In a global context marked by the climate crisis, accelerated urban growth, and the scarcity of water resources, the Tianjin Xianda 150,000-ton-per-day Seawater Desalination Project emerges as a visionary response to one of the most pressing challenges of the 21st century: ensuring safe and sustainable water in regions where every drop counts. Today, more than 3 billion people live under severe water stress, and projections estimate that by 2030, global water demand will exceed supply by 40%. In this scenario, northern China, one of the world’s most affected areas by structural water scarcity, requires bold solutions capable of combining innovation, efficiency, and climate resilience.
Located in the Nangang Industrial Zone, Tianjin, the Xianda project represents a technological and strategic leap forward in the water economy. With an investment of 4.9 billion yuan and a footprint of 330,000 m², the plant applies a dual-membrane system combining dissolved air flotation, ultrafiltration, and double-pass reverse osmosis (SWRO–BWRO), capable of converting seawater into 150,000 m³ of high-quality industrial water per day. This capacity equals the annual consumption of more than 600,000 residents or 40% of the industrial needs of the area. Its energy efficiency, less than 2 kWh/m³, and integration of photovoltaic solar energy reduce its carbon footprint, positioning the project as a model of sustainable desalination.
More than infrastructure, Tianjin Xianda symbolizes a structural transformation: it replaces 50 million tons of surface water annually, freeing natural sources for ecological and urban uses. Operated under a BOO (Build–Own–Operate) model with a 50-year lifespan, it integrates the principles of additionality, traceability, and intentionality of the Water Positive framework, generating measurable and verifiable Volumetric Water Benefits (VWB). In partnership with technological actors, water authorities, and environmental verifiers, this project not only produces water but also redefines how a nation manages resilience in the face of climate change, driving a new generation of water solutions for the future.
Northern China suffers from a structural water deficit, with less than 200 m³ of freshwater available per person per year, placing the region at a critical scarcity level. Tianjin’s rapid industrial development has multiplied demand, causing a sustained imbalance between supply and consumption that threatens both local ecosystems and economic stability. Against this backdrop, the Tianjin Xianda Desalination Project emerges as a strategic solution, transforming seawater into a clean, safe, and permanent industrial resource.
The plant, located in the Nangang Industrial Zone, converts 150,000 m³ of seawater per day, equivalent to the consumption of more than 600,000 people, into treated industrial water through a dual-membrane system with dissolved air flotation, ultrafiltration, and double-pass reverse osmosis (SWRO–BWRO). This process not only guarantees quality and continuity of supply but also avoids the extraction of 50 million tons of surface water annually, reducing pressure on reservoirs and aquifers. Immediate benefits include reduced emissions thanks to solar energy use and heat recovery, improved regional water resilience, and the replacement of pollutive sources with a sustainable one.
The initiative is made possible through coordination between Xianda (Tianjin) Seawater Resources Development Co., Ltd. as developer and operator under a BOO model, along with technological partners and environmental agencies ensuring operational control, traceability, and external validation. This model demonstrates that next-generation desalination can be economically profitable, environmentally safe, and socially necessary. Its replicable nature allows adaptation to other coastal areas facing structural water deficits, consolidating a new era of Water Positive solutions.
Action is urgent. Each year of delay increases northern China’s water deficit and aggravates risks for industry, cities, and ecosystems. Companies with ambitious ESG goals, particularly in the energy, manufacturing, and infrastructure sectors, will find in this model an opportunity to lead the transition toward water-sustainable operations. Beyond regulatory and reputational compliance, investing in projects like Tianjin Xianda means gaining visibility, competitive differentiation, and credibility under global sustainability frameworks such as VWBA 2.0 and NPWI.
The proposed technical solution combines high-efficiency physico-chemical and membrane processes, developed under a hybrid approach that integrates gray infrastructure with digital control systems. The project’s operational core relies on a sequential treatment line beginning with dissolved air flotation (DAF) to remove solids and oils, followed by ultrafiltration and double-pass reverse osmosis (SWRO–BWRO). This modular design ensures a capacity of 150,000 m³/day, achieving purity levels that meet international standards for industrial water. After evaluating alternatives such as multi-stage flash (MSF) thermal desalination and hybrid nanofiltration systems, this configuration was chosen for its lower energy consumption, operational flexibility, and compatibility with renewable energy, achieving a 15% reduction in energy demand compared to conventional systems.
