Search

Background In addition to energy benefits, anaerobic digestion offers other interesting advantages. The cork industry is of great environmental, economic and social significance in the western Mediterranean region, with Portugal beingthe world-leading producer and exporter. Cork boiling wastewater (CBW) is a toxic and recalcitrant organic effluent produced by this sector, which constitutes a serious environmental hazard. However, there is no documented research on anaerobic treatment/valorization performed with this effluent. The work presented here was developed with the aim to use the anaerobic digestion process to convert the CBW polluting organic load into an energy carrier gas and valuable molecules for industry. Results No lag phases were observed and a methane yield of 0.126 to 0.142 m3 kg-1chemical oxygen demand (COD)addedwas registered in the mesophilic consortium experiments carried out in batch flasks at 37 ± 1°C. Anaerobic digestion can be advantageously connected to ultrafiltration or electrochemical processes, due to the following: 1) reduction of ellagic acid content and consequentdecrease of CBW viscosity; and 2) increase in conductivity after the anaerobic process, avoiding the electrolyte application of the electrochemical process. The improvement of several CBW biochemical features shows that anaerobic digestion may provide additionally useful molecules. The rise in concentration of some of these compounds, belonging to the benzoic acid family (gallic, protocatechuic, vanillic and syringic acids), is responsible for the increase of antiradical activity of the phenolic fraction. Additionally, some enzymatic activitywas also observed and while the laccase activity increased in the digested effluent by anaerobiosis, xylanase was formed in the process. Conclusions The multidisciplinary approach adopted allowed the valorization of CBW in terms of energy and valuable biomolecules. By exploiting the anaerobic digestion process potential, a novel methodology to toxic and recalcitrant cork processing wastewater was developed. [ABSTRACT FROM AUTHOR]

This article discusses the lack of technological innovations involved in the manufacture of corks, particularly during the late 19th and early 20th centuries in the region of Andalusia, Spain. The author comments on the widespread industrial revolutions occurring in the Western hemisphere and emphasizes their failure to influence cork manufacturing. He also considers the various aspects of cork-making, including labor productivity, wages, and profitability. The exploitation of oak forests in the region for the cork industry is also explored.

Highlights: [•] An alternative to the recovery of waste resulting from the cork industry is identified. [•] The feasibility of obtaining a pellet with good physical and energetic characteristics is demonstrated. [•] Pelletised cork waste has proven to be suitable for energy applications. [•] Cork pellets have similar characteristics similar to forest waste, together with higher bulk density. [•] Cork pellets also acquire transportation capacity, because of their low density. [ABSTRACT FROM AUTHOR]

Highlights: [•] The fraction with molecular size >100kDa corresponds to 56% of the organic load. [•] Molecular size of pollutants is a major constraint to biodegradability. [•] Ozone efficiency for improving biodegradability increases with molecular size. [•] To raise biodegradability by ozonation the best outcome was with compounds >20kDa. [Copyright &y& Elsevier]

Abstract: Cork, a natural, recyclable, non-toxic and renewable resource, which stems from the bark of a cork oak in the Mediterranean cork forest (Montado), is an excellent material for Sustainable Product Design. This article describes a project, developed for the Portuguese Cork Industry, on the sustainable innovation of cork products, using the method of “Design Interventions” for new product development, combined with the method of “Eco-efficient Value Creation”. Design Intervention is a method to generate innovative products in a structured way with a team of designers, focussing on maximum customer perceived value. The method has four levels: project strategic level, concept development level, design implementation level and product diffusion level. It includes workshops, combined with work in the design studios of the individual designers. The design concepts are analysed with respect to sustainability, and the market value of the prototypes are tested. Eco-efficient value creation is LCA based method with a double objective: 1. reduce the eco-burden of a product (and/or service), and at the same time, 2. enhance the customer perceived value. In this method, the combination of customer perceived value and eco-burden of the product is optimised, aiming at a high level of eco-effectiveness. The eco-burden is determined by means of Life Cycle Assessment (according to ISO 14040/44). The customer perceived value is determined by the price of the product in the market. The project showed that this two dimensional approach, generated good results: 27 out of the 36 new designs ended up with better characteristics (lower eco-costs at a higher value) than their reference products. Products have been exhibited in several international cities, and are sold in design shops. [Copyright &y& Elsevier]

