Textile dye removal by Acacia dealbata Link. Pollen adsorption combined with UV-A/NTA/Fenton Process

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGThe decolourization of an aqueous solution of the textile dye Acid Red 88 (AR88) and the control of the invasive plant species Acacia dealbata Link. (ADL) were addressed in this work. The aims of the study were (1) characterization of the ADL pollen, (2) application of the pollen powder in adsorption processes, (3) selection of the best operational conditions for nitriloacetic acid (NTA)-UV-A-Fenton process and (4) assess the efficiency of the combined treatment adsorption and NTA-UV-A-Fenton in AR88 decolourization. In a first step, ADL pollen was used as a AR88 bioadsorbent. Fourier-transform infrared spectroscopy (FTIR) analysis were performed and revealed the presence of proteins, fatty acids, carbohydrates and lignin in the pollen. Afterwards, trough scanning electron microscopy (SEM), it was possible to verify that ADL pollen has several empty spaces that can be used for dye adsorption. Biosorption results showed higher adsorption of AR88 with application of pH 3.0 and [pollen] = 3.0 g/L with 18.8 mg/g of dye adsorbed. The best fitting was observed with Langmuir, SIPS and Jovanovic isotherms (0.993, 0.996 and 0.994, respectively). To complement the biosorption, a UV-A-Fenton process was applied, and results showed a higher AR88 removal with (NTA) addition. Higher irradiance power favored the oxidation process with high Ф photodegradation value and low Electric Energy per Order (EEO) and Specific Applied Energy (ESAE). The combination of biosorption with NTA-UV-A-Fenton was the most efficient system with an AR88 decolourization of 98.5% and a total organic carbon (TOC) removal of 83.5%.Fundação para a Ciência e a Tecnologia | Ref. UI/BD/150847/202

Agro-industrial wastewater treatment with Acacia dealbata coagulation/flocculation and photo-fenton-based processes

The removal of dissolved organic carbon (DOC) and total polyphenols (TPh) from agro-industrial wastewater was evaluated via the application of coagulation–flocculation–decantation (CFD) and Fenton-based processes. For the CFD process, an organic coagulant based on Acacia dealbata Link. leaf powder (LP) was applied. The results showed that the application of the LP at pH 3.0, with an LP:DOC ratio of 0.5:1 (w/w), achieved a high removal of turbidity, total suspended solids (TSS), and volatile suspended solids (VSS) of 84.7, 79.1, and 76.6%, respectively. The CFD sludge was recycled as fertilizer in plant culture (germination index ≥ 80%). Afterwards, the direct application of Fenton-based processes to raw WW was assessed. The Fenton-based processes (UV/Fenton, UV/Fenton-like, and heterogeneous UV/Fenton) showed high energy efficiency and a cost of 1.29, 1.31 and 1.82 €/g/L DOC removal, respectively. The combination of both processes showed the near complete removal of TPh and DOC after 240 min of reaction time, with high energy efficiency. In accordance with the results obtained, the combination of CFD with Fenton-based processes achieves the legal limits for the disposal of water into the environment, thus allowing the water to be recycled for irrigation.Fundação para a Ciência e a Tecnologia | Ref. UIDB/00616/2020Fundação para a Ciência e a Tecnologia | Ref. UI/BD/150847/2020CCRN - Comissão de Coordenação da Região Norte | Ref. NORTE-01-0145-FEDER-00004

Combined organic coagulants and photocatalytic processes for winery wastewater treatment

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGDue to the consumers demand for quality wines, washing and disinfection operations are necessary in wine productions, leading to the generation of large volumes of winery wastewater (WW) with a high organic content which has the potential to cause irreversible environmental impacts. The aim and novelty of this work is the production of natural organic coagulants (NOCs) to be applied in coagulation-flocculation-decantation (CFD) process. To complement this treatment process, it is also aimed the performed a photo-Fenton process, combining hydrogen peroxide (H2O2) and potassium persulfate (KPS). The Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) showed that NOCs are carbon-based materials with adsorption capacity. Under the best operational conditions, NOCs achieved a turbidity removal between 86.2 and 98.9%, a total suspended solids (TSS) removal ranging between 85.0 and 94.9% and a dissolved organic carbon (DOC) removal ranging between 14.1 and 44.9%. To degrade the DOC present in the WW, different advanced oxidation processes (AOPs) were tested. Results showed that KPS-photo-Fenton, under the best operational conditions [Fe2+] = 2.5 mM, [KPS] = 1.0 mM, pH = 3.0, radiation UV-C mercury lamp (254 nm), agitation 350 rpm, temperature 298 K, reaction time 240 min achieved a DOC removal of 91.2 and 96.8%, with a H2O2 consumption of 156.9 and 199.0 mM, respectively for red and white WW. With application of combined CFD-KPS-photo-Fenton process, it was observed an increase of DOC removal with lower H2O2 consumptions. The energy consumption of the photosystem was evaluated by application of electric energy per mass (EEM). The application of KPS-photo-Fenton process achieved an EEM of 0.308 and 0.0309 kWh/g/L DOC, with a cost of 2.05 and 2.59 €/g/L DOC respectively for red and white WW. The combination of CFD-KPS-photo-Fenton decreased significantly the costs of treatment and the treated wastewater achieved the Portuguese legal values for wastewater discharge. This work shows that NOCs are a promising technology that can be an alternative to traditional metal salts, the combination of sulfate radicals with hydroxyl radicals can achieve high DOC removal and the combination of CFD with KPS-photo-Fenton process can decrease the operational costs.Fundação para a Ciência e a Tecnologia | Ref. UIDB/00616/2020Fundação para a Ciência e a Tecnologia | Ref. UI/BD/150847/202

