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[EN] Management of wastewater is a major challenge nowadays, due to increasing water demand, growing population and more stringent regulations on water quality. Wastewaters from food conservation are especially difficult to treat, since they have high salinity and high organic matter concentration. The aim of this work is the treatment of the effluent from a table olive fermentation process (FTOP) with the aim of reusing it once the organic matter is separated. The process proposed in this work consists of the following membrane-based technologies: Ultrafiltration (UF) (UP005, Microdyn Nadir), Forward Osmosis (FO) (Osmen2521, Hydration Technology Innovation) and Nanofiltration (NF) (NF245, Dow). The FO process was implemented to reduce the salinity entering the NF process, using the FTOP as draw solution and, at the same time, to concentrate the centrate produced in the sludge treatment of a municipal wastewater treatment plant with the aim of obtaining a stream enriched in nutrients. The UF step achieved the elimination of 50% of the chemical oxygen demand of the FTOP. The UF permeate was pumped to the FO system reducing the volume of the anaerobically digested sludge centrate (ADSC) by a factor of 3 in 6.5 h. Finally, the ultrafiltrated FTOP diluted by FO was subjected to NF. The transmembrane pressure needed in the NF stage was 40% lower than that required if the ultrafiltration permeate was directly nanofiltered. By means of the integrated process, the concentration of organic matter and phenolic compounds in the FTOP decreased by 97%. Therefore, the proposed process was able to obtain a treated brine that could be reused in other processes and simultaneously to concentrate a stream, such as the ADSC., This research was funded by CDTI (Centre for Industrial and Technological Development) depending on the Spanish Ministry of Science and Innovation through the INNPRONTA program, grant number IPT-20111020.

[EN] The membrane process of ultrafiltration (UF) has been investigated as a pretreatment previous to the further recovery and concentration of phenolic compounds from residual table olives fermentation brines. Two UF membranes were tested: a permanently hydrophilic polyethersulfone (PES) membrane with a molecular weight cut-off (MWCO) of 30 kDa and a PES membrane with a MWCO of 5 kDa. Transmembrane pressure and crossflow velocity were varied from 1 to 3 bar and from 2.2 to 3.7 m s(-1), respectively. The best membrane in terms of permeate flux and selectivity was that with MWCO of 5 kDa and the best operating conditions were transmembrane pressure of 3 bar and crossflow velocity of 2.2 m s(-1). In these conditions permeate flux was 21.6 L h(-1).m(-2), while the rejection of COD and phenolic compounds were 50.0% and 21.9%, respectively and the removal of colour and turbidity was almost complete. In addition, an alkaline cleaning protocol was proposed, which was effective to restore the initial permeability of the selected membrane. (C) 2018 Elsevier Ltd. All rights reserved., The authors of this work wish to gratefully acknowledge the financial support of CDTI (Centre for Industrial Technological Development) depending on the Spanish Ministry of Science and Innovation (INNPRONTA program, ITP-20111020).

This work was supported by the Spanish Ministerio de Economia y Competitividad. (CTM2014-54546-P).

[EN] In this work, the fouling mechanisms that dominate the ultrafiltration of residual brines from table olive packing plant wastewaters were investigated. For that purpose, Hermia's models adapted to crossflow filtration, resistance-in-series model and a model combining intermediate blocking and cake formation mechanisms were fitted to the experimental data. Tests were performed with a 5 kDa polyethersulfone membrane at transmembrane pressures between 1 and 3 bar and crossflow velocities between 2.2 and 3.7 m s(-1). Results demonstrated that the resistance-in-series model was the most accurate to predict permeate flux evolution with time. The predominant fouling mechanism was cake formation followed by intermediate blocking/adsorption. The fouling resistances that were determined by means of the resistance in series model were tested using a well-established mathematical model proposed by Mondal and De that also combines both fouling phenomena (intermediate pore blocking and cake formation). Results demonstrated that the predicted resistances are consistent with those determined by Mondal and De's model. (C) 2016 Elsevier Ltd. All rights reserved., The authors of this work wish to gratefully acknowledge the financial support of CDTI (Centre for Industrial Technological Development) depending on the Spanish Ministry of Science and Innovation (INNPRONTA program, ITP-20111020).

