In comparison to the range of SSA of other candidate wetland
materials reported in literature such as 2.6–3.9m2 g1 (Roger, 2000)
and 6.8–31.4m2 g1 (Drizo et al., 1999), the Al-WTR used herein can
be seen to have a comparatively higher SSA. This further relates to
having adequate surface area for biofilm growth and attachment.
The micropore, mesopore and pore volumes of the Al-WTR
were determined to be 0.0125 cm3 g1, 0.0210 cm3 g1 and
0.0410 cm3 g1 respectively. The mesopore volume was about 1.7
times the micropore volume and the mesopores also account for
about 51.2% of the entire pore volume of the Al-WTR. The XRD
diffraction pattern did not reveal any sharp diffraction characteristic
peak over a broad range of d-spacings (10–80, 2q). This indicates
poorly ordered particles within the Al-WTR and it also illustrates
that, even though the SEM–EDX results highlight the predominance
of aluminium in the Al-WTR, it is likely to be amorphous aluminium.
This observation is also in agreement with other authors (Dayton
and Basta, 2001; Makris and O’Connor, 2007). Similarly, the FTIR
spectrum ranging from 500 to 4000 cm1 did not provide clear
information regarding peaks.
3.2. Chemical