The quality of cork is one of the most important issues for the cork industry. It is a complex process that requires evaluating many factors and simultaneously handles continuous and discrete variables, sometimes with a high degree of subjectivity. There are two objectives, in first place to establish the relationship between the commercial quality of the cork and the porosity measured by image analysis at different stages of industrial processing (planks, sheets, and stoppers), and in second place, to evaluate the potential of NIRS technology as a method of assessing the porosity and, therefore, the industrial quality. For this, there has been used a sample group formed by 479 planks, 176 sheets and 90 one piece natural cork stoppers, classified industrially into 4, 2 and 3 quality classes, respectively. The coefficient of porosity was evaluated into two and three classes of color by using image analysis techniques. NIRS spectra were obtained in the transverse section (planks and stoppers), in the tangential section (sheets and stoppers) and in the radial section (stoppers), with a spectrophotometer Foss NIRSystems 6500 SY II, by remote reflectance mode. Statistical analysis of the relationship between quality and coefficient of porosity, measured by image analysis, discriminates two quality classes for planks and sheets, and three classes for stoppers. Classifying the image into a larger number of clusters improves the results. Best NIRS calibrations were obtained measuring the porosity into 3 classes of color, matching the results obtained by image analysis. This allow to discriminate two quality classes in planks (refuse and race), the two classes in sheets (R²=0.83; r² =0.78) and the three classes for stoppers (R²=0.67; R²=0.53). Due to the difficulties of automated image analysis in the early stages of industrial processing, NIRS technology could be an objective tool to evaluate the porosity and to differentiate two classes of quality in planks and sheets, and three classes in stoppers. [ABSTRACT FROM AUTHOR]

Abstract: This study presents an environmental analysis of the cork sector by integrating and evaluating the production of the products that are most commonly made of cork: natural cork stoppers, champagne cork stoppers, white cork granulate and black cork granulate, in order to propose environmental strategies that could contribute to minimising the potential impacts of the cork sector. Life Cycle Assessment (LCA) was the methodology used in order to assess the potential environmental impacts of the cork sector and its main products. Inventory was supported by 15 companies in Catalonia. Different environmental midpoint impact categories were reported and analysed according to CML 2001 method such as Abiotic Depletion (ADP), Acidification Potential (AP), Eutrophication Potential (EP), and many other. Also, the Global Warming Potential (GWP 100 years), was assessed, and it was found that the cork sector contributed to fixing carbon dioxide and consequently can help to mitigate climate change, besides generating cork products. Specifically, 3.4 tonnes of CO2 eq. were emitted to convert a tonne of raw cork from the forest into products, while 18 tonnes of CO2 are fixed per tonne as a result of the existence of cork oak forests; the resulting balance was that 14.6 tonnes of CO2 are fixed. A sensitivity analysis was carried out of the distribution of environmental impacts between products; it was observed that allocation rules were an important point of the assessment. The use of cork, a natural, renewable and local material, can help to reduce the environmental impact of products. The use of cork stoppers contributes to reducing the carbon footprint of beverages such as wines, champagnes, beers, ciders, brandies and many other beverages. [Copyright &y& Elsevier]

