Searched for: author%3A%22van+Halem%2C+D.%22
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Bicudo, Bruno (author), Medema, G.J. (author), van Halem, D. (author)
Electrochemical ferrous iron (Fe<sup>2+</sup>) wastewater treatment is gaining momentum for treating municipal wastewater due to its decreasing costs, environmental friendliness and capacity for removal of a wide range of contaminants. Disinfection by iron electrocoagulation (Fe-EC) has been occasionally reported in full scale industrial...
journal article 2022
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Roy, M. (author), van Genuchten, Case M. (author), Rietveld, L.C. (author), van Halem, D. (author)
Groundwater contaminated with arsenic (As) must be treated prior to drinking, as human exposure to As at toxic levels can cause various diseases including cancer. Conventional aeration-filtration applied to anaerobic arsenite (As(III)) contaminated groundwater can remove As(III) by co-oxidizing native iron (Fe(II)) and As(III) with oxygen (O...
journal article 2022
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Bicudo, Bruno (author), Van Der Werff, Bart Jan (author), Medema, G.J. (author), van Halem, D. (author)
Electrochemical water treatment is gaining increasing popularity due to its wide range of potential applications, its decreasing costs, and its suitability as a decentralized treatment alternative, but mainly due to it being considered a "green technology". In the field of municipal wastewater treatment, the use of iron electrocoagulation (Fe...
journal article 2022
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Annaduzzaman, M. (author), Rietveld, L.C. (author), Hoque, Bilqis Amin (author), van Halem, D. (author)
Sequential iron (as Fe<sup>2+</sup>) oxidation has been found to yield improved arsenic (as As(III)) uptake than the single-step oxidation. The objective of this study was to gain a better understanding of interactions with phosphate (PO<sub>4</sub><sup>3−</sup>) and silicate (SiO<sub>4</sub><sup>2−</sup>) during sequential Fe<sup>2+</sup>...
journal article 2022
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Spit, T.P.M. (author), van der Hoek, J.P. (author), de Jong, Coen (author), van Halem, D. (author), de Kreuk, M.K. (author), Bicudo, Bruno (author)
At wastewater treatment plants (WWTPs), additional steps are introduced for removal of organic micropollutants (OMPs) from the treated effluents, especially pharmaceutical residues. At the same time, a new concern is emerging: antibiotic resistance (AR). This research studied the effect of ozonation, coagulation and granular activated carbon ...
journal article 2022
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Goedhart, R.C. (author), Müller, S. (author), van Loosdrecht, Mark C.M. (author), van Halem, D. (author)
Iron in anaerobic groundwater is commonly removed by oxidation followed by sand filtration. This produces large volumes of iron(III)(hydr)oxide sludge with little value. Our research investigates the novel concept of anaerobic iron(II) recovery from groundwater as the valuable mineral vivianite (Fe<sub>3</sub>(PO<sub>4</sub>)<sub>2</sub> • 8...
journal article 2022
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Wei, L. (author), Zietzschmann, F.E. (author), Rietveld, L.C. (author), van Halem, D. (author)
Millions of people worldwide are exposed to excessive concentrations of fluoride (F<sup>−</sup>) from groundwater sources. Ca-Al-CO<sub>3</sub> layered double hydroxides (LDHs) have shown promising defluoridation efficiency; however, defluoridation by Ca-Al-CO<sub>3</sub> LDHs is highly pH sensitive. This study showed that simultaneous...
journal article 2021
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Roy, M. (author), van Genuchten, Case M. (author), Rietveld, L.C. (author), van Halem, D. (author)
Arsenic (As) is a toxic element present in many (ground)water sources in the world. Most conventional As removal techniques require pre-oxidation of the neutral arsenite (As(III)) species to the negatively charged arsenate (As(V)) oxyanion to optimize As removal and minimize chemical use. In this work, a novel, continuous-flow As removal...
journal article 2021
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Bicudo, Bruno (author), van Halem, D. (author), Trikannad, S.A. (author), Ferrero, Giuliana (author), Medema, G.J. (author)
In this paper we analyse the feasibility of low voltage iron electrocoagulation as a means of municipal secondary effluent treatment with a focus on removal of microbial indicators, Antibiotic Resistant Bacteria (ARB) and nutrients. A laboratory scale batch unit equipped with iron electrodes was used on synthetic and real secondary effluent...
journal article 2021
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Wei, L. (author), Li, Z. (author), Ye, G. (author), Rietveld, L.C. (author), van Halem, D. (author)
Excessive F<sup>-</sup> in drinking water due to natural and anthropogenic activities is a serious health hazard affecting humans worldwide. In this study, a comparative assessment was made of eight mineral-based materials with advantageous structural properties for F<sup>-</sup> uptake: layered-double-hydroxides (LDHs), geopolymers,...
