Issue 5, 2020

Pilot-scale ozone/biological activated carbon treatment of reverse osmosis concentrate: potential for synergism between nitrate and contaminant removal and potable reuse

Abstract

With limited budgets, utilities may forego potable reuse of municipal wastewater to meet regulations requiring nitrate and contaminant removal from discharges. At 85% recovery, reverse osmosis (RO)-based potable reuse rejects contaminants into a concentrate flowrate that is 6.7-fold lower than wastewater discharges. This study evaluated the footprint and cost savings associated with treating nitrate and contaminants in RO concentrate vs. wastewater effluent. Pilot-scale ozone and biological activated carbon (BAC) treatment of RO concentrate provided design parameters needed for this comparison. Addition of 60 mg C per L methanol as a carbon source was needed to achieve complete denitrification of 70 mg N per L nitrate within a 30 min BAC empty bed contact time. Combined with pre-ozonation at 0.5 mg O3/mg DOC, this treatment removed >74% of fipronil, imidacloprid, atenolol, DEET and sulfamethoxazole. Estimates indicated that applying ozone/BAC treatment to RO concentrate rather than conventional wastewater effluent for contaminant removal prior to discharge would offset 60% of the footprint and 25% of the cost required for the RO-based potable reuse train. Considering these savings, the reuse train cost could be recouped if the product water were sold at rates below those current in southern California. These results suggest synergy rather than competition between potable reuse and contaminant removal.

Graphical abstract: Pilot-scale ozone/biological activated carbon treatment of reverse osmosis concentrate: potential for synergism between nitrate and contaminant removal and potable reuse

Supplementary files

Article information

Article type
Paper
Submitted
06 Jan 2020
Accepted
17 Mar 2020
First published
18 Mar 2020

Environ. Sci.: Water Res. Technol., 2020,6, 1421-1431

Author version available

Pilot-scale ozone/biological activated carbon treatment of reverse osmosis concentrate: potential for synergism between nitrate and contaminant removal and potable reuse

Z. Zhang, J. F. King, A. Szczuka, Y. Chuang and W. A. Mitch, Environ. Sci.: Water Res. Technol., 2020, 6, 1421 DOI: 10.1039/D0EW00013B

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements