Remediation of perchloroethylene contaminated groundwater using Fe0/ZnS embedded in a highly porous polymer: Experimental results on pilot-scale photoreactor and kinetic modeling analysis for industrial scale-up

Perchloroethylene (PCE) is a pollutant toxic to aquatic life and suspected of being a human carcinogen. It is also recalcitrant to degradation. Therefore remediation of PCE-contaminated groundwater is currently still a challenging task. In this work, the efficiency of a UV-assisted oxidation process exploiting a photocatalyst composed of zero-valent iron supported on commercial zinc sulfide (Fe/ZnS) and incorporated in a highly porous polymer, is investigated. The experimental studies were carried out, for about six months, on a pilot-scale photoreactor operating in continuous mode at the Solofra (Campania, Italy) wastewater plant, to evaluate the effectiveness and stability of the photocatalytic system. The results show that it is possible to reach a PCE degradation in natural groundwater in the range of 85-95%%. Furthermore, a kinetic model is developed and compared with collected experimental data. The mathematical model well describes the experimental data of the photocatalytic system operating both in batch and continuous mode and therefore it can be potentially used for further scale-up of photocatalytic systems devoted to PCE degradation, allowing to estimate the catalyst weight required for total PCE removal as a function of the liquid flow rate to be treated and inlet PCE concentration.