Mobility and redox transformation of arsenic during treatment of artificially recharged groundwater for drinking water production

WATER RESEARCH

卷:178

Article

Ahmad, Arslan^1,2,3,4  Heijnen, Leo¹  de Waal, Luuk¹  Battaglia-Brunet, Fabienne⁵  Oorthuizen, Wim⁶  Pieterse, Brent⁶  Bhattacharya, Prosun²  van der Wal, Albert^3,4 

[1] KWR Water Cycle Res Inst, Groningenhaven 7, NL-3433 PE Nieuwegein, Netherlands

[2] KTH Royal Inst Technol, Dept Sustainable Dev Environm Sci & Engn, KTH Int Groundwater Arsen Res Grp, Tekn Ringen 10B, SE-10044 Stockholm, Sweden

[3] Wageningen Univ & Res WUR, Dept Environm Technol, Droevendaalsesteeg 4, NL-6708 PB Wageningen, Netherlands

[4] Evides Water Co NV, Schaardijk 150, NL-3063 NH Rotterdam, Netherlands

[5] French Geol Survey BRGM, 3 Ave Claude Guillemin,BP 36009, F-45060 Orleans 02, France

[6] Dunea Duin & Water NV, Pl Verenigde Naties 11-15, NL-2719 EG Zoetermeer, Netherlands

关键词: Arsenic;    Drinking water;    Co-precipitation;    Fe(III)(oxyhydr)oxides;    Rapid sand filtration;   

DOI  :  10.1016/j.watres.2020.115826

来源: Elsevier

【 摘 要 】

In this study we investigate opportunities for reducing arsenic (As) to low levels, below 1 mu g/L in produced drinking water from artificially infiltrated groundwater. We observe that rapid sand filtration is the most important treatment step for the oxidation and removal of As at water treatment plants which use artificially recharged groundwater as source. Removal of As is mainly due to As co-precipitation with Fe(III)(oxyhydr)oxides, which shows higher efficiency in rapid sand filter beds compared to aeration and supernatant storage. This is due to an accelerated oxidation of As(III) to As(V) in the filter bed which may be caused by the manganese oxides and/or As(III) oxidizing bacteria, as both are found in the coating of rapid sand filter media grains by chemical analysis and taxonomic profiling of the bacterial communities. Arsenic removal does not take place in treatment steps such as granular activated carbon filtration, ultrafiltration or slow sand filtration, due to a lack of hydrolyzing iron in their influent and a lack of adsorption affinity between As and the filtration surfaces. Further, we found that As reduction to below 1 mu g/L can be effectively achieved at water treatment plants either by treating the influent of rapid sand filters by dosing potassium permanganate in combination with ferric chloride or by treating the effluent of rapid sand filters with ferric chloride dosing only. Finally, we observe that reducing the pH is an effective measure for increasing As co-precipitation with Fe(III)(oxyhydr)oxides, but only when the oxidized arsenic, As(V), is the predominant species in water. (C) 2020 The Author(s). Published by Elsevier Ltd.

【 授权许可】

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