[EN] In this work, six identical laboratory SBRs treating simulated wastewater were operated in parallel studying the effect of three food-to-microorganisms ratio (F/M ratio; 0.20, 0.35 and 0.50 kg COD¿kg MLSS-1¿d-1), two hydraulic retention times (HRT; 24 and 16 h) and two values of number of cycles per day (3 and 6). Influence of these operational parameters on the SMPs production and reactor performance, were studied. Results indicated that the highest F/M ratio, HRT and cycles/day produced 72.7% more of SMP. In a second experimental series, biological process yielding the maximal and the minimal SMPs production were replicated and both mixed liquors (ML) and treated effluents were ultrafiltrated. The flux decay in the conditions of minimum and maximum SMPs production were 52% and 72%, when the SBRs effluents were ultrafiltrated while no significant differences in the ultrafiltration of ML were found. In terms of permeability recovery, this was lower for the case of the ML (73% and 49% of initial permeability recovered for effluent and ML ultrafiltration, respectively)., This work was supported by the Spanish Ministerio de Economia y Competitividad (CTM2014-54546-P).

[EN] The fermentation brines from table olive processing (FTOP) are hypersaline effluents (conductivities higher than 75 mS·cm-1) with high organic matter concentrations (COD around 10 g·L-1), which also include phenolic compounds (between 700 and 1500 mg TY·L-1). In this work, an integrated process for the FTOP reuse as brine in the table olive processing has been evaluated. This integrated process consisted of a biological treatment followed by a membrane system, which included ultrafiltration (UF) plus nanofiltration (NF). The biological treatment was carried out by 6 L laboratory sequencing batch reactor (SBR). UF and NF were performed in laboratory plants for flat membranes of 0.0125 and 0.0072 m2, respectively. Each stream generated during the FTOP treatment (SBR effluent, and UF and NF permeates) were evaluated. The SBR eliminated around 80% of COD and 71% of total phenols concentration. In the final NF permeate the COD concentration was lower than 125 mg·L-1; while the turbidity, colour and phenolic compounds, were completely removed., The authors of this work thank the financial support of CDTI (Centre for Development Technological Industrial) depending on the Spanish Ministry of Science and Innovation.

One of the main drawbacks for the application of membranes technologies to the treatment of textile effluents is the fouling. Fouling phenomenon causes a flux decline and reduces the quality of the treated water. Previous studies have pointed at dyes that remain in the water after rinse processes, as one of the fouling agents. In this study several UF and NF membranes were tested using three synthetic reactive dyes solutions as feed streams. The influence of applied transmembrane pressure (TMP) on normalised flux, color, COD and salt retentions was studied. The extent of fouling phenomenon was evaluated in terms of filtration resistance (R s/R t ratio) and normalized flux also with TMP. The obtained results showed that R s/R t for NF and 1kDa membranes were not nearly affected by TMP, except for 10kDa one. In these cases R s/R t ratio was lower than 0.5 showing a negligible fouling phenomenon. Similar tendency was observed with the normalized flux results. For the 10kDa one, the normalized flux decreased progressively with TMP reaching a total normalized flux reduction of 60%, This work was supported by Ministerio de Asuntos Exteriores y Cooperacion of Spain (project ref: A/024821109). We also thank the technicians from the Microscope Services from UPV for their support in SEM analysis.

Tanneries wastewaters are characterized by high organic matter and salt concentrations. Beamhouse operations, in particular unhairing, are the processes that provide the most concentrated effluents concerning the organic matter. Besides, the unhairing wastewater includes a high sulphides concentration. Thus, the separated management of the unhairing effluents has been considered in the last 20 years with the aim of their recycling and reuse. Ultrafiltration was a promising technique to separate the organic matter from the chemicals (lime and sulphides) that could be reused in the unhairing process. However, the membrane fouling has avoided its application at an industrial scale. The main aims of this paper are to study the influence of the reuse of the ultrafiltration permeate on the quality of the final leather and the comparison among different types of membrane cleaning. Ultrafiltration experiments, including cleaning procedures, were carried out in a module for plane membranes with 30 cm2 of active surface. Sodium dodecyl sulphate, two different enzymes and sodium hypochlorite were used as cleaning chemicals. In addition, the module configuration with only a plane membrane let the study of the effect of providing air from the permeate side. Laboratory drums with a 5 L maximum capacity were used for the permeate reuse and further hide samples processing in order to study the final quality of the leathers. Results showed that the final quality of the leather was not modified by using ultrafiltration permeate for the unhairing process. Concerning the membrane cleaning, the best results in terms of flux recovery were achieved with 1000 mg L−1 of sodium hypochlorite (92% of flux recovery) and with the air dosing from the permeate side. Flux recovery with enzymatic cleaning hardly reached an efficiency of 35%.

