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High efficiency and cost-effective remediation technologies are needed to remove tetrachloroethylene (PCE) from the source zones in soil and groundwater systems. This work evaluated the ability of a biodegradable surfactant (Tween 80) coupled with an effective oxidant (Fe 2+ (activation agent)–citrate (chelating agent) activated persulfate (PS, oxidant)) to remove PCE from porous media. Batch experiments were used to optimize the oxidant by testing the effects of PS, citrate, and Fe 2+ concentrations on the PCE degradation. The optimal molar ratio of PS/citrate/Fe 2+ /PCE was 15:15:5:1 for PCE degradation in presence of the surfactant. Four sandbox experiments were performed to compare the effectiveness of the surfactant and the combination of the surfactant with the optimized oxidant in the removal of PCE from homogeneous and heterogeneous porous media. PCE saturation distributions in the sandboxes were quantified using a light transmission system. In addition, the PCE, PS, and Cl − concentrations in the effluents were also monitored during the experiments. While the Tween 80 solution removed about 52% and 67% of PCE from the homogeneous and heterogeneous porous media; the combination solution was more effective with removal rates of 80% and 84%, respectively. The enhanced PCE removal was due to the combined effects of the surfactant solubilization and PS oxidation: (1) Tween 80-enhanced solubilization resulted in an enlarged effective contact and reaction between PCE and PS; and (2) PS degraded the PCE from the soluble phase and thus facilitated its dissolution from the source zone, resulting in more efficient use of Tween 80. Findings from this work indicate that the combination of surfactant and oxidant can provide an effective way for the remediation of PCE in soils and groundwater.

A non-covalent modified boron nitride(n-CMBN) was obtained by non-covalent modification successfully and used to prepare poly(ether ether ketone)(PEEK) composites. The non-covalent modifier is polyetherimide(PEI), which has high compatibility with PEEK. Particularly, only a small amount of PEI was used to modify BN, which made the thermal conductivity of 30 wt% n-CMBN/PEEK reached 1.01 W·(m·K)−1, 16% higher than that of BN/PEEK. Modified Hashin-Shtrikman model demonstrated that n-CMBN/PEEK possessed 7% lower total thermal resistance compared with BN/PEEK. Moreover, the tensile strength and elongation at break remains above 99.0 MPa and 14.6% respectively, demonstrating the relatively good mechanical properties in high thermally conductive composites. The introduction of 10 wt% n-CMBN decrease the friction coefficient of PEEK composites, which was as low as 0.33 of 30% lower than that of PEEK. In addition, the 5% weight loss temperature were above 557 °C, exhibiting the excellent heat resistant.

A new carbon-supported PdNi (PdNi/C) catalyst is prepared by a simple simultaneous reduction reaction with sodium borohydride in glycol solution. The results show that the performance of PdNi/C catalyst for formic acid oxidation is greatly improved compared with that of Pd/C. X-ray diffraction (XRD) results show that Ni exists in the catalyst both as NiO and as PdNi alloy. The value of the apparent activation energy shows that the activity of formic acid oxidation on the PdNi/C is more sensitive to temperature compared with Pd/C.