International evolution of fat, oil and grease (FOG) waste management - A review

In recent years, issues relating to fat, oil and grease (FOG) in sewer systems have intensified. In the media, sewer blockages caused by FOG waste deposits, commonly referred to as 'fatbergs', are becoming a reminder of the problems that FOG waste can cause when left untreated. These FOG blockages lead to sanitary sewer overflows, property flooding and contamination of water bodies with sewage. Despite these financial and environmentally detrimental effects, a homogenous FOG waste management method has not been developed internationally.  However, some successful enduring FOG management programmes have been established, such as in Dublin city and in Scandinavian countries. The aim of this paper is to carry out a review on existing FOG research and management approaches. FOG management involves comprehending: (1) FOG deposition factors in the sewer, (2) FOG prevention and awareness tactics undertaken internationally and (3) potential utilisation methods for FOG waste. This review will highlight that preventing FOG from entering the sewer is the most common approach, often through simple awareness campaigns. The diverted FOG is rarely valorised to bioenergy or biomaterials, despite its potential. Thus, all facets of the FOG waste lifecycle must be identified and managed. Advancements in processes and techniques must be assessed to best determine the future evolution of FOG waste management to assist in achieving a sustainable urban environment.