Biodegradability and waste behavior of industrial wood-based construction materials

Abstract

Industrial wood-based construction materials: chipboard, plain and overlaid plywood, phenolic surface film, laminates and selected synthetic polymers were studied for their biodegradability under aerobic and anaerobic conditions and for the environmental quality of the degradation residue. The yields of carbon dioxide plus methane from the wood-based materials in 6 months under anaerobic conditions at 33°C ranged from ⩽3% to 79% compared to that obtained from starch, and under aerobic conditions from ⩽7% to 55% of that obtained from acetate, measured in 28 days at 25°C. The plywoods were more readily degraded under aerobic and anaerobic conditions. The microbes attacked mainly the S2-layer of the plywoods and started from the S3-layer of the wood cells of chipboard in the compost. Extensive cavities, occupied with microbes, were observed by electron microscopy in the decaying plywoods, chipboard and laminates. The contents of Cu, Cr, Pb, Ni, and Cd of the wood-based construction materials were low, <10 mg kg−1, compared to PVC and to a typical municipal solid waste. Toxicity and the amount of leachable organic halogen from the wood-based construction materials were low, EC50 of 4–8 g L−1 to V. fischeri and <12 μg adsorbable organic halogen (aox) of g−1. The results show that the wood-based construction materials studied were aerobically biodegradable and the plywoods also anaerobically. There was no toxicity towards photobacteria or substances of environmental concern in the biodegradation and incineration residues of the materials tested. Journal of Industrial Microbiology & Biotechnology (2000) 24, 210–218.