Browsing by Author "Jorge, Ruben Ferreira"
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- Aerobic biological treatment of wastewaters containing dichloromethanePublication . Moura, Sandra C.; Jorge, Ruben Ferreira; Duque, Anouk; Boaventura, Rui A.R; Castro, Paula M. L.BACKGROUND: Volatilization has been advanced as one of the predominant phenomena contributing to volatile organic carbon emissions from wastewater treatment plants (WWTPs). In this study, strategies for minimizing such air stripping losses when treating a liquid stream containing dichloromethane (DCM), aiming at decreasing the overall emission inventory from WWTPs, were investigated. RESULTS: System R1, consisting of a continuous flow stirred tank reactor (CSTR) treating a liquid stream containing DCM at a concentration of 12 mmol dm−3 presented a biodegradation efficiency (BE) of 68%, based upon chloride release, with 10% of measurable losses, mainly due to volatilization, and 22% of unmeasurable losses. System R2 introduced operational designs aiming at decreasing DCM volatilization. In Experiment R2.1, a biotrickling filter, through which the air stripped from the CSTR was driven, was introduced leading to a reduction from 10% to 7% on the measurable losses. In Experiment R2.2, the air stripped from the CSTR was recirculated at a flow rate of 2.4 dm3 h−1 through the reactormedium before entering the biotrickling filter. The BE was improved from 69% to 82% and the losses associated with air stripping were successfully reduced to 2%. The proposed design, including air recirculation and the biotrickling filter, increased the ratio between the biodegradation rate and the volatilization rate from 7 to 41. CONCLUSIONS: Recirculation of the gaseous effluent through the reactor medium, which allowed for higher residence time within the bioreactor, was shown to be a successful strategy for improving the treatment process, thus minimizing DCM volatilization losses.
- Biological treatment of a contaminated gaseous emission from a paint and varnish plant—from laboratory studies to pilot-scale operationPublication . Bastos, Filipe S.C.; Castro, Paula M.L.; Jorge, Ruben FerreiraA Vapour-Phase Bioreactor (VPB), namely a biotrickling filter, was scaled-up and operated in-situ for the treatment of gaseous emissions from a paint and varnish industrial plant. A microbial culture able to degrade the target compounds was enriched and a laboratory-scale VPB was established in order to evaluate the treatment's performance. The VPB presented removal efficiencies higher than 90% when exposed to Organic Loads (OL) of ca 50 g h−1 m−3 of reactor. The VPB was exposed to dynamic conditions often found in-situ (eg night and weekend shutdown periods) and showed a fast capacity to recover, with and without mineral medium recirculation. After a prolonged interruption period (10 months), the VPB was not able to cope with OL of ca 25 g h−1 m−3 of reactor and re-inoculation was required in order to recover the treatment performance. The VPB also showed limited treatment when exposed to higher OL (ca 500 g h−1 m−3 of reactor). The VPB was then scaled-up and a 3 m3 VPB was operated in-situ, showing removal efficiencies higher than 50% when exposed to an OL of c 5 g h−1 m−3 of reactor, thus complying with current legal demands. The addition of a maintenance feed was shown to be a useful tool for VPB pilot-scale operation when shutdown periods occurred. A factorial design of experiments was carried out, which allowed reduction to one-tenth of the initial supply of the main mineral medium constituents, namely phosphate buffer, ammonium and magnesium salts, and also elimination of the metal supplement. Overall, the VPBs were shown to be robust equipment, being able to respond actively to dynamic treatment scenarios, particularly night and weekend shutdown periods. Copyright © 2003 Society of Chemical Industry
- Characterisation of high added value compounds in wastewater throughout the salting process of codfish (Gadus morhua)Publication . Ferraro, Vincenza; Cruz, Isabel B.; Jorge, Ruben Ferreira; Malcata, F. Xavier; Castro, Paula M. L.; Pintado, Manuela E.In Portugal Atlantic codfish (Gadus morhua) is dry-salted with food-grade marine salt for 6 days. During this process, codfish incorporates salt and drains away water up to 22%(w/w) of its weight, which contains important compounds, such as free amino acids, peptides and proteins. Hence, the chemical profile of such water, composed of various soluble nitrogen fractions, was thoroughly determined. Along the salting process, the ratio of water released to trichloroacetic acid-soluble nitrogen remained constant, but the proportion between water released and phosphotungstic acid-soluble nitrogen decreased because of proteolysis. The concentration of free amino acids increased from 2.68 g/l to 5.41 g/l within 6 days, but myofibrillar proteins were found to be approximately constant, ca. 3.31 g/l. Creatine, aspartic and glutamic acids, glycine, taurine and tryptophan were the dominant free amino acids, the release of which was successfully modelled. Total biogenic amines concentration in wastewater at the end of the salting process was ca. 100 mg/kg.
