The presence of oil in various forms in water is considered as a threat for environment, biodiversity, aquatic life and terrestrial ecosystem and therefore, an efficient separation in an ecofriendly way needs to be carried out to conserve and restore the above stated. Conventional separation techniques such as centrifugation, gravity separation, and chemical-physical membrane separation have limitations in effectively treating stable and micro emulsified oil present in wastewater. Furthermore, the requirement of toxic chemicals by many of these methods further limits the applicability of the processes as these chemicals have detrimental effect on human and aquatic life. In addition to the above, the developed methodology must be eco-friendly and sustainable in nature for the successful implementation in the process. The current investigation is based on the development of various novel oil-water separation methodologies, including the synthesis of superhydrophobic sponge, magnetic coagulant, and electrocoagulation technique. Superhydrophobic sponge (151.1°) is designed using hexadecyltrimethoxysilane (HDTMS) and illustrates remarkable separation efficiency of 99.5% and this process is associated with high fabrication cost and moderate durability characteristics. In this case, contact angle separation time and oil concentration decide the final separation efficiency. Therefore, in the next step, magnetic coagulant was developed using natural coagulant as chitosan with impregnated ferrous ions through a one-step coprecipitation process. This approach shows an oil separation efficiency of 99.6% in the absence of detrimental characteristics such as moderate durability and high fabrication cost. Finally, electrocoagulation method employing chitosan-coated aluminium electrodes offers a chemical-free approach, achieving a promising 99.68% separation efficiency. The electrocoagulation method is controlled by process variables such as electrode spacing, applied voltage, time and oil concentration and in this case the maximum sustainability has been identified as the process allows to reuse the electrode. By using Box-Behnken factorial design methodology, the individual and interactional effect on separation efficiency have been studied separately for each process and also the mathematical behaviour of the processes has been estimated by developing different correlations. In addition to the above, the conditions for optimum response have also been identified. Finally, a comprehensive comparative study has been included to identify the pros and cons of the investigated processes with respect to literature and this indicates that separation by electrocoagulation method is the most efficient among all.