Browsing by Author "Silva, P. C."
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- Activated Carbon Produced from Tanning Industry Residues Used to Remove Carbamazepine from WastewaterPublication . Marques, David; Freitas, Maria Madalena; Silva, P. C.According to UNESCO, emerging pollutants are posing a threat to ecosystems and human health. These compounds can be either synthetic or natural chemicals or microorganisms, that are not usually regulated, and can be found in hospital wastewater, even after conventional treatment processes. Carbamazepine is a mood stabilizing drug and an anticonvulsant. Due to its persistence, carbamazepine is one of the most frequently detected pharmaceuticals in wastewater. Though there are many methods to remove such pollutants, adsorption is one of the most effective treatments. To remove carbamazepine from solution, an activated carbon prepared from leather residues and a commercial activated carbon were used as adsorbents. The adsorption tests show that the leather residue derived activated carbons have higher specific surface area (>1500 m’/g) and higher adsorption capacity (q > 300 mgcnz/g) for carbamazepine when compared to commercial activated carbon (992 m’/g and q < 180 mgcaz/g, respectively).
- Adding Value to Tannery Fleshings Part I – Oils and Protein Hydrolysates – Production and ApplicationPublication . Bragança, I.; Crispim, Alfredo; Sampaio, A.; Ramalho, Elisa; Crispim, F.; Caetano, Nídia; Silva, P. C.The tanning industry generates a high quantity of solid wastes. Therefore, there is a need to create valorization [added value] options for these wastes. The present work had as its main objective creating added value by production of fat and hydrolyzed protein. To this end, fleshings were treated by hydrolysis with regard to the influence of various factors. The best result was found for a temperature of 60°C, 4 hours of hydrolysis, 2% of enzyme and 100% of water, with a fat extraction yield of 93%. The fat obtained through the hydrolysis process was used to produce sulphated oils. The protein hydrolysate was concentrated to about 40% of solids content and used to prepare co-products of protein hydrolysate and glutaraldehyde. Sulphated oils were applied in leather fatliquoring and the different protein hydrolysates were tested in leather retannage. The leather samples obtained were evaluated by physical-mechanical tests and the results were compared to those obtained through a standard process. The results were very satisfactory and, in some cases better than the specified standard. The process of adding value to this waste results in a double advantage for the leather industry, reducing the environmental impact and allowing production of alternative products for leather fatliquoring and retannage.