On the suitability of phillipsite-chabazite zeolitite rock for ammonia uptake in water. Some general zeolite features and a case study

Abstract

Ionic exchange tests have been performed on superfcial wastewaters to remove ammonia using a volcanic zeolitized rock from Lazio Region (Central Italy). The zeolitite (natural zeolite) is characterized by chabazite, phillipsite and minor amounts of sanidine, leucite and analcime. After preliminary column experiments in laboratory focused to determine the saturation time of the zeolitite, a pilot plant was built up on a little water course near the area of San Giustino channel (Abruzzo Region, Central Italy). Wastewaters, characterized by starting ammonia value ranging between 5 and 120 mg/l, were fltered with a zeolitic bed. The frst experimental results indicate a positive ammonia reduction of about 80-90% and, in all cases, NH4+ concentration values under the EU law limits. A main purpose of this paper is to evidence that most of studies published on uptake of ammonia by means of zeolitite lead with clinoptilolite-dominant zeolitite despite the large and best performance of phillipsite-chabazite zeolites (up to 61-79% improvement of ammonia uptake). Last but not least, a large number of published studies are of difcult comparison because of poor characterization of the zeolitite used.