Hypersaline organic wastewater treatment: Biotechnological advances and engineering challenges

The sustainable treatment of hypersaline organic wastewater (HSOW) remains a significant challenge in industrial wastewater management, as conventional approaches often fail to meet stringent discharge standards and low-carbon sustainability targets. Halotolerant and halophilic microbial strains offer promising solutions, yet their application is hindered by limited stress resistance, thus hindering effective treatment and achieving near-zero liquid discharge. In this review, we systematically examine endogenous strategies, such as microbial mutualism and genetic engineering, alongside exogenous approaches, including functional materials, electrical and magnetic stimulation, and 3D bioprinting, to improve microbial resilience in hypersaline environments. Furthermore, we propose an integrated treatment framework that combines physicochemical and biochemical processes, leveraging biological detoxification and biological desalination to enhance the treatment of HSOW while minimizing environmental impact and carbon emissions. By advancing the understanding of microbial stress adaptation and optimization strategies, this review provides critical insights into the development of sustainable, low-carbon wastewater treatment solutions.