Cork oak grows endemically in a narrow region bordering the western Mediterranean, and especially in the Iberian Peninsula. The importance of cork agro-forestry systems lies in the fact that a natural and renewable raw material – cork – can be extracted sustainably without endangering the tree or affecting biodiversity. This paper describes an environmental analysis of the extraction of raw cork in cork oak forests in Catalonia, using data from five representative local forest exploitations. The evaluation was carried out using life cycle assessment (LCA) methodology, and all the forestry management required to obtain a tonne of raw cork was included. The aim of the study was to evaluate the environmental impacts – in terms of global warming, acidification, eutrophication, human toxicity, and so on – caused by cork extraction and determine the carbon dioxide balance of these forestry systems, with a tree lifespan of about 200 years. During the life cycle extraction of cork in Catalonia, 0.2 kg of CO2 eq. was emitted per kg of raw cork extracted. Moreover, cork cannot be extracted without the tree, which will be fixing carbon dioxide throughout its technological useful life (200 years), despite the fact that the bark is removed periodically: every 13–14 years. If the emission from extraction and the carbon contained in the material is discounted, the carbon dioxide balance indicates that 18 kg of CO2 are fixed per kg of raw cork extracted. Therefore, cork is a natural, renewable and local material that can replace other non-renewable materials, at local level, to reduce the environmental impacts of products, and particularly to reduce their carbon footprint. [Copyright &y& Elsevier]

Abstract: Cork manufacturing is a traditional industry in Southern Europe, being the main application of this natural product in wine stoppers and insulation. Cork processing begins at boiling the raw material. As a consequence, great volumes of dark wastewaters, with elevated concentrations of chlorophenols, are generated, which must be depurated through costly physicochemical procedures before discarding them into public water courses. This work explores the potential of bacteria, isolated from cork-boiling waters storage ponds, in bioremediation of the same effluent. The bacterial population present in cork-processing wastewaters was analysed by DGGE; low bacterial biodiversity was found. Aerobic bacteria were isolated and investigated for their tolerance against phenol and two chlorophenols. The most tolerant strains were identified by sequencing 16S rDNA. The phenol-degrading capacity was investigated by determining enzyme activities of the phenol-degrading pathway. Moreover, the capacity to form biofilms was analysed in a microtitre plate assay. Finally, the capacity to form biofilms onto the surface of residual small cork particles was evaluated by acridine staining followed by epifluorescence microscopy and by SEM. A low-cost bioremediation system, using phenol-degrading bacteria immobilised onto residual cork particles (a by-product of the industry) is proposed for the remediation of this industrial effluent (self-bioremediation). [Copyright &y& Elsevier]

Abstract: Cork is a natural and renewable material extracted mainly in the Western Mediterranean area. Apart from natural cork stoppers and discs, the most important product of the cork sector is cork granulate, because it represents a solution for the large quantities of waste generated during natural cork industry production and during forestry activities. Cork granulates have not yet been studied from an environmental perspective, although this ecomaterial could substitute other non-renewable and more harmful materials, such as petroleum derivates. This study presents an environmental analysis of the production of cork granulates, following the life-cycle assessment (LCA) methodology. All the operations after forest management were analysed, from the extraction of the resources to the use of these intermediate products. Research also sought to identify the operations that contribute most to potential environmental impact during production. Inventory data was collected from three representative local producers that all use standard technology. Regarding environmental burdens, trituration and classification-sieving were the operations which contribute most to the environmental impact of granulate production; together representing between 90% and 97% of the environmental burdens for the studied categories. It was also stated that 35% of the initial raw material that enters the system became dust during production. Cork dust is a potential material that can be used as a fuel to substitute other non-renewable sources of energy such as diesel oil or electricity. However, it was observed that the use of this waste as an energy source was still at an incipient point of implantation. [Copyright &y& Elsevier]