- Characterisation of soluble nitrogen and muscle proteins in wastewater throughout the salting process of Codfish (Gadus morhua)Publication . Ferraro, Vincenza; Cruz, Isabel B.; Jorge, Ruben Ferreira; Malcata, F. Xavier; Castro, Paula M. L.; Pintado, Manuela E.In Portugal, Atlantic codfish (Gadus morhua) is usually consumed after dry salting; this process is carried out by mixing deboned codfish with food–grade marine salt followed by stacking in a tank for 6 days. Along the salting process, codfish incorporates salt as well as it is partially dried by the release of water - up to 22 % (w/w). Currently, this wastewater is treated as a residue not being further valorized. However, the presence of a significant amount of valuable compounds in this rest, such as amino acids and proteins, may allow for valorization opportunities not yet explored. The present work focuses on the identification of the nitrogen-containing compounds present in such wastewater. Total nitrogen (WSN), trichloroacetic acid-soluble nitrogen (TCASN) and phosphotungstic acid-soluble nitrogen (PTASN) were evaluated by the micro-Kjeldahl method; Biuret method was used for total protein determinations and SDS-Page was performed for protein molecular weight screening. The results revealed an increase of WSN, TCASN and PTASN with time, with corresponding values of 3.17 g/L (WSN), 1.62 g/L (TCASN) and 1.16 g/L (PTASN) by the end of the process; the evolution of WSN versus the released water was approximately constant during the salting process, as well as the ratios of TCASN/WSN and PTASN/WSN with values of 51.25 and 36.55 % (w/w) at equilibrium, respectively.
- Effects of physical parameters onto adsorption of the Borderline Amino Acids Glycine, Lysine, Taurine, and Tryptophan upon Amberlite XAD16 ResinPublication . Ferraro, Vicenza; Cruz, Isabel B.; Jorge, Ruben Ferreira; Pintado, Manuela E.; Castro, Paula M. L.The adsorption of the borderline amino acids glycine, lysine, taurine, and tryptophan on the commercial resin Amberlite XAD16 was investigated. The effect of amino acid hydrophobicity/hydrophilicity and effects of environmental conditions upon adsorption equilibrium were evaluated. Optimal settings for a maximum recovery of a selected amino acid, namely, taurine, were obtained by the response surface methodology. Changes in temperature, pH, ionic strength, percentage of ethanol added to the amino acid solution, amino acid concentration, and adsorbent dose showed effects on the recovery of each amino acid upon the uncharged, nonfunctionalized, and hydrophobic matrix of the Amberlite XAD16 resin. Adsorption was favored at the lower temperature investigated, 10 degrees C; a pH decrease down to 2 favored adsorption of glycine, lysine, and tryptophan; the addition of ethanol allowed an increase in amino acid recovery except for lysine. The addition of sodium chloride up to the value of 1.5 M showed a positive effect on adsorption of all amino acids. A dose of 10 g Amberlite XAD16 for 100 mL of solution was the most adequate at the amino acid concentrations tested. Optimal conditions for the maximum recovery of taurine were achieved at a temperature of 13.5 degrees C and at a ionic strength of 1.32 M NaCl.
- Extraction of high-added-value compounds from codfish (Gadus morhua) salting wastewaterPublication . Ferraro, Vincenza; Cruz, Isabel B.; Jorge, Ruben Ferreira; Pintado, M. E.; Castro, Paula M. L.The fish processing industry is widespread and extremely varied in terms of type and scale of operation. Codfish (Gadus morhua L.) is one of the most processed white fish in Europe, where it is usually consumed salt-cured. Significant amounts of waste and byproducts result from its processing. Salt induces the release of substantial volumes of physiological water (∼200 l for each ton of fresh fish), which drains away significant amounts of nutrients (∼10 g/l). In this chapter we discuss the recovery of muscle proteins and free amino acids from codfish salting wastewater by sorption using a commercial resin. The free amino acid extract shows important biological properties, such as antioxidant activity and in vitro intestinal permeability. The chapter discusses the application of this mixture and of muscle protein in food, feed, cosmetic, and pharmaceutical formulations.
