ELECTROPLATING RINSE WASTE-WATER TREATMENT BY ION-EXCHANGE

Purification of copper containing waste waters from electroplating pla nts by means of different ion exchange units has been studied. The cop per containing waste water with a range of copper concentration 55-60 mg/l, pH 3.3-3.5 has been treated of following schemes: (I) Weak base anion exchanger (OH-form)-weak acid cation exchanger (H-form)-strong b ase anion exchanger (OH-form); and (II) Modified with thiocarbamide st rong acid cation exchanger-weak base anion exchanger (OH-form). It has been established that the breakthrough capacities of the tested weak acid cation exchangers (towards Cu2+) are 1.40-1.80 eq/l and of the mo dified cation exchangers 7.45-1.90 eq/l. The concentration of Cu2+ and SO42- in the purified water is below 0.05 mg/l and the water can be r eused. Twenty cycles of exhaustion with copper containing waste water- regeneration of tested ion exchangers were carried out. The total exch ange capacities and the moisture content of non-used (new) and used io n exchangers were determined. The microscopically investigations and s tructural porosity studies have been also carried out. The data obtain ed show that the total capacities and the moisture content changes ins ignificantly.