Long-term phosphorus removal by Ca and Fe-rich drainage filter materials under variable flow and inlet concentrations

TY - JOUR

T1 - Long-term phosphorus removal by Ca and Fe-rich drainage filter materials under variable flow and inlet concentrations

AU - Pugliese, Lorenzo

AU - Canga, Eriona

AU - Hansen, Hans Chr Bruun

AU - Kjærgaard, Charlotte

AU - Heckrath, Goswin J.

AU - Poulsen, Tjalfe G.

N1 - Publisher Copyright: © 2023 The Author(s)

PY - 2023/12

Y1 - 2023/12

N2 - Phosphorus (P) losses from tile-drained agricultural fields may degrade surface water quality by accelerating eutrophication. Among the different edge-of-field technologies, compact filter systems using different filter materials have been identified as potentially effective solutions for removing P from drainage water before discharge downstream. This study investigated the long-term (>696 days) P removal efficiency of 5 different filter materials in a column setup, using artificial drainage water (pH 6). Filter materials included two iron-based granulates (calcinated diatomaceous earth (CDE), ferric hydroxide granules (CFH)), and three calcium-based granulates (seashells, limestone, calcinated silicate/calcium oxide (Filtralite-P)). Experiments were performed under variable flow rates (0.037 and 1.52 L h−1; hydraulic retention time of 26–43 min and 18–30 h) and inlet P concentrations (0.14 and 0.7 mg L−1). An overall analysis revealed that the Fe-based materials achieved higher P retention than Ca-based materials. In particular, CFH was capable of retaining 99 and 98 % of the high and low inlet P concentrations, respectively. Conversely, limestone retained only 25 % of the high P load. CDE performed moderately well, independently of the inlet P concentration. Filtralite-P and Seashells performed well at high inlet P concentration but relatively poorly at low P concentration. The sensitivity of filter material P removal efficiency to variations in P loading was generally lowest for CFH and highest for limestone.

AB - Phosphorus (P) losses from tile-drained agricultural fields may degrade surface water quality by accelerating eutrophication. Among the different edge-of-field technologies, compact filter systems using different filter materials have been identified as potentially effective solutions for removing P from drainage water before discharge downstream. This study investigated the long-term (>696 days) P removal efficiency of 5 different filter materials in a column setup, using artificial drainage water (pH 6). Filter materials included two iron-based granulates (calcinated diatomaceous earth (CDE), ferric hydroxide granules (CFH)), and three calcium-based granulates (seashells, limestone, calcinated silicate/calcium oxide (Filtralite-P)). Experiments were performed under variable flow rates (0.037 and 1.52 L h−1; hydraulic retention time of 26–43 min and 18–30 h) and inlet P concentrations (0.14 and 0.7 mg L−1). An overall analysis revealed that the Fe-based materials achieved higher P retention than Ca-based materials. In particular, CFH was capable of retaining 99 and 98 % of the high and low inlet P concentrations, respectively. Conversely, limestone retained only 25 % of the high P load. CDE performed moderately well, independently of the inlet P concentration. Filtralite-P and Seashells performed well at high inlet P concentration but relatively poorly at low P concentration. The sensitivity of filter material P removal efficiency to variations in P loading was generally lowest for CFH and highest for limestone.

KW - Agricultural tile drainage water

KW - Filter materials

KW - Long-term removal efficiency

KW - Phosphorus losses

KW - Sensitivity analysis

KW - Bays

KW - Phosphorus

KW - Calcium Carbonate

KW - Iron

KW - Silicates

UR - http://www.scopus.com/inward/record.url?scp=85175631771&partnerID=8YFLogxK

U2 - 10.1016/j.watres.2023.120792

DO - 10.1016/j.watres.2023.120792

M3 - Journal article

C2 - 37925858

AN - SCOPUS:85175631771

SN - 0043-1354

VL - 247

JO - Water Research

JF - Water Research

M1 - 120792

ER -