Combined iron-loaded zeolites and ozone-based process for the purification of drinking water in a novel hybrid reactor: Removal of faecal coliforms and arsenic

Abstract

This study was carried out to provide a novel solution to treat drinking water at house-hold levels, specifically removing arsenic (As) and faecal coliforms (microbes). In the current in-vestigation, a synergistic iron-loaded zeolites and ozonation process (O3/Fe-ZA) was used for the first time in a modified batch reactor to remove coliform bacteria and arsenic in tap water. More-over, the study utilizes the human health risk assessment model to confirm the health risk due to As intake in drinking water. The risk assessment study revealed a health risk threat among the residents suffering from the adverse effects of As through its intake in drinking water. Further-more, the results also suggested that the O3/Fe-ZA process significantly removes faecal coliforms and As, when compared with single ozonation processes. Additionally, the ozone dose 0.2 mg/min and Fe-ZA dose of 10 g (in the O3/Fe-ZA process) gives the maximum removal efficiency of 100% within 15 min for faecal coliform removal. In 30 min, the removal efficiency of 88.4% was achieved at the ozone dose of 0.5 mg/min and 93% removal efficiency was achieved using 10 g Fe-ZA for the removal of As in the O3/Fe-ZA process. Hence, it was concluded that the O3/Fe-ZA process may be regarded as an effective method for removing faecal coliforms and As from drinking water compared to the single ozonation processes.