Utilization of reeds to sequester Ni and/or Cu from wastewater and to produce valuable products

Abstract

Abstract This project evaluated the potential of common reed to uptake Ni and Cu from wastewater and then investigated the feasibility of converting the resulted biomass to valuable products. Common reeds were grown in 25, 50, or 75 ppm Ni and/or Cu solutions for 4 weeks to evaluate its potential to uptake metals followed by converting the contaminated biomass to valuable products by hydrothermal conversion (HTC). The higher concentration of metals in solution, the more metals accumulated in plants. The amounts of metals accumulated in different parts of reeds were root > stem > rhizome ~ leave. Roots and stems treated with binary metals contained less Ni/Cu than those cultured in single metal. The yields of bio-oils and hydrochars from reeds treated with different levels of metals were similar. About 6%-10% of bio-oil, 50%-60% of hydrochars were produced. The results suggest that metal accumulated in reeds does not affect the utilization of contaminated reeds via HTC. About 0.1–1.5% of Cu and/or Ni were transmitted from contaminated reeds to bio-oils after HTC at 250°C.