Mercury removal from municipal secondary effluent with hydrous ferric oxide reactive filtration. (8th February 2019)

• Record Type: Journal Article
• Authors: Beutel, Marc W.; Dent, Stephen R.; Newcombe, Remy L.; Möller, Gregory
• Is Part Of: Water environment research. Volume 91:Number 2(2019)
• Page Start: 132
• Page End: 143
• Publication Date: 2019-02-08
• Subjects: hydrous ferric oxide -- mercury -- reactive filtration -- secondary effluent; Water quality management -- Periodicals; Water -- Purification -- Periodicals; Water -- Pollution -- Periodicals; Water -- Pollution; Water -- Purification; Water quality management; Sewage; Water Pollution; Periodicals; Electronic journals; Periodicals; 628.16
• DOI: 10.1002/wer.1007
• Languages: English
• ISSNs: 1061-4303

Abstract

Abstract: This study evaluated the ability of hydrous ferric oxide reactive filtration (HFO‐RF) to remove mercury (Hg) from municipal secondary effluent at four study sites. Pilot HFO‐RF systems (136 m 3 /day) at two sites demonstrated total Hg concentration removal efficiencies of 96% (inflow/outflow mean total Hg: 43.6/1.6 ng/L) and 80% (4.2/0.8 ng/L). A lightly loaded medium‐scale HFO‐RF system (950 m 3 /day) had a concentration removal efficiency of 53% (0.98/0.46 ng/L) and removed 0.52 mg/day of total Hg and 2.2 μg/day of methyl‐Hg. A full‐scale HFO‐RF system (11, 400 m 3 /day) yielded a total Hg concentration removal efficiency of 97% (87/2.7 ng/L) and removed an estimated 0.36 kg/year of Hg. Results suggest that the quality of secondary effluent, including dissolved organic matter content, affects achievable minimum total Hg concentrations in effluent from HFO‐RF systems. Low HFO‐RF effluent concentrations (<1 ng/L) can be expected when treating secondary effluent from suspended‐growth biological treatment systems. Practitioner points: Trace levels of mercury in municipal secondary effluent can negatively impact receiving waters. Hydrous ferric oxide reactive filtration (HFO‐RF) can remove mercury from municipal secondary effluent to levels below the Great Lakes Initiative discharge standard of 1.3 ng/L. Mercury removal to low concentrations (< 1 ng/L) using HFO‐RF appears to be associated with secondary effluents with low dissolved organic matter content. HFO‐RF can also remove total phosphorus and turbidity to low concentrations.