Abstract: The wine industry has developed greatly over recent years, and it could be stated that what was once a traditional industry has become a very productive and technical sector. One aspect that has not been studied until now is the cork stopper, despite the fact that most wine bottles are sealed with this product, and practically all corks are produced in the Iberian Peninsula. This study presents the environmental analysis of the production of natural cork stoppers, using life cycle assessment (LCA) methodology. The research was supported by data from four Catalan representative companies and all the stages involved in the production after the forest management have been taken into account. The purpose of this research was to provide reference data for the Catalan cork industrial sector (Northeast Spain), and also contribute to deciding which aspects of natural cork stopper production must be improved and further researched. Another objective of this research was to emphasise and demonstrate that LCA methodology could be an interesting tool for improving traditional industry, from a cleaner production perspective. Results could be used by other sector companies to analyse and compare themselves with in order to know if they could improve their production with the current available technology. Impact assessment results indicate that the manufacturing stage was the stage causing the greatest impact, but also an evaluation of the influence of the initial transport from the forest reveals that this stage could notably increase the impact when raw cork was moved from distant forests. [Copyright &y& Elsevier]

Abstract: Wastewater from cork processing industry present high levels of organic and phenolic compounds, such as tannins, with a low biodegradability and a significant toxicity. These compounds are not readily removed by conventional municipal wastewater treatment, which is largely based on primary sedimentation followed by biological treatment. The purpose of this work is to study the biodegradability of different cork wastewater fractions, obtained through membrane separation, in order to assess its potential for biological treatment and having in view its valorisation through tannins recovery, which could be applied in other industries. Various ultrafiltration and nanofiltration membranes where used, with molecular weight cut-offs (MWCO) ranging from 0.125 to 91 kDa. The wastewater and the different permeated fractions were analyzed in terms of Total Organic Carbon (TOC), Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD), Total Phenols (TP), Tannins, Color, pH and Conductivity. Results for the wastewater shown that it is characterized by a high organic content (670.5–1056.8 mg TOC/L, 2285–2604 mg COD/L, 1000–1225 mg BOD/L), a relatively low biodegradability (0.35–0.38 for BOD5/COD and 0.44–0.47 for BOD20/COD) and a high content of phenols (360–410 mg tannic acid/L) and tannins (250–270 mg tannic acid/L). The results for the wastewater fractions shown a general decrease on the pollutant content of permeates, and an increase of its biodegradability, with the decrease of the membrane MWCO applied. Particularly, the permeated fraction from the membrane MWCO of 3.8 kDa, presented a favourable index of biodegradability (0.8) and a minimized phenols toxicity that enables it to undergo a biological treatment and so, to be treated in a municipal wastewater treatment plant. Also, within the perspective of valorisation, the rejected fraction obtained through this membrane MWCO may have a significant potential for tannins recovery. Permeated fractions from membranes with MWCO lower than 3.8 kDa, presented a particularly significant decline of organic matter and phenols, enabling this permeates to be reused in the cork processing and so, representing an interesting perspective of zero discharge for the cork industry, with evident environmental and economic advantages. [Copyright &y& Elsevier]

Natural manufactured materials are highly heterogeneous. The remarkable variability exhibited from one sample to another makes it impossible to find two samples with the same morphological distribution in their texture. This fact makes automatic quality measurement of the properties of naturally textured objects a desirable though challenging problem in industrial applications where costs are paramount. Cork, as a natural and heterogeneous material with fully seven quality classes, defies easy automatic quality classification. This paper describes an improved computer vision system for measuring the quality of industrial cork samples by incorporating techniques based on the biological configuration of human vision and human reasoning, such as Gabor filtering techniques and neurofuzzy computing. These techniques have provided important texture detection improvements over previous results. Neurofuzzy classification system performance has proved to be better than results obtained with other classification algorithms. The proposed neurofuzzy classifier includes in its feature space three wavelet-based texture quality features. The results obtained from the final proposed system showed an error rate of only 4.85% that is lower than previous similar systems designed for this application. The system proposed in this paper has the potential to reduce costs, time, and current conflicts in the cork industry. [ABSTRACT FROM AUTHOR]

