:

•  1.Cheng, R.J, et al. "Characterization of Particulate from Power Plants."
•         Journal of the Air Pollution Control Association, Vol. 26, No. 8, August 1976.
• 2. Cheng R.J, et al, "A Study of Marble Deterioration, City Hall, Schenectady, New York."
•         Journal of the Air Pollution Control Association, Vol. 34, No.1, January 1984.
• 3. Cheng R.J. "Industrial Emissions and Marble Deterioration."
•         Proceedings: the Sixth World Congress on Air quality, Paris, France, May 16-20, 1983.

• A STUDY of MARBLE DETERIORATION at CITY HALL,
• SCHENECTADY, NEW YORK
• Roger J CHENG and Raymond CASTILLO
• ATMOSPHERIC SCIENCES RESEARCH CENTER
• The UNIVERSITY at ALBANY