Abstract

Abstract Biofilters are effectively used for drinking water treatment. However, the long ripening time of virgin media for manganese (Mn) removal is a major concern. In this study, the influence of the flow regime on the ripening time of virgin pumice medium was investigated. For this purpose, pilot-scale experiments were performed to compare the start-up of flow-through and recirculating filter columns using inherent inoculation with the same groundwater source. The systems were operated at 2 m·h−1 with gradual flow increments up to 5 m·h−1 and avoiding Fe-loading. Effective Mn removal (>90%) in flow-through and recirculating columns was achieved after 8 and 23 days, respectively. Flow-through columns reached compliance with a local drinking water criterion (Mn < 0.1 mg·L−1) at 15 cm filter depth in 11 days. Recirculating filter columns required 32 days to reach compliance at 30 cm depth. The start-up in recirculation regime resulted in a water consumption reduction of about 50% compared with flow-through regime. The intermittent provision of the Mn-loading in recirculating regime impacted the Mn-oxidizing bacteria (MOB) concentration in the pumice stone medium. Both flow regimes required a similar total Mn-loading (0.16 and 0.11 kg·Mn·m−2, respectively), suggesting that Mn-loading was the limiting factor for the ripening of pumice.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.