journal article 2021
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Annaduzzaman, M. (author), Rietveld, L.C. (author), Amin Hoque, Bilqis (author), Bari, Md Niamul (author), van Halem, D. (author)
Generally, abstracted groundwater is aerated, leading to iron (Fe<sup>2+</sup>) oxidation to Fe<sup>3+</sup> and precipitation as Fe<sup>3+</sup>-(hydr)oxide (HFO) flocs. This practice of passive groundwater treatment, however, is not considered a barrier for arsenic (As), as removal efficiencies vary widely (15–95%), depending on Fe/As ratio...
journal article 2021
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Annaduzzaman, M. (author), Rietveld, L.C. (author), Ghosh, D. (author), Hoque, Bilqis A. (author), van Halem, D. (author)
Storage containers are usually used to provide a constant water head in decentralized, community groundwater treatment systems for the removal of iron (Fe) and arsenic (As). However, the commonly practiced aeration prior to storage assists in rapid and complete Fe<sup>2+</sup> oxidation, resulting in poor As removal, despite sufficient native...
journal article 2021
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Soliman, Mona Youssef Moawad (author), Medema, G.J. (author), Estrada Bonilla, B.A. (author), Brouns, S.J.J. (author), van Halem, D. (author)
Cu and Ag have been used as bactericidal agents since ancient times, yet their antiviral capacity in water remains poorly understood. This study tested the effect of copper (Cu) and silver (Ag) on model RNA and DNA viruses MS2 and PhiX 174 in solution at pH 6–8. Cu caused MS2 inactivation with similar rates at pH 6 and 7 but was inert towards...
journal article 2020
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Wei, L. (author), Zietzschmann, F.E. (author), Rietveld, L.C. (author), van Halem, D. (author)
In this study, F<sup>−</sup> removal by Ca–Al–CO<sub>3</sub> layered double hydroxides (LDHs) was investigated at environmentally-relevant concentration ranges (2–12 mg/L) to below the WHO guideline, with an emphasis on the effect of LDHs’ modification, as well as the effects of initial F<sup>−</sup> concentration, adsorbent dose, pH,...
journal article 2020
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Soliman, Mona Youssef Moawad (author), van Halem, D. (author), Medema, G.J. (author)
Ceramic pot filters are household water treatment and safe storage (HWTS) systems designed to improve the microbial quality of drinking water. They yield high log reduction values (LRVs) for bacterial and protozoan pathogens but provide very little removal of viruses. This study investigated virus removal of ceramic filter discs (CFDs), using...
journal article 2020
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Gonzalez Rodriquez, B.J. (author), Heijman, Sebastiaan (author), Rietveld, L.C. (author), van Halem, D. (author)
In Nicaragua, a Central American country, geothermally influenced waters are frequently found to be contaminated with arsenic (as As(V)). This study investigated the effect of high-temperatures (25–50 °C), as found in geothermally influenced source waters, on the rejection of monovalent H2AsO4 - and divalent HAsO4 2- species (at pH 6,7 and 8)...
journal article 2019
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Gonzalez Rodriquez, B.J. (author), Rietveld, L.C. (author), Longley, A. J. (author), van Halem, D. (author)
Several surveys have been conducted in Nicaragua between 1996 and 2015 confirming the presence of high levels of arsenic (&gt;10 μg/L). In this paper, these peer-reviewed (n = 2) and non-peer reviewed sources (n = 14) have been combined to provide an extensive overview of the arsenic contamination of drinking water sources in Nicaragua. So...
review 2019
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Gonzalez Rodriquez, B.J. (author), Heijman, Sebastiaan (author), Rietveld, L.C. (author), van Halem, D. (author)
This research evaluated the effect of different fluxes (16, 23 &amp; 30 L/m <sup>2</sup> h) and temperatures (31,35 &amp; 43 °C) on the rejection of As(V) during nanofiltration (NF) of natural geothermal influenced groundwater in Nicaragua. A NF pilot plant powered by solar panels was built and operated in rural community Telica, exposed to...
journal article 2019
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Gutiérrez, Juan Pablo (author), van Halem, D. (author), Uijttewaal, W.S.J. (author), del Risco, Efraín (author), Rietveld, L.C. (author)
As a consequence of the suspended sediments in river water, cake formation on the streambed and clogging of the aquifer may occur, leading to a decline in the production yield of riverbank filtration systems, particularly in highly turbid river waters. However, naturally occurring flow forces may induce sufficient scouring of the streambed,...
journal article 2018
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Gude, J.C.J. (author), Rietveld, L.C. (author), van Halem, D. (author)
In the top layer of aerated rapid sand filtration systems, uncharged As(III) is biologically converted to charged As(V). Subsequently, the main removal mechanism for As(V) is adsorption onto oxidised, flocculated Fe(III) (hydrous ferric hydroxides; HFO). The aim of this research was to understand the interactions between As and Fe in...
journal article 2018
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