Adsorption of Cu(II) ions from aqueous solutions on biochars prepared from agricultural by-products.
In this study, the adsorption of Cu(II) from aqueous solutions by agricultural by-products, such as rice husks, olive pomace and orange waste, as well as compost, was evaluated. The aim was to obtain sorbent materials (biochars) through hydrothermal treatment (300 °C) and pyrolysis (300 °C and 600 °C). The effect of adsorbent dose, pH, contact time and initial Cu(II) concentration in batch-mode experiments was investigated. The optimum Cu(II) adsorption conditions was found to occur at 5-12 g/L adsorbent dose, initial pH 5-6, and reaction time 2-4 h. Furthermore, the adsorption kinetics were best described by the pseudo-second order model for all the tested materials, while the adsorption equilibrium best fitted by the linear and Freundlich isotherms. Comparing rice husks and olive pomace, the higher adsorption capacity resulted after pyrolysis at 300 °C. With respect to the orange waste and compost, the highest adsorption capacity was observed using biochars obtained after hydrothermal treatment and pyrolysis at 300 °C.
Department of Environmental Engineering, Technical University of Crete, Politechnioupolis, 73100 Chania, Greece.
Frantseska-Maria
FM
Pellera
Apostolos
A
Giannis
Dimitrios
D
Kalderis
Kalliopi
K
Anastasiadou
Rainer
R
Stegmann
Jing-Yuan
JY
Wang
Evangelos
E
Gidarakos
D000327:Adsorption; D032084:Citrus sinensis / Q000737:chemistry; D003300:Copper / Q000302:isolation & purification*; D019649:Food Industry; D006361:Heating; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D007700:Kinetics; D031658:Olea / Q000737:chemistry; D012275:Oryza / Q000737:chemistry; D012987:Soil / Q000737:chemistry; D012996:Solutions; D013696:Temperature; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
D007220:Industrial Waste; D012987:Soil; D012996:Solutions; D014874:Water Pollutants, Chemical; D003300:Copper