Water plays an essential role in production and refining processes. Many industries that use petrochemicals also require water, especially for cleaning purposes. The wastewaters released by these processes are often rich in petroleum pollutants, which requires significant treatment prior to disposal. The presence of petroleum contaminants in rivers and oceans is a significant threat to human health, as well as to many animal species. A current challenge for most industries and conventional effluent treatment plants is compliance with accepted disposal standards for oil-polluted wastewater. Of particular importance is the processing of dispersed oil in water, as well as oil in water emulsion. Conventional oil and water separation methods for processing oil in water contamination have several technology gaps in terms of applicability and efficiency. The removal and effective processing of dispersed oil and emulsions from oily wastewater is a costly and significant problem. The objective of this paper is to provide a review of the principles associated with oil in water emulsion separation, with the aim of providing a more definitive understanding of the terminology, processes, and methodologies, which will assist the development of a more efficient, innovative and environmentally friendly process for the separation of oily wastewater.

The agricultural sector is one that requires and consumes enormous amounts of fresh water globally. Commercial wine production in particular uses large volumes of fresh water and, through various processes, generates significant quantities of wastewater. The wastewater produced by wineries typically exhibits elevated levels of chemical oxygen demand (COD), total suspended solids (TSS), an acidic pH, and varying salinity and nutrient contents. The overall characteristics of winery wastewater indicate that it is a potential environmental hazard if not processed and disposed of appropriately. Due to significant variations in wastewater contaminant levels among wineries, the implementation of a universally applicable, environmentally friendly, and sustainable waste management system seems practically unattainable. This study investigated the design, fabrication, and modification of a shear enhanced flotation separation (SEFS) pilot plant to be used as a primary treatment stage during winery wastewater processing. This technology combines the synergistic advantages of hydrodynamic shear, coagulation, flocculation, and dissolved air flotation. To date, there have been only limited publications on the feasibility and application of hydrodynamic shear and its potential to assist with coagulation/flocculation and flotation efficiencies specifically for winery wastewater treatment. The results obtained indicate that the SEFS pilot plant may well be able to process winery wastewater to a quality level where reuse of the water for irrigation of crops may be considered.

The process of wine making is well known to produce large amounts of wastewater with highly variable characteristics. The disposal of untreated winery wastewater is strictly prohibited since it adversely affects the recipient environment. Due to the variability in characteristics of winery wastewater, developing a treatment system which can handle high organic and inorganic loads, especially during the vintage season, is a complex challenge. This study investigated the theory, methodology and implementation of a wastewater treatment technology called shear enhanced flotation separation (SEFS) as a potential primary treatment stage towards the treatment of winery wastewater. Winery effluent was subjected to a coagulation process in a high shear environment, with and without the introduction of air, followed by flocculation. Upon successful optimization of operating parameters, a polymeric-based coagulant AB121 and polyelectrolyte flocculant AB796 yielded the highest reduction in turbidity (95%) with typical values of 630 NTU for the raw wastewater and 25 NTU for the SEFS-treated effluent. A substantial reduction in total suspended solids (97%) was achieved with average raw winery wastewater values of 2275 mg/L compared to the 50 mg/L obtained for the SEFS-treated effluent. Furthermore, a notable reduction (54%) in COD (from 11,250 mg/L to 5220 mg/L) using SEFS technology was achieved.