http://dr.lib.sjp.ac.lk/handle/123456789/1357 Wed, 07 Jan 2026 03:59:27 GMT 2026-01-07T03:59:27Z http://dr.lib.sjp.ac.lk/handle/123456789/8403 Clay-biochar composites for sorptive removal of tetracycline antibiotic in aqueous media Premarathna, K.S.D.; Rajapaksha, Anushka Upamali; Adassoriya, Nadeesh; Binoy Sarkar, Binoy; Sirimuthu, Narayana M.S.; Cooray, Asitha; Ok, Yong Sik; Vithanage, Meththika The focus of this research was to synthesize novel clay-biochar composites by incorporating montmorillonite (MMT) and red earth (RE) clay materials in a municipal solid waste (MSW) biochar for the adsorptive removal of tetracycline (TC) from aqueous media. X-ray Fluorescence Analysis (XRF), Fourier Transform Infrared Spectroscopy (FTIR), Powder X-ray Diffraction (PXRD) and Scanning Electron Microscopy (SEM) were used for the characterization of the synthesized raw biochar (MSW-BC) and clay-biochar composites (MSW-MMT and MSW-RE). Results showed that minute clay particles were dispersed on biochar surfaces. The FTIR bands due to Si-O functional group vibrations in the spectra of the clay-biochar composites provided further evidence for successful composite formation. The kinetic TC adsorption data of MSW-MMT were well fitted to the Elovich model expressing high surface activity of biochar and involvement of multiple mechanisms in the adsorption. The kinetic TC adsorption data of MSW-BC and MSW-RE were fitted to the pseudo second order model indicating dominant contribution of chemisorption mechanism during the adsorption. The adsorption differentiation obtained in the kinetic studies was mainly due to the structure of the combined clay material. The adsorption isotherm data of all the adsorbents were well fitted to the Freundlich model suggesting that the adsorption of TC onto the materials occurred via both physisorption and chemisorption mechanisms. In comparison to the raw biochar and MSW-RE, MSW-MMT exhibited higher TC adsorption capacity. Therefore, MSW-MMT clay-biochar composite could be applied in the remediation of TC antibiotic residues in contaminated aqueous media. Tue, 01 Jan 2019 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/8403 2019-01-01T00:00:00Z http://dr.lib.sjp.ac.lk/handle/123456789/8389 Fluorocarbon Separation in a Thermally Robust Zirconium Carboxylate Metal–Organic Framework Darshika K. J. A. Wanigarathna; Jiajian Gao; Bin Liu Mon, 01 Jan 2018 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/8389 2018-01-01T00:00:00Z http://dr.lib.sjp.ac.lk/handle/123456789/8371 Biofilm mediated synergistic degradation of hexadecane by a naturally formed community comprising Aspergillus flavus complex and Bacillus cereus group Madushika Perera; Dilrukshi Wijayarathna; Sulochana Wijesundera; Manoj Chinthaka; Gamini Seneviratne' Attached Tue, 01 Jan 2019 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/8371 2019-01-01T00:00:00Z http://dr.lib.sjp.ac.lk/handle/123456789/7006 Synthesis, Structural Characterization, and Volatility Evaluation of Zirconium and Hafnium Arnidate Complexes Karunarathne, M.C.; Baumann, J.W.; Heeg, M.J.; Martin, P.D. Attached; Treatment of tetrakis(dimethylamido)zirconium or tetrakis(dimethylamido)hafnium with four equivalents of N-rerr-butylacetamide. N-isopropylisobutyramide. N-isopropylacetamide. N-methylacetamide. or N-terr-butylformamide in refluxing toluene. followed by sublimation of the crude products at 105 -125 °CI0.05 Torr. afforded tetrakis(N-rerr-butylacetamido )zirconium (81 %). tetrakis(Nisopropylisobutyramido )zirconium (87%). tetrakis(N-isopropylacetamido )zirconium (51 %), tetrakis(Nterr-butylacetamido )hafnium (83%), tetrakis( N-isopropyliso-butyramido )hafnium (79%), tetralds(Nisopropylacetamido)hafnium (67%), tetrakis(N-methylacetamido)zirconium (5%), and tetrakis(N-rertbutylformamido)zirconium (1%) as colorless crystalline solids. The structural assignments for the new complexes were based upon spectral and analytical data and by X-ray crystal structure determinations for tetr akisl N-rerr -butylaceta m ido )zircon iurn. tetrakis( N-isopropylacetamido)z ircon iurn, tetrakis( N-isopropylacetamido)hafnium. tetralds(N-methylacetamido)zirconium, and tetrakis(N-rert-butylformamido) zirconium. These complexes are monomeric in the solid state, with eight-coordinate metal centers surrounded by four K 2-N,O-amidate ligands. Six of the eight new complexes undergo sublimation on a preparative scale from 130 to 140 °C at 0.05 Torr, with 84.5-95.8% sublimed recoveries and 0.68-3.06% nonvolatile residues. Tetrakis(N-methylacetamido jzirconium and tetrakis(N-terr-butylformamido )zirconium decompose extensively upon attempted sublimation. Solid state decomposition temperatures for the zirconium complexes range between 218 and 335 "C and 290-360 O( for the hafnium complexes. Tetrakis(N-isopropylisobutyramido)zirconium, tetrakis(N-tert-butylacetamido)hafnium, and tetrakis(Nisopropylacetamido)hafnium exhibit the highest solid state decomposition temperatures in the series, possess good volatility, and have useful properties for chemical vapor deposition and atomic layer deposition precursors. Sun, 01 Jan 2017 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/7006 2017-01-01T00:00:00Z