Use of posnjakite containing sludge as catalyst for decoloring dye via photo-Fenton-like process.

The use of sediment wastes after water treatment, from traditional wastewater management to secondary resource recycling, has attracted increasing attention. In this work, the feasibility, catalytic effect and mechanism of using artificial copper-based precipitation as photo-Fenton-like catalysts were investaged. According to the XRD, SEM-EDS, XPS and various photoelectric characterizations, the copper-based precipitation showed the potential acting as a photo-Fenton-like catalyst due to its abundant copper ions and photoresponse characteristics. The 0.06 g L−1 copper-based precipitation decolors 97% of methylene blue with initial concentration of 20 mg L−1 within 20 min assisted by H 2 O 2 and light, which is superior to the commonly used catalysts in terms of decolorization rate and catalysts dosage. Excellent catalytic performance is by virtue of the enhanced reduction reaction from Cu(II) to Cu(I), resulting in an increasing utilization rate of hydrogen peroxide, and increasing ·OH for decoloration. In addition, the catalyst activity can be replicated in successive experiments without a significant decline, further suggesting the feasibility from wastes to materials. The research progress shows the potential value of secondary resources containing posnjakite based on its unique character. [Display omitted] • Novel use of posnjakite containing sludge as a photo-catalyst. • Higher decolorization rate and lower catalyst dosage than common catalysts. • Enhanced reduction from Cu(II) to Cu(I) assisted with photoelectron. [ABSTRACT FROM AUTHOR]