The discharges from industrial processes constitute the main source of copper contamination in aqueous ecosystems. In this study, we investigated the capacities of different types of biochar (derived from chicken manure, eucalyptus, corncob, olive mill, and pine sawdust) to remove copper from aqueous solutions in a continuous-flow system. The flow rate of the system strongly influenced the amount of copper retained. For example, the adsorption to the corncob biochar varied from 5.51 to 3.48 mg Cu g(-1) as the flux was decreased from 13 to 2.5 mL min(-1). The physicochemical characteristics of the biochar determine the copper retention capacity and the underlying immobilization mechanisms. Biochars with high inorganic contents were found to retain the largest amounts of copper and might be suitable for use in water treatment systems for the removal of heavy metals. The copper retention capacities of the biochars investigated ranged between similar to 1..3 and 26 mg g(-1) and varied in the following order: chicken manure > olive mill >> corncob > eucalyptus > sawdust pine.