In this setting, the use of low-cost materials (industrial, agricultural
or urban residues) for recovering heavy metals from
contaminated industrial effluent has emerged as a potential alternative
method to conventional techniques. For example, some
of the non-conventional low cost adsorbents recently used for
the removal of heavy metals are hazelnut shell, apple residues,
banana pith, tree leaves, mandarin peels, rice polish, seeds of
Capsicum annuum and Ceiba pentandra hulls