Textile industries are rated as the most polluting among all industrial sectors taking into account both wastewater volume and composition. In order to be able to reuse these effluents, membrane technologies have been proven as a viable alternative. However, these technologies show some drawbacks, such as the retentate stream management and the worsening of their performance due to membrane fouling. Therefore, effluents must be pre-treated in order to prevent fouling. Membrane technologies also provide some alternatives for these pre-treatments by means of the application of ceramic ultrafiltration among others. This work studies the performance of ceramic membranes by carrying out experiments with three commercial ceramic membranes with molecular weight cut-offs (MWCO) of 30, 50 and 150 kDa, respectively. Moreover, the effect of cross-flow velocity (CFV) was studied by performing the essays at different flow velocities of 3, 4 and 5 m/s. According to the obtained results, ceramic UF membranes proved to be a feasible pre-treatment alternative. Permeate flux increased as flow velocity was increased for most of the cases, owing to the fact that the cake layer formation was limited. Furthermore, flux decline along operating time was negligible for the higher flow velocities, whereas it was noticeable for the lowest flow velocity tested. For the lowest MWCO analyzed, lower cross-flow velocities were needed in order to limit the cake layer formation and reach the steady-state. This implies that, although fouling was significant for all the three molecular weight cut-off studied, it was much more noticeable when MWCO was increased. Slightly better results in terms of permeate quality were achieved as MWCO was lower. In addition, higher chemical oxygen demand (COD) and conductivity retention coefficients were obtained for the lowest cross-flow velocity. Turbidity and color removals seemed to be more influenced by water composition than CFV, with rejections higher than 99% and between 84 and 98%, respectively.

Water scarcity makes industrial wastewater reuse necessary, especially in those industries characterized by both high water consumptions and extremely polluted effluents as textile industries. Membrane technologies are very efficient to treat industrial effluents for water reuse successfully, since their application entails important reductions in pollutant concentration. In the present work, a direct treatment of a textile industry effluent by means of a combination of ultrafiltration (UF) followed by a final nanofiltration (NF) stage is presented. Two different NF membranes were tested in order to compare their behaviors. For that, the influence of the feed water pH and transmembrane pressure (TMP) of the NF process were investigated. The UF results showed that the highest permeate fluxes were achieved at pH 11. Related to NF experiments, NF270 reached for the same operational conditions higher fluxes and salts rejection values than the Duraslick NF. No influence of pH was found for the permeate flux. However, the pH effect was manifest for the salts rejection. Although COD, color, and turbidity removals were high in all tests, Duraslick NF showed an average slightly better removal of COD and color. The results obtained confirm the viability of this treatment for water reuse in most of the different processes carried out in these kinds of industries.

Due to the water scarcity in Spain and in particular in the Mediterranean areas such as Valencian Region, water authorities have enhanced the wastewater reuse in the municipalities. Different treatments can be applied according to the aim of the wastewater reclamation. In this work different alternatives of tertiary treatment (conventional treatments and one treatment including ultrafiltration) were evaluated using two pilot plants (2 m 3 /h of capacity) located in the wastewater treatment plant of Quart-Benager in Valencia. Settling (with and without chemicals addition), conventional sand filtration, UV disinfection and ultrafiltration were the processes included in the different alternatives. Results showed that the most efficient conventional alternative consisting in settling + filtration + UV radiation and the treatment including ultrafiltration eliminated almost the 100% of the total coliforms. However COD removal was very much higher in the alternative including ultrafiltration (60%) in comparison with the other process combinations.