This paper presents a solution to a problem existing in the cork industry: cork stopper/disk classification according to their quality using a visual inspection system. Cork is a natural and heterogeneous (remarkable variability among different samples, being impossible to find two samples with the same morphological distribution in its defects) material; therefore, its automatic classification (seven quality classes exist) is very difficult. The solution proposed in this paper evaluates the following procedures: quality discriminatory features extraction and classifiers analysis. Each procedure focused on the study of aspects that could influence cork quality. Experiments show that the best results are obtained by system specific features: cork area occupied by defects (after thresholding), size of the biggest defect within the cork area (morphological operations), and the Laws TEMs E5L5TR, E5E5TR, S5S5TR, W5W5TR, all working on a Neuro-Fuzzy classifier. In conclusion, the results of this study represent an important contribution to improve quality control in the cork industry. [ABSTRACT FROM AUTHOR]

This paper presents a quality control vision system developed for the inspection of cork parquets that is already applied in the Portuguese cork industry. It is devoted specifically to the most critical quality issues: visibility of the lowest layer (BASE) on the noble layer (UPPER) and the homogeneity of this noble layer. Since these aspects are related with the texture of the raw material, the system was based on texture segmentation techniques. Features used were extracted from detail images of the wavelet transform. The classifier consists of a fuzzy grammar inference system. The segmentation procedure revealed a good performance indicated by high classification rates. Behavior in the industrial environment has been demonstrating high performance, revealing good perspectives for full spread industrialization. [ABSTRACT FROM AUTHOR]

Acetovanillone [Ethanone, 1-(4-hydroxy-3-metoxyphenyl)] is one of the major pollutants that is present in the wastewater produced during the boiling of raw material in the cork industry. The oxidation of its aqueous solutions by monochromatic UV radiation alone and combined with hydrogen peroxide, Fenton's reagent and the photo-Fenton system has been investigated. In the single UV radiation process, the apparent rate constants and the quantum yields are determined, and in the UV/H 2 O 2 combination, the additional efficiency in the oxidation process due to the presence of hydrogen peroxide is established. The influence of some operating variables, such as initial concentrations of H 2 O 2 and Fe(II), as well as the pH, is discussed in the Fenton and photo-Fenton systems, and the partial contribution of the radical pathways to the global oxidation rates are evaluated. The rate constant for the reaction of acetovanillone with hydroxyl radicals is also determined by means of a competition kinetics model, its value being 5.62× 10 9 M -1 s -1 . Finally, chemical oxidation experiments of wastewaters generated in this industry were carried out by using the same advanced oxidation processes. Specifically, the elimination of acetovanillone in these effluents was determined, and the removal of the global organic pollutant content was also evaluated. [ABSTRACT FROM AUTHOR]

The ozonation of esculetin (6,7-dihydroxycoumarin), a major pollutant present in the wastewater generated in the cork industry, was accelerated at high pH, with apparent second-order rate constants in the range from 3.3 ⊗ 104 L/(mol·s) at pH .= 2 to 8.4 ⊗ 107 L/(mol·s) at pH = 9. The acid-base equilibrium of esculetin was studied, resulting in a pKa value of 7.37. Taking into account this pKa, the rate constants for the reaction between ozone and the un dissociated and dissociated forms of esculetin were 3.0 ⊗ 104 and L/(mol·s) 6.67 ⊗ 108 L/(mol·s), respectively. Apparent first-order rate constants for the photolysis by U V irradiation were also evaluated, with values between 0.12 ⊗ 10-2 min-1 at pH = 2 and 1.15 ⊗ 10-2 min-1 at pH = 9, while the quantum yields for this photo-degradation reaction varied from 0.99 ⊗ 10-2 mol/Eins to 11.1 ⊗ 10-2 mol/Eins at these pHs. The Fenton's reagent system was used for the generation of hydroxyl radicals, and the rate constant for the reaction between esculetin and these radicals was determined to be 1.06 ⊗ 1010 L/(mol·s). Finally, several chemical oxidation systems were used in the degradation of this pollutant: single oxidants (ozone, UV irradiation) and advanced oxidation processes (Fenton's reagent, UV/ H2O2, O3/H2O2, O3/UV, O3/H2O2 /UV, and photo-Fenton System). The results revealed that the most efficient methods in terms of esculetin removal were ozonation among the single oxidants, and the photo-Fenton system among the combined processes. [ABSTRACT FROM AUTHOR]

