Bergmann and Stein (1) have described a procedure for the isolation and purification of naturally occurring n-leucine based upon the precipitation and recrystallization of the slightly soluble salt of this amino acid with naphthalene-fi-sulfonic acid. The product obtained was stated to be 97 per cent pure and to be free from methionine, a common contaminant of less pure preparations of n-leucin...

Although concentrated sulfuric acid saccharification is not a novel method for breaking down lignocellulosic biomass, the process by which saccharification affects biomass decomposition, sugar recovery, and by-product generation is not well studied. The present study employed Taguchi experimental design to study the effects of seven parameters on corn stover concentrated sulfuric acid saccharif...

This study aims to understand the acid-leaching behavior of metals from 2 to 4 mm waste printed circuit boards (WPCBs) containing 22.0% ± 1.1 Cu, 6.7% ± 0.2 Ca, 0.68% ± 0.02 Sn, 0.59 ± 0.01 % Pb, 2.71% ± 0.08 Al, 0.22% ± 0.01 Fe, etc.. Copper leaching was increased for sulfuric acid concentrations up to 1.2 mol/L and hydrogen peroxide concentrations of 10.0 vol% for a pulp density of 100 g/L at...

Abstract— SDAWS (Spray drying absorption waste sludge) and BFA (bag filter ash), which are the wastes generated in the SDA (pray drying absorption) process, are only partially recycled as cement additives, gypsum boards, building materials, and the rest are being landfilled in managed landfills. However, wastes that have not been disposed of at the landfill are accumulated around the landfill. ...

Sulfuric acid {[3-(3-silicapropyl)sulfanyl]propyl}ester (SASPSPE) is employed as a recyclable catalyst for the synthesis of α-amino nitriles. These syntheses were performed via a one-pot three-component condensation of aldehydes, amines, and trimethylsilyl cyanide under mild reaction conditions at room temperature. The catalyst could be recycled and reused several times without any loss of effi...

Occupational exposure to strong inorganic acid mists containing sulfuric acid is specifically associated with laryngeal and lung cancer. Studies of one U.S. cohort of male workers in pickling operations in the steel industry found excesses of laryngeal cancer (approximately twofold) after adjustment for smoking and other potentially confounding variables (Steenland et al. 1988). A ten-year foll...

Atmospheric aerosols often contain a substantial fraction of organic matter, but the role of organic compounds in new nanometer-sized particle formation is highly uncertain. Laboratory experiments show that nucleation of sulfuric acid is considerably enhanced in the presence of aromatic acids. Theoretical calculations identify the formation of an unusually stable aromatic acid-sulfuric acid com...