Original Articles: 2011 Vol: 3 Issue: 1
Biosorption of Cr3+, Pb2+, and Cd2+ ions from aqueous solution using modified and unmodified millet chaff
The potential of both the modified and unmodified millet chaff- an agricultural solid waste as adsorbent were investigated in this work. The adsorbent was used to remove Pb2+, Cr3+ and Cd2+ ions from aqueous solution. The effects of contact time, pH, temperature, concentration and adsorbent dose in addition to adsorption isotherm were investigated. The result showed that both the modified and unmodified millet chaff sorbed more than eight-five percent of the metal ions investigated. For the time dependent study, metal ion adsorption onto the chaff biomass was very rapid within 30 to 120 minutes. The optimum pH for the metal binding to the biomass was found at 4.5 while at the room temperature of 300C, the metal binding was effective. As the adsorbent dose increased from 0.5g to 2.0g, the higher the metal ions adsorption unto the millet biomass. The sorption process was examined by means of Langmuir isotherm. The result showed that Langmuir model provides an appropriate description of metal ion sorption process unto millet biomass. This result showed that millet chaff biomass is good adsorbent for the removal of metal ions from aqueous solution.