A solar photocatalytic floating reactive barrier for aqueous gas emissions interception and treatment

Reduced sulfur compounds produced as a by-product of anaerobic digestion pose a significant health and environmental hazard for nearby communities. Here we assessed a novel floating reactive barrier (FRB), comprised of buoyant photocatalysts (BPCs), as a passive solution to intercept and treat malodorous compounds before crossing the air-water interface. Using industry provided samples of oil sands process water (OSPW) containing anaerobically produced aqueous sulfide, the FRB system was evaluated at both the bench and pilot scale. The photocatalytic FRB demonstrated a 95% reduction in H2S emissions at the lab scale and up to 98% at the pilot-scale under outdoor weather conditions and natural sunlight. H2S emissions intercepted by the FRB were found to be oxidized to non-volatile sulfate. An empirical reactive transport model describing the performance of the FRB is proposed informed by the results obtained in this work. The photocatalytic FRB described herein is proven to be an effective measure for the mitigation of potentially hazardous reduced sulfur compound emissions under solar UV conditions.