A study was performed to evaluate the suitability of zeolitized tuffs to restore degraded soils. Ca-saturated Neapolitan yellow tuff or clinoptilolite-rich tuff from Turkey were mixed with organic matter either as humic matter (tannic acid, humic acids) or non-humic matter (polygalacturonic acid). Organic matter was strongly stabilized in clinoptilolite-rich tuff aggregates based on humic matter, whereas it was more easily oxidized in models with nonhumic matter. Cation exchange capacity (CEC) was determined according to Ba/Mg-TEA method and by ammonium acetate procedure. The former method underestimated the CEC of the zeolitized tuffs, but was able to detect the contribution of organic matter to the CEC of aggregates. The latter method provided consistent CEC values for the zeolitized tuffs, but underestimated the exchange activity of the organic components of aggregates. CEC of aggregates including tannic acid was practically nil. Binding tannic acid to zeolite via Cabridges, results evidently in occlusion of zeolite pores.
A. Buondonno M. Rubino C. Colella A. Colella E. Coppola B. de Gennaro M. de Gennaro N.Gargiulo A. Langella A. P. Leone A. Letizia
CRA-Istituto Sperimentale Agronomico, Via Celso Ulpiani 5, 70125 Bari, Italy Dipartimento di Scienze Ambientali, polo Scientifico di Caserta, Seconda Università di Napoli, Via V Dipartimento di Ingegneria dei Materiali e della Produzione, Università Federico II; P.le V. Tecchio Dipartimento di Scienze della Terra, Università Federico II; Via Mezzocannone 8, 80134 Napoli, Italy Dipartimento di Studi Geologici e Ambientali, Università del Sannio, Via Port’Arsa 11,82100 Benevent CNR-ISAFOM, Via Patacca, 85, 80056, Ercolano (NA), Italy