Thermal modified sediments photocatalyst: A new strategy using waste to treat waste for tetracycline degradation and transformation product-associated risks

Sediment (SM) is composed of multiple components and exhibits a complex surface morphology, enabling it to adsorb water pollutants and result in sediment pollution. It is noted that SM can convert into material for reuse after calcination to decompose the adsorbed organic pollutants, which remains efficient photocatalytic performance. Our research demonstrates that SM-raw degrades 61.4 % of tetracycline (TC) within 240 min, and after adding Peroxysulphate (PDS) and hydrogen peroxide (H 2 O 2 ), the SM-350 (calcined at 350 °C) and the SM-250 (calcined at 250 °C) could remove 94.7 % and 95.7 %. Quenching experiments reveal that •O 2 − , 1 O 2 , and h + primarily contribute to TC degradation in SM-350/PDS and SM-250/H 2 O 2 systems. In addition, the SM samples maintained good degradation performance after five consecutive cycles. Additionally, the possible pathway of TC degradation and its product risk assessment was established to verify the toxicity of the intermediate products gradually decreased. In conclusion, this study offers a novel insight into the potential of SM as a cost-effective photocatalyst for the effective remediation of sediment and water pollution, but also plays an important role in environmental governance as a new strategy of “waste to treat waste”.