Reduction of Nitrogen Load in a Zootechnical Wastewater Using a Natural Chabazite Zeolite: An Investigation on Sorption Mechanisms

The use of zeolite-rich tuffs is a valid method for recovering nitrogen from wastewaters. This paper aims at describing the NH4+ adsorption processes of an Italian chabazite zeolite tuff used for the treatment of raw liquid swine manure. The effects of temperature, grain size and contact time were investigated. The isothermal analysis showed a multilayer adsorption behavior, well explained by the Harkins–Jura model, while kinetics was explained by pseudo-second-order, Elovich and intraparticle diffusion models. This study highlighted the complexity of the adsorption process from raw liquid manure, as well as the significant differences between tested particle sizes of the same zeolite tuff

Ammonium adsorption by chabazite zeolite-tuff from swine manure for soil amendment

T he use of natural sorbent geomaterials, like zeolitites (rocks containing > 50% of zeolites) is recognized as a valid method to recover N in the form of ammonium ions (NH4 +) from Zootechnical Wastewaters (ZoWs). Using zeolite-rich tuff as N sorbent from ZoWs lead to varius advantages like the decrease in environmental impact of ZoWs (decreased N content) and the subsequent creation of a high-value soil amendment employable also in organic agriculture (NH4-charged zeolite-tuff). In order to understand the characteristics of NH4-charged zeolites (CZ) as sorbent, it is mandatory a deep investigation on their sorption dynamics when they react with ZoWs. Scientific literature is rich of studies about sorption in sintetic solutions (especially NH4CL) while it lacks studies about sorption in real ZoWs. The aim of this work was therefore to characterize the NH4 sorption dynamics of a chabazite zeolite tuff from swine manure. In particular, two grain sizes were selected, a micronized (< 125 μm, CHAμ) and a granular one (0.7-2.0 mm, CHAg). A series of batch experiments were performed to investigate the effects of temperature, contact time and grain size on sorption of NH4. Equilibrium data were fitted with appropriate isothermal models; kinetic models were also investigated to characterize the kinetik sorption reactions and the thermodinamic parameters like change in free energy (ΔG), enthalpy (ΔH) and entropy (ΔS). Results have shown a significant grain size effect with respect to the equilibrium loading (qe), with better performances for CHAμ in all the temperatures investigated; the isothermal data showed that the influence of temperature is less for CHAμ with respect to CHAg. The kinetic data differs from the two grain size investigated, in particular CHAg showed an initial external surface adsorption and macropore diffusion during the first 60 minutes of contact, then the diffusion occurs also inside the micropores. The Intraparticle Diffusion model (ID) for CHAμ showed that the diffusion in the macropores are much more fast than CHAg and the intercept indicates the formation of a boundary layer thicker than CHAg. Pseudo-second-order kinetic model well explained CHAg behavior but not that of CHAμ. Both grain sizes were well explained by Elovich equation wich is a model used to explain the sorption kinetics for energetically heterogeneous solids surfaces (as likely the surface of the zeolite-tuff employed). Thermodinamic data showed that the energy in the liquid-solid adsorption surfaces increased during adsorption (ΔH ˃ 0), thus the cation exchange reaction needs energy from the liquid phase. The free standard entropy change (ΔS) is also positive, indicating that the NH4 sorption is a directional process with no significant differences with respect to the tested temperatures and that the randomness at the solid-solution interface increased during adsorption. The negative values of Gibbs free energy (ΔG) indicates that the NH4 sorption is an exergonic process (spontaneous reaction)

Geochemistry of noble gas and CO2 in fluid inclusions from lithospheric mantle beneath Eifel and Siebengebirge (Germany)

No abstract available

Exploring the Combined Effects of Different Nitrogen Sources and Chabazite Zeolite-Tuff on Nitrogen Dynamics in an Acidic Sandy-Loam Soil

