2.4. Influence of particle size in the removal efficiency
In order to determinate the influence of the particle size in the
removal efficiency, two different particle sizes (1 and 2 mm) were
used for banana cortex in experiments for the removal of lead in
solution without reload. In order to perform these experiments,
the methodology described in Section 2.3 was used except for
the reloading of the solution eluted. The result of this assessment
was used to decide the best conditions to be applied in other metals
assays.
2.5. Analytical tests
Metal concentration measurements during the experimental
assessments were performed by atomic absorption using a standard
calibration curve including 1.5, 2.5, 5 and 10 mg/L of every
metal. Those concentrations were selected in agreement the Mexican
legislation (NOM-001-ECOL-1996), establishing the maximum
permissible limit in waste water discharges and onto national
goods (