Removal of heavy metals from wastewater using chitosan

In this research work natural bio polymer “chitosan” was synthesized using locally available shrimp shells and adsorption of chromium by chitosan was studied. Synthesize of chitosan involved four main stages as preconditioning, demineralization, deprotenisation and deacetylation. Chitosan was characterized using Fourier Transform Infrared Spectroscopy (FTIR) and X-ray diffraction (XRD). Both characterization techniques confirm the existence of chitosan. The affinity of chitosan for chromium was studied using K2Cr2O7 solution as the heavy metal solution containing Cr (VI) ions. Adsorption of chromium ions by chitosan was investigated under different conditions. The effect of reaction temperature, particle size of chitosan and pH of solution were studied. Amount of chromium absorbed under different conditions was evaluated using atomic adsorption spectroscopy

First-principles calculation on electronic properties of Bismuth-halide inorganic perovskites for solar cell

Solar energy is a commonly used alternate source of energy and it can be utilized based on the principle of the photovoltaic effect. The photovoltaic effect converts sun energy into electrical energy using photovoltaic devices (solar cells)

Synthesizing and characterization of natural biopolymer chitosan derived from shrimp type, penaeus monodon

In this study natural biopolymer "chitosan" was synthesized using locally available shrimp type of Penaeus monodon. Synthesis of chitosan involved four main stages: preconditioning, demineralization, deprotenisalion and deacetylation. The first stage, "preconditioning " process, is a new step introduced in this research. Effect of deacetylation conditions such as alkali concentration, number of limes deacetylation was performed and reaction temperature was investigated. Yields of chitin and chitosan from R monodon were calculated. Chitosan was characterized using Fourier Transform Infrared (FTIR) Spectroscopy and X-ray diffraction. Degree of deacetylation of synthesized powder was calculated using FTIR spectra. Both characterization techniques confirm the existence of chitosan

Fabrication of dye sensitized solar cells using locally available sensitizers

Dye sensitized solar cells (DSSC) were fabricated using the dyes extracted from locally available natural plants of Mangosteen, Centella, Beetroot, Turmeric. Extracted dyes were analyzed using UV-vis spectrometer. Photo anodes were prepared by using regent grade TiO2 Powder. The TiO2 films were coated on Fluorine doped Tin Oxide (FTO) using doctor blade method and spray coating method. The film quality was examined using X-ray diffractometer and Scanning electron microscope (SEM). The film prepared using spray coating method has better uniformity. DSSCs fabricated using the dye extracted from mangosteen have shown high efficiency than the DSSCs of other dyes. Combined dye absorptions of X (mangosteen and centella) and Y (mangosteen and turmeric) were done to increase the efficiency. The DSSC fabricated with mangosteen and centella combination of dyes yielded the maximum performance

Effect of Reflux temperature on synthesis of hdroxyapatite by wet chemical precipitation technique

In this study, hydroxyapatite HA, [(Ca>o(P04)6(OHi:,j] was synthesized using wet chemical precipitation technique at different reflux temperatures. Calcium hydroxide [Ca(OH)J powder and Phosphoric acid [H3PO4] solution were used as starting materials. Variation in PH value of Ca(OHsuspension during the addition of H}P04 solution was analyzed. The effect of reflux temperature for the synthesis HA was investigated. Characteristics of synthesized powder were analyzed by Fourier transformed infrared (FTIR) spectroscopy and X-ray dijfraction (XRD). The powder characteristic has demonstrated that, the reflux temperature played an important role in the synthesis of pure and single phase HA powder