Raffaella Pascale

Validation of an analytical method for simultaneous high-precision measurements of greenhouse gas emissions from wastewater treatment plants using a gas chromatography-barrier discharge detector system.

Wastewater treatment plants (WWTPs) emit CO2 and N2O, which may lead to climate change and global warming. Over the last few years, awareness of greenhouse gas (GHG) emissions from WWTPs has increased. Moreover, the development of valid, reliable, and high-throughput analytical methods for simultaneous gas analysis is an essential requirement for environmental applications. In the present study, an analytical method based on a gas chromatograph (GC) equipped with a barrier ionization discharge (BID) detector was developed for the first time. This new method simultaneously analyses CO2 and N2O and has a precision, measured in terms of relative standard of variation RSD%, equal to or less than 6.6% and 5.1%, respectively. The methods detection limits are 5.3ppmv for CO2 and 62.0ppbv for N2O. The methods selectivity, linearity, accuracy, repeatability, intermediate precision, limit of detection and limit of quantification were good at trace concentration levels. After validation, the method was applied to a real case of N2O and CO2 emissions from a WWTP, confirming its suitability as a standard procedure for simultaneous GHG analysis in environmental samples containing CO2 levels less than 12,000mg/L.

Mass spectrometry-based phytochemical screening for hypoglycemic activity of Fagioli di Sarconi beans (Phaseolus vulgaris L.)

The present study deals with the evaluation of antidiabetic activities of Fagioli di Sarconi beans (Phaseolus vulgaris), including 21 ecotypes protected by the European Union with the mark PGI (i.e., Protected Geographical Indication), and cultivated in Basilicata (southern Italy). For this purpose, α-glucosidase and α-amylase assays were assessed; among all bean ecotypes, the tight green seed colour of Verdolino extracts exhibited the highest α-glucosidase and α-amylase inhibitory activity with IC50=1.1±0.1μg/ml and IC50=19.3±1.1μg/ml, respectively. Phytochemical compound screening of all Fagioli di Sarconi beans performed by flow injection-electrospray ionization-ultrahigh resolution mass spectrometry (uHRMS) and based on the calculation of elemental formulas from accurate m/z values, was helpful to annotate specific compounds, such as alkaloids, saponins, flavonoids, and terpenoids, which are most likely responsible for their biological activity.

N2O and CO2 Emissions from Secondary Settlers in WWTPs: Experimental Results on Full and Pilot Scale Plants

Data about Greenhouse Gas (GHG) emissions from settling units in wastewater treatment plants (WWTPs) are limited, probably because of the increased difficulties in evaluating direct emissions when there is absence of an induced air stream through the liquid volume (Caivano et al. 2016). Particularly, gas samples collection is not immediate and easy due to the low off-gas flow leaving the liquid surface.

CO2 and N2O from water resource recovery facilities: Evaluation of emissions from biological treatment, settling, disinfection, and receiving water body

Water resource recovery facilities (WRRFs) contribute to climate change and air pollution, as they are anthropogenic potential sources of direct and indirect emission of greenhouse gases (GHGs). Studies concerning the monitoring and accounting for GHG emissions from WRRFs are of increasing interest. In this study, the floating hood technique for gas collection was coupled with the off-gas method to monitor and apportion nitrous oxide (N2O) and carbon dioxide (CO2) emissions from both aerated and non-aerated tanks in a municipal water resource recovery facility, in order to investigate its carbon footprint (CFP). To our knowledge, this is the first time that the chamber technique was applied to evaluate gas fluxes from the settler, where an emission factor (EF) of 4.71 ∗ 10-5 kgCO2,eq kgbCOD-1 was found. Interesting results were found in the disinfection unit, which was the major contributor to direct N2O emissions (with a specific emission factor of 0.008 kgCO2,eq kgbCOD-1), due to the chemical interaction between hydroxylamine and the disinfectant agent (hypochlorite). The specific emission factor of the biological aerated tank was 0.00112 kgCO2,eq kgbCOD-1. The average direct CO2 emission was equal to 0.068 kgCO2 kgbCOD-1 from the activated sludge tank and to 0.00017 kgCO2 kgbCOD-1 from the secondary clarifier. Therefore, taking into account the contribution of both direct N2O and CO2 emissions, values of 0.069 kgCO2,eq kgbCOD-1, 0.008 kgCO2,eq kgbCOD-1 and 0.00022 kgCO2,eq kgbCOD-1, were found for the net CFP of the aerated compartment, the disinfection unit and the clarifier, respectively. The plant energy Footprint (eFP) was also evaluated, confirming that the aeration system is the major contributor to energy consumption, as well as to indirect CO2 emission, with a specific eFP of 1.49 kWh kgbCOD-1.

