Microbial and Physicochemical Approaches in Sustainable Management of Sugar Mill Effluent

Sugar mill effluent (SME) is a major industrial pollutant characterized by high organic load, dark coloration, and elevated nutrient and metal concentrations, collectively posing risks to environmental quality and human health. Untreated SME disrupts aquatic ecosystems, degrades water quality, and alters soil physicochemical properties, ultimately impairing native microbial communities and reducing agricultural productivity. While numerous physicochemical treatment methods exist, their high cost, sludge generation, and limited sustainability have prompted growing interest in biological alternatives. In response to this issue, research has focused on sustainable microbial-based strategies for SME remediation, with particular emphasis on an under-explored yet highly promising methanotrophs as soil microbial communities. Methanotrophs offer a distinct dual-function advantage due to their metabolic versatility and broad-spectrum methane monoxygenase enzyme, enabling co-metabolic degradation of SME-derived pollutants, while simultaneously oxidizing methane, a potent greenhouse gas emitted during the anaerobic decomposition of untreated effluent discharge. Though numerous research investigations describe the role of methanotrophs in mineralization and degradation of many inorganic, organic, and hydrogenated persistent pollutants from soil, the role of soil methanotrophs community composition in degradation and detoxification of SME discharged pollutants has not been investigated so far. Therefore, it is expected that involving methanotrophs into SME discharged soil system might be a viable option to mineralize and detoxify the complex pollutants. This review outlines the application of methanotrophs to the SME polluted soils and treatment systems, as a low-cost, environmentally aligned, and eco-friendly approach to detoxify SME pollutant load that generate good soil health and long-term safe agricultural crop productivity.