Due to the high conductivity of the global wastewater from a tannery industry, wastewater reuse is only possible if a reverse osmosis process is implemented in the wastewater treatment. The supernatant of a physical-chemical treatment is still very polluted, containing high COD values between 3000 mg/l and 4000 mg/l and conductivities of nearly 20 ms/cm. In this work, a combination of filtration, ultrafiltration and reverse osmosis is evaluated as treatment for the physical-chemically treated wastewater. Filtration was carried out using microfilters as a previous stage to ultrafiltration process. Ultrafiltration tests were performed in a laboratory plant. Organic membranes from Orelis with different cut-offs were tested to optimize the rejection and the permeate flux. Finally, the reverse osmosis step was carried out using an ESPA-1 membrane from Hydranautics. Results showed high COD values in ultrafiltration permeates (between 2000 and 3000 mg/l). A polyethersulfone membrane with cut-off of 30 kD was chosen for the pre-treatment of the reverse osmosis membrane. Permeate fluxes of the reverse osmosis membrane reached 40 l/(m 2 h) at 30 bar. Though membrane fouling was not observed during RO experiments, an industrial scale plant should pay special attention to a probable flux decrease due to the scaling if a high conversion is aimed.

This work is focused on the treatment of a textile plant wastewater. The industry mainly manufactures socks, stockings and panties, and the water is treated in order to be reused. The wastewater was characterized and jar-tests experiments were carried out with different coagulants and flocculants, at different concentrations and pH in order to obtain clarified water that can be treated by means of ultrafiltration (UF) or nanofiltration (NF). The combination of the physico-chemical treatment and the nanofiltration leads to a COD removal of almost 100%.

Wastewater reclamation and reuse has become one of the most important environmental issues nowadays. Thus, municipal wastewater treatment plants are being upgraded converting conventional activated sludge processes into membrane bioreactors in order to improve the quality of the treated wastewater. However, operational costs increase because of higher energy consumption and membrane fouling. Wastewater composition is one of the factors affecting membrane fouling, though its influence is difficult to describe. In this work, a study about wastewater pretreatment and filterability has been carried out in view of achieving valuable information for a further implementation of a membrane bioreactor. Experiments were performed with samples of four municipal wastewater treatment plants taken from the plant influent, the biological process influent and the plant effluent. Filterability was evaluated by membrane filtration resistances using the resistance in series model. Resistances were measured with ultrafiltration tests performed with flat membranes. Results showed that suspended solids concentration was the most influential parameter on the total membrane resistance when pretreated wastewater is filtered. No statistical correlation between the membrane resistances of biological process influent and plant effluent was found.

Ultrafiltration and nanofiltration processes were used to treat synthetic reactive dyes aqueous solutions and a raw textile effluent supplied from rinsing baths of Spanish textile industry. The influence of the reactive dyes molecular weights and the effect of the used membranes types and cut-offs were investigated with regard to the permeate flux at different transmembrane pressures (2–7 bar for UF and 4–15 bar for NF). The extent of colour retention, COD and conductivity was determined in order to monitor the membrane's separation efficiencies aiming at waste water treatment, water reuse and chemical usage minimisation. High COD retentions (80–100%) were achieved using UF and NF processes. Good conductivity rates (80%) and high COD and colour retention rates (> 90%) were obtained for both NF 200 and NF 270 membranes for all studied dyes solutions. An improvement of the rinsing wastewater quality was obtained using UF and NF processes.

Nanofiltration is a process used to separate mineral salts from lactose, having previously removed the proteins by ultrafiltration. Both proteins and lactose can be used as raw materials to prepare a variety of products. In this paper, we studied the feasibility of demineralizing sweet whey obtained from the cheese industry of the Comunidad Valenciana (Spain) using membrane technologies. The NF200 membrane showed the highest volumetric flux and solute rejection values, whereas the DS-5 DL membrane showed the lowest values. The volumetric fluxes obtained with the NF200 and DS-5 DL membranes in these experiments with the ultra-filtered whey demonstrated significant differences between membranes. Concerning solute rejection, the highest values were obtained using the NF200 membrane. The chosen parameter to evaluate the demineralization capability was solute flux. In this way, the values obtained for chloride ion were 9.90 and 32.42 g/ (m 2 ·h) for the NF200 and DS-5 DL membranes, respectively, with the highest demineralization rates being achieved with the DS-5 DL membrane.