Biosorption of nickel with barley straw

Wastewater containing nickel sulphate generated from a nickel plating industry is of great concern. In the present work, biosorption of nickel by barley straw from nickel sulphate solution was investigated. Nickel uptake at room temperature (23 ± 0.5 °C) was very sensitive to solution pH, showing a better uptake value at a pH of 4.85 ± 0.10 among the tested values. The nickel biosorption isotherm fitted well the Langmuir equation. When the ionic strength (IS) of the solution was increased from less than 0.02–0.6 M, nickel uptake was reduced to 12% of that obtained at IS of less than 0.02 M. Barley straw showed a higher nickel uptake (0.61 mmol/g) than acid washed crab shells (0.04 mmol/g), demonstrating its potential as an adsorbent for removal of nickel.