Erionite is a zeolite representing a well-known health hazard. In fact, exposure of humans to its fibers has been unequivocally associated with occurrence of malignant mesothelioma. For this reason, a multi-methodological approach, based upon field investigation, morphological characterization, scanning electron microscopy (SEM)/energy-dispersive spectroscopy (EDS) chemical analysis, and structure refinement through X-ray powder diffraction (XRPD), was applied to different samples of potentially carcinogenic erionite from Northern Italy. The studied crystals have a chemical composition ranging from erionite-Ca to erionite-Na and display variable morphologies, varying from prismatic, through acicular and fibrous, to extremely fibrous asbestiform habits. The fibrous samples were characterized by an unusual preferred partition of aluminum (Al) at tetrahedral site T1 instead of tetrahedral site T2. Further, a mismatch between the a-parameter of erionite-Ca and levyne-Ca that are intergrown in the asbestiform sample was detected. This misfit was coupled to a relevant micro-strain to maintain structure coherency at the boundary. Erionite occurs in 65% of the investigated sites, with an estimated quantity of 10 to 40 vol% of the associated minerals. The presence of this mineral is of concern for risk to human health, especially if one considers the vast number of quarries and mining-related activities that are operating in the zeolite host rocks. The discovery of fibrous and asbestiform erionite in Northern Italy suggests the need for a detailed risk assessment in all Italian areas showing the same potential hazard, with specific studies such as a quantification of the potentially respirable airborne fibers and targeted epidemiological surveillance.

Compatibility with endothelial cell attachment and growth appears to be an important requisite of vascular prosthetic materials, possibly influencing thrombosis, pseudointimal hyperplasia, and accelerated atherosclerosis at the site of blood-material interaction. Since deposition of pyrolytic carbon (PC) on prosthetic surfaces has been associated with enhanced hemocompatibility, in the present study we assessed whether a thin layer (0.5 microns) of PC deposited onto materials such as knitted Teflon and Dacron enhanced endothelial cell attachment and growth. Cultured human umbilical vein endothelial cells (HUVEC) were seeded at a density of 4.5 x 10(4) cells/cm2 on PC-coated and uncoated grafts. In order to quantify endothelial cell attachment on the fabrics, the area of Teflon and Dacron fabrics covered by endothelial cells was estimated on day 2 after seeding using the point counting method in scanning electron micrographs. Subsequently, on days 2 and 4 after seeding, endothelial cell proliferation was measured both as number of endothelial cells and as total proteins of the endothelial cells covering the fabrics. On day 2 endothelial cell growth on PC-coated fabrics was greater (mean +/- SE; area 42.3 +/- 9.9 mm2, n = 6; cell number 3.9 x 10(4) +/- 3.03 x 10(3) cells, n = 4; total proteins 14.9 +/- 1.2 micrograms, n = 4) than on uncoated fabrics (area 10.6 +/- 4.6 mm2, n = 6; cell number 2.9 x 10(4) +/- 4.3 x 10(3) cells, n = 4; total proteins 11.3 +/- 1.7 micrograms, n = 4; P less than 0.001, less than 0.05 and less than 0.05, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Willhendersonite is a rare zeolite, with very few occurrences reported globally (Terni Province, Italy; the Eifel Region, Germany; Styria, Austria). Moreover, the data available from these sites are very limited and do not allow a detailed picture of this zeolite’s mineralogical and chemical characteristics. In this work, a new willhendersonite occurrence is reported from the Tertiary volcanic rocks of the Lessini Mounts, northern Italy. Morphology, mineralogy and chemical composition of selected crystals were studied by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), X-ray Diffraction (XRD), and electron probe microanalyser (EPMA). Willhendersonite occurs within basanitic rocks as isolated, colorless, transparent crystals with prismatic to flattened morphologies. Individual crystals often grow together to form small elongated clusters and trellis-like aggregates. The diffraction pattern exhibits 33 well-resolved diffraction peaks, all of which can be indexed to a triclinic cell with unit cell parameters a = 9.239(2) Å; b = 9.221(2) Å; and c = 9.496(2) Å, α = 92.324(2)°, β = 92.677(2)°, γ = 89.992° (Space Group P1¯). The chemical data point to significant variability from Ca-rich willhendersonite (K0.23Na0.03)Σ=0,26Ca1.24 (Si3.06Al3,00Fe3+0.01)Σ=6,07 O12·5H2O) to Ca-K terms (K0.94Na0.01)Σ=0,95Ca0.99 (Si3.07Al2.93Fe3+0.00)Σ=6,00O12·5H2O). Willhendersonite from the Lessini Mounts highlights the existence of an isomorphous series between the Ca-pure crystals and Ca-K compositions, possibly extended up to a potassic end-member.

Anaerobic digestion (AD) is a well-known biological conversion process to obtain a gaseous biofuel from organic matter: in fact, upgrading biogas to biomethane is a mean to substitute conventional natural gas. It is also known that biochar can improve the biogas production in AD processes. In this work, different biochars have been produced from various feedstocks at different process conditions. Biochars obtained from the carbonization of wheat straw (WS) and poplar (P) were produced in a Thermo Gravimetric Analyser at lab scale, at a temperature of 400 °C and 2 h of retention time at the maximum temperature, with a heating rate of 20 °C min−1. Another biochar from poplar (Pc) was also produced in a pilot plant (CarbOn, RE-CORD) working in oxidative pyrolysis conditions, at a temperature range between 500 and 600 °C. Biochars were oxidized with Oxone® using two different methods (ball-milling and simple aqueous solution mixing) to increase the amount of functional groups on their surface. Oxidized biochars (Ws_Ox and P_Ox) were characterized by FTIR, BET, and CEC, and their impact on biogas production was investigated through a lab scale biochemical methane potential (BMP) test using maize silage as substrate. 0.33 g of biochar was used for each treatment. BMP test shows that all batches containing biochar as additive produced more biogas than control (C). WS_Ox and P_Ox produced respectively a + 7.7% and + 11.3% of biogas than C, obtaining the higher productivities with respect to not oxidized biochars. The addition of P and Pc biochars were similar performances in AD, thus highlighting that no significant differences are due to different biochar production scales and process parameters from the same feedstock. This study highlights how in addition to the various examined parameters (nature of the feedstock, pyrolysis parameters, size of biochar and its concentration in AD), also the presence of specific functional groups on the biochar surface influences the AD performance.

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