Riverbank filtration is a nature-based water treatment strategy known for its effective removal of organic micropollutants. Yet, the mechanisms governing their biodegradation, especially the role of redox transitions in mediating biotransformation, remain insufficiently understood. Here, we integrate metagenomic profiling with chemical analytics in a 10 m simulated riverbank filtration system to demonstrate how sequential oxidizing–reducing degradation enhances organic micropollutant transformation. Oxygen stratification structured distinct microbial and enzymatic pathways: oxidizing zones (>+200 mV redox potential) facilitated cytochrome P450-mediated oxidation (oxidizing condition, OXD), while subsequent redox shifts to reducing conditions (←400 mV, sequential oxidizing–reducing (SOR) conditions) activated reductive transformations (e.g., via nitronate monooxygenase and aldehyde dehydrogenase) and conjugation pathways. These SOR conditions significantly enhanced the removal of recalcitrant compounds, including irbesartan (+25.3%), benzotriazole (13.4%), and gabapentin (+9.7%). Metagenomic analysis revealed redox-driven microbial specialization, with Pseudomonadota and Nitrospirota dominating in oxidizing zones and reducing microzones enriched in pathways associated with nitrotoluene and ethylbenzene degradation, providing genomic evidence for sequential organic micropollutant breakdown. These findings establish a mechanistic framework for harnessing oxidizing–reducing microbial partnerships to amplify organic micropollutant removal in nature-based water treatment systems, which can be used for riverbank filtration site selection and well field construction and optimization.

A core-shell structured Zn/La magnetic mesoporous silica (denoted as Zn/La-MMS) composite we successfully constructed via etching and co-deposition techniques, achieving exceptionally efficient adsorption of phosphate. At an optimized Zn/La ratio of 0.5 (i.e., Zn/La-0.5 MMS), the composite exhibited an ordered mesoporous structure and superior adsorption performance with a maximum phosphate adsorption capacity of 140.9 mg P/g (15-fold higher than the pristine MMS). High adsorption performance was achieved across a broad pH range of 3 to 11 and in the presence of substantial amounts of co-existing ions/substances (Cl⁻, NO₃⁻, SO₄²⁻, HCO₃⁻, and humic acid at concentrations 20–50 times that of the PO₄³⁻-P concentration). After five adsorption-regeneration cycles, 79 % adsorption capacity remained with material recovery rates >95 % via magnetic separation. A bimetallic synergistic mechanism was revealed via X-ray absorption fine-structure characterizations and density functional theory (DFT) calculations. The electronegativity difference between La and Zn induces interfacial electron redistribution, driving electron back-donation from the La/Zn-O hybridized orbitals to the O 2p antibonding orbitals of HPO₄²⁻, forming stable covalent coordination bonds (La-O-P/Zn-O-P), which allowed the exceptionally high and efficient adsorption of phosphate. This phenomenon is expected to have important implications for the development of novel adsorption materials for advanced removal of phosphate.