B corp certification and its impact on funding rounds over time

This paper studies the impact of B Corp certification and its interaction with the B Impact Assessment score on companies' funding rounds over time. The results reveal that these factors are associated with an increase in organizations' ability to raise capital. Traditional VCs and impact investors have both a role in generating additional investment in B Corps. Moreover, we explore the reverse causality issue and find that most of the increase in companies' funding happens right before the certification. We conclude that firms use part of their financing to pay the internal re-organization costs required to be come B Corps

Secondo contributo alla conoscenza della flora esotica dell'Arcipelago Toscano, Italia

Si presenta qui un secondo contributo per la realizzazione di una Checklist della flora esotica dell'Arcipelago Toscano. Per ogni taxon sono riportati lo status di naturalizzazione, sia per ciascuna isola che per l'intero Arcipelago, e i dati relativi alla distribuzione locale. Delle 31 specie elencate, 18 risultano nuove per il territorio dell'Arcipelago Toscano, tra le quali 4 nuove per l'intera Toscana; le restanti sono nuove per una o più isole

Cr6+ adsorption by modified vermiculite

This work aimed at investigating the adsorption of Cr6+ in water by exfoliated vermiculite. The adsorbant tested in this experiment was a vermiculite (from China) which has been subjected to heating at 1000 °C for 1 minute, resulting in an exfoliated vermiculite. Three effects were studied: 1) contact time; 2) initial concentracion of Cr6+; 3) adsorbent mass. Samples were analysed by X Ray Fluorescence (XRF), X Ray Diffraction (XRD) and the solutions with Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to quantify the adsorbed Cr6+ by the vermiculite. Results from XRD diffraction showed a conversion of vermiculite into flogopite after heating at 1000°C for 1 minute because of: 1) high content of potassium, 2) dehydration and 3) structural re-ordering; after the contact of vermiculite with Cr6+, the mineral structure did not change. The adsorption of Cr6+ was studied by Langmuir, Freundlich and Dubinin-Kaganer-Radushkevich (DKR) isotherm models. DKR model, indicative of a cooperative process, described adsorption equilibrium better than the other two models and the maximum adsorption capacity obtained was of 2.81 mol/g. Kinetic was studied using pseudo-first and pseudo-second order kinetic models, with a better description of the process by pseudo-second order model with correlation coefficient almost unitary (R2=0.9984; other kinetic parameters were k2=0.0015 and the absorption initial rate of 0.2x10-8 mg g-1 h-1). The present study demonstrates the effectiveness of modified vermiculite adsorbents for the treatment of hexavalent chromium-contaminated waters and that its adsorption depends on the experimental conditions (such as contact time, initial concentracion of Cr6+ and adsorbent mass)

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)

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