Biological Oxygen-dosed Activated Carbon (BODAC) filters – A bioprocess for ultrapure water production removing organics, nutrients and micropollutants

Biological oxygen-dosed activated carbon (BODAC) filters in an Ultrapure water plant were demonstrated to have the potential to further treat secondary wastewater treatment effluent. The BODAC filters were operated for 11 years without carbon regeneration or replacement, while still functioning as pre-treatment step to reverse osmosis (RO) membranes by actively removing organic micropollutants (OMPs) and foulants. In this study, the removal of nutrients and 13 OMPs from secondary wastewater treatment effluent was investigated for 2 years and simultaneously, the granules’ characterization and microbial community analysis were conducted to gain insights behind the stable long-term operation of the BODAC filters. The results showed that the BODAC granules' surface area was reduced by ∼70 % of what is in virgin carbon granules and covered by biofilm and inorganic depositions. The BODAC filters reduced the concentration of soluble organics, mainly proteins, performed as an effective nitrification system, and almost completely removed manganese. During the 2 years of observation, the filters consistently removed some OMPs such as hydrochlorothiazide, metoprolol, sotalol, and trimethoprim by at least 70 %. Finally, through microbial community analysis, we found that nitrifying and manganese-oxidizing bacteria were detected in high relative abundance on BODAC granules, supporting BODAC performance in removing OMPs and manganese as well as converting nitrogenous species in the water.</p

Biological Oxygen-dosed Activated Carbon (BODAC) Technology:exploring the potential of a bioprocess for the simultaneous removal of organics, metals, and micropollutants in wastewater reclamation practice

Wastewater reclamation for industrial purposes has been increasingly discussed as a solution for more sustainable water utilization. Removing organic micropollutants (OMPs) from the reclaimed wastewater is crucial to ensure safe re-application. The Ultrapure Water factory (Emmen, The Netherlands) is a successful example of a wastewater reclamation project. Several consecutive treatment steps at this plant, including Biological Oxygen-dosed Activated Carbon (BODAC) filters, are implemented to treat wastewater treatment plant (WWTP) secondary effluent. The purified water is used to produce ultrapure water with low conductivity (&lt;0.2 µS cm-1) used in steam production for an oil extraction process. BODAC filters were filled with thermally activated granular activated carbon, and later changed into biologically activated carbon due to extensive microbial growth over the years. Regular oxygen dosing maintained aerobic conditions along the filter bed. The original carbon has never been regenerated during its service life, suggesting that in situ regeneration occurred. At the start of this research, BODAC filters prevented the biofouling of the subsequent reverse osmosis membranes. Moreover, BODAC filters could also remove several OMPs from the treated WWTP effluent to a great extent (up to 99%), maintaining consistent good water quality. In this thesis, the physicochemical and microbiological characteristics of the aged BODAC granules were investigated to understand how, and to what extent, efficient bio-regeneration of BODAC granules and operational process parameters (oxygen dosing and backwashing) may contribute to the long service life of the BODAC filters and the removal of organics, metals, and OMPs from WWTP effluent

Biological Oxygen-dosed Activated Carbon (BODAC) Technology:exploring the potential of a bioprocess for the simultaneous removal of organics, metals, and micropollutants in wastewater reclamation practice

Wastewater reclamation for industrial purposes has been increasingly discussed as a solution for more sustainable water utilization. Removing organic micropollutants (OMPs) from the reclaimed wastewater is crucial to ensure safe re-application. The Ultrapure Water factory (Emmen, The Netherlands) is a successful example of a wastewater reclamation project. Several consecutive treatment steps at this plant, including Biological Oxygen-dosed Activated Carbon (BODAC) filters, are implemented to treat wastewater treatment plant (WWTP) secondary effluent. The purified water is used to produce ultrapure water with low conductivity (&lt;0.2 µS cm-1) used in steam production for an oil extraction process. BODAC filters were filled with thermally activated granular activated carbon, and later changed into biologically activated carbon due to extensive microbial growth over the years. Regular oxygen dosing maintained aerobic conditions along the filter bed. The original carbon has never been regenerated during its service life, suggesting that in situ regeneration occurred. At the start of this research, BODAC filters prevented the biofouling of the subsequent reverse osmosis membranes. Moreover, BODAC filters could also remove several OMPs from the treated WWTP effluent to a great extent (up to 99%), maintaining consistent good water quality. In this thesis, the physicochemical and microbiological characteristics of the aged BODAC granules were investigated to understand how, and to what extent, efficient bio-regeneration of BODAC granules and operational process parameters (oxygen dosing and backwashing) may contribute to the long service life of the BODAC filters and the removal of organics, metals, and OMPs from WWTP effluent