Volcanic tuffs rich in chabazite zeolites have been extensively examined for their potential to enhance soil properties and increase fertilizer efficiency, both in their natural state and when enriched with nitrogen (N). However, there is a scarcity of data regarding their utilization in acidic sandy soil, particularly when used alongside organic fertilizers. This paper presents the findings of a 50-day laboratory incubation study that investigated the dynamics of N pools in an acidic sandy-loam agricultural soil treated with various N sources. These sources included urea, N-enriched chabazite zeolite tuff, and pelleted composted manure applied at a rate of 170 kg N/ha. Additionally, the N sources were tested in combination with chabazite zeolite tuff mixed into the soil to assess its role as a soil conditioner. The results revealed distinct behaviours among the tested N sources, primarily impacting soil pH and N dynamics. Soil fertilized with manure exhibited slow N mineralization, whereas N-enriched zeolite displayed a more balanced behaviour concerning net NO3−-N production and NH4+-N consumption. Both N-enriched zeolite and urea temporarily altered the soil pH, resembling a “liming” effect, while pelleted manure facilitated a prolonged shift towards neutral pH values. Considering the water adsorption capacity of zeolite minerals, caution is advised when adjusting water content and employing combustion methods to measure soil organic matter in zeolite treated soil to avoid potential inaccuracies. In summary, N-enriched chabazite zeolite tuff emerged as a valuable N source in acidic sandy-loam soil, offering a promising alternative to synthetic fertilizers and showcasing a sustainable means of N recycling

Reducing Nitrogen Fertilization in Olive Growing by the Use of Natural Chabazite-Zeolitite as Soil Improver

In order to improve the sustainability and productivity of modern agriculture, it is manda tory to enhance the efficiency of Nitrogen (N) fertilizers with low-impact and natural strategies, without impairing crop yield and plant health. To achieve these goals, the ZeOliva project conducted an experiment using a zeolite-rich tuff as a soil amendment to improve the efficiency of the N fertiliz ers and allow a reduction of their inputs. The results of three years of experimentation performed in three different fields in the Emilia-Romagna region (Italy) are presented. In each field, young olive trees grown on zeolite-amended soil (−50% of N-input) were compared to trees grown on unamended soil (100% N-input). Soils and leaves were collected three times every year in each area and analyzed to monitor the efficiency of the zeolite treatment compared to the control. Vegetative measurements were performed along with analysis of pH, Soil Organic Matter and soluble anions in soil samples, whereas total C and N, C discrimination factor and N isotopic signature were investigated for both soils and leaves. Besides some fluctuations of nitrogen species due to the sampling time (Pre-Fert, Post-Fertilization and Harvest), the Total Nitrogen of leaves did not highlight any difference between treatments, which suggest that plant N uptake was not affected by lower N input in the zeolite treatment. Results, including vegetative measurements, showed no significant differences between the two treatments in all the observed variables, although the control received twice the N-input from fertilization. Based on these results, it is proposed that zeolite minerals increased the N retention time in the soil, allowing a better exploitation by plants which led to the same N uptake of the control notwithstanding the reduction in the N inputs. The use of zeolite-rich tuff in olive growing thus allows a reduction in the amount of fertilizer by up to 50% and improves the N use efficiency with many environmental and economic benefits

Leaching behaviour of a sandy soil amended with natural and NH4+and K+saturated clinoptilolite and chabazite

Using saturated or enriched zeolites as slow release fertilizers (SRFs) is considered as an environmental-friendly strategy to enhance use of macronutrients in sandy soils. In this paper, two natural zeolites, clinoptilolite (CLI) and chabazite (CHA) were used as mineral precursors to prepare NH4+/K+saturated clinoptilolite (NH4+/K+-CLI) and chabazite (NH4+/K+-CHA) as zeolitic nutrient sources (ZNSs). Comparison between the nutrient retention capabilities of these ZNSs was one of the main objectives of this study. The NH4+/K+-CLI and NH4+/K+-CHA were prepared by soaking the zeolites in NH4Cl and KCl solutions, respectively. Leaching tests were performed on a sandy soil amended with chemical fertilizers (CFs), NH4+/K+-CLI and NH4+/K+-CHA to evaluate the leaching properties of them. The results indicated that approximately 84% and 88% of the NH4+and K+of soils fertilized with CFs were lost during the experiment, respectively. While, the NH4+and K+losses from soils amended with NH4+/K+-CLI and NH4+/K+-CHA were 29%, 23%, and 14%, 24%, respectively. Despite of drastic changes in leaching behavior of CFs, nutrient losses from ZNSs were more uniform during the experiments. No significant difference was found between the two studied zeolites on reduction of K+loss. However, CHA was more effective in preventing NH4+loss during leaching

