Adsorption of Congo Red (CR) from aqueous solution onto chitosan was investigated in a batch system. The effects of solution pH, initial dye concentration, and temperature were studied. Results indicated that chitosan could be used as a biosorbent to remove the azo dyes from contaminated water. Synthesize of chitosan involved three main stages as preconditioning, demineralization, deproteinization and deacetylation. Chitosan was characterized using Fourier Transform Infrared Spectroscopy (FTIR) and solubility in 1% acetic acid.

In this study, three heavy metals (mercury, nickel and copper) in twenty eight canned fish and meat samples were determined by atomic absorption spectrophotometer. The metal contents, expressed in ppm (mg/ L), varied from 0.01 to 3 ppm in canned fish and from 0.001 to 2 ppm in canned meat for mercury, from 0.0001 to 0.0003 ppm in canned fish and from 0.0001 to 0.0007 ppm in canned meat for a nickel, and from 0.001 to 0.01 ppm in canned fish and from 0.001 to 0.1 ppm in canned meat for copper. The results of this study showed the concentration of mercury in fish and meat samples exceed normal levels, and statistical analysis of results by ANOVA showed significant differences between fish and meat in some samples for mercury.