These methods suffer from some drawback such as high capital and operational costs
or the treatment and disposal of the residual metal sludge. The main advantages of ion
exchange over chemical precipitation are recovery of metal value, selectivity, less sludge
volume produced and the meeting of strict discharge specifications. In ion exchange systems,
polymeric resins are usually employed [12]. Ion exchange using synthetic resins is the
method of choice in manywater treatment processes for removing inorganic contaminants in
water andwastewater [13]. Tiravanti et al. [9] studied the pretreatment of tannerywastewater
by an ion exchange process for Cr(III) removal and recovery. They found that a considerable
decrease in the use of chemical compounds, a sludge production reduced by 80% with
respect to the traditional treatment and lower costs for sludge treatment and disposal.