Selective catalytic reduction (SCR) technology increasingly is being applied for controlling emissions of nitrogen oxides (NOx) from coal-fired boilers. Some recent field and pilot studies suggest that the operation of SCR could affect the chemical form of mercury (Hg) in coal combustion flue gases. The speciation of Hg is an important factor influencing the control and environmental fate of Hg...

Non-road diesel engines are significant contributors to air pollution in the United States (USEPA, 2004). These engines emit particulate matter (PM), nitrogen oxides (NOx), sulfur dioxide (SO2), and other pollutants. The Clean Air Non-road Diesel Rule was put in place to reduce emission levels from agricultural, construction, and industrial diesel powered equipment. This rule calls for a reduct...

Iron(III) (oxyhydr)oxides can represent the dominant microbial electron acceptors under anoxic conditions in many aquatic environments, which makes understanding the mechanisms and processes regulating their dissolution and transformation particularly important. In a previous laboratory-based study, it has been shown that 0.05 mM thiosulfate can reduce 6 mM ferrihydrite indirectly via enzymatic...

The rate coefficient, k, of the reaction is, however, the same as for R34 of WAE, i.e., k = 3.6 10 12 cm s . The above correction in R34 impacts the SO2 abundance and lifetime somewhat, as discussed below. [2] Once in the atmosphere, SO2 is photodissociated to produce SO, which is further photodissociated to form sulfur atoms. The reaction of SO with O2 or OH recycles sulfur atoms back to SO2 (...

Elemental sulfur (S8) is often present in considerable amounts in sour gas reservoirs at the reservoir conditions (pressure and temperature). For the isothermal conditions in the reservoir, the reduction in reservoir pressure below a critical value will cause the elemental sulfur to deposit in the formation. Sulfur deposition can cause severe loss in the pore space available for gas, and in tur...

BACKGROUND Elemental sulfur exists is a variety of forms in natural systems, from dissolved forms (noted as S8(diss) or in water as S8(aq)) to bulk elemental sulfur (most stable as α-S8). Elemental sulfur can form via several biotic and abiotic processes, many beginning with small sulfur oxide or polysulfidic sulfur molecules that coarsen into S8 rings that then coalesce into larger forms: [For...

Chromate (CrVI) reduction by sulfide was conducted in anaerobic batch experimental systems. The molar ratio of the reduced CrVI to the oxidized S(-II) was 1:1.5 during the reaction, suggesting that the product of sulfide oxidation was elemental sulfur. Under the anaerobic condition, the reaction was pseudo first order initially with respect to CrVI, but the rate was dramatically accelerated at ...

Sulfur dioxide (SO2) is a gaseous environmental pollutant which is routinely used in industry as a preservative and antimicrobial. Recent data suggests that SO2 may have value as a therapeutic agent. However, due to its gaseous nature, localizing SO2 generation is challenging. Herein, various 1,3-dihydrobenzo[c]thiophene 2,2-dioxides (benzosulfones) were prepared as candidates for photochemical...