Removal ofHeavy Metals From Effluents Using Ion-Exchange Resin

The presence ofheavy metals in the environment is major concern due to their toxicity.
Contamination of heavy metals in water supplies has steadily increased over the last
years as a result of expansion of industrial activities. Removal of trace amounts of heavy
metals can be achieved by means of selective ion-exchange processes. In the present
study, the removal of Ni(2+), Fe(3+),and Cr(3+) from industrial effluent was
investigated. Experimental investigations were undertaken using the ion-exchange resin
Amberlyst 15 wet resin (strongly acidic) and were compared with Activated Carbon.The
influence of contact time , metal concentration and amount of resins on the removal
process was investigated. For the determination ofthe adsorption behavior of
the resin, the adsorption isotherms of metal ions have also been studied. The
concentrations of metal ions have been measured by batch techniques. For investigations
different amounts of resin were contacted with a fixed volume of Ni(2+), Fe(3+),and
Cr(3+) ion containing effluent. The obtained adsorption affinity sequence in the presented
work was Ni(2+)>Fe(3+)>Cr(3+). The metal ion concentrations were measured by AAS
methods. The uptake of metal ions by the ion-exchange resins was
reversible and thus has good potential for the removal of Ni(2+), Fe(3+),and Cr(3+) from
the effluent. Selectivity increased in the series: Ni(2+)>Fe(3+)>Cr(3+). Ni(2+) and
Fe(3+) shown 100% removal result using 20g of each resins and Cr(3+) shows promising
percentage of removal. The results obtained showed that the Amberlyst 15 wet resin and
Activated Carbon resin performed well for the removal of the heavy metals. As a low
cost adsorbent, activated carbon is more preferable for the removal of heavy metals from
the wastewater.
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