Arsenic and fluorine in the Etnean volcanics from Biancavilla,Sicily, Italy: environmental implications     

S.?Mazziotti-TaglianiEmail author  M.?Angelone  G.?Armiento  R.?Pacifico  C.?Cremisini  A.?Gianfagna 《Environmental Earth Sciences》2012,66(2):561-572

Mineralogical and geochemical studies were undertaken in the volcanic area of Biancavilla (Catania, Italy) with the aim of explaining the nature of the high As and F contents of the area’s rocks. As and F contents in soils and groundwater were also investigated. The metasomatised benmoreite lavas show fluorine and arsenic concentrations up to about 3,000 and 1,000 mg/kg, respectively. Mineralogical analyses show that fluorine occurs mostly in fluoro-edenite and apatite-(CaF) crystals, both abundantly present in the altered rocks, while As is exclusively attributed to the apatite-(CaF) crystals. Specifically, arsenic was observed only at the borders of these apatite crystals. Leaching tests and sequential extraction procedures were carried out to evaluate the potential remobilisation of As and F by the mineral phases and the eventual risks induced by their spreading. The results of the leaching tests suggest that As is almost totally associated with the ‘easily reducible’ fraction and that it is released by the preferential dissolution of the arsenic enriched rims of apatite-(CaF) crystals. In soils, As concentration is relatively low (about 15 mg/kg, on average), while F ranges from 236 to 683 mg/kg. The underground waters supplying the town of Biancavilla show As and F contents lower than the allowed limits for drinking water, (As:10 μg/L, F:1–1.5 mg/L). The limited distribution of these rocks and the relatively limited mobilisation by the minerals both contribute to maintain low As and F values, in soils and groundwaters, despite the high values in metasomatised lava samples.  相似文献   

Soil-erosion assessment at basin scale through 137Cs content analysis based on pedo-morphological units     

S. Grauso  F. Onori  M. Esposito  M. Neri  G. Armiento  P. Bartolomei  C. Crovato  F. Felici  M. Marcinnò  P. Regina  C. Tebano 《Environmental Geology》2008,54(2):235-247

Soil loss evaluation by means of radioisotopic content measurements represents a promising technique, half-way between field surveys and theoretical models, which still suffers from its practical limits when applied at basin scale. A main limit is represented by the costs of field investigations and laboratory investigations on the high number of soil samples required by a traditional sampling scheme, such as regular grid or transects. A non-conventional soil sampling scheme was tested with the aim to consider a relative scanty number of soil samples and to verify the feasibility of this technique on large areas. This scheme was based on the hypothesis that land analysis and classification could point out areas characterised by homogeneous behaviour with respect to the ¹³⁷Cs deposition and transmission model. A Geographic Information System (GIS)-aided procedure allowed to classify the selected basin area in pedo-morphological units, representative of the different pedologic, morphologic and land-use conditions, to locate few sampling points for each unit. Outcomes pointed out a low correlation between ¹³⁷Cs contents and soil physical and compositional characteristics. Nevertheless, the isotopic methodology allowed to estimate a total soil loss value at basin scale almost consistent with both observed data, given by reservoir sedimentation measurements and estimates from the application of the RUSLE model. Thus, the results can be considered encouraging and they allow to deem that the isotopic methodology can be refined in order to account for erosion and deposition processes even at river basin scale and with a limited number of soil samples.  相似文献   

Role of high-elevation groundwater flows in the hydrogeology of the Cimino volcano (central Italy) and possibilities to capture drinking water in a geogenically contaminated environment     

Piscopo  V.  Armiento  G.  Baiocchi  A.  Mazzuoli  M.  Nardi  E.  Piacentini  S. M.  Proposito  M.  Spaziani  F. 《Hydrogeology Journal》2018,26(4):1027-1045

Origin, yield and quality of the groundwater flows at high elevation in the Cimino volcano (central Italy) were examined. In this area, groundwater is geogenically contaminated by arsenic and fluoride, yet supplies drinking water for approximately 170,000 inhabitants. The origin of the high-elevation groundwater flows is strictly related to vertical and horizontal variability of the rock types (lava flows, lava domes and ignimbrite) in an area of limited size. In some cases, groundwater circuits are related to perched aquifers above noncontinuous aquitards; in other cases, they are due to flows in the highly fractured dome carapace, limited at the bottom by a low-permeability dome core. The high-elevation groundwater outflow represents about 30% of the total recharge of Cimino’s hydrogeological system, which has been estimated at 9.8 L/s/km². Bicarbonate alkaline-earth, cold, neutral waters with low salinity, and notably with low arsenic and fluoride content, distinguish the high-elevation groundwaters from those of the basal aquifer. Given the quantity and quality of these resources, approaches in the capture and management of groundwater in this hydrogeological environment should be reconsidered. Appropriate tapping methods such as horizontal drains, could more efficiently capture the high-elevation groundwater resources, as opposed to the waters currently pumped from the basal aquifer which often require dearsenification treatments.

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