BIOSORPTION OF CHROMIUM (VI) FROM AQUEOUS SOLUTION USING HUSK OF ANACARDIUM OCCIDENTALE L.

Chromium (Cr) (VI) is an acutely toxic and carcinogenic metal ion. It is mobile in environment and is widely used in electroplating, stainless steel production, leather tanning, paint and textile manufacturing. Due to its known harmful effects, a focus on methods to remove this harmful metal ion is very important. In our study, we examined the potential ability of pre-treated testa (husk) of Anacardiumoccidentale (Cashew) in removal of Cr (VI) from aqueous solutions when usedas an adsorbent. We looked at effects of temperature, pH, initial concentration of adsorbate, and adsorbent dosage on effective removal of Cr (VI). Data obtained was analyzed using Freundlich and Langmuir adsorption isotherms at different temperatures and related parameters for each adsorption isotherm were determined. The Langmuir adsorption potential was found to be 56.9 mg/g and the Freundlich constants Kf and n were 1.002 [mg/g (1/mg) n] and 3.4. The study also included results on the kinetic dimensions of adsorption of the Cr (VI) on derived adsorbent. Fourier transform infrared spectroscopy (FTIR) studies confirmed that carboxyl and hydroxyl groups were the main groups involved in the metal uptake. Abbreviations:-Cr- Chromium; FTIR – Fourier transform infrared spectroscopy; ppm – parts per million.