1 research outputs found
Assessment of the use of industrial by-products for induced reduction of As, and Se potential leachability in an acid soil
8 pages, photos, figures, and tables statistics.Four industrial by-products (phosphogypsum, PG; red gypsum, RG; sugar foam, SF and ashes from the
combustion of biomass, ACB) were evaluated as possible amendments for reducing the leachability and
bioavailability of As and Se in a metalloid-spiked acidic soil. The treatments were applied as single, double
and triple amendments and at two different rates. The effectiveness of the treatments was evaluated after
a series of leaching experiments using a chelating agent (DTPA solution) or a weak acidification (acetic
acid at pH 4.93). The most effective treatments (ACB and RG, both applied at high rate) were identified by
means of Cluster Analysis using the leachability indexes. Different sorption mechanisms involved in the
overall reduction of metalloid leachability were identified using scanning electron microscopy (SEM-BSE
and SEM-EDS). In the ACB-treated samples, Se was found associated to organic matter aggregates and to
Fe compounds. In the RG-treated samples, EDS analyses showed that As and Se were associated to Fe/Ti
(hydr)oxides phases which are present not only in the by-product as maghemite and rutile, but also in the
soil as hematite and goethite. In addition, the application of RG induced the formation of non-crystalline
Al-hydroxy polymers with As and Se in their composition.ElsevierPeer reviewe