- In vitro intestinal absorption of amino acid mixtures extracted from codfish (Gadus morhua L.) salting wastewaterPublication . Ferraro, Vincenza; Jorge, Ruben Ferreira; Cruz, Isabel B.; Antunes, Filipa; Sarmento, Bruno; Castro, Paula M. L.; Pintado, Manuela E.This study reports on the intestinal permeability of salt-containing mixtures of amino acids extracted from codfish salting wastewater. Permeability was evaluated in vitro using the Caco-2 cell line model; cell integrity during exposure to mixtures of amino acids was estimated by measuring the transepithelial electrical resistance (TEER). The effect of salt (NaCl) on the permeability and on the intestinal cell’s integrity was also examined. Permeation rate (i.e. transport) was ≥95% for all amino acids except for creatine, for which it was 6%. Values for apparent permeability coefficients, Papp > 10 5 cm s 1, for mixture with isotonic concentration of NaCl suggest that amino acids are very likely to be absorbed in humans. Mixture with a hypertonic level of NaCl exerts a cytotoxic effect in intestinal cells resulting in a loss of epithelium integrity. Results show that isotonic mixture of amino acids extracted from codfish salting wastewater could be used in food, feed, cosmetic and pharmaceutical formulations. These applications could contribute to the fish industry sustainability.
- Kinetics of release of water and nutrients from codfish (gagus Morrhual L.) throught a heavy-saltingPublication . Ferraro, Vincenza; Cruz, Isabel B.; Jorge, Ruben Ferreira; Pintado, Manuela E.; Castro, Paula M. L.Through the typical 6 days heavy-salting, codfish releases 25% (w/w) of its physiological water due to the incorporation of high amounts of salt, 20% (w/w). Besides changes in water-holding capacity, major effects imparted by salt are modifications in muscle proteins conformation with subsequent denaturation and loss, and release of free amino acids. Water is liberated from codfish according to a power-law kinetics, which describes biological reactions under molecular crowding. Proteins and amino acids are released by pseudo-first and pseudo-second order kinetics, which describe proteolysis. Despite the loss of nutrients through salting, the nutritional value of codfish can be considered unchanged. A reduction by weight of 0.45% in muscle proteins, 1.24% aspartic acid, 1.4% glutamic acid, 2% arginine, 11% creatine, 0.2% glycine, 0.5% lysine, 0.4% methionine, 0.3% phenylalanine, 3.4% taurine and 3% tryptophan is noticed.
- A membrane bioreactor for biotransformations of hydrophobic molecules using organic solvent nanofiltration (OSN) membranesPublication . Valadez-Blanco, Rogelio; Ferreira, Frederico Castelo; Jorge, Ruben Ferreira; Livingston, Andrew GuyThiswork reports the application of organic solvent nanofiltration (OSN) membranes to a membrane bioreactor for biotransformations (MBB). An organic solvent phasewas employed, allowing high substrate loadings and efficient product removal. The aqueous and organic phases were separated by an OSN membrane. The biotransformation of geraniol to R-citronellol by baker’s yeast was used as the model reaction, and n-hexadecane and toluene as the organic solvents. The performance of the MBB was compared to that of a direct contact biphasic (DCB) bioreactor. The MBB system resulted in lower productivities than the DCB system due to mass transfer limitations. For the n-hexadecane system, the membrane was the main mass transfer resistance, whereas for the toluene system the contribution of the aqueous liquid film mass transfer resistance became predominant. Further investigations are needed to improve the substrate transfer rates. Despite this, the MBB system prevented aqueous breakthrough, and thus the formation of two-phase emulsions. Toluene toxicity to the biocatalyst was also minimized, although it caused a reduction in the reaction enantiospecificity. This work showed that OSN-MBB systems avoid the formation of emulsions, thus reducing downstream separation and allowing increased substrate loadings.
- Recovery of free amino acids and muscle proteins from codfish (Gadus morhua L.) salting wastewater by sorption on Amberlite XAD16Publication . Ferraro, Vincenza; Jorge, Ruben Ferreira; Cruz, Isabel B.; Castro, Paula M. L.; Pintado, Manuela E.BACKGROUND: The objective of this research was the valorization of an agro-food industry residue, namely codfish salting wastewater, through the recovery of valuable bioactive compounds. Approximately 200 L of salted wastewater are generated for each ton of fresh codfish, carrying protein and free amino acids at a concentration of c. 10 g L−1, and sodium chloride (NaCl) at c. 250 g L−1. RESULTS: Protein and free amino acids were selectively recovered by sorption with the Amberlite XAD16 resin. Food-grade acetone was used to elute amino acids while a solution of sodium hydroxide (NaOH) desorbed protein. Recovery of protein and of hydrophobic to neutral amino acids was 100%; NaCl was also partially recovered from the salting wastewater, at a level of 33%. Kinetics and mechanisms of adsorption and desorption were investigated. CONCLUSIONS: The process implemented can be considered as a valuable management option for codfish saltingwastewater, it can contribute to the fish industry sustainability and can serve as a source of nutrients. Free amino acids and protein extracts can find application in animal and human nutrition through incorporation into functional food and drinks, as well as in cosmetics and in pharmaceutical formulations.