Recently, an alternative technology

Recently, an alternative technology was developed to use engineered/
modified biochars to remove various pollutants, including
phosphate, heavy metals, and organic compounds, from aqueous
solutions (Inyang et al., 2010, 2011; Yao et al., 2011a, b; Zhang
et al., 2012). For example, anaerobically digested biomass residues
were used as feedstock materials to produce engineered biochars
that have high adsorption abilities for heavy metals and phosphate
(Inyang et al., 2012, 2011; ; Yao et al., 2011a, b). H2O2 modification
of biochar hydrothermally produced from peanut hull can lead to
an activation and greatly enhance its ability to remove heavy metals,
particularly lead, from water (Xue et al., 2012). Because exhausted
biochar adsorbents may contain a great number of
pollutants, when biochar-based adsorbents are applied to treat
natural water bodies, there is a need to develop a technique to collect
the pollutant-laden adsorbents from aqueous solutions to
avoid secondary contaminations. Such technique can realistically
accomplish the commercialization of biochar-based adsorbents