Reducing arsenic toxicity using the interfacial oxygen nanobubble technology for sediment remediation

lO2 nanobubble technology is developed to tackle the As pollution in hypoxic waters.lO2 nanobubbles induced biotic and geochemical reactions to mitigate the As risk.lDark-produced hydroxyl radicals are dominant contributors to As abiotic oxidation.lO2-related functional microbial changes contribute to the As biotic transformation.lFe-(hydr)oxide becomes the major sequestrator of As(V) in oxic sediments. The arsenic (As)-bearing eutrophic waters may suffer from the dual conditions of harmful algal blooms and release of As, driven by algal-induced hypoxia/anoxia. Here, we investigate the use of interfacial oxygen (O2) nanobubble technology to combat the hypoxia and control As exposure in simulated mesocosm experiments. It was observed that remediation of algal-induced hypoxia at the sediment-water interfaces (SWI) by application of O2 nanobubbles reduced the level of dissolved As from 23.2 μg L−1 to