*2.2.1 Synthesis of pine-magnetite composites*

A mixture of FeSO47H2O (2.1 g) and of Fe(SO4)3XH2O (3.1 g) were dissolved under inert atmosphere in 100 cm3 of double-distilled water with vigorous stirring. Thereafter, 20 cm<sup>3</sup> of 28% ammonium hydroxide and the appropriate amount of pine powder was added. The reaction was left to run for 45 min at 80°C under constant stirring. The resulting particles, consisting of magnetite attached to the cellulose (hereafter referred to as bio-composite) were washed several times with deionized water and ethanol and dried in a vacuum oven at 60°C overnight. To determine the optimum conditions to achieve the desired products of the biocomposites, we experimented with the following variables: volume of NH4OH 5, 10, 20, 30, and 40 cm<sup>3</sup> ; weight of pine powder 1.0, 1.5, 2.0, 2.5, 3.0 and 3.5 g; temperatures 40, 60, 80 and 100°C and reaction times 15, 30, 45 and 60 min.

## *2.2.2 Synthesis of grafted pine magnetite composite*

1 g of pine magnetite composite (PMC), 20 ml of 1.5 M acrylicamide and 135 ml of deionised water were transferred into a three neck round bottom flask at a temperature of 42°C. The reaction was bubbled under nitrogen gas for 30 min to remove the dissolved oxygen under stirring. 10 ml of 0.5 M CAN, dissolved in 0.3 M HNO3 was slowly added to the reaction to initiate graft co-polymerization and stirring was continued for 2 h. Reaction mass was neutralised by 50% NaOH and precipitated in methanol and thereafter washed with methanol/water (90:10) several times, so that the unreacted PMC and ceric salt were removed. The final residue was dried in a vacuum oven at 40°C.
