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• The FeOCl/PMS/Vis system could efficiently remove and mineralize aquatic organic pollutants. • It was significantly enhancing the activation and utilization efficiency of PMS. • Operation across a broad range of environmental conditions. • The synergistic mechanism between photocatalysis and PMS activation in FeOCl/PMS/Vis system was revealed. Inspired by the photosensitivity and self-heal properties of iron oxychloride (FeOCl), we used photocatalysis coupling peroxymonosulfate (PMS) activation for effective aquatic decontamination in a cost-efficient and environmentally friendly method. Synthesized FeOCl was appointed to activate PMS to degrade bisphenol A (BPA, 2,2-bis(4-hydroxydiphenyl) propane) persistently under visible light. The best performance of FeOCl/PMS/Vis system was ∼100% BPA degradation efficiency which achieved in 20 min. The BPA removal efficiency had a positive correlation with the dosages of FeOCl and PMS, but negatively related to BPA concentration. The FeOCl/PMS/Vis system also presented impressive degradation performance at a wide pH range (pH = 3–11) and showed well excellent stability and reusability. The addition of either bicarbonate or chloride had impressive promotion effect on BPA removal. The reaction mechanism of FeOCl/PMS/Vis system was studied deeply. PMS was activated to generate active radicals (SO 4 − and HO) by Fe(II) of FeOCl for BPA degradation. Then the as-formed Fe(III) was reduced to Fe(II) via trapping photoexcited electrons in conduction band (CB) of FeOCl, which effectively inhibited the recombination of photo-generate charges and the pollutants oxidation would recur via facilitating the Fe(II)/Fe(III) redox recycle. Thus, the activation and utilization efficiency of PMS was effectively improved. This work indicated the FeOCl/PMS/Vis system was a promising application in wastewater treatment. [ABSTRACT FROM AUTHOR]

The synthesized Bi 2 Fe 4 O 9 nanosheets exhibit excellent piezocatalytic activity for molecular oxygen activation. The Fe2+ sites in Bi 2 Fe 4 O 9 nanosheets as active centers preferentially adsorb molecular oxygen and donate electrons to molecular oxygen to generate O 2 ∙ - for degrading organic pollutants, which is then regenerated by accepting the piezo-electrons, resulting in outstanding piezocatalytic performance. [Display omitted] • Bi 2 Fe 4 O 9 nanosheets exhibit outstanding piezocatalytic activity for molecular oxygen activation. • The O 2 ∙ - and piezo-holes are the major active species for piezocatalytic degradation of sulfamethoxazole. • Fe2+ in Bi 2 Fe 4 O 9 nanosheets as active sites activate molecular oxygen into O 2 ∙ - via donating electrons. • The Fe2+ can be regenerated by accepting the piezo-electrons. Piezocatalytic molecular oxygen activation has been regarded as a promising and low energy-cost strategy for environment remediation, yet the piezocatalytic activity is still far from satisfactory and little is known on its activation mechanism, which greatly hinders its further development. Herein, the piezocatalyst Bi 2 Fe 4 O 9 nanosheets (BFO NSs) are synthesized via a facile hydrothermal method, which exhibit excellent piezocatalytic performance for sulfamethoxazole degradation. O 2 ∙ - generated via the molecular oxygen reduction reaction by piezo-electrons and the piezo-holes were confirmed as major active species for organic pollutants degradation. Further theoretical calculations and XPS analyses confirm the Fe2+ sites as active centers activate molecular oxygen into O 2 ∙ - via donating the electrons to molecular oxygen and the piezo-electrons reduce Fe3+ to Fe2+. This work provides atomic-scale insights into the active sites of piezocatalytic molecular oxygen activation, which can inspire the development of more efficient piezocatalysts for environment application. [ABSTRACT FROM AUTHOR]

