Whey separation using TiO₂-modified ultrafiltration membrane

Nowadays, the membrane filtration technique is a commonly used method for the separation of whey. The most significant limitation of membrane applications is fouling, which causes flux decline. During this work, regenerated cellulose membranes covered by TiO2-nanoparticles were investigated and applied to the separation of whey solution. Experiments were carried out in a dead-end ultrafiltration cell, and the changes in filtration parameters and the photocatalytic effects of the UV irradiated TiO2 modified membrane surface on the membrane fouling were examined. Our results showed that the water flux decreased with increasing TiO2 layer thickness, but the retention of turbidity and of COD increased. After separation, the membrane surface was cleaned by UV irradiation by means of photocatalytic oxidation. It was found that the original flux was recoverable, while the retention of the membrane decreased after cleaning

Examination of whey de-fatting by enhanced membrane filtration

The largest quantities of by-products of dairy processing originates from the cheese making. Whey proteins are used for animal feeding and human nutrition as well, for example in dry soups, infant formulas, and supplements. The fat components of the whey might impair its use. The aim of our experiments was to investigate the separation of the lipid fraction of whey. The microfiltration is said to be a gentle and energy efficient method for this task. During the measurements 0.2 μm microfiltration membranes were used and the membrane separation was enhanced by vibration, inserting static mixer and air sparging. The de-fatting efficiency, the retention of the whey components, the flux values, and the resistances in different combinations were compared in this paper

Investigation of the applicability of TiO2, BiVO4, and WO3 nanomaterials for advanced photocatalytic membranes used for oil-in-water emulsion separation

In the present study, a commercial TiO2, several BiVO(4)photocatalysts, a WO(3)nanomaterial, and their composites were used to prepare photocatalytic polyvinylidene fluoride (PVDF) ultrafilter membranes. Their photocatalytic activities and the effects of coatings on the filtration of oil-in-water emulsion (crude oil; c(oil)= 100 mg L-1) were investigated. Fluxes, filtration resistances, purification efficiencies, and fouling resistance abilities-like flux decay ratios (FDRs) and flux recovery ratios (FRRs)-were compared. The solar light-induced photocatalytic decomposition of the foulants was also investigated. WO(3)was used as a composite component to suppress the electron-hole recombination with the goal of achieving higher photocatalytic activity, but the presence of WO(3)was not beneficial concerning the filtration properties. However, the application of TiO2, one of the investigated BiVO(4)photocatalysts, and their composites was also beneficial. In the case of the neat membrane, only 87 L m(-2)h(-1)flux was measured, whereas with the most beneficial BiVO(4)coating, 464 L m(-2)h(-1)flux was achieved. Pure BiVO(4)coating was more beneficial in terms of filtration properties, whereas pure TiO(2)coating proved to be more beneficial concerning the photocatalytic regeneration of the membrane. The TiO2(80%)/BiVO4(20%) composite was estimated to be the most beneficial combination taking into account both the aspects of photocatalytic activity and filtration properties

The Possibilities of Bioenergy Production from Whey

Abstract: The wastes and the by-products of food industrial technologies are suitable for bioenergy generating because of the high organic matter content. Anaerobic digestion is the eldest technology for waste stabilization and however by controlled decomposition a high value and marketable energy source can be produced. Whey is normally used as a component of dairy products or as an additive for food product. In our work we focused on another utilization method: biogas generating from membrane separated fractions i.e.: permeate and concentrate of whey. The effect of the pH, thermal, microwave pre-treatment and their combinations on the biogas yield were investigated. Our results showed that the applied pre-treatments had significant effect on biogas production. In consequence of the hydrolysis of large molecules the biodegradability of the pre-treated whey fractions was enhanced, therefore the biogas and methane production yield increased significantly

Single and Multi-Stage Membrane Separation for Dairy Wastewater Purification

Before discharging into sewerage or living waters, dairy effluents need to be effectively treated to meet the requirements defined by the strict environmental protection regulations. In addition to the commonly used technologies such as sedimentation or oxidation, membrane separation can offer a novel solution to the problem. Although the advantages of membrane separations are remarkable, membrane fouling still often limits its industrial scale application. Module vibration can reduce membrane fouling by altering the cake layer on the surface of the membrane. In the first part of the experiment our aim was to investigate the effect of the increased membrane surface shear rate on the membrane flux, rejection and specific energy demand. The shear rate was increased by using a laboratory mode Vibratory Shear Enhanced Processing (VSEP). Furthermore, single ultrafiltration (UF) and nanofiltration (NF) with different membrane molecular weight cut offs (MWCO) were tested and the permeates were analyzed and compared. These tests revealed that vibration has a positive effect on flux, specific energy demand and rejections. In the second part of the project multi-stage separation experiments were carried out. During the multi-stage UF/NF tests, when NF of the UF permeates were done, the UF was practically a prefiltration process. By comparing these multi-stage experiments with the single NF ones, the effect of the pre-filtration was investigated. Furthermore, when NF of the UF concentrates were carried out, the aim was to process the concentrates until a much higher volume reduction ratio (VRR). These experiments showed that multi-stage separations can be successfully applied for achieving a higher VRR, thus, resulting in a concentrate with higher chemical oxygen demand (COD) in a smaller volume, which may increase the efficiency of post-treatments such as biogas production. Furthermore, these two-stage processes succeeded in producing a permeate with a lower COD value than single-step filtrations did

Modeling of membrane separation and applying combined operations at biosystems

The importance of the treatment of water and wastewater has been steadily increasing because of the ever greater demands to eliminate environmental pollution. Pressure-driven membrane separation processes, including ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO), have been widely used in water and wastewater treatment and are applied on an industrial scale worldwide. The aim of our paper is to introduce the results of our research team on this field. The main research area within the membrane separation was the reduction of resistances. The effect of ozonation, vibration and application of dolly particles were examined in our scientific works

Concentration of meat processing industry wastewater by reverse osmosis and anaerobic digestion of the concentrate

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