Adsorption of gold(III) from waste rinse water of semiconductor manufacturing industries using Amberlite XAD-7HP resin

Advanced hydrometallurgical separation
processes are gaining significant importance
for the recovery of gold from the aqueous
solutions viz. leach liquor of waste electronics,
plating material solutions, and waste wash
water from electronic industries. In the present
investigation, gold adsorption from the waste
rinse water of semiconductor manufacturing
industries is reported using Amberlite XAD-
7HP. For experimental purposes, chloride waste
rinse water that contained primarily Au (281 mg/
L) with trace amounts of Cu, Ni, Zn, Sn etc was
used. Batch studies were carried out to optimize
various process parameters, including contact
time, acidity of solution, and resin dosage for
the adsorption of gold from the above waste
effluent. Adsorption of 92.25% gold was found
from the waste solution within a contact time of
30 minutes at an aqueous to resin (A/R) ratio of
25 mL/g and an equilibrium pH of 0.63. In optimal
conditions, the loading capacity of resin for gold
was observed to be 58.82 mg of gold/g of resin.
The gold adsorption phenomena were confirmed
by the comparative FT-IR spectroscopic
characterization studies of fresh resin and gold