A. Gomes - Academia.edu (original) (raw)
Papers by A. Gomes
Macromol
Active packaging with biobased polymers aim to extend the shelf life of food and to improve the e... more Active packaging with biobased polymers aim to extend the shelf life of food and to improve the environmental sustainability of the food industry. This new concept was tested with samples of fresh poultry meat wrapped with chitosan reinforced with 2.5% of commercial nanocellulose (NC) incorporating 1% of essential oils (EO) from Aloysia citrodora (ACEO) and Cymbopogon citratus (CCEO). The performance of the bionanocomposites containing EOs was assessed and compared with unwrapped meat samples and samples wrapped with chitosan/NC, during a 13 day period of refrigerated storage for several physicochemical parameters related to food deterioration and microbial growth. Wrapping the meat with the chitosan/NC polymer helped to increase the shelf life of the meat. The incorporation of EOs added extra activity to the biocomposites, further delaying the meat deterioration process, by halting the lipid oxidation and the Enterobactereaceae growth until the 9th day. The composition of both EOs ...
Journal of Biotechnology, 2005
Journal of Membrane Science, 2005
Water Science & Technology, 68(10), 2214-2219, Oct 2013
Biodegradability enhancement and detoxification of cork boiling wastewater (CBW) are required for... more Biodegradability enhancement and detoxification of cork boiling wastewater (CBW) are required for the successful implementation of biological treatment options. We studied the possibility of achieving these goals through ozonation pre-treatment by experimenting on the effect of ozone dose and pH. The CBW used had a pH of 5.81, a chemical oxygen demand (COD) of 1,865 mg L1, a biochemical oxygen demand (BOD5) of 498 mg L1 and total phenol (TP) and tannin compounds concentrations of 523 and 399 mg L1, respectively. The ozone doses ranged from 0.27 to 2.63 for the O3(applied)/COD0 ratios with samples at natural pH and set to 3.33 and 9.96. Ozonation allowed the BOD20/COD ratio (biodegradability index) to increase from 0.37 to 0.63 and a toxicity reduction from 3.08 to 1.24 TU (Microtox). The corresponding removals obtained were 15.2–62.0%, 38.4–83.2% and 56.7–92.1% for COD, TP and colour, respectively. The best outcome of ozonation pre-treatment requires O3(applied)/COD0 ratios over 1.5 and an acid pH. The increase of TP removals with ozone dose at acid pH led to biodegradability enhancement and CBW detoxification. However, for similar conditions the highest COD removals were obtained at alkaline pH due to the hydroxyl radicals’ high oxidation ability but lack of selectivity.
Bioresource Technology, 147, 143-151, Sep 2013
Cork boiling wastewater pollutants were fractionated by sequential use of four ultrafiltration me... more Cork boiling wastewater pollutants were fractionated by sequential use of four ultrafiltration membranes and five fractions were obtained: four retentates (>100, 50–100, 20–50 and 10–20 kDa) and one permeate (<10 kDa); which were used to study the correlation of molecular size with biodegradability and toxicity before and after ozonation. The results show that molecular size is correlated with organic load and restrains biodegradability. The fraction with >100 kDa corresponds to 56% of the organic load and the one with <10 kDa only 8%. The biodegradability of fractions increased 182% with fractions molecular size reduction from >100 to < 10 kDa and the chemical oxygen demand (COD) was from 3436 to 386 mg L−1. For biodegradability enhancement the best outcome of ozonation was obtained with compounds having molecular size >20 kDa and range from 5% up to 175% for applied ozone doses to COD ratios between 0.15 and 0.38.
The performance of two constructed wetlands (CWs) with horizontal subsurface flow (HSSF) configur... more The performance of two constructed wetlands (CWs) with horizontal subsurface flow (HSSF) configuration was investigated during a three phases treatment of cork boiling wastewater (CBW). The two CWs were filled with LECA. One was planted (CWP) with common reeds (Phragmites australis) and the other was kept unplanted as a control unit (CWC). The feeding CBW was sequentially diluted to 500, 600 and 750 mg/L COD and pH was set to 6.5-7.5. Other features of the feed solution were the intense dark colour, total phenols (TPh) concentration ranging from 36 to 62 mg/L and low biodegradability. Both CW units showed similar COD (44.7 and 56.6%, respectively) and TPh (40 and 65%, respectively) removal rates for a working period of 4 months. First results indicate that the presence of plants improved the system performance only in terms of total phosphorus (TP) removal (33% and 9% in the CWL and CWC unit, respectively). After phase 1 (500 mg/L influent COD) the major drawback was the absence of ...
