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The heavy metals and organic substances has deterioration of the ecosystem, resulting in serious environmental pollutions, thus urgent solutions need to be developed in treating these waste water problems. Functional compounds modified 3D polyurethane foams, with high surface to volume ratio has paid much attentions due to their high efficiency of absorption capability. In this study, polyethyleneimine (PEI) was used to incorporated into polyurethane foam (PUF) loaded with sodium carboxymethylcellulose (SCMC), resulting in a cross-linked, 3D interconnective porous polyurethane foam (PCPUF). The results of adsorption experiments demonstrated that PCPUF exhibited a strong adsorption capacity for both MO and Cd2+, with corresponding maximum adsorption capacity of 415.198 mg/g (at 328 K, pH 7) and 166.48 mg/g (at 343 K, pH 7), respectively. Furthermore, the results of cyclic adsorption experiments showed that the removal rates of MO and Cd2+ after five cycles are 90 % and 85 %, respectively, indicating that PCPUF has a good recyclability. Therefore, 3D porous polyurethane foams show promise as an effective adsorbent for removing metal ions and organic substances. [Display omitted] [ABSTRACT FROM AUTHOR]

A convenient and effective method was developed to fabricate zirconium-based calcium sulfate whiskers (Zr-CSWs), an environmentally friendly adsorption material designed to clean excessive fluoride from wastewater. Zr-CSWs, which potentially provide high adsorption activity toward fluoride in wastewater, overcome an aggregation problem typical of Zr-based species that may block the pore structure of the supporting material and degenerate its treatment performance. The results indicate that Zr-CSWs show excellent equilibrium adsorption capacity compared to other Zr-based materials in practical water solutions with pH values of 6–7. The adsorption of fluoride on Zr-CSWs was further evaluated in accordance with the Langmuir equation and the pseudosecond-order model. Coexisting anions had a minor effect on the removal of fluoride, and a strong alkali solution regenerated the used adsorbent. Density functional theory (DFT) calculations were performed to determine the mechanism of fluoride removal. The calculations demonstrated that the removal of fluoride by Zr-CSWs was mainly achieved by ion exchange between fluoride ions and OH- on the surface of the adsorbent, where a protonation process created low-coordination Zr atoms. [Display omitted] • Zirconium decorated calcium sulfate whisker (Zr-CSW) was prepared in a simple and low-cost way. • Zr-CSW has high capacity and good selectivity for the removal of fluoride in water. • The adsorption follows Langmuir model and pseudosecond-order dynamic equation. • The mechanism for fluoride removal has been revealed by density of functional theory (DFT). [ABSTRACT FROM AUTHOR]