Due to rapid industrialization and population growth uncontrolled release of heavy metals are entered into the waters. Among these heavy metals Pb(II) is one of the major toxic metal and in recent years the production and consumption of lead is increasing worldwide. Pb(II) can be entered to aqueous streams from several industries and can enter into the humans food chain through drinking water and crop irrigation. Lead can causes severe damage to the kidney, nervous system, reproductive system, liver and brain. The permissible level for lead in drinking water is 0.05 mg/l. Thus in recent years a number of methods and materials were developed to removal Pb(II) from aqueous solutions. Among these material bio-chars obtained from plant materials have gained special attention due to their low-cost and abundant nature. In present investigation we have developed magnetic bio-char composite from pine bark. Pine trees are wide spread throughout the South Korea and the bark from pine tree has no commercial use and is available as waste. Thus we have utilized this waste inexpensive material from preparing bio-char composite. The pin bark obtained was initially made into fine powder and washed several times with water and was filtered. To this powder an appropriate amounts of nitrate salts of cobalt and iron dissolved in ethanol solution was added and stirred for 15 minutes. This solution was oven dried at 70℃ and this was further calcined at 900℃ in nitrogen atmosphere. As obtained material was washed several times with water and dried in oven over night. This was used as adsorbent for treating lead contaminated aqueous solutions. As obtained bio-char composite was used to remove Pb(II) from aqueous solutions. Various parameters influencing Pb(II) removal like initial pH, contact time and initial concentration were studied. Effect of pH on Pb(II) removal was studied in the pH range from 2-8 at Pb(II) concentration 10 mg/L using an adsorbent dose of 300 mg. At below pH 3 a lower percent removal was observed whereas above pH 4>90% removal was observed. Further effect of contact time on Pb(II) removal was studied from time range between 10-180 min. Two kinetic models pseudo-first, pseudo-second-order models were used to evaluated the kinetic data and found that the data was better fitted to the pseudo-second-order model. From the overall results it was found that as prepared magnetic bio-char composite prepared from pin bark waste was effective and economic for treating Pb(II) contaminated aqueous solutions.

• D. Harikishore Kumar Reddy(Department of Environmental Engineering, Kwandong University)
• Hyun-Hun Jung(Department of Environmental Engineering, Kwandong University)
• Seung-Mok Lee(Department of Environmental Engineering, Kwandong University)