Search results for "ALCA"

Pedogenic carbonates and carbon pools in gypsiferous soils of a semiarid Mediterranean environment in south Italy

2013

Abstract Soil carbonates are key features in soils of arid and semiarid environment, playing an important role from pedogenetic, landscape history, paleoclimatic and environmental points of view. The objectives of this work were (i) to study pathways of pedogenic carbonate (PC) formation, (ii) to distinguish between lithogenic and pedogenic inorganic C by using the natural C isotope abundance, and (iii) to estimate the soil C pools in a gypsiferous semiarid Mediterranean environment (Sicily, Italy). Five soil pedons developed on calcareous and non-calcareous parent materials from Holocene (10,000 years BP) to Upper Tortonian (7.2–5.3 Ma BP) in age were surveyed. During field soil descriptio…

Spatial and temporal variations of water repellency and probability of its occurrence in calcareous Mediterranean rangeland soils affected by fires

2013

Abstract Water repellency (WR) is a common soil property in many fire-affected ecosystems, but it also occurs in long-unburned terrain. It can vary in space at different scales (between point and pedon or slope and catchment) and time (during the same day, between seasons or years, or with a post-fire recovery period). This paper: i) reports on the occurrence and persistence of WR in fire-affected calcareous forest soils under Mediterranean climatic conditions, examining its spatial variability at macro-, meso- and micro-scales, and monthly changes with soil moisture content; and ii) develops exploratory models to estimate the probability of the natural background (not fire-induced) WR to o…

The growth of “black crusts” on calcareous building stones in Palermo (Sicily): a first appraisal of anthropogenic and natural sulphur sources

2008

Chemical, mineralogical and isotopic composition (34S/32S) analyses were carried out on “black crusts” developed on the old buildings of Palermo (Sicily) with the aim to distinguish between natural and anthropogenic sulphur sources. Furthermore individual samples of total suspended particulate (TSP) were collected and analysed in order to estimate the influence of air pollution on the decay process of calcareous stones in a typical southern Mediterranean coastal environment. SEM/EDS analysis, X-ray diffractometry, IR spectroscopy and liquid chromatography led to the compositional characterization of “black crusts” and airborne particulate matter in the city. Sulphur isotopic compositions of…

Calcareous nannofossil surface sediment assemblages from the SicilyChannel (central Mediterranean Sea): palaeoceanographic implications.

2008

Quantitative analysis of 67 calcareous nannofossil assemblages from surface sediments recovered in a wide area across the Sicily Channel has been carried out in order to improve the interpretation of palaeontological data based on this planktonic group in a key area for Mediterranean palaeoceanographic studies. The investigation focused on three case studies that demonstrate the high potentiality of such a combined approach, taking into account the recent distribution of taxa or groups of taxa on the sea floor and the palaeontological record. The distribution of reworked specimens over the northern Sicily Channel sea floor validates the role of southern Sicily as a source region for reworke…

A high-resolution record of the last deglaciation in the Sicily Channel based on foraminifera and calcareous nannofossil quantitative distribution

2003

Abstract Relative abundance fluctuations in planktic foraminiferal and calcareous nannofossil assemblages are reported on the basis of a high-resolution study of ODP Leg 160 Hole 963D, drilled in the Sicily Strait, near Capo Rossello (southern Sicily). With its 8 m of undisturbed sediments, the core covers the interval from 1.5 to 23 kyr, allowing a 50–100-yr sampling resolution. All the short warm and cold events and sub-events recorded in this time interval in the GRIP Greenland ice core and at several Mediterranean sites were recognized. On this basis, a total number of nine ecozones based on planktic foraminifera and seven ecozones based on calcareous nannofossils were identified. A sho…

Discrimination of Lithogenic and Anthropogenic Metals in Calcareous Agricultural Soils: A Case Study of the Lower Vinalopó Region (SE Spain)

2008

Analysis of heavy metal concentrations in soils and their sources is required to identify agricultural areas affected by contamination on a regional level, according to the European Thematic Strategy for Soil Protection. Pseudo-total and EDTA-extractable concentrations of nine elements (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) in eighteen agricultural soils with vegetable crops in the Lower Vinalopo region (southeast Spain) were determined. The main aim was to assess the present state of the agricultural soils in relation to contamination processes by heavy metals for a representative area of the Mediterranean region under semiarid conditions. The pseudo-total concentrations for heavy metals …

Oil-degrading bacteria from a membrane bioreactor (MBR) system for treatment of saline oily waste: isolation, identification and characterization of …

2015

This study was focused on the microbial community characterization during operation of a Membrane Bioreactor System, used for the treatment of saline oily wastes, originated from marine transportation. A collection of forty-two (42) strains was obtained during microbiological screening and the bacterial diversity analyzed by amplification and 16S rRNA sequencing. Taxonomic analysis has shown a high level of identity with recognized sequences for a total of seven (7) distinct bacterial genera (Alcanivorax, Erythrobacter, Marinobacter, Microbacterium, Muricauda, Rhodococcus and Rheinheimera). The biotechnological potential of all isolates was identified by the estimate of two key factors, suc…

The barren Messinian Tripoli in Sicily and its palaeoenvironmental evolution: suggestions on the exploration potential

2016

New observations on the Sicily Messinian Tripoli have yielded a variably thick diatomitic, calcareous and shaly rock interval marked by an upwards disappearance of calcareous and siliceous plankton (barren lithosome), coexisting with a variability in vegetal remains and significant amounts of amorphous organic matter (AOM). Facies analysis associated with biostratigraphy and palaeoecology of the several field and borehole sections has been framed in a well-accepted chronological scheme that points to this barren interval coinciding with the stratigraphic upper and younger part of some Tripoli sections (bituminous Tripoli) located in the northern part of the study area. Biostratigraphically,…

Depositional and diagenetic environments of the Messinian Calcare di Base and sulfur-bearing carbonates from Sicily and Calabria

2009

Selective enrichment of heterotrophic nitrifiers <em>Alcaligenaceae</em> and <em>Alcanivorax</em> spp. from industrial wastew…

2020

Removal of nitrogen from wastewaters (WW) represents a global problem. The low nitrification rate during WW treatment is often caused by ecotoxicity. This problem is attributed mostly to the industrial WW. Our study was focused on the testing of industrial WW and activated sludge (AS) with the aim to reveal the abundance of nitrifiers and increase their biomass, thus, providing the additional step, i.e., bioaugmentation, within the technological process of WW treatment. Plating of AS on the selective solidified media designated for the 1st and 2nd nitrification stages, resulted in the shift in bacterial community structure with dominated Alcaligenaceae and Alcanivorax for the 1st stage, and…