Biosorption and desorption of cadmium(II) by biomass of Laminaria japonica.
Biosorption and desorption properties of cadmium(II) from aqueous solutions by the biomass of marine alga Laminaria japonica were investigated. Results indicated that the uptake capacities were solution pH dependent and a maximum uptake capacity of about 1.3 mmol g-1 (dry weight) was observed at pH 6. The adsorbed cadmium cannot be desorbed by distilled water, but it can be effectively recovered by using acidic or EDTA solutions. The equilibrium isotherms can be described well with the Langmuir adsorption equation. Biomass, pre-treated with calcium solution exhibited a higher (about 30%) uptake capacity and can be easily settled from aqueous solutions. Batch kinetics experiments indicated that more than 90% of the adsorption occurred within 20 minutes of agitation and equilibrium was reached within one hour. Fixed-bed experiments showed similar uptake capacities to those of batch results and sharp breakthrough curves were obtained. This study indicated that the biomass of L. japonica can be used as an efficient biosorbent for the removal and recovery of cadmium(II) from waste water streams.
Yin
P
P
Department of Chemistry, Jinan University, Guangzhou 51063, P.R. China.
Yu
Q
Q
Lin
Z
Z
Kaewsarn
P
P
D000327:Adsorption; D001673:Biodegradation, Environmental; D018533:Biomass; D002104:Cadmium / Q000493:pharmacokinetics*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007795:Laminaria / Q000502:physiology*; D012995:Solubility; D013696:Temperature; D014867:Water; D014874:Water Pollutants, Chemical / Q000493:pharmacokinetics*
D014874:Water Pollutants, Chemical; D002104:Cadmium; D014867:Water