On copper removal from aquatic media using simultaneous and sequential iron-perlite composites

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The use of affordable and inert adsorbents to mitigate copper pollution, with a lesser burden on the environment, is desirable. However, aiding the adsorption process of a promising adsorbent, e.g. expanded volcanic glass (perlite), with a reducing companion, e.g. solid iron, that can displace and dispose of copper from polluted water has never been tested before. In this laboratory study, we investigated the removal of Cu2+, resulting from contaminating freshwater with copper sulphate pentahydrate, using simultaneous or non-simultaneous (sequential) mixes of expanded perlite and iron coarse powder over 23 h. The percentage of copper removal was calculated over time using induced coupled plasma (ICP-OES). A rapid removal of 71 % at 120 min was achieved when the perlite and iron were added simultaneously in separate permeable pouches; the application of the iron after the perlite led to 78 % of removal at 1380 min that was almost identical to what was accrued under perlite alone (77 %). This, therefore, suggests that the presence of iron is most advantageous in the short run as it leads to fast uptake of Cu2+, attributable to the combined action of the reduction of Cu2+ by iron and Cu2+ adsorption by perlite. Further investigation was carried out using Energy-Dispersive X-Ray Spectroscopy (EDAX), X-Ray Diffraction (XRD), Brunauer, Emmett and Teller (BET), and Fourier-Transform Infrared Spectroscopy (FTIR). This multidisciplinary work provides insights and mechanisms for prompt heavy metal removal using novel time-specific metal-adsorbent combinations and thus merits wider testing across different classes of adsorbents, pollutants, and water systems.

Bibliographical metadata

Original languageEnglish
Article number101842
JournalJournal of Water Process Engineering
Early online date2 Dec 2020
Publication statusPublished - 1 Apr 2021