Abstract: Soil protection from heavy metal contamination requires scientific assessment on the linkage between site-specific pollutant discharge and environmental effects. However, this kind of linkage is usually disregarded due to the lack of assessment tools in environmental policies, e.g., some developed coastal cities in China have forced their highly polluting industries out to less developed interior areas without consideration of the impacts from pollution transfer. This paper developed a soil adsorption fraction (SAF) model to characterize the emissions-to-adsorption relationship between heavy metal emission and the adsorption by soil. Case studies were carried out for two adjacent southern cities in China, i.e., Guangzhou and Shaoguan. The results indicated that the average SAF of cadmium was 5.38×10−3 for Shaoguan and 1.28×10−3 for Guangzhou, i.e., cadmium released from Shaoguan threatened the soil environment 4.2 times of that from Guangzhou. Further analysis showed the polluting pathway and abundance of water resources were the main influencing factors on SAF. Soil contamination will be exaggerated by relocating heavy metal polluting industries from coastal areas to interior areas. The results should be useful to prompt site-specific policies on heavy metal pollution control. [Copyright &y& Elsevier]

The application of promising persulfate-based advanced oxidation processes (AOPs) for environment remediation is limited by the poor charge separation and the sluggish kinetic for active centers regeneration of the catalysts. Piezocatalytic activation has been proposed to solve the above concern recently, but little is known on its mechanism. Herein, novel piezocatalyst Bi 2 Fe 4 O 9 nanosheets (BFO NSs) are demonstrated to significantly improve peroxydisulfate (PDS) activation efficiency via piezocatalysis, resulting SO 4 •− and •OH as the dominant active species for organic pollutants degradation. Further DFT calculations and experimental investigations confirm that the Fe2+ in BFO NSs as active sites donate electrons for PDS to generate SO 4 •−, and simultaneously that the piezo-electrons can accelerate the regeneration of Fe2+, thus leading to the superior catalytic activity. This work provides atomic-scale insights of catalytic sites and mechanisms of piezocatalytic PDS activation and may inspire the development of more efficient piezocatalysts and AOPs. Highly efficient piezocatalytic activation of peroxydisulfate over Bi 2 Fe 4 O 9 nanosheets was demonstrated. Fe2+ in Bi 2 Fe 4 O 9 as active centers can activate S 2 O 8 2– into SO 4 •− through donation electrons for organic pollutants degradation, meanwhile the piezo-electrons can accelerate the regeneration of Fe2+, thus resulting in excellent catalytic activity. [Display omitted] • The novel piezocatalyst Bi 2 Fe 4 O 9 nanosheets are synthesized through a facile hydrothermal approach. • The piezocatalysis of Bi 2 Fe 4 O 9 can significantly improve peroxydisulfate activation efficiency. • The piezo-electrons can accelerate the regeneration of Fe2+ active sites. [ABSTRACT FROM AUTHOR]

• FeOCl/MoS 2 catalyst shows supreme efficiency for OH generation. • FeOCl/MoS 2 catalyst can effectively degrade various organic pollutants. • FeOCl/MoS 2 catalyst has high pH and salinity tolerance in Fenton-like reactions. • The Fe − O–Mo electron mediator facilitates the active Fe2+ regeneration in FeOCl. FeOCl Fenton-like catalyst has drawn much attention due to its high catalytic activity. Nevertheless, the potential application of FeOCl is significantly hindered by the sluggish reduction kinetics of Fe3+ to active Fe2+. Here, we report that the incorporation of Fe − O–Mo electron mediator into FeOCl via forming a FeOCl/MoS 2 composite can facilitate the Fe2+ regeneration through the oxidation of Mo4+ to Mo6+, which boosts the hydroxyl radicals yields, thus leading to a significantly improved catalytic performance. The removal efficiency of methylene blue (MB, 50 mg L−1) achieves ∼100% within 2 min. with low dosage of FeOCl/MoS 2 (0.2 g L−1) and H 2 O 2 (0.6 mM). FeOCl/MoS 2 not only has broad working pH range (∼3 − 9) and high salinity tolerance (100 mM), but also capable to degrade various organic pollutants. For practical application, the fabricated FeOCl/MoS 2 membrane effectively degrades continuous MB flow. This study demonstrates that incorporating an electron mediator is an effective way to improve the catalytic performance of heterogeneous Fenton-like catalysts. [ABSTRACT FROM AUTHOR]