A NEW STRATEGY FOR PENTACHLOROPHENOL MONITORING IN WATER SAMPLES USING ULTRA-HIGH PERFORMANCE LIQUID CHROMATOGRAPHY - MASS SPECTROMETRY TANDEM

A novel sensitive and rapid analytical approach based on ultra-high performance liquid chromatography - mass spectrometry (UHPLC/MS/MS) tandem was developed for the monitoring of pentachlorophenol in water samples. Chromatographic separation was carried out on Acquity BEH C18 (100 x 2.1 mm, 1.7 µm) column under gradient mode using a mobile phase consisting of acetonitrile/ultrapure water/formic acid. Quantification of pentachlorophenol was performed on a triple-quadrupole tandem mass spectrometer under multiple reaction monitoring (MRM) mode, via a negative electrospray ionization (ESI - ). The limit of quantification of the developed instrumental method was 0.3 µg L -1 . The linearity was validated within the concentration range 0.1-100 µg L -1 with a correlation coefficient (R 2 ) of 0.998. Intra-day and inter-day precision values were 99.78 and 99.12%, respectively. Moreover, for the application to real water samples, a solid phase extraction method (SPE) was proposed for the extraction and preconcentration of analyte. Some of the main factors involved in the SPE extraction process such solid phase material, elution solvent and sample volume were investigated and optimized in order to maximize the extraction efficiencies. Oasis HLB cartridges showed the best results in term of extraction recovery. High analyte recoveries (between 98.2% and 100.18%) were achieved with the proposed SPE procedure and the extraction RSD was less than 3.1%. In addition, the whole new analytical strategy (SPE-UHPLC/MS/MS) was then successfully applied for pentachlorophenol quantification in natural waters at low part per trillion levels.

MAGNETIC CONTAMINATION OF ENVIRONMENT - LABORATORY SIMULATION OF MIXED IRON OXIDES IMPACT ON MICROORGANISM CELLS

Magnetic contamination is considered more and more as a challenging issue related to biosphere pollution with magnetic materials originating in natural and artificial sources (volcanic eruptions and respectively industrial activities that contributed to iron and other metal compounds spreading in air, water and soil). Aiming to study the impact of magnetic metal ions such as iron and cobalt on the metabolism of some environmental microorganisms, in this paper an experimental simulation of magnetic contamination was carried out based on mixed iron/cobalt oxides as source of ions. Magnetic nanoparticles were prepared following chemical route with appropriately adjusting of their surface to ensure uniform dispersion in water. Typical crystalline structure of studied nanoparticles was evidenced with X-ray diffraction, while microstructural and magnetic properties were investigated by scanning electron microscopy and respectively vibrating sample magnetometry. Increased level of peroxidase activity in a fungus mycelium has suggested microorganism adaptation to higher levels of reactive oxygen species following the supply with magnetic nanoparticles suspensions (0-10-20-30-35 mg/L, comparable with detected levels of iron in the living organism). Lipid peroxidation was evidenced also; being assigned to the increased level of hydrogen peroxide that catalase seems enable to balance - as resulted from its decreasing activity. The variations of analyzed indicators of oxidative stress were of no more than 15%, reflecting organism adaptation to environmental constraints but also possible damages of cell membrane system.

MATHEMATICAL MODELLING OF MECHANICAL BEHAVIOUR OF CELLULOSE-BASED FIBRES EXPOSED TO GAMMA RAYS AND HYDROTHERMAL TREATMENT

The deterioration of the natural polymers is a very complex process, and a problem that can be best addressed through modelling. The approach for modelling the rheological behaviour of different cellulose-based textile fibres (cotton, hemp, flax) when subjected to a hydrothermal treatment, followed by exposure to different doses of gamma-rays (5, 10, 15 and 25 kGy) is presented here. In order to predict the optimum radiation dose limit and hydrothermal aging time, the mathematical model was developed using MATLAB computational technique. To study the mechanical behaviour of the tested fibres, tensile tests were carried out using a TINIUS OLSEN dynamometer H5KT according to ISO 2062 norm. The model of correlation between the mechanical properties of the fibres and the independent variables was based on a polynomial second-degree equation, with the Least-Squares fitting approach that led to the coefficients of the mathematical model.

PNiPAM-FUNCTIONALIZED MESOPOROUS CARBON FOR THE ADSORPTION OF VITAMIN B2

REMOVAL OF CARBAMAZEPINE BY ELECTROCOAGULATION: INVESTIGATION OF SOME KEY OPERATIONAL PARAMETERS

The performance of electrocoagulation (EC) process, a non-specific electrochemical technology, was investigated for the removal of carbamazepine (CBZ), an antiepileptic drug, from water. Experiments were carried out in synthetic wastewater in a batch cell. The respective influences of some key process parameters were studied, such as mixing conditions, initial pH, and current on aluminium electrodes. Experimental results showed that a CBZ removal efficiency of 62% was observed under slightly acidic initial conditions (pH 4) with a current density as high as 44 mA cm -2 (I=4.5 A) using Al electrode. This clearly indicates that CBZ removal proceeds through an electrochemical mechanism, while the adsorption of CBZ onto the aluminum hydroxide flocs was shown to be negligible. Furthermore, the increase of initial pH to alkaline values was shown to decrease the drug elimination efficiency. Conversely, as expected, an increase of current intensity improved the removal of CBZ. As a result, low initial pH 4 coupled with high current elevates the electrochemical elimination of CBZ: in this case, one metabolite could also be detected.

