Optimization of adsorption of nickel by silybum marianum

Heavy metals have been a major preoccupation for many years because of their toxicity towards aquatic life, human beings and the environment. [1]. A number of technologies such as adsorption, precipitation, solvent extraction, ion exchange have been developed for the removal of metal ions [2]. Adsorption is now recognized as an effective and economic method for heavy metal wastewater treatment. The adsorption process offers flexibility in design and operation and in many cases will produce high-quality treated effluent [3]. Biosorption of heavy metals from solutions is a new process that has been confirmed a promising process in the removal of heavy metal. The major advantages of biosorption are its high effectiveness in reducing the heavy metals and the use of inexpensive biosorbents [3]. This investigation focuses on the potential use of Silybum marianum as adsorbent for the removal of Nickel. The adsorption studies were carried out under various parameters, such as pH, biosorbent dosage, contact time and initial ion concentration. In this project the most appropriate pH level reported for Nickel was 3. The best time of exposure that has been achieved in this biomass is 60 minutes and it has been observed that after increasing the amount of absorbent to its optimum amount, 2 grams, the amount of adsorption remained unchanged. The experimental results show that the adsorption of Silybum marianum increases with an increase in the adsorbent dosage .The experimental data was tested using different isotherms and their parameter were determined.