Two sulfur-mediated reactions are resulting in the eutrophication of Lake Biwa, Japan. The iron (II) phosphate mineral vivianite is dissolving in sulfide-enriched sediments that in places results in porewater concentrations of phosphate exceeding 3 mg l Ϫ1 . The dissolution of phosphate is evident in profiles of total phosphorus where zones of dissolution and a zone of precipitation in the most oxic surface sediments are visible. At times sulfate reduction in these surface sediments results in pH values as high as 9.9, which can dissolve phosphate adsorbed to iron (III). This release of phosphorus from sediments is at least partially responsible for the recent appearance of blue-green algal blooms.
Sediment treatment options include dredging, physical and chemical capping, and in situ sediment treatment. In our studies, in situ sediment treatment has been used to oxidize sediment sulphides, control eutrophication and bioremediate organic contaminants. Sediment contamination of various types was studied in 22 sites from six countries in North America, Europe and Asia. In Hong Kong, field testing of sediment treatment oxidized 99% of sulphide and controlled odours. In Lake Biwa, Japan, where excess nutrients in sediments enhanced growth of toxin producing algae, sediment treatment with calcium nitrate blocked growth of these algae. Oxidation of sulphide in Lake Biwa sediments precipitated > 80% of the porewater phosphorus. Oxidation of sulphides and addition of nutrients biodegraded more than half of the organic contaminants in Hamilton Harbour, Canada. The biotreatability of polynuclear aromatic hydrocarbons is very site specific and is faster in sites with higher concentrations of oil.
Panosialin(I), an enzyme inhibitor, has been shown to be a mixture of 5-alkylbenzene-l,3-disulfates.The structures of the three major components are 5-isopentadecylbenzene-l,3-disulfate (la), 5-?z-pentadecylbenzene-l,3-disulfate (Ib), and 5-isohexadecylbenzene-l,3-disulfate (Ic).The 5-w-alkyl homologs including Ib have been synthesized.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.