Despite producing diversified dairy products, the dairy business produces excessive waste and by-products. As these wastes have high chemical oxygen demand levels and abundances of nutrients (fat, lactose, and protein), other possible industrial utilization must be found. Considering the definition of the efficient use of dairy wastewater in manufacturing different microbiological products such as enzymes, biofuel, polymer, biomass production, organic acid, etc., this work critically assesses the fermentation-engineering issues. To improve microbial cell activities, techno-economic studies have been performed on the viability of associated processes and the homogenization of specific microbiological products in biorefineries. Overall, it appears promising for business strategies to include dairy wastes in the specified microbial processes. The production of biogas at the facility will have a payback period (PBP) and a positive net present value (NPV) in the span of a decade, mainly when dairy wastes are digested with cow dung and/or other substrates.