CHALLENGES AND OPORTUNITIES IN GREEN PLASTICS: AN ASSESSMENT USING THE ELECTRE DECISION-AID METHOD

Bioplastics are biobased materials, usually easy biodegradable, derived from renewable resources. Evolution of bioplastics production is related to: bio starch and starch mixtures (74.5%); bioplastic products from fermentation (13%), bioplastic from petrochemicals materials (12.5%). They are seen as a viable solution to avoid some environmental impacts caused by the use of fossil-based conventional plastics. In this context, the general objectives of this study entail the analysis and selection of the optimal alternative of bioplastics able to be used for packaging production, considering social, economic and environmental criteria. In order to accomplish these objectives, we applied the ELECTRE method (ELimination Et Choix TRaduisant la RealitE), a multi-criteria analysis method. Application of this method enables the use of qualitative and quantitative discrete criteria, making also possible alternatives ranking. The application of ELECTRE method in our study consisted in selecting different types of bioplastics which were compared considering some consistent criteria so as to assess their economic and environmental performances. Based on the application of multiple criteria evaluation we concluded that bioplastics, in particular polyhydroxyalkanoates (PHAs) are suitable from economic and environmental points of views for manufacturing and utilization of packaging.

RESONANT TECHNIQUES AS NON-DESTRUCTIVE TECHNIQUES (NDT) APPLIED TO COMPOSITE MATERIALS: CASE STUDY ON LOW VELOCITY IMPACTS DETECTION

Impact damage is considered the primary cause of in-service delamination in composite materials and promotes significant reduction in residual strength. Non-destructive techniques (NDT) include several methods able to detect the shape and the size of the interior damages without destruction of the structure or component, which is economically advantageous. The aim of this paper is to evaluate the properties after low velocity impacts using an experimental-numerical procedure based on the resonant frequencies. Experimental tests were carried out on [0i, 90i]s (i=2, 3, 4) laminates and the C-Scan technique was used to characterize the internal damage after impact. The resonant technique was applied before and after impact tests, in order to observe the effect of delamination on resonant frequencies. However, the delaminations experimentally observed by C-scan technique were found to have a limited effect on the resonant frequencies. The delaminations deteriorate the composite matrix but its global rigidity is mainly determined by the fibres.

CO2 AND ENERGY FOOTPRINT OF DIFFERENT RETAINING WALLS SOLUTIONS. MASONRY RETAINING WALL vs. CANTILEVER RETAINING WALL

The paper presents the most economical and less polluting retaining wall system, calculated for the same site, having few different common heights used in design. The paper will highlight the importance of an environmentally friendly solution, but also the most economical solution, which should be the main criteria in the design. Two of the tools used in environmental life cycle assessments (LCA) are the carbon footprint and the energy footprint. The quantification of the carbon and the energy footprint associated to the two types of retaining walls for three different heights is presented. The assessment procedure is performed for the construction stage. The retaining walls are designed, using European norms embedded in Geo 5 software, in similar ground conditions, similar loads and weather conditions. Considering the computed cross sections, the materials quantities and on site assembly are calculated and also the CO2 footprint, the energy footprint and cost. Few different constructive solutions were compared, and the outcome of the paper is the most economic retaining wall in terms of emissions of carbon dioxide, energy consumption, and not the least, the cost.

DICLOFENAC REMOVAL FROM AQUEOUS SOLUTIONS BY ELECTROOXIDATION AT BORON-DOPED DIAMOND (BDD) ELECTRODE

Diclofenac (DCF), which belongs to nonsteroidal anti-inflammatory drugs (NSAIDs), is a biorefractory micropollutant and its removal from wastewaters has become strongly necessary. This paper dealt with the DCF removal from aqueous solutions by electrooxidation at boron-doped diamond (BDD) electrode. In addition, the dual character of BDD electrode in electrochemical degradation processes and their control was investigated. The electrooxidation process was assessed based on ultraviolet (UV) spectra and total organic carbon (TOC) determinations in the electrolysed solutions. Also, the specific power consumption was determined for various applied current densities (1 7.5 mA/cm) and DCF concentrations (10 200 mg/L). Cyclic voltammograms (CVs) recorded on BDD in the presence of DCF were used as analytical tool for the degradation process characterisation. The peak currents recorded at +0.7 and +1 V/SCE allowed characterizing accurately DCF degradation process. UV spectra, TOC removal and CV results proved that the BDD was highly effective in the DCF degradation and mineralization. Thus, TOC removal of about 90% was obtained for all studied DCF concentrations.

RECOVERY OF SEWAGE SLUDGE ON AGRICULTURAL LAND IN LOMBARDY: CURRENT ISSUES AND REGULATORY SCENARIOS

Issues concerning the treatment and the recovery/disposal of sludge derived from the municipal WWTPs (Wastewater Treatment Plants) are gaining importance both in Italy and abroad. In Lombardy Region this aspect is particularly relevant due to both the amount of sludge produced and its remarkable reuse in agricultural soils. This paper discusses different strategies for land application of sludge in order to provide technical and regulatory guidance at regional level. The work is based on a survey concerning qualitative and quantitative characteristics of sewage sludge (derived from WWTPs and sent to Sludge Treatment Plants STPs authorized for the treatment on behalf of third parties) reused for agricultural application. Then, the effects of six different regulatory scenarios (considering the rules of the European Commission, national legislation and the laws of regions neighbouring to Lombardy) on the qualitative characteristics of sludge reused in agricultural soils have been evaluated. The results of this work have been incorporated into regional guidelines that were approved with Decree of Regional Government (DGR) n. X/2031 dated 1 July 2014. On the basis of this work, the principles of the regional guidelines are: 1) improvement in the quality of the sludge spread on agricultural land; 2) protection of the high-quality sludge (ingoing to the STPs), avoiding its mixing with other sludge suitable for agricultural reuse, but with qualitative characteristics closer to the regulatory limits; 3) minimization of the problems concerning the odour emissions (one of the main critical issue).