Xuan-Thanh Bui

Water is intrinsically entwined with multiple elements such as energy, food, resource (otherwise waste), greenhouse gas emissions, ecosystem, and land system, which make these complex interdependencies challengeable to manage at different regions and scales. This roadmap charts actionable pathways toward water-positive, waste-zero, and net-zero–aligned water resource management by treating water services as a coupled water–energy–waste–carbon system rather than a stand-alone infrastructure sector. It synthesizes current status, binding constraints, and deployment-ready interventions across treatment, reuse, resource recovery, agriculture, watershed management, and digital decision-support, with attention to technology readiness, institutional capacity, and regional feasibility. The roadmap emphasizes that many failures in water sustainability are not primarily technical but arise from governance, incentives, legitimacy, and data quality, and therefore integrates social-science insights on public acceptance, equity, and workforce development alongside engineering solutions. To move beyond aspirational recommendations, it proposes an auditable measurement framework, minimum indicators for water efficiency and security, energy intensity, greenhouse-gas emissions, materials circularity, and service equity, and outlines a phased implementation pathway (near-, mid-, and long-term) with stakeholder responsibilities and monitoring, reporting, and verification requirements. It also highlights cross-sector risks and trade-offs, including climate-driven volatility, emerging contaminants, cybersecurity, and the potential for burden shifting between water and energy decarbonization. By providing a systems-oriented structure for prioritization, scenario evaluation, and accountable deployment, this roadmap is intended to support policymakers, utilities, basin authorities, financiers, and researchers in designing credible, context-specific strategies that deliver resilient water services while advancing circular economy and climate goals.

Canal pollution poses a persistent environmental challenge in Ho Chi Minh City (HCMC), Vietnam, requiring innovative and sustainable restoration approaches. This study examined residents’ perceptions of the structure, functions, and benefits of Floating Treatment Wetlands (FTWs)—a nature‐based solution implemented in the Hang Bang Canal to enhance water quality and urban landscapes. Data were collected from a survey of 202 residents and visitors between March and April 2024 using questionnaires that assessed demographics, perceptions of canal pollution, and evaluations of FTWs. Results indicated that most participants were aware of the FTW system through direct observation, with 36.6% visiting the site daily. The majority (86.6%) appreciated its landscape function, and 61.9% recognized its role in water filtration. Plants were the most favored component (78.7%), followed by environmentally friendly materials such as bamboo (58.7%). Furthermore, 80.2% identified landscaping and 64.3% identified improved water quality as the main benefits of FTWs, while 17.8% expressed concern about mosquito breeding. Awareness of canal pollution was higher among younger and more educated respondents. Overall, 82.2% were willing to recommend FTWs, and 62.4% showed interest in participating in their management—mainly through garbage collection (87.3%). Logistic regression analysis confirmed associations between awareness and demographic factors, including age, education, and occupation. The findings highlight FTWs’ potential for urban water restoration and underscore the importance of integrating community education and participation to enhance public support and ensure long‐term sustainability.

In the context of rapid urbanization and increasing demand for decentralized wastewater treatment, membrane-based technologies offer high effluent quality with a reduced footprint. Direct microfiltration (DMF) is a promising approach for simplified wastewater treatment. In this study, a lab-scale DMF system was operated for 65 h at an initial flux of 20 LMH to evaluate membrane fouling behavior with actual sewage. The results showed that the trans-membrane pressure (TMP) followed a typical three-stage fouling pattern, with a TMP jump between hours 10 and 15 at a fouling rate of 16 kPa/hour, sharply reducing permeate flux. Analysis of fouling resistance revealed that cake resistance (Rc) accounted for 94% of the total resistance, while membrane (Rm) and irreversible fouling (Rf) contributed only 2% and 4%, respectively, highlighting the dominant role of cake formation. These findings suggest that DMF systems are feasible for municipal sewage treatment at fluxes around 20 LMH. Finally, mitigation strategies such as backflushing, pretreatment and chemical cleaning to control early-stage fouling should be further investigated.

This study advances circular nutrient management by using FBHC technology to co-recover PO ₄ ³⁻ and NH ₄ ⁺ from swine wastewater, minimizing eutrophication risks and generating reusable high-purity struvite fertilizer.