A technique for preparing heterobimetallic frameworks with tunable metal sites is demonstrated by the synthesis of a new two-dimensional metal-organic framework that is constructed from tetra(4-carboxyphenyl)porphyrin and Cd(II) species. The solid can be prepared in the presence of other divalent transition metals to yield the same framework with the smaller metal ions occupying the porphyrin l...

Enhancing the robustness of functional biomacromolecules is a critical challenge in biotechnology, which if addressed would enhance their use in pharmaceuticals, chemical processing and biostorage. Here we report a novel method, inspired by natural biomineralization processes, which provides unprecedented protection of biomacromolecules by encapsulating them within a class of porous materials t...

A rapid and simple method is described for the preconcentration and discrimination between the organic fraction and the labile fraction of the metals Mn, Cd, Cu, Z, V, Ni, Pb, and Fe from seawater using 8-hydroxyquinoline, which forms neutral complexes with these metals, followed by adsorption on C18 chemically bonded silica gel. The sample flow rate through the C18 column was about 4 ml min. T...

Hussainsagar lake in the heart of Hyderabad city receives domestic sewage and industrial effluents through five streams draining the catchment area of 245 sq. km around the lake. Lake used to receive untreated industrial effluents through streams during 1970 -1990. Over the years, sediments in the lake have adsorbed the heavy metals and have reported elevated concentrations. Metal speciation of...

Concentrations of Hg, total organic carbon (TOC), Al, Fe and Mn were determined in sediment of the Amba Estuary between the mouth and the head over a distance of 24 km in December and May during 1997-2002. Temporal and spatial changes in metal concentrations appear to be due to sediment movement associated with tidal movements. The Hg concentration varies in 0.05 -2.66 μg g range and the profil...

An analyticai procedure involving Sequential chemical extractions has been developed for the partitioning of Particulate trace metals (Cd, Co, Cu, Ni, Pb, Zn, Fe, and Mn) into five fractions: exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter, and residual. Experimental results obtained on replicate samples of fluvial bottom sediments demonstrate that the relative...