Publication Date:
2021-03-29
Description:
Continuous gravity-fed column experiments using the methylene blue (MB) discoloration
method were performed to characterize the suitability of a pozzolan (PZ) specimen as alternative
admixing aggregate for metallic iron filters (Fe0-filters). Investigated systems were: (i) pure sand,
(ii) pure PZ, (iii) pure Fe0, (iv) Fe0/sand, (v) Fe0/PZ, and (vi) Fe0/sand/PZ. The volumetric proportion
of Fe0 was 25%. The volumetric proportions of the Fe0/sand/PZ system was 25/45/30. The initial
MB concentration was 2.0 mg L1, 6.0 g of Fe0 was used, and the experiments lasted for 46 days.
The individual systems were fed with 3.9 to 8.4 L (7.80 to 16.69 mg of MB) and were characterized by
the time-dependent changes of: (i) the pH value, (ii) the iron breakthrough, (iii) the MB breakthrough,
and (iv) the hydraulic conductivity. Results showed that the Fe0/sand/PZ system was the most
efficient. This ternary system was also the most permeable and therefore the most sustainable.
The suitability of MB as a powerful operative indicator for the characterization of processes in
the Fe0/H2O system was confirmed. The tested PZ is recommended as an alternative material for
efficient but sustainable Fe0 filters.
Description:
Open-Access-Publikationsfonds 2018
Keywords:
aqueous corrosion; packed-bed filters; pozzolan; water treatment; zero-valent iron
;
551
Language:
English
Type:
article
,
publishedVersion
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