Extraction of antioxidant compounds from enzymatic hydrolysis of brewer's spent grain after solid-state fermentation

Phenolic compounds have antioxidant properties that can benefit human health and food preservation. During solid-state fermentation (SSF) of lignocellulosic substrates, filamentous fungi produce carbohydrate degrading enzymes which can amplify the quantity of phenolics released linked to vegetable matrix when applying enzymatic hydrolysis (EH). In this work, brewer's spent grain (BSG) was fermented with Aspergillus ibericus and later the lignocellulolytic enzymes were extracted and used on an EH of fermented BSG. EH was optimized by a Box-Behnken design approach, studying the effect of three factors in the extraction of antioxidant compounds, namely the quantity of SSF-crude extract added, load of fermented solid and addition of -glucosidase. The maximum increase of phenols and antioxidant activity in comparison to unhydrolyzed BSG were 42.9 mg/g and 83.5 mol trolox/g, respectively. -glucosidase addition and low solid-load had a positive effect on the phenols released and antioxidant activity. The quantities of crude SSF-extract studied did not had a significant effect on phenols and antioxidant released.Helena Fernandes was supported by PhD grant (SFRH/BD/131219/2017). Funded by the European Regional Development Fund (ERDF) under the Project SPO3 (ref.: POCI-01-0145-FEDER030377) BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the ERDF under the scope of Norte2020-Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

An electronic nose as a non-destructive analytical tool to identify the geographical origin of Portuguese olive oils from two adjacent regions

The geographical traceability of extra virgin olive oils (EVOO) is of paramount importance for oil chain actors and consumers. Oils produced in two adjacent Portuguese regions, Côa (36 oils) and Douro (31 oils), were evaluated and fulfilled the European legal thresholds for EVOO categorization. Compared to the Douro region, oils from Côa had higher total phenol contents (505 versus 279 mg GAE/kg) and greater oxidative stabilities (17.5 versus 10.6 h). The majority of Côa oils were fruity-green, bitter, and pungent oils. Conversely, Douro oils exhibited a more intense fruity-ripe and sweet sensation. Accordingly, different volatiles were detected, belonging to eight chemical families, from which aldehydes were the most abundant. Additionally, all oils were evaluated using a lab-made electronic nose, with metal oxide semiconductor sensors. The electrical fingerprints, together with principal component analysis, enabled the unsupervised recognition of the oils’ geographical origin, and their successful supervised linear discrimination (sensitivity of 98.5% and specificity of 98.4%; internal validation). The E-nose also quantified the contents of the two main volatile chemical classes (alcohols and aldehydes) and of the total volatiles content, for the studied olive oils split by geographical origin, using multivariate linear regression models (0.981 ≤ R2 ≤ 0.998 and 0.40 ≤ RMSE ≤ 2.79 mg/kg oil; internal validation). The E-nose-MOS was shown to be a fast, green, non-invasive and cost-effective tool for authenticating the geographical origin of the studied olive oils and to estimate the contents of the most abundant chemical classes of volatiles.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES (PIDDAC) to CIMO (UIDB/00690/2020 and UIDP/00690/2020), to CEB (UIDB/04469/2020) and to the Associate Laboratory SusTEC (LA/P/0007/2020). The authors are also grateful to the “Project OLIVECOA—Centenarian olive trees of Côa Valley region: rediscovering the past to valorize the future” (ref. COA/BRB/0035/2019), financed by FCT (Portugal). Nuno Rodrigues thanks the National funding by FCT- Foundation for Science and Technology, P.I., through the institutional scientific employment program-contract.info:eu-repo/semantics/publishedVersio

