Inertization of metals and hydrogen production as a byproduct from water hyacinth and water lettuce via plasma pyrolysis.

Water hyacinth and water lettuce have been extensively used for phytoremediation of metals and metalloids. However, the reasonable disposal of phytoremediation plants is a difficult problem. This study aims to reduce metals and metalloids from water hyacinth and water lettuce, and produce hydrogen (H) and methane (CH) via an atmospheric-pressure microwave plasma reactor based on the circular economy concept. Inertization of metals and metalloids can be obtained by more than 60% for both water hyacinth and water lettuce. H and CH production of water hyacinth and water lettuce were 56.28%/57.30% and 3.75%/2% of volume fractions, respectively. Furthermore, total VOCs concentrations from the effluent gas were detected only at the values of 0.511% (water hyacinth) and 0.08% (water lettuce) of volume fractions, respectively. Overall, water hyacinth and water lettuce treated by atmospheric-pressure microwave plasma showed the potential of H and CH production as a by-product for alternative energy and inertization of metals/metalloids for the phytoremediation plants.