Membrane separation processes have become increasingly popular in many industries because of their ability to treat wastewater and purify water. However, one of the main problems related to the processes is organic fouling, which can significantly reduce their efficiency and cause membrane damage. This review provides a summary of the various forms of organic fouling that can occur in membrane separation methods and examines the factors that lead to their development. The article evaluates the progress made in different techniques designed to manage and reduce organic fouling, such as physical cleaning methods, chemical cleaning agents, and modifications to the membrane surface, including ultrasonic and membrane vibration methods. The review also highlights recent advances in emerging 3D printing technology to mitigate membrane fouling. Finally, the review provides a brief summary of the conclusions and future directions for research in the field of organic fouling control and mitigation in membrane separation processes.

Water pollution caused by population growth and human activities is a critical problem exacerbated by limited freshwater resources and increasing water demands. Various sectors contribute to water pollution, with the dairy industry being a significant contributor due to the high concentrations of harmful contaminants in dairy wastewater. Traditional treatment methods have been employed, but they have limitations in terms of effectiveness, cost, and environmental impact. In recent years, membrane separation technology (MST) has emerged as a promising alternative for treating dairy wastewater. Membrane processes offer efficient separation, concentration, and purification of dairy wastewater, with benefits such as reduced process steps, minimal impact on product quality, operational flexibility, and lower energy consumption. However, membrane fouling and concentration polarization present major challenges associated with this technique. Therefore, strategies have been implemented to mitigate these phenomena, including pre-treatment prior to MST, coagulation, and adsorption. Recently, 3D printing technology has gained prominence as one of the latest and most notable advancements for addressing these issues. This comprehensive review examines the drawbacks and benefits of conventional methods employed in dairy wastewater treatment and explores the utilization of membrane technology as an alternative to these approaches. Additionally, the latest technologies implemented to mitigate or alleviate the limitations of membrane technology are discussed.

The dairy industry generates large quantities of nutrient-rich by-products, particularly cheese whey, and buttermilk, which are valuable sources of bioactive proteins and phospholipids. Whey proteins exhibit notable therapeutic potential, offering various health benefits such as antihypertensive effects, immune modulation, and opioid antagonism. Similarly, buttermilk-derived phospholipids demonstrate bioactive properties, including cholesterol reduction, anti-inflammatory activity, and neuroprotective effects. This review critically assesses recent advances in protein separation techniques, comparing conventional thermal methods, known to potentially compromise protein functionality, with emerging non-thermal approaches such as high-pressure processing and membrane filtration, which enable efficient recovery while preserving bioactivity. Additionally, advanced methodologies such as multi-level processing and enzymatic hydrolysis further expand the protein separation techniques. Key technical challenges, including high mineral content in whey and the low solids concentration in buttermilk, are discussed alongside potential innovative solutions. Whey’s elevated mineral levels can reduce protein isolation efficiency and diminish the emulsifying properties of whey proteins, potentially restricting their functional applications. Meanwhile, the low total solids content in buttermilk poses challenges in achieving high protein concentration yields, requiring advanced separation techniques. Further, this review examines contemporary trends in cheese whey and buttermilk valorization, highlighting their opportunities for enhanced food applications. It also explores cross-sectoral utilization in biofuels, biodegradable materials, pharmaceuticals, and agriculture, supporting economic and sustainability goals in the dairy sector.

We investigated the effect of land use based on the dominant phytoplankton and physical-chemical variables in the different areas of the Tigris River, within the city of Mosul. Agricultural and urban activities have a significant impact on the water quality of the river. Regardless of physical and chemical variables, phytoplankton act as a bio-indicator of water quality due to their fast and sensitive response to changes in the environment. Our research was conducted in the Tigris River within the city of Mosul by examining the phytoplankton species and the physical-chemical variables at 16 sites during each vegetation period. Point and non-point source pollutants have affected the Tigris River within the city of Mosul, getting into the river from upstream through agricultural activities and by urban activities in the middle section of the city, respectively from both banks. Based on our results, we observed the highest phytoplankton abundance during the October sampling periods, while the lowest occurred during the July sampling period, which was associated with maximum water temperature and absence of rain. According to our study, land use (e.g., agricultural, and urban activities) greatly affected the dominant phytoplankton species and physical-chemical variables of the Tigris River. Oscillatoria sp. dominated all seasons in the agricultural region, while at the same time, we observed an increase in the number of phytoplankton species caused by the nutrient availability upstream on the river. The effects of climate have very significant and characteristic effects in this area, which basically determine the community of organisms and the water quality; the effects resulting from anthropogenic activity significantly modify this. Based on our investigation, in the part of the Tigris River connected to Mosul, we found a clear connection between the pollution caused and the effects of different land uses, through the examination of the algal community and physical-chemical variables in different periods of the year.

Designing turbulence promoters with optimal geometry and using them for ultrafiltration systems has been a key challenge in mitigating membrane fouling. In this study, six different turbulence promoters were created using three-dimensional printing technology and applied in dead-end ultrafiltration. Three-dimensional-printed (3DP) turbulence promoter configurations were integrated into a classical batch ultrafiltration cell. The effects of these configurations and the stirring speeds on the permeate filtration flux, organic rejections, and membrane resistances were investigated. The fouling control efficiency of the 3DP promoters was evaluated using two polyethersulfone membranes in a stirred ultrafiltration cell with model dairy wastewater. The Hermia and resistance-in-series models were studied to further investigate the membrane fouling mechanism. Of the Hermia models, the cake layer model best described the fouling in this membrane filtration system. It can be concluded that the 3DP turbulence promoters, combined with intense mechanical stirring, show great promise in terms of permeate flux enhancement and membrane fouling mitigation. Using a well-designed 3DP turbulence promoter improves the hydrodynamic flow conditions on the surface of the stirred membrane separation cells based on computational fluid dynamics modeling. Therefore, the factors effecting the fabrication of 3DP turbulence promoters are important, and further research should be devoted to revealing them.

Dairy factories annually generate an increasing amount of wastewater, which can cause eutrophication due to high concentrations of amino acids and lipids. To address this issue, membrane technology has emerged as a promising solution, but membrane fouling remains a significant challenge, since it can cause decreased flux, decrease membrane rejection performance, and increased energy demand. This study aimed to reduce membrane fouling by integrated a three-dimensional printed (3DP) turbulence promoter into an ultrafiltration dead-end cell and varying stirring speeds. Two mathematical models, Hermia and resistance-in-series, were used to analyze the fouling process. According to both models, the cake layer formation model indicated the most prevalent fouling mechanism. Specific energy demand, permeate flux, membrane rejection, and membrane reversible and irreversible resistances were measured, calculated, and compared. The results suggest that the combination of an integrated 3DP turbulence promoter and high stirring speeds can effectively reduce membrane fouling in a dairy wastewater treatment module.