Environmental factors influencing landfill gas biofiltration: Lab scale study on methanotrophic bacteria growth

ABSTRACT The post-management of landfills represents an important challenge for landfill gas treatment. Traditional systems (energy recovery, flares, etc.) present technical problems in treating flow with low methane (CH4) concentrations. The objective of this study was to isolate methanotrophic bacteria from a field-scale biofilter in order to study the bacteria in laboratories and evaluate the environmental factors that mostly influence Microbial Aerobic Methane Oxidation (MAMO). The soil considered was sampled from the biofilter located in the landfill of Venosa (Basilicata Region, Italy) and it was mainly composed of wood chips and compost. The results showed that methanotrophic microorganisms are mainly characterized by a slow growth and a significant sensitivity to CH4 levels. Temperature and nitrogen (N) also have a very important role on their development. On the basis of the results, biofilters for biological CH4 oxidation can be considered a viable alternative to mitigate CH4 emissions from landfills.

Method development and optimization for the determination of benzene, toluene, ethylbenzene and xylenes in water at trace levels by static headspace extraction coupled to gas chromatography–barrier ionization discharge detection

Benzene, toluene, ethylbenzene, and xylenes, more commonly named BTEX, represent one of the most ubiquitous and hazardous groups of atmospheric pollutants. The goal of our research was the trace quantification of BTEX in water by using a new simple, low-cost, and accurate method, based on headspace (HS) extraction and gas chromatography (GC) coupled to barrier ionization discharge detector (BID). This water application dealt with simple matrices without protein, fat, or humic material that adsorb target analytes, thus the external standard calibration was suitable to quantify each compound. The validation steps included the study of linearity, detection and quantification limits, and accuracy. LODs and LOQs varied from 0.159 to 1.845 μg/L and from 0.202 to 2.452 μg/L, respectively. The recovery was between 0.74 ± 0.13 and 1.15 ± 0.09; relative standard deviations (% RDSs) were less than 12.81% (n = 5) and 14.84% (n = 10). Also, GC performance was evaluated in term of efficiency, peak tailing and resolution. Preliminary results from practical applications to analyses of real samples are presented. The results indicate that static HS coupled to GC-BID is a successful method for BTEX analysis in water samples at the μg/L levels, provided that hydrocarbons interference occur at similar concentration levels. GC-BID may become a routine reference method alongside the official analytical techniques for quality control purposes of contaminated waters. Moreover, the new method is amenable to automation by using commercial HS units.

Disinfection Unit of Water Resource Recovery Facilities: Critical Issue for N2O Emission

In this study, the floating hood technique for gas collection has been coupled with the off-gas method to monitor greenhouse gas emissions from the chlorination unit in a municipal water resource recovery facility located in Italy. Experimental measurements of direct nitrous oxide (N2O) from chlorination step were performed in order to investigate the contribution of this unit on the net carbon footprint. Interesting results were found on the chlorination unit which proved to be the major contributor to direct N2O emissions, due to the chemical interaction between hydroxylamine and the disinfectant agent (i.e. hypochlorite). For the first time, we measured for the chlorination unit a specific emission factor of 0.008 kgCO2,eq \( {\text{kg}}_{\text{bCOD}}^{ - 1} \), proving the innovativeness of our findings.

Sequence protein identification by randomized sequence database and transcriptome mass spectrometry (SPIDER-TMS): from manual to automatic application of a 'de novo sequencing' approach.

Sequence protein identification by a randomized sequence database and transcriptome mass spectrometry software package has been developed at the University of Basilicata in Potenza (Italy) and designed to facilitate the determination of the amino acid sequence of a peptide as well as an unequivocal identification of proteins in a high-throughput manner with enormous advantages of time, economical resource and expertise. The software package is a valid tool for the automation of a de novo sequencing approach, overcoming the main limits and a versatile platform useful in the proteomic field for an unequivocal identification of proteins, starting from tandem mass spectrometry data. The strength of this software is that it is a user-friendly and non-statistical approach, so protein identification can be considered unambiguous.