Macromol
Active packaging with biobased polymers aim to extend the shelf life of food and to improve the e... more Active packaging with biobased polymers aim to extend the shelf life of food and to improve the environmental sustainability of the food industry. This new concept was tested with samples of fresh poultry meat wrapped with chitosan reinforced with 2.5% of commercial nanocellulose (NC) incorporating 1% of essential oils (EO) from Aloysia citrodora (ACEO) and Cymbopogon citratus (CCEO). The performance of the bionanocomposites containing EOs was assessed and compared with unwrapped meat samples and samples wrapped with chitosan/NC, during a 13 day period of refrigerated storage for several physicochemical parameters related to food deterioration and microbial growth. Wrapping the meat with the chitosan/NC polymer helped to increase the shelf life of the meat. The incorporation of EOs added extra activity to the biocomposites, further delaying the meat deterioration process, by halting the lipid oxidation and the Enterobactereaceae growth until the 9th day. The composition of both EOs ...
Journal of Biotechnology, 2005
Journal of Membrane Science, 2005
Water Science & Technology, 68(10), 2214-2219, Oct 2013
Biodegradability enhancement and detoxification of cork boiling wastewater (CBW) are required for... more Biodegradability enhancement and detoxification of cork boiling wastewater (CBW) are required for the successful implementation of biological treatment options. We studied the possibility of achieving these goals through ozonation pre-treatment by experimenting on the effect of ozone dose and pH. The CBW used had a pH of 5.81, a chemical oxygen demand (COD) of 1,865 mg L1, a biochemical oxygen demand (BOD5) of 498 mg L1 and total phenol (TP) and tannin compounds concentrations of 523 and 399 mg L1, respectively. The ozone doses ranged from 0.27 to 2.63 for the O3(applied)/COD0 ratios with samples at natural pH and set to 3.33 and 9.96. Ozonation allowed the BOD20/COD ratio (biodegradability index) to increase from 0.37 to 0.63 and a toxicity reduction from 3.08 to 1.24 TU (Microtox). The corresponding removals obtained were 15.2–62.0%, 38.4–83.2% and 56.7–92.1% for COD, TP and colour, respectively. The best outcome of ozonation pre-treatment requires O3(applied)/COD0 ratios over 1.5 and an acid pH. The increase of TP removals with ozone dose at acid pH led to biodegradability enhancement and CBW detoxification. However, for similar conditions the highest COD removals were obtained at alkaline pH due to the hydroxyl radicals’ high oxidation ability but lack of selectivity.
Bioresource Technology, 147, 143-151, Sep 2013
Cork boiling wastewater pollutants were fractionated by sequential use of four ultrafiltration me... more Cork boiling wastewater pollutants were fractionated by sequential use of four ultrafiltration membranes and five fractions were obtained: four retentates (>100, 50–100, 20–50 and 10–20 kDa) and one permeate (<10 kDa); which were used to study the correlation of molecular size with biodegradability and toxicity before and after ozonation. The results show that molecular size is correlated with organic load and restrains biodegradability. The fraction with >100 kDa corresponds to 56% of the organic load and the one with <10 kDa only 8%. The biodegradability of fractions increased 182% with fractions molecular size reduction from >100 to < 10 kDa and the chemical oxygen demand (COD) was from 3436 to 386 mg L−1. For biodegradability enhancement the best outcome of ozonation was obtained with compounds having molecular size >20 kDa and range from 5% up to 175% for applied ozone doses to COD ratios between 0.15 and 0.38.
The performance of two constructed wetlands (CWs) with horizontal subsurface flow (HSSF) configur... more The performance of two constructed wetlands (CWs) with horizontal subsurface flow (HSSF) configuration was investigated during a three phases treatment of cork boiling wastewater (CBW). The two CWs were filled with LECA. One was planted (CWP) with common reeds (Phragmites australis) and the other was kept unplanted as a control unit (CWC). The feeding CBW was sequentially diluted to 500, 600 and 750 mg/L COD and pH was set to 6.5-7.5. Other features of the feed solution were the intense dark colour, total phenols (TPh) concentration ranging from 36 to 62 mg/L and low biodegradability. Both CW units showed similar COD (44.7 and 56.6%, respectively) and TPh (40 and 65%, respectively) removal rates for a working period of 4 months. First results indicate that the presence of plants improved the system performance only in terms of total phosphorus (TP) removal (33% and 9% in the CWL and CWC unit, respectively). After phase 1 (500 mg/L influent COD) the major drawback was the absence of ...