Sulfur concentration, high

Smah concentrations of HI reduce concentrated sulfuric acid to sulfurous acid high concentrations of HI reduce it to hydrogen sulfide (56). 

Sulfur Dioxide. High concentrations are found at Xalostoc (NE) and Santa Ursula (SW) stations during fall and winter, the former is located close to a power plant, and the latter near an asphalt factor the Standard was exceeded 5 and 9 days respectively from October 1989 to February 1990. 

The metal is not attacked by hydrochloric acid, nor does it react with dilute nitric and sulfuric acids. High purity selenium reacts slowly with concentrated nitric acid. The crude metal, however, dissolves in cold concentrated nitric acid. 

Results For the St. Louis data, the target transformation analysis results for the fine fraction without July Uth and 5th are given in table 6. The presence of a motor vehicle source, a sulfur source, a soil or flyash source, a titanium source, and a zinc source are indicated. The sulfur, titanium and zinc factors were determined from the simple initial test vectors for those elements. The concentration of sulfur was not related to any other elements and represents a secondary sulfate aerosol resulting from the conversion of primary sulfur oxide emissions. Titanium was found to be associated with sulfur, calcium, iron, and barium. Rheingrover ( jt) identified the source of titanium as a paint-pigment factory located to the south of station 112. The zinc factor, associated with the elements chlorine, potassium, iron and lead, is attributed to refuse incinerator emissions. This factor could also represent particles from zinc and/or lead smelters, though a high chlorine concentration is usually associated with particles from refuse incinerators ( ). The sulfur concentration in the refined sulfate factor is consistent with that of ammonium sulfate. The calculated lead concentration in the motor vehicle factor of ten percent and a lead to bromine ratio of about 0.28 are typical of values reported in the literature (25). The concentration of lead in... 

Hydroprocessing is utilized to reduce fuel sulfur concentrations. Fuels classed as high-sulfur diesel typically contain up to 5000 ppm of sulfur. Fuels classed as low-sulfur diesel typically contain up to 500 ppm of sulfur. Ultra-low sulfur or sulfur-free fuels typically have sulfur values of 15 ppm or less. 

Despite the high reactivity and the low cost of the reagents, the use of sulfuric acid is however connected with some disadvantages. First of all, because it captures all the water liberated, it cannot be recycled directly without a high temperature dehydrating step (sulfuric concentration SC). If no SC is operated, the outcoming aqueous sulfuric acid has to be neutralized and produces highly salty effluents, non desirable for the environment. Furthermore, dilute sulfuric acid can produce severe corrosion problems of the reaction vessels. 

Black et al. (89) found the overall oxidation to go almost completely to sulfate within the first minute of the reaction at pH of slightly less than 5 but the extent of reaction decreased with increasing pH to minimum at about pH 9. Choppin et al. (90), in their studies with hypochlorite, found a distinct minimum in the production of sulfate in the region of about pH 10, with increased sulfate formation at values above and below this point. In addition, they found high sulfide concentrations increased the formation of sulfur and high hypochlorite concentration increased sulfate formation. 

Great Salt Lake. During the past 25,000 years, Great Salt Lake has varied from the deep (300 meters), freshwater Lake Bonneville to a very shallow (<8 meters), highly saline lake. The first-order expectation for sulfur concentrations in a lake alternating between fresh water (low sulfate) and saline water (high sulfate) are ... 

---