Impact of hydraulic retention time on phosphorus removal from wastewater using reactive media

TY - JOUR

T1 - Impact of hydraulic retention time on phosphorus removal from wastewater using reactive media

AU - Benzing, S.

AU - Couceiro, F.

AU - Barnett, S.

AU - Williams, J. B.

AU - Pearce, P.

AU - Stanford, C.

N1 - Funding Information: The authors would like to thank Southern Water for their financial support, and acknowledgement to the consultancy of Pete Pearce and Aleksandra Drizo for their experienced knowledge. For technical assistance the authors are grateful for the help of Tim Holloway and Anita Carey. Publisher Copyright: © IWA Publishing 2020. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/12/15

Y1 - 2020/12/15

N2 - Phosphorus (P) discharge from wastewater treatment plants into the environment contributes to eutrophication issues. Reactive media filters represent an effective, simple and cost-effective solution to decrease the P content. Previous research used various experimental designs and often synthetic wastewater, making assessment of real-world performance difficult. This study assesses the impact of the hydraulic retention time (HRT) on P removal using real wastewater to refine design criteria for full-scale installations. Four media were compared in column experiments for >200 days. Different HRTs were applied and initially the media achieved low P effluent concentrations of >0.1 mg/L PO4-P, increasing over time. Best P removal was observed for the highest HRT with on average >99%. HRT was seen to be the driving factor for P removal rather than media capacity. Three of the four materials showed pH levels above 12 initially, decreasing over time. Water quality parameters, including organics, solids and metals, were monitored. In-depth analysis confirmed formation of calcium phosphate precipitation on the media's surface. The results suggest the importance of an optimal HRT to achieve high P removal and show that the reactive media application is an appropriate technology for P removal on small sites if the elevated pH is addressed.

AB - Phosphorus (P) discharge from wastewater treatment plants into the environment contributes to eutrophication issues. Reactive media filters represent an effective, simple and cost-effective solution to decrease the P content. Previous research used various experimental designs and often synthetic wastewater, making assessment of real-world performance difficult. This study assesses the impact of the hydraulic retention time (HRT) on P removal using real wastewater to refine design criteria for full-scale installations. Four media were compared in column experiments for >200 days. Different HRTs were applied and initially the media achieved low P effluent concentrations of >0.1 mg/L PO4-P, increasing over time. Best P removal was observed for the highest HRT with on average >99%. HRT was seen to be the driving factor for P removal rather than media capacity. Three of the four materials showed pH levels above 12 initially, decreasing over time. Water quality parameters, including organics, solids and metals, were monitored. In-depth analysis confirmed formation of calcium phosphate precipitation on the media's surface. The results suggest the importance of an optimal HRT to achieve high P removal and show that the reactive media application is an appropriate technology for P removal on small sites if the elevated pH is addressed.

KW - Columns

KW - Phosphorus removal

KW - Reactive media

KW - Wastewater treatment

UR - http://www.scopus.com/inward/record.url?scp=85098724172&partnerID=8YFLogxK

U2 - 10.2166/wst.2020.526

DO - 10.2166/wst.2020.526

M3 - Article

C2 - 33341781

AN - SCOPUS:85098724172

VL - 82

SP - 2920

EP - 2928

JO - Water Science and Technology

JF - Water Science and Technology

SN - 0273-1223

IS - 12

ER -