Coupling sorption and biodegradation of Emerging Organic Compounds with geochemical modeling

Understanding the fate of Emerging Organic Compounds (EOCs) is quite complex. It depends on several direct processes (e.g. sorption or biodegradation) but also on indirect ones (e.g. reduction oxidation processes, soil-water interaction). For that, modeling is a useful tool to evaluate it. Nevertheless, most of the models in literature are quite simple. Most of them are completely disconnected from the geochemical conditions of the environmental systems and it has been widely proved that both sorption and degradation of EOCs depends on that, specially, on pH and reduction oxidation dynamics. For that, in this work we have evaluated different conceptual models of EOC’s fate in the context of Managed Aquifer Recharge. The tested models were from the simplest one (fully disconnected from the geochemistry) to the more complex one (coupling both EOC’s sorption and biodegradation to the geochemistry). The models were validated with a column experiment, which reproduced the fate five EOC’s (paracetamol, diuron, benzophenone-3, carbamazepine and sulfamethoxazole)  in an infiltration pond with a reactive barriers made up of compost (3 types of columns, 0% of compost, 10% and 50%) (Modrzyński et al., 2021). The EOC’s models were also coupled with a previous geochemical model focused in carbon and nitrogen cycle and validated with the same experiments (Canelles et al., 2021). Our results demonstrate that a better reproduction is achieved when both sorption and biodegradation are coupled with a geochemical reactive transport, specially for systems with a higher presence of organic carbon.   

This work was financially supported by the Catalan Research Project RESTORA (ACA210/18/00040), by the Spanish Ministry of Science and Innovation through MONOPOLIOS (RTI2018-101990-B-100, MINECO/FEDER), as well as the EU project MARADENTRO (PCI2019-103425).