CO2‐Rich Xenoliths at Mt. Vulture Volcano (Southern Italy): New Constraints on the Volcano Plumbing System

This study provides new mineral chemistry data together with micro-thermometric measurements on fluid inclusions hosted in ultramafic xenoliths (lherzolite, wehrlite, and dunite) brought to the surface by the last Mt. Vulture volcano activity (140 ka; southern Italy), and fed by melilitite-carbonatite magmas. Petrographic evidence and mineralogical compositions of Mt. Vulture xenoliths are consistent with an origin in the upper mantle. Fluid inclusions in rock-forming minerals of lherzolite and wehrlite xenoliths are CO2-dominated. The equilibrium temperature calculated by geothermometric estimates ranges from 1039 C (+/- 36 degrees C) to 1142 degrees C (+/- 15 degrees C), and entrapment pressures of fluid inclusions with post-trapping re-equilibration correspond to the local crust-mantle boundary (32 km depth), and to a shallow reservoir located at 12-14 km depth. These results contribute to constrain the origin of these xenoliths and the depth of storage of magmas erupted from Mt. Vulture, where carbonatite-like metasomatism and mantle-derived CO2 degassing occur

Effectiveness of enzymatic hydrolysis for reducing the allergenic potential of legume by-products

The interest in agri-food residues and their valorization has grown considerably, and many of them are today considered to be valuable, under-exploited sources of different compounds and notably proteins. Despite the beneficial properties of legumes by-products, there are also some emerging risks to consider, including their potential allergenicity. In this work the immunoreactivity of chickpea, pea, and white bean by-products was assessed, and whether the production of enzymatic hydrolysates can be an effective strategy to reduce this allergenic potential. The results presented clearly indicate that the efficiency of this strategy is strongly related to the enzyme used and the food matrix. All legume by-products showed immunoreactivity towards serum of legume-allergic patients. Hydrolysates from alcalase did not show residual immunoreactivity for chickpea and green pea, whereas hydrolysates from papain still presented some immunoreactivity. However, for white beans, the presence of antinutritional factors prevented a complete hydrolysis, yielding a residual immunoreactivity even after enzymatic hydrolysis with alcalase

Gross Ammonification and Nitrification Rates in Soil Amended with Natural and NH4-Enriched Chabazite Zeolite and Nitrification Inhibitor DMPP

Using zeolite-rich tuffs for improving soil properties and crop N-use efficiency is becoming popular. However, the mechanistic understanding of their influence on soil N-processes is still poor. This paper aims to shed new light on how natural and NH4+-enriched chabazite zeolites alter short-term N-ammonification and nitrification rates with and without the use of nitrification inhibitor (DMPP). We employed the 15N pool dilution technique to determine short-term gross rates of ammonification and nitrification in a silty-clay soil amended with two typologies of chabazite-rich tuff: (1) at natural state and (2) enriched with NH4+-N from an animal slurry. Archaeal and bacterial amoA, nirS and nosZ genes, N2O-N and CO2-C emissions were also evaluated. The results showed modest short-term effects of chabazite at natural state only on nitrate production rates, which was slightly delayed compared to the unamended soil. On the other hand, the addition of NH4+-enriched chabazite stimulated NH4+-N production, N2O-N emissions, but reduced NO3-N production and abundance of nirS-nosZ genes. DMPP efficiency in reducing nitrification rates was dependent on N addition but not affected by the two typologies of zeolites tested. The outcomes of this study indicated the good compatibility of both natural and NH4+-enriched chabazite zeolite with DMPP. In particular, the application of NH4 +-enriched zeolites with DMPP is recommended to mitigate short-term N losses