Recuperación de polifenoles de aguas residuales del procesado de aceituna de mesa mediante membranas
[EN] Wastewaters generated in the industrial processes of the food sector present high pollutant loads and not all are treated. One example are the wastewaters from the production of table olives, which are characterised by their high salinity and high concentration of organic matter and phenolic co...
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| Format: | master thesis |
| Publication Date: | 2017 |
| Country: | España |
| Institution: | Universitat Politècnica de València (UPV) |
| Repository: | RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia |
| Language: | Spanish |
| OAI Identifier: | oai:riunet.upv.es:10251/89644 |
| Online Access: | https://riunet.upv.es/handle/10251/89644 |
| Access Level: | Open access |
| Keyword: | Nanofiltración Ultrafiltración Polifenoles Aguas residuales Aceitunas de mesa INGENIERIA QUIMICA Máster Universitario en Seguridad Industrial y Medio Ambiente-Màster Universitari en Seguretat Industrial i Medi Ambient |
| Summary: | [EN] Wastewaters generated in the industrial processes of the food sector present high pollutant loads and not all are treated. One example are the wastewaters from the production of table olives, which are characterised by their high salinity and high concentration of organic matter and phenolic compounds. These phenolic compounds present a problem when treating this type of water in a conventional treatment plant due to their phytotoxic character and, on the other hand, they have a characteristic that makes them very valuable, outstanding antioxidant properties, which is of great interest to the cosmetic, pharmaceutical and food industries. This work is focused on the recovery of these phenolic compounds present in the residual brine from the fermentation process of table olives, by the joint use of two membrane processes, ultrafiltration (UF) and nanofiltration (NF) to obtain a permeate low in organic load and salts, but enriched in these antioxidant compounds. All the assays were carried out at laboratory scale as a starting research point for future industrial implementation. Four assays were proposed, two using UF+NF process, being the UF permeate the NF feed, where the UF assays were performed with a membrane (UP005) and operating conditions considered as optimal after previous tests. For the NF tests, two membranes with different characteristics were compared, M1, with hollow fiber configuration (PENTAIR HFW1000) and M2 with flat configuration (NF245). The NF assays were performed varying two parameters: crossflow velocity and transmembrane pressure (0.5, 1.0, 1.5 m-1 and 1.0, 1.5, 2 bar for M1 and 0.5, 0.75; 1.0 m·s-1 and 5, 10, 15 bar for M2), to evaluate how these parameters affect permeate flux, membrane fouling and phenolic compounds recovery. The third group of tests was performed with concentration of the feed solution. These tests were performed with the membrane and operating conditions that presented the best results in the previous tests. Thus, the effect of the volume reduction factor (VRF) on the permeate flux and polyphenols recovery was evaluated. The fourth test was performed without the previous UF process, evaluating the behaviour of the M1 membrane when it is directly fed with the residual brine, because of the molecular weight cut-off of this membrane (1000Da) is intermediate between a UF and a NF membrane. The results showed that the UF membrane almost completely eliminated the The results showed that the UF membrane almost completely eliminated the turbidity and suspended solids of the residual brine. The NF membrane M1 presented 8 low rejection towards the COD, salts and phenolic compounds, whereas M2 showed a great capacity to reduce the concentration of COD and salts, and at the same time to enrich the permeate stream in phenolic compounds. The best operating conditions in the nanofiltration step, in terms of permeate flux, COD removal and recovery of phenolic compounds, were obtained with the NF245 membrane at 10 bar and 0.75 m·s-1 . The assays with the M1 membrane without the UF process as pretreatment showed a similar behaviour to the assays performed with the UF membrane, obtaining similar final concentrations in the permeate, so its characteristics are close to a UF membrane type. |
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