Mercury loads and fluxes from wastewater: A nationwide survey in Switzerland

WATER RESEARCH

卷:175

Article

Suess, Elke¹  Berg, Michael¹  Bouchet, Sylvain^1,2  Cayo, Lara¹  Hug, Stephan J.¹  Kaegi, Ralf¹  Voegelin, Andreas¹  Winkel, Lenny H. E.^1,2  Tessier, Emmanuel³  Amouroux, David³  Buser, Andreas M.⁴ 

[1] Eawag, Swiss Fed Inst Aquat Sci & Technol, CH-8600 Dubendorf, Switzerland

[2] Swiss Fed Inst Technol, Inst Biogeochem & Pollutant Dynam, CH-8092 Zurich, Switzerland

[3] Univ Pau & Pays Adour, CNRS, E2S, MIRA,Inst Sci Analyt & Phys Chim Environm & Mat I, Pau, France

[4] Swiss Fed Off Environm FOEN, CH-3063 Ittigen, Switzerland

关键词: Mercury and methyl mercury;    Discharge;    Wastewater;    Sewage sludge;    Incineration;    Surface water;   

DOI  :  10.1016/j.watres.2020.115708

来源: Elsevier

【 摘 要 】

Mercury (Hg) pollution threatens ecosystems and human health. Wastewater treatment plants (WWTPs) play a key role in limiting Hg discharges from wastewaters to rivers and lakes, but large-scale studies to estimate Hg loads and discharge at national levels are scarce. We assessed the concentration, flux, speciation, and removal of Hg in municipal wastewater throughout Switzerland by investigating 64 WWTPs in a pre-study and a subset of 28 WWTPs in the main study. We also studied the behavior and pathways of Hg along the various treatment steps in a state-of-the-art WWTP. The resulting dataset, representative of industrialized countries, provides an overview of (i) current Hg concentration ranges, (ii) average per capita loads, and (iii) wastewater Hg inputs into surface waters. The results allowed estimation of a total Hg (THg) load in Swiss wastewater of 130 +/- 30 kg THg/year (15.7 mg/capita/y), of which 96 +/- 4% is retained in sewage sludge. About 4.7 +/- 0.5 kg THg/year (0.57 mg/capita/y) is discharged with the treated wastewater into surface waters. This corresponds to only 1.5-3% of the THg load carried by the major Swiss rivers, indicating that >95% of riverine Hg originates from other sources. Extrapolation to the population of Europe would yield a total amount of 11,700 kg THg/year in raw wastewater, with some 480 kg THg/year discharged to surface waters. Monomethyl mercury on average accounted for 0.23% of THg, and its fraction remained constant along the different treatment steps. (C) 2020 The Authors. Published by Elsevier Ltd.

【 授权许可】

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