Phytoremediation of municipal biosolids: Terrestrial and wetland approaches
Growth room experiments were conducted to examine terrestrial and wetland-based phytoremediation approaches as alternatives to biosolids management. Results from both experiments show that biosolids do not need to be amended with soil to encourage plant growth and optimize biomass yields. In the terrestrial phytoremediation approach, two harvests per growth cycle produced greater switchgrass biomass yield than a single harvest but had no significant effect on cattail biomass yield during the first cycle. Repeated harvesting also significantly increased mean nutrient uptake in Cycle 1, reflecting the greater biomass yield from two harvests compared with a single harvest. In the wetland experiment, nutrient phytoextraction under two harvests was 4.25% of initial N content and 2.28% of initial P content compared with 2.9% and 1.58%, respectively, under a single harvest. Terrestrial phytoremediation could be beneficial to small communities that cannot afford the costly excavation, trucking, and eventual spreading of biosolids on agricultural land.
Phytoremediation, constructed wetland