Strategically, this technology addresses a dual challenge: alleviating the structural water deficit in northern China and ensuring stable industrial supply under increasing climatic variability. The system is fully traceable through IoT sensors and SCADA control, allowing real-time adjustment of pressures, flows, and energy use, ensuring consistent performance even under temperature or salinity variations. The solution is classified as hybrid, combining gray (physical infrastructure and membranes) and digital technologies for predictive monitoring.
Expected benefits are multiple and quantifiable. The project generates 50 million tons of water annually, directly substituting surface withdrawals and contributing to the regeneration of the Bohai basin. Simultaneously, it reduces approximately 35,000 tons of CO₂ per year thanks to solar integration and heat recovery. Socially, it guarantees stability for more than 600,000 indirectly benefited residents and fosters specialized technical employment. Economically, it provides operational resilience, reduces extraction and maintenance costs, and enhances competitiveness across industrial sectors.
Operational risks include potential membrane failure, fluctuations in seawater quality, storm-related impacts, and possible saline intrusion in intake areas. To mitigate these, redundancies are implemented in pumping and filtration lines, along with early fouling detection sensors, automated cleaning protocols, and backup power systems. Shared governance among the operator, environmental authorities, and local research institutes ensures rapid contingency response and continuous quality control. Emergency plans have been defined to prevent contamination or supply interruption, supported by predictive maintenance protocols and seasonal hydrological modeling ensuring resilience to climate variability.
Regarding scalability, the model can be replicated in other coastal areas with similar water stress, such as Hebei, Shandong, or Jiangsu, or in industrial parks with high water demand. It requires controlled discharge regulatory frameworks, renewable energy availability, and technical-environmental governance. With a production cost competitive against other supply alternatives (0.55 USD/m³) and digital traceability, it stands as an adaptable solution for global contexts. Public-private partnerships, academic collaboration, and regulatory cooperation strengthen its expansion potential within China’s Water Positive strategy, ensuring additionality, traceability, and intentionality for every cubic meter produced.
The project is implemented under a phased and adaptive approach, structured in five technical stages ensuring precision in execution and complete traceability of results. The first phase develops the environmental and hydrological diagnosis of the intake and discharge areas, incorporating flow modeling, energy simulations, and marine impact studies. This stage establishes the technical baseline, volume, salinity, physico-chemical parameters, and water quality, through on-site monitoring, remote sensing, and certified laboratory analyses. The data define VWBA and WQBA indicators to measure future system performance.
The second phase, detailed design, defines treatment processes, hydraulic sizing, energy balance, and control schemes. The selected technology, dissolved air flotation (DAF), ultrafiltration, double-pass reverse osmosis (SWRO–BWRO), and energy recovery through pressure exchangers, was chosen over other options for efficiency, operational stability, and solar compatibility. This stage integrates control and monitoring instruments: electromagnetic flow meters, multiparameter probes for pH, turbidity, and conductivity, IoT pressure sensors, and a SCADA system for remote control and data storage.
The third phase covers construction and installation of infrastructure: civil works, membrane mounting, high-pressure pumps, photovoltaic systems, and auxiliary electrical networks. It is scheduled for 18 months, with mid-term validation by external supervisors. Nominal capacity reaches 150,000 m³/day with a 45% recovery rate and energy efficiency below 2 kWh/m³. Redundant pumping and filtration systems guarantee operational continuity even during maintenance.
The fourth phase includes commissioning and validation, during which sensors are calibrated, pressures adjusted, and hydraulic and water quality tests conducted. Lasting 4–6 months, this phase validates performance, permeate quality, and energy stability. Data are compared to the baseline to determine actual improvement in water availability and quality.
The fifth phase encompasses continuous operation, monitoring, and ongoing improvement. KPIs include volume produced, energy efficiency (kWh/m³), recovery rate, permeate conductivity, avoided CO₂ emissions, and operational resilience. Indicators are automatically logged in the SCADA/IoT platform and reported quarterly to authorities and external verifiers under VWBA 2.0 and NPWI standards. Deviation alarms trigger automatic responses and operator notifications. Digital traceability is complemented by annual physical audits and certified blockchain reports.
