Kinetics and products study of the reaction of BrO radicals with gaseous mercury

Bro reactions of elemental mercury was as a major candidate for near complete depletion of elemental mercury in polar region. The kinetics of the reaction between BrO radicals with gaseous mercury was identified using relative rate method by Gas Chromatography with Mass spectroscopic Detection (GC-MS) at room temperature ($298\pm1$ K) and at atmospheric pressure $760 \pm 1$ Torr in the $N_2$ diluent. Propane, DMS and butane were used as reference molecules. The upper and lower limits rate constant for reaction of $\rm Hg^0$ with BrO was estimated to be $1.0 \times 10^{-13}$ and $1.0 \times 10^{15}$ cm$^3$ molecules$^{-1}$ s$^{-1}$, respectively. BrO radicals were produced from the photolysis of bromine and dibromomethane in presence of ozone and detected by MS at $\rm m/e = 95$ or 97. Ozone was produced in a Silent discharged generator. Reaction products were identified using direct mass spectrometer with chemical ionization ion source

Removal of Mercuric Ion from Aqueous Solutions Using Sawdust Coated by Polyaniline

This paper deals with a new application of polyaniline synthesized chemically, coated on sawdust via cast method in the form of emeraldine base (EB) from formic acid as solvent, and used as an effective adsorbent for removal of mercuric ion or other heavy metals from aqueous solution. Among the different parameters investigated, the effect of pH was found to be the most prominent. It was found that metal uptake is occurred under neutral or slightly alkaline conditions, while under relatively strong acidic media, the sorption of the investigated metal ions was negligible and desorption is a predominant process

Some like it cold: microbial transformations of mercury in polar regions

The contamination of polar regions with mercury that is transported from lower latitudes as inorganic mercury has resulted in the accumulation of methylmercury (MeHg) in food chains, risking the health of humans and wildlife. While production of MeHg has been documented in polar marine and terrestrial environments, little is known about the responsible transformations and transport pathways and the processes that control them. We posit that as in temperate environments, microbial transformations play a key role in mercury geochemical cycling in polar regions by: (1) methylating mercury by one of four proposed pathways, some not previously described; (2) degrading MeHg by activities of mercury resistant and other bacteria; and (3) carrying out redox transformations that control the supply of the mercuric ion, the substrate of methylation reactions. Recent analyses have identified a high potential for mercury-resistant microbes that express the enzyme mercuric reductase to affect the production of gaseous elemental mercury when and where daylight is limited. The integration of microbially mediated processes in the paradigms that describe mercury geochemical cycling is therefore of high priority especially in light of concerns regarding the effect of global warming and permafrost thawing on input of MeHg to polar regions