Current advances and future outlook on pretreatment techniques to enhance biosolids disintegration and anaerobic digestion: A critical review.

Waste activated sludge (biosolids) treatment is intensely a major problem around the globe. Anaerobic treatment is indeed a fundamental and most popular approach to convert organic wastes into bioenergy, which could be used as a carbon-neutral renewable and clean energy thus eradicating pathogens and eliminating odor. Due to the sheer intricate biosolid matrix (such as exopolymeric substances) and rigid cell structure, hydrolysis becomes a rate-limiting phase. Numerous different pretreatment strategies were proposed to hasten this rate-limiting hydrolysis and enhance the productivity of anaerobic digestion. This study discusses an overview of previous scientific advances in pretreatment options for enhancing biogas production. In addition, the limitations addressed along with the effects of inhibitors in biosolids towards biogas production and strategies to overcome discussed. This review elaborated the cost analysis of various pretreatment methods towards the scale-up process. This review abridges the existing research on augmenting AD efficacy by recognizing the associated knowledge gaps and suggesting future research. [Display omitted] • Biosolids (Waste activated sludge) is a significant resource for biogas generation. • Various pretreatment strategies were adopted to improve rate limiting step (hydrolysis). • Pretreatment of biosolids reduces the expenditure of digestion process. • Existence of the inhibitors in the biosolids affect the pretreatment efficiency. • Not all the pretreatment approaches are implemented in large scale. [ABSTRACT FROM AUTHOR]