Sensory intensity assessment of olive oils using an electronic tongue

Olive oils may be commercialized as intense, medium or light, according to the intensity perception of fruitiness, bitterness and pungency attributes, assessed by a sensory panel. In this work, the capability of an electronic tongue to correctly classify olive oils according to the sensory intensity perception levels was evaluated. Cross-sensitivity and non-specific lipid polymeric membranes were used as sensors. The sensor device was firstly tested using quinine monohydrochloride standard solutions. Mean sensitivities of 14±2 to 25±6 mV/decade, depending on the type of plasticizer used in the lipid membranes, were obtained showing the device capability for evaluating bitterness. Then, linear discriminant models based on sub-sets of sensors, selected by a meta-heuristic simulated annealing algorithm, were established enabling to correctly classify 91% of olive oils according to their intensity sensory grade (leave-one-out cross-validation procedure). This capability was further evaluated using a repeated K-fold cross-validation procedure, showing that the electronic tongue allowed an average correct classification of 80% of the olive oils used for internal-validation. So, the electronic tongue can be seen as a taste sensor, allowing differentiating olive oils with different sensory intensities, and could be used as a preliminary, complementary and practical tool for panelists during olive oil sensory analysis.This study was supported by Fundação para a Ciência e a Tecnologia (FCT),Portugal and the European Community fund FEDER, under the Program PT2020 (Project UID/EQU/50020/2013); under the strategic funding of UID/BIO/04469/2013 unit; and by Project POCTEP through Project RED/AGROTEC – Experimentation network and transfer for development of agricultural and agroindustrial sectors between Spain and Portugal

Experimental fully contextual correlations

Quantum correlations are contextual yet, in general, nothing prevents the existence of even more contextual correlations. We identify and test a noncontextuality inequality in which the quantum violation cannot be improved by any hypothetical postquantum theory, and use it to experimentally obtain correlations in which the fraction of noncontextual correlations is less than 0.06. Our correlations are experimentally generated from the results of sequential compatible tests on a four-state quantum system encoded in the polarization and path of a single photon.Comment: REVTeX4, 6 pages, 3 figure

Sustainability indicators of subsurface flow constructed wetlands in Portuguese small communities

The discharge of untreated domestic wastewater in the receiving waters creates a negative and environmental impact, inversely proportional to its autodepuration ability. Conventional wastewater treatment plants involve large capital investments and operating costs, and could be economically unsustainable for small-medium communities. So, constructed wetlands as natural low-cost systems can be an appropriate alternative, because they require low maintenance, give rise to good performances and provide a natural appearance. This work presents a synthesis of data obtained through an extensive survey performed in twenty Portuguese constructed wetlands utilities. Based on this information, some sustainable indicators and removal pollutant efficiencies were calculated. Besides identifying the main operational problems observed, it was also possible to detect inadequate monitoring procedures, aiming, with some proposed corrections, to improve the performance of these low-cost wastewater treatment utilities. The results obtained in this work encourage the development of future studies to increase the performance of these wastewater systems based on a better knowledge of the influence of hydraulic parameters, like flow, retention time and hydraulic application rate, in the pollutants removal efficiencies.(undefined

Performance evaluation of Portuguese constructed wetlands for municipal wastewater treatment

Constructed wetlands have been used as a technology appropriate for the treatment of municipal or domestic wastewater in some villages in Portugal. Most of constructed wetlands present a low cost (installation and maintenance), low energy requirements and technical skills of operators, environment friendly landscape, and good efficiency and reduced production of sludge. In a situation where is a need of appropriate wastewater treatment from a large number of rural villages, it is appropriate to evaluate the performance of some constructed wetlands systems operate in Portugal, in order to validate them as a credible alternative to conventional methods of wastewater treatment. This work presents a characterization of twenty constructed wetlands, an analysis of unit costs of treatment and the unit areas, and proceeds to the evaluation of their efficiency on the main wastewaters quality parameters. Moreover, the analysis identifies the major operational problems of these systems, suggesting a few mitigating measures and/or corrective to both the improvement of its operation, and the streamlining of its procedures for an accurate monitoring.(undefined

Treatment of winery wastewater with a combination of adsorption and thermocatalytic processes

The release of winery wastewater (WW) into the environment, without proper treatment, can cause severe problems to freshwater quality and natural fauna and flora. Therefore, in this work a treatment process was studied, combining adsorption and thermocatalytic oxidation processes. In a more specific way, it optimized the combination of activated sodium bentonite (Na-Mt) and potassium persulfate (KPS)/sodium percarbonate (SPC) as oxidant agents. With the combination of best operational conditions of adsorption ([Na-Mt] = 5.0 g/L, pH = 3.0, V = 500 mL, agitation 350 rpm, T = 298 K, t = 24 h) and thermocatalytic oxidation processes (S2O82−/H2O2 ratio = 1:0.25, S2O82−/H2O2 dosage = 0.1:0.025 (g/g), pH = 7.0, T = 343 K, agitation 350 rpm, t = 2 h), a total organic carbon, chemical oxygen demand and total polyphenols removal of 76.7, 81.4 and >99% was achieved, respectively. Finally, it was evaluated the effect of the treatment processes in the germination index (GI) of different plant seeds. A GI > 80% was achieved, showing a low phytotoxicity effect of the processes applied in the winery wastewater treatment.CCRN - Comissão de Coordenação da Região Norte | Ref. NORTE-01-0145-FEDER-000041Fundação para a Ciência e a Tecnologia | Ref. UIDB /00616/2020Fundação para a Ciência e a Tecnologia | Ref. UI/BD/150847/202