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Heavy metal biosorption from aqueous solutions by algae inhabiting rice paddies in Vietnam

2016; Elsevier BV; Volume: 4; Issue: 2 Linguagem: Inglês

10.1016/j.jece.2016.04.038

2213-3437

Hang Thi Tran, Ngo Dinh Vu, Masahito Matsukawa, Maiko K. Okajima, Tatsuo Kaneko, Kaori Ohki, Shinya Yoshikawa,

Heavy metals in environment

The gelatinous colonies collected from rice fields in Phu Tho Province, Viet Nam (Al-VN) were investigated to remove heavy metal ions from water for the first time. The biosorption of Cu2+, Cd2+ and Pb2+ by dried Al-VN was tested at various pHs, temperatures, contact times, biosorbent doses and initial metal ion concentrations under laboratory conditions. Metal ion adsorptions on Al-VN were strongly dependent on pH, with the optimum pH for adsorption of Cu2+, Cd2+ and Pb2+ solutions being 4, 5–7 and 5–6, respectively. The biosorption capacity of metal ions by Al-VN was independent of temperature. After one hour of contact time, the adsorption capacity reached equilibrium. The maximum adsorption capacity (qm) of Cu2+, Cd2+ and Pb2+ was 27.78, 28.57 and 76.92 mg/g, respectively. Both the Langmuir and Freundlich adsorption models were suitable for biosorption of Cu2+, Cd2+ and Pb2+ by Al-VN. The desorption studies indicated that 0.1 M HNO3 was an efficient desorbent for recovery of Cu2+, Cd2+ and Pb2+, and the maximum desorption was >90%. These results indicate that Al-VN can be used as an efficient and economic biosorbent for the removal and recovery of toxic heavy metal ions from polluted water.