Waste sludge may be used to recovery wastewater contaminated with heavy metals. The waste sludge is an inexpensive readily available source of biomass for biosorption with metal-bearing wastewater. The biosorption of heavy metals such as Pb(II), Cu(II), Cr(II), and Cd(II) onto waste sludge was investigated in batch experiments and waste sludge loaded heavy metals was separated by dissolved air flotation. The biosorption equibria of heavy metals could be described by Langmuir and Freundich isotherms. The adsorption capacity for waste sludge was in the sequence of Pb(II)>Cr(II)>Cu(II)>Cd(II). The system attained equilibrium about 20 min. The Langmuir and Freundlich adsorption model effectively described the biosorption equilibrium of Cu(II) and Cr(II) ions on waste sludge. Maximum adsorption capacity of Cu(II) and Cr(II) were 196.08 and 158.73 mg/g, respectively. Solid-liquid separation efficiencies were kept above 95% on waste sludge loaded heavy metals, and were decreased with pH increasing.

• 이창한(부산가톨릭대학교 환경과학부) | Chang-Han Lee
• 안갑환(부산가톨릭대학교 환경과학부) | Kab-Hwan Ahn Corresponding Author