Toxicity of Effluent from a Titanium Dioxide Factory on some Marine Animals

Toxicity of effluent from a titanium dioxide factory containing sulphuric acid residue with soluble iron metallic salts and insoluble material such as silica, etc. on fishes, decapods and molluscs was studied. The effluent caused changes in pH and oxygen depletion of the sea water. Sublethal effects of the precipitate of ferrous salts were also studied. Dilutions of effluent up to 1:150 were LC100 for all organisms used while 1:200 dilution was LC50 for fishes at 36 hr and for other organisms at 48 hr. But death of organisms at this concentration was caused by pH changes and oxygen depletion and did not account for the effects of the precipitate. Below this level precipitation started soon after mixing with sea water causing death of organisms by choking their gills and siphons. Dilutions,< 1:1000 were 96 hr LCO.

Investigations on some amino acid based single crystals for nonlinear optical applications and amino acid capped nanocrystals

Organic crystals possess extremely large optical nonlinearity compared to inorganic crystals. Also organic compounds have the amenability for synthesis and scope for introducing desirable characteristics by inclusions. A wide variety of organic materials having electron donor and acceptor groups, generate high order of nonlinearity. In the present work, a new nonlinear optical crystal, L-citrulline oxalate (LCO) based on the aminoacid L-citrulline was grown using slow evaporation technique. Structural characterization was carried out by single crystal XRD. It crystallizes in the noncentrosymmetric, orthorhombic structure with space group P21 P21 P21. Functional groups present in the sample were identified by Fourier transform infra red (FTIR) and FT-Raman spectral analysis. On studying the FTIR and Raman spectra of the precursors L-citrulline and oxalic acid, used for growing L-citrulline oxalate crystal, it is found that the significant peaks of the precursors are present in the spectra of the L-citrulline oxalate crystal . This observation along with the presence of NH3 + group in the spectra of L-citrulline oxalate, confirms the formation of the charge transfer complex