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A novel adsorbent (FeOOH@PU) for hexavalent chromium [Cr(VI)] removal was synthesized using a polyurethane foam (PU) and FeOOH via a facile one-step method. Scanning electron microscopy (SEM), FTIR, X-ray photoelectron spectroscopy (XPS), and energy dispersive spectroscopy (EDS) characterized the adsorbent. The influence of environmental factors was investigated to evaluate the adsorption behavior for Cr(VI). Furthermore, adsorption dynamic and adsorption isotherm models described the adsorption performance. This adsorbent also treated electroplating wastewater and remediated simulated Cr(VI) contaminated soil. The adsorbent effectively removed Cr(VI) with a high adsorption rate; its equilibrium rate constant was 13 times that of FeOOH. Cr(VI) removal was a monolayer adsorption process and the maximum adsorption capacity of FeOOH@PU reached 34.9 mg Cr/g. Electrostatic attraction was the mechanism of Cr(VI) removal. Electroplating wastewater became clear and the Cr(VI) concentration decreased from 9.76 to 0.042 mg/L after treatment with FeOOH@PU. Cr enrichment in rice seedlings grown in remediated soil decreased from 7.687 to 6.295 mg Cr/kg. These results suggested that FeOOH@PU was a promising adsorbent for Cr(VI) removal and Cr(VI) stabilization. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) was prepared by using the natural graphite as raw materials via the modified Hummers’ method and ultrasonic stripping method. GO was reduced online after its anchoring on the surface of polyurethane sponges by a dip-coating method, then in situ reduced graphene oxide-based polyurethane (IRGOPU) sponges were fabricated. The characterizations of IRGOPU sponges were investigated using Field emission scanning electron microscope (FESEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and contact angle measurement. The IRGOPU sponges had an adsorption capacity for a broad range of oils up to 21.7 ~ 55 g/g. A simulation experiment of large-scale oil spill using a simple IRGOPU sponge hollow tube component was designed. The process of continuous oil removal from water surface was quick and effective, and the oil/water separation efficiency could be up to 99.6%. The results indicated that the IRGOPU sponge hollow tube may be an optimum candidate for the oil/water separation of large-scale oil spill. [ABSTRACT FROM AUTHOR]