Persistent organic pollutants (POPs) in marine sediments of the Arctic fjord Kongsfjorden, Svalbard Islands.

New data on the occurrence of POPs, including polychlorinated biphenyls (PCBs) and legacy pesticides (LPs), along with current-use pesticides (CUPs) in the surface marine sediments of Kongsfjorden over five years (2018-2022) are presented. LPs examined were p,p'-dichlorodiphenyltrichloroethane (DDT), p,p'-l,l-dichloro-2,2-bis(chlorophenyl)ethylene (DDE), and hexachlorocyclohexane (HCH), while CUPs included chlorpyrifos (CPF), dacthal (DAC), and endosulfan (ENDO). LPs (0.

New method for simultaneous determination of dissolved organic carbon and its stable carbon isotope ratio in liquid samples: environmental applications.

This study reports the development of an all-in-one elemental analyser isotope ratio mass spectrometry (EA-IRMS) system modified for simultaneous analysis of dissolved organic carbon (DOC) concentration and its stable carbon isotope footprint (C) in aqueous samples. The method involves a quantitative oxidation of DOC in a 200 µL liquid sample to CO, after sample acidification and stripping by nitrogen. The detection limit of the method for DOC quantification was 0.

Groundwater quality trend and trend reversal assessment in the European Water Framework Directive context: an example with nitrates in Italy.

Groundwater resources are of utmost importance in sustaining water related ecosystems, including humans. The long-lasting impacts from anthropogenic activities require early actions, owing to the natural time lag in groundwater formation and renewal. The European Union (EU) policy, within the implementation of the Water Framework Directive (WFD), requires Member States to identify and reverse any significant and sustained upward trend in the concentration of pollutants, defining specific protection measures to be included in the River Basin Management Plans (RBMP).

Antarctic snow: metals bound to high molecular weight dissolved organic matter.

In this paper we studied some heavy metals (Cu, Zn, Cd, Pb, As, U) probably associated to high molecular weight organic compounds present in the Antarctic snow. Snow-pit samples were collected and analysed for high molecular weight fraction and heavy metals bound to them by means of ultrafiltration treatment. High molecular weight dissolved organic matter (HMW-DOM) recovered by ultrafiltration showed a dissolved organic carbon concentration (HMW-DOC) of about 18-83% of the total dissolved organic carbon measured in Antarctic snow.

Morphological and physiological responses of barley plants grown on soils characterised by metal toxicity and metal deficiency.

Aim of this work was to investigate which are the effects on barley crops grown on two different soils: a soil lacking in Cu, an essential micronutrient (A) and a naturally polluted soil rich in lead, zinc, copper (B). In particular we investigated the relationship between some ecophysiological parameters such as biomass, chlorophyll concentration and guaiacolo peroxidase activity and the chemical-physical properties of the soils like pH, organic matter and heavy metal content. Because metals uptake by plants is strongly correlated with the bioavailable fraction rather then their total amount in a soil, we have measured also metal exchangeable forms, using a single extraction method (MgCl2 as extractant).

The increase of iron phytoavailability in soils ammended with paper mill sludge.

In soils characterized by low organic matter and high pH values (7.5-8.59) iron availability to plants is limited even if the content of total Fe(III) is high.

Metal bioavailability: how does its significance change in the time?

The significance of terms "metal bioavailability" and "bioavailable metal fraction" is evolved in the time, passing from a very simple concept to a complex concept bound to abiotic and biotic aspects. At the beginning metal toxicity was related to metal fraction present in water phase, than only free metal ion activity was considered and the free ion activity model (FIAM) was proposed. Successively, due to the exceptions observed and to the consciousness that metal bioavailability could be considered as dynamic characteristic the concept of metal bioavailability became very complex, depending on physical, chemical and biological factors.

Transport and modification of humic substances present in Antarctic snow and ancient ice.

We performed a study of fulvic acids extracted from fresh and aged snow, and from recent and ancient ice in Antarctica. The fresh snow samples were collected in coastal and inland sites to evaluate the influence of the distance from the sea on organic matter transport. Moreover, in a site (Melbourne Mountain) samples were collected at different heights to study the influence of altitude on transport.

The role of organic matter on metal toxicity and bio-availability.

A short review concerning the role of organic matter on metal toxicity and bio-availability in aqueous systems is carried out. The complexity of the issue derives both from the high number of natural and anthropogenic organic compounds and from the variability of their structures. In fact, the binding capacity and affinity is dependent on the number and type of ligands, on their position in the structures, on the ligand/metal ratio.

Laboratory studies on waste water sludge application for acid soil remediation.

In this work the effects of sludge disposal on pH values, buffer capacity and adsorption capacity of an acid soil were studied. A stabilized waste water sludge and a paper mill sludge were employed; the pH values of both sludges were higher than 8. The observed differences between soil-urban sludge and soil-paper mill sludge systems can be ascribed to the nature of the compounds present in the sludges and adsorbed on the soil.