Ammonia Removal from Tannery Wastewaters by Selective Ion Exchange on Slovak Clinoptilolite

The purpose of the work was to verify and demonstrate, on a pilot plant scale, the applicability of the Slovak clinoptilolite as a natural selective ion exchanger for the removal of ammonia from tannery wastewaters. During the pilot treatment experiments at an industrial wastewater treatment plant of the Shoe Manufacturing Industry Svit-Otrokovice, about 260 m³ of wastewaters were treated. The regeneration process was carried out with 2% NaCl (pH = 9, NaOH) and the eluate was distributed into 3 fractions. Only the most concentrated ammonia fraction was stripped in the renovation step. The economic efficiency of the studied method was compared with the biological nitrification-denitrification method.