Removal of Cr(III) from water by polyurethane foam, green liquor dregs and polyurethane foam incorporated with green liquor dregs

•Chromium contamination of water is widespread due to its industrial uses.•Removal of Cr(III) from water by polyurethane foam, green liquor dregs and their composite was evaluated.•Green liquor dregs (a celulose-rich waste) disaplayed high removal of Cr(III) from water. Chromium compounds are prominent contaminants due to their widespread use in various industries. The limited effectiveness of effluent treatment facilities and the expensive procedures needed for metals removal from water raise serious concerns about water quality. In this study, rigid polyurethane (PU) foam - green liquor dregs composite and their isolated phases were evaluated for removal of Cr(III) from laboratory water amended with Cr(III). The isolated dregs removed 81.93% of Cr(III), with a adsorption capacity of 135.45 mg g−1. On the other hand, the dregs-foam composite displayed a Cr(III) percent removal and adsorption capacity of 36.02% and 57.56 mg g−1, respectively; and was comparable to plain PU. Results indicate that green liquor dregs can be used to remove chromium from water and for the construction of dregs-PU hybrid material for potential extraction of Cr(III) from water.