Fabrication of a novel immobilization system and its application for removal of anthracene from soil

• A novel immobilization system, Ca-alginate/poly-ε-caprolactone/corn-cobs, was fabricated.
• Cost reduction is got by encapsulating mushroom mycelia instead of enzymes.
• Removal of ANT reached 96.2% in soil after 20 days of incubation.
• The ANT removal from soil followed third-order reaction model.
• Extreme environment factors have little influence on ANT removal.

The remediation of anthracene (ANT) polluted soil has become a concern due to its difficult diffusion from soil particles and adverse impacts on environmental and human health. To remove ANT from soil efficiently, Ganoderma lucidum (G.lucidum) mycelia pellets combined with corn-cobs were encapsulated in hydrophobically modified Ca-alginate (CA) by poly-ϵ-caprolactone (PCL), without the need for enzyme purification. The optimum PCL concentration in CA/PCL/corn-cobs bead was 12%, which provided enzymes secreted by the G.lucidum mycelia with a good storage stability and a similar activity to the immobilized laccase. Scanning Electron Microscope and Brunauer–Emmett–Teller method were applied to characterize the bead. CA/PCL/corn-cobs ensured the highest ANT removal efficiency regardless of different pH values and temperatures. The ANT removal from soil followed third-order reaction model. Removal of ANT reached 96.2% ± 2.0% from soil after 20 days of incubation at pH 5.0 and 45 °C, which is attributed to the fast secretion of enzymes stimulated by lignocellulosic substances of the corn-cobs, the protection of enzymes by matrix capsules, and the strong adsorption of ANT on the relatively hydrophobic surface of bead. The efficient ANT removal was also observed in aged soil samples simulated by addition of soil organic matter.

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