Characterization and evaluation of chabazite- and mordenite-rich tuffs, and their mixtures as soil amendments and slow release fertilizers

Abstract

In the present study, zeolite tuffs of diverse chemistry, mineralogy and origin were characterized and tested for their efficiency as slow release fertilizers (SRF) through a series of leaching tests. Mixtures of zeolite tuffs were created and tested as loamy soil additives, in order to evaluate any synergistic effect on their cation exchange capacity (CEC) and SRF properties. The studied materials were a chabazite-rich tuff (SOR), a mordenite-rich tuff (KIM), 3 mixtures of them (SOR/KIM 30/70, 50/50 and 70/30) and a commercial clinoptilolite-rich tuff (BLG). CEC (sodium acetate method) was 95.7 for BLG, 100.9 for KIM and 92.2 cmol kg -1 for SOR, while their mixtures displayed intermediate values. SRF values vary, with the SOR/KIM 30/70 exhibiting the slowest NH 4 + release in 29 days (1.7%) compared to the control sample (19%). Zeolites promoted PO 4 -3 release, while their selectivity for Mg 2+ and K + was clearly affected by their different structure and chemistry. BLG exhibited the strongest selectivity for Mg 2+ , having the lowest release (39%). The results demonstrate that mixtures of zeolite tuffs could have a potential use in agricultural processes, by improving parameters like: chemistry, mineralogy, CEC and SRF efficiency,and resulting in the production of a competitive and functional soil additive.

Petrology and Genesis of the Italian Zeolite Tuffs Used in the Construction Industry

“…According to their chemistry, all tuffs studied exhibit shoshonitic affinity and trachytic composition (Figure 2). All Italian tuffs studied have different mineralogy and chemistry compared to those originated from the Balkans and Hungary which are rich in clinoptilolite and/or mordenite and are also used in construction (building stones and cement raw material) [5,23,24]. 2.…”

Use of zeolite and biogenic silica rich rocks as olive oil mill waste absorbents

“…The zeolite-rich SOR sample had the highest pH value (Table 5), which is common in this type of rocks (Stamatakis et al, 2017), whereas the opal-A rich ELS sample showed the lowest pH value. SOR was the only sample to have an effect on OOMW pH (5.01), neutralising it to 6.96 after 24 h of treatment.…”

“…The poorest value was displayed by the opal-A-rich ELS sample, being in accordance with the Derkowski et al 2015measurements, where opal-A CEC was 8 cmol(+)/kg. The SOR chabazite tuff exhibited high CEC values, characteristic for such zeolite deposits (Stamatakis et al, 2017). CYP and SAM samples had intermediate values, due to the coexistence of minerals with diverse CEC (zeolites, clay minerals and opal-CT).…”

“…CYP and SAM samples had intermediate values, due to the coexistence of minerals with diverse CEC (zeolites, clay minerals and opal-CT). Common CEC values for chabazite, clinoptilolite are 180-190 cmol(+)/kg, illite-smectite mixtures 59 cmol(+)/kg and opal-CT 13 cmol(+)/kg (Derkowski et al, 2015;Stamatakis et al, 2017). Note: a calculation of the SSA using the BET theory; b calculation of the pores distribution using the BJH theory between 1,000 and 3,000.000 Å width; c adsorption average pore width (4V/A by BET).…”

Geochemical processes during the stabilization of potentially toxic elements (PTEs) in contaminated soil by using mineral amendments

“…This volcanic activity during Pleiocene is related to the significant industrial mineral deposits of the island. The genesis, properties and applications of the zeolite and bentonite deposits have been extensively studied (Fragoulis et al, 1997;Christidis, 1998b;Stamatakis et al, 1998Stamatakis et al, , 2000Stamatakis et al, , 2017Giannatou et al, 2016).…”