Ecophysiological characteristics and biogas production of cadmium-contaminated crops

The present study proposes a novel strategy to get a rational production of biogas of the biomass residues from phytoremediation. This study investigates physiological responses, cadmium (Cd) accumulation and biogas production from canola, oat and wheat in pot and batch experiments. The results indicate that (1) aerial biomasses for canola, oat and wheat were enhanced by 5 mg Cd/kg soil by 19.41%, 8.78% and 3.38%, and the upper limit of Cd concentration that canola, oat and wheat can tolerate for aerial biomass production were 50, 10 and 10 mg Cd/kg soil; (2) canola accumulates more Cd than oat and wheat in its aerial parts; (3) cumulative biogas yields were 159.37%, 179.23% and 111.34% of the control when Cd in the shoot were 2.00 ± 0.44, 39.80 ± 1.25 and 6.37 ± 0.15 mg Cd/kg biomass for canola, oat and wheat. Phytoremediation in cooperation with bioenergy production provide new insights for both soil remediation and energy research.