A two-step protocol was used for the identification of 52 yeasts isolated from bark of cork oak at initial stages of the manufacturing process of cork stoppers. The first step in the identification was the separation of the isolates into groups by their physiological properties and RFLPs of the ITS-5.8S rRNA gene. The second step was the sequencing of the D1/D2 domains of the 26S rRNA gene of selected isolates representing the different groups. The results revealed a predominance of basidiomycetous yeasts (11 species), while only two species represented the ascomycetous yeasts. Among the basidiomycetous yeasts, members representing the species Rhodosporidium kratochvilovae and Rhodotorula nothofagi, that have been previously isolated from plant material, were the most abundant. Yeasts pertaining to the species Debaryomyces hansenii var. fabryii, Rhodotorula mucilaginosa and Trichosporon mucoides were isolated in small numbers. [Copyright &y& Elsevier]

Objectives. To evaluate allergic sensitisation to Chrysonilia sitophila, Penicillium glabrum, and Trichoderma longibrachiatum in cork workers with asthma. Methods. Skin prick tests with a battery of common allergens and with the three fungi were performed on ten cork workers with asthma and eight non-exposed asthmatics. Based on serial peak expiratory flow measurements, five were classified as having occupational asthma (AO) and five as having non-occupational asthma (NOA). In exposed patients, specific antibodies for the three fungi were also studied by immunoblotting Results. Two out of ten patients with occupational exposure and four out of eight of the control group showed positive results for skin prick tests for common allergens. Moreover, two out of five patients with OA and three out of eight controls exhibited sensitisation to storage mites. All exposed patients (with OA or NOA) had negative skin prick test results for the fungal extracts. In patients with asthma and occupational exposure, immunoblotting results confirmed the absence of specific IgE. However, specific IgG4 was present in some cases. Conclusions. Atopy does not seem to characterise occupational asthma in cork workers. Despite their long exposure to moulds, we could not find evidence of IgE sensitisation to the three most prevalent cork fungi in patients with OA, which points to the search for other causative agents, such as cork chemical compounds or contaminants. [ABSTRACT FROM AUTHOR]

Suberosis is an occupational lung disorder of cork industry workers usually presenting as an extrinsic allergic alveolitis, but airway involvement in some cases makes the diagnostic approach complex. We assessed peak expiratory flow rates (PEF) in 17 cork workers with asthma symptoms that worsened at work, comparing three methods of PEF graph analysis. Complete agreement (three observers) was found in 12 of 17 cases (70.6%) with the visual inspection of mean daily values and in 11 of 17 cases (64.7%) with the minimum, maximum, and mean daily values (without any consensus in two cases). According to the mean PEF graph, there were eight positive readings (47%), five negative readings (29%), and four dubious readings (24%); with the other graphic analysis, two of the dubious cases were reclassified as negative. When we analyzed daily variability ≥20%, we found only three positive results, one of which was in absolute disagreement with the visual analysis. Our results suggest that it is possible to demonstrate occupational asthma in cork work exposure. The visual inspection of PEF monitoring shows a greater number of positive results than the index of daily variability; however, the latter may help to sort out dubious cases. [ABSTRACT FROM AUTHOR]

Describes a cork stopper quality control system using morphological filtering and contour extraction and following CEF as the feature extraction method, and a fuzzy-neural network as a classifier. Proposition of an adaptive image thresholding method using iterative and localized scheme; Successful testing of a fully functioning prototype of the system.