Governance assigns distinct responsibilities: Xianda (Tianjin) Seawater Resources Development Co., Ltd. acts as the technical operator, while local water authorities oversee compliance and external verifiers validate water and energy benefits. A data-driven preventive and predictive maintenance plan includes membrane inspection, sensor calibration, and marine diffuser cleaning. Operational decisions follow a shared governance model between the company, environmental authority, and technical community.
Continuous improvement operates through a digital feedback system comparing the with-project and without-project scenarios, allowing process optimization and technological updates according to basin and climate evolution. VWBA/WQBA monitoring mechanisms quantify regenerated water, recovered energy, and pollutants removed, ensuring additionality, intentionality, and long-term benefit permanence. This implementation model ensures not only technical efficiency but also long-term operational and environmental sustainability, establishing an adaptable, replicable infrastructure expandable to 300,000 m³/day as industrial demand grows.
The Tianjin Xianda Seawater Desalination Project represents a strategic milestone in China’s water transition toward a resilient water economy. Through advanced membrane technologies, efficient energy management, and byproduct valorization, it redefines the paradigm of sustainable industrial water production. Its relevance lies in offering an additional, traceable solution to northern China’s water stress, ensuring secure industrial supply without compromising natural sources.
Strategically, this model adds value to China’s national Water Positive roadmap, establishing a replicable framework for other coastal regions. Its impact is measured not only in volumetric terms (50 million m³/year of substituted natural water) but also in environmental and economic sustainability. With a 50-year operational life, full traceability, and minimal environmental footprint, the project stands as a reference for smart, scalable water infrastructure aligned with VWBA 2.0 principles.
The Tianjin Xianda Seawater Desalination Project is a high-impact, comprehensive intervention designed to transform seawater into a sustainable industrial resource. The main intervention is based on a double-pass reverse osmosis (SWRO–BWRO) membrane desalination system, complemented by dissolved air flotation (DAF) and ultrafiltration, forming a complete treatment line that guarantees permeate purity above 99.7%. The facility covers 330,000 m² and has a treatment capacity of 150,000 m³/day, equivalent to 50 million tons of regenerated water annually. The process is supported by renewable energy through an integrated photovoltaic system and heat recovery, reducing energy demand to less than 2 kWh/m³. It complies with ISO 14046 standards, national discharge regulations, WHO industrial water guidelines, and European sustainability frameworks (Directive 2000/60/EC and Regulation 2020/741 on water reuse).
This solution gains relevance amid northern China’s structural scarcity and aquifer overexploitation. The project replaces continental extractions with treated seawater, freeing natural sources and reducing saline intrusion risk. Compared to the baseline marked by chronic deficit and high climatic vulnerability, Tianjin Xianda introduces a stable, energy-efficient, and environmentally neutral water supply. Its pertinence lies in guaranteeing water resilience, reducing pressure on reservoirs, and providing a secure source for critical industries.
Expected results are measurable and multidimensional. In terms of volume, 50 million m³/year of desalinated water are generated, avoiding continental consumption. Water quality improves by eliminating suspended solids, oils, metals, and salts to optimal industrial levels. Environmentally, 35,000 tons of CO₂/year are avoided, and flows in reservoirs and aquifers are regenerated. Socially, the project ensures supply continuity, creates specialized technical employment, and strengthens water security for more than 600,000 people.
From a strategic and commercial perspective, Tianjin Xianda aligns with China’s Water Positive roadmap, serving as a sustainable infrastructure reference under VWBA 2.0 principles of additionality, traceability, and intentionality. Its implementation enhances ESG compliance by improving corporate reputation, ensuring social license to operate, and providing tangible climate mitigation evidence. This model allows industries with SBTi, NPWI, or ESRS E3 targets to integrate verifiable water benefits into sustainability reports and value chains.
The project is fully replicable and scalable across other coastal basins such as Shandong, Jiangsu, or Hebei, where scarcity and industrial growth demand low-impact, high-efficiency solutions. Replicability relies on technical modularity, digital traceability, and adaptability to varying
