Mean TOC of the Al-WTR averaged 97.5 mg g1 (Yang et al.,
2006), while LOI averaged 49.4%. These values may be attributed to
humic substances contained in the raw water being treated. The
presence of humic substances in raw water being treated has also
been reported by other authors (Domany et al., 2002). The
elemental composition of the Al-WTR, in comparison with some
other wetland materials is given in Table 2. It is clear that the
primary coagulant (aluminium sulphate) used during the water
treatment process is reflected in the composition of the Al-WTR.
The aluminium component in the Al-WTR is about 1–5 orders of
magnitude greater than all other elements analyzed in the Al-WTR.