Disinfection in municipal wastewater reclamation for industrial applications: a review

Abstract The growing scarcity of freshwater resources and rising industrial water demand underscore the importance of diversifying water sources, for instance through municipal wastewater reclamation, to support sustainable water management. Although reclaimed water is widely used in agriculture, its industrial application remains limited, largely due to challenges in meeting application-specific quality requirements and achieving cost-effective treatment. Disinfection is crucial to ensuring the microbiological safety of reclaimed water. Conventional methods such as chlorination, ozonation, and ultraviolet (UV) irradiation each present drawbacks, including disinfection by-product (DBP) formation, limited effectiveness against selected pathogens, microbial regrowth risk, and lack of residual protection. This paper presents a narrative review of conventional and advanced disinfection technologies for municipal wastewater reclamation with a focus on their suitability for industrial reuse. The reviewed studies were synthesized qualitatively, considering differences in wastewater matrix, treatment conditions, reported water-quality parameters, and microbial inactivation. An indicative comparison of selected literature data with World Health Organization (WHO) guidance values suggests that, while the performance of disinfection methods depends strongly on wastewater characteristics and operating conditions, advanced processes (e.g., UV/chlorination, UV/H₂O₂, and UV/O₃) may enhance microbial inactivation and help mitigate selected limitations of stand-alone treatments under specific conditions. However, their suitability should be evaluated on an application-specific basis, considering treatment-train configuration, residual protection, energy demand, capital costs, and environmental impacts. The review emphasizes the need for balanced approaches to wastewater reclamation that combine pre-treatment and disinfection while accounting for microbiological safety, chemical stability, and operational, economic, and environmental considerations relevant to industrial reuse.