The AMERIGO Lander and the Automatic Benthic Chamber (CBA): Two New Instruments to Measure Benthic Fluxes of Dissolved Chemical Species

Marine environments are currently subject to strong ecological pressure due to local and global anthropic stressors, such as pollutants and atmospheric inputs, which also cause ocean acidification and warming. These strains can result in biogeochemical cycle variations, environmental pollution, and changes in benthic-pelagic coupling processes. Two new devices, the Amerigo Lander and the Automatic Benthic Chamber (CBA), have been developed to measure the fluxes of dissolved chemical species between sediment and the water column, to assess the biogeochemical cycle and benthic-pelagic coupling alterations due to human activities. The Amerigo Lander can operate in shallow as well as deep water (up to 6000 m), whereas the CBA has been developed for the continental shelf (up to 200 m). The lander can also be used to deploy a range of instruments on the seafloor, to study the benthic ecosystems. The two devices have successfully been tested in a variety of research tasks and environmental impact assessments in shallow and deep waters. Their measured flux data show good agreement and are also consistent with previous data

Bringing AMS radiocarbon into the Anthropocene: Potential and drawbacks in the determination of the bio-fraction in industrial emissions and in carbon-based products

In the frame of the general efforts to reduce atmospheric CO2 emissions different efforts are being carried out to stimulate the use of non-fossil energy sources and raw materials. Among these a significant role is played by the use of waste in Waste to Energy (WTE) plants. In this case a relevant problem is related to the determination of the proportion between the bio and the fossil derived fraction in CO2 atmospheric emissions since only the share of energy derived from the bio-fraction combustion can be labelled as "renewable". We discuss the potential of radiocarbon in this field by presenting the results of different campaigns carried out by analysing CO2 sampled at the stack of different power plants in Italy with different expected bio-content of the released carbon dioxide. The still open issues related to the calculation procedures and the achievable precision and accuracy levels are discussed

AMS-14C determination of the biogenic-fossil fractions in flue gases

The determination of the proportion between the biogenic and the fossil-derived fraction in carbon dioxide emissions from industrial stationary sources is a relevant aspect in the frame of the worldwide efforts to reduce greenhouse gas emissions into the atmosphere. In this field the 14C-based method has gained importance over the years and has been included in standard protocols accepted at both the national and international levels. The advantages of the method, based on the large difference in terms of 14C signature between fossil and biogenic carbon, are reviewed as well as some critical aspects related to its application. In particular the results of a study aimed at validating the method by analyzing synthetic gas mixtures produced in a dedicated plant and with a tuneable proportion between fossil and biogenic carbon dioxide are presented. © 2018 by the Arizona Board of Regents on behalf of the University of Arizona

Extraction of dissolved inorganic carbon (DIC) from seawater samples at cedad: Results of an intercomparison exercise on samples from Adriatic sea shallow water

A dedicated sample processing line for the extraction of dissolved inorganic carbon (DIC) from seawater and groundwater for accelerator mass spectrometry (AMS) radiocarbon analysis has been developed at CEDAD, the Center for Dating and Diagnostic of the University of Salento, Lecce, Italy. The features of the new system are presented together with tests carried out to determine its functionality and background levels. The first results obtained at CEDAD for analyzing seawater samples taken from the Northern Adriatic compare well with results obtained for the same samples analyzed at ETH Zurich