A Nine-Year Water Project Just Won China's Top Civil-Engineering Prize
A Nine-Year Water Project Just Won China's Top Civil-Engineering Prize
A nine-year water-recycling project in Yantai, China, has won one of the country's highest engineering honors after turning wastewater, sludge and energy recovery into an integrated circular system.
The Taozi Bay Wastewater, Reclaimed Water and Sludge Circular Economy Demonstration Project, led by Wanhua Chemical, received the 21st China Civil Engineering Zhan Tianyou Award in September 2026. The award recognizes major projects for engineering quality, technological innovation and broader social benefits.
From Wastewater to a Circular Resource System
Rather than treating wastewater as an end-of-pipe waste stream, the project has developed an integrated system linking:
Wastewater treatment
Reclaimed-water production
Sludge resource recovery
Biogas power generation
Solar power
Wastewater-source heat pumps
Advanced membrane treatment
The resulting system is designed around a circular chain of “wastewater–reclaimed water–sludge–resources.”
47 Million Liters of Wastewater Every Hour
The overall Taozi Bay wastewater system has a treatment capacity of approximately 470,000 cubic meters per day.
That is equivalent to roughly 47 million liters of wastewater being treated every day, making the project one of the major municipal water-recycling systems serving Yantai and its industrial economy.
The project has evolved over several decades. The Taozi Bay wastewater treatment plant dates back to 1987, with successive expansion and upgrading projects gradually increasing treatment standards and adding advanced water-reuse capabilities.
Its development has included early biological nutrient removal, a large semi-underground membrane bioreactor facility and later systems designed to enable extensive reuse of treated wastewater.
Reclaimed Water Becomes an Industrial Feedstock
One of the project's most important features is its ability to convert municipal wastewater into industrial water.
High-quality reclaimed water is transported through a dedicated pipeline network to the Wanhua Industrial Park, where it serves industrial users that would otherwise require freshwater resources.
The reclaimed-water system has a production capacity of approximately 200,000 cubic meters per day, while the associated pipeline network extends for tens of kilometers.
This approach effectively creates a second water source for industry and reduces pressure on conventional freshwater supplies.
Yantai authorities reported that the reclaimed-water system could save more than 70 million tonnes of freshwater annually when operating at full utilization.
Advanced Membrane Technology at the Core
Membrane technology is a major component of the project's water-reuse system.
Wanhua Chemical supplied ultrafiltration and reverse-osmosis membrane products and solutions, with more than 10,000 membrane units deployed in the reclaimed-water system.
According to the China Membrane Industry Association, Wanhua's reinforced anti-fouling reverse-osmosis membranes achieve stable desalination performance, while its tubular ultrafiltration membranes provide the pretreatment required for reverse osmosis.
The combination of membrane filtration and reverse osmosis allows treated municipal wastewater to be converted into higher-quality water suitable for industrial applications.
Sludge Is Turned Into Energy
The circular model extends beyond water.
The project also uses sludge fermentation and biogas generation to recover energy from wastewater-treatment residues.
Biogas generated from sludge digestion is used for power generation, while photovoltaic installations provide additional renewable electricity. The facility also incorporates wastewater-source heat pumps for heating applications.
The combination creates a multi-energy system in which wastewater treatment, sludge management and renewable-energy production are connected rather than operated as separate processes.
More Than 56,000 Tonnes of CO₂ Emissions Avoided
According to Wanhua Chemical, the project reduces approximately 56,620.75 tonnes of CO₂ emissions annually through its combination of resource recovery and energy-efficiency measures.
The project also uses photovoltaic generation and wastewater-source heat-pump technology to reduce reliance on conventional energy sources.
The reported emissions reduction demonstrates how wastewater infrastructure can contribute to industrial decarbonization when water recovery is combined with energy recovery.
A Major Water Source for Wanhua's Industrial Operations
The project has particular importance for Wanhua Chemical because reclaimed water is supplied to its nearby industrial operations.
Wanhua operates one of the world's major MDI production bases in Yantai, making reliable industrial water supply strategically important for the company's manufacturing activities.
By replacing part of the industry's conventional freshwater demand with treated municipal wastewater, the system links urban water management directly with industrial resource security.
This model can be particularly valuable in regions where industrial expansion and limited freshwater availability create competing demands for water resources.
Why the Zhan Tianyou Award Matters
The China Civil Engineering Zhan Tianyou Award was established in 1999 by the China Civil Engineering Society and the Beijing Zhan Tianyou Development Foundation for Science and Technology.
It is regarded as China's highest honor for technological innovation in civil engineering, with projects evaluated on engineering quality, scientific and technological innovation and overall benefits.
The Taozi Bay project's recognition places wastewater recycling and resource recovery alongside major infrastructure projects recognized in the 21st edition of the award.
A Nine-Year Engineering Effort
Wanhua describes the latest development as the result of nine years of dedicated construction and technical optimization, involving 11 interconnected sub-projects.
During development, the project team continuously upgraded treatment processes and introduced new approaches to water and resource recovery.
The result is not simply a larger wastewater treatment plant. It is an integrated infrastructure system designed to recover water, energy and materials from municipal wastewater streams.
The Model Could Be Replicated in Other Industrial Cities
The Taozi Bay project demonstrates a model that could become increasingly relevant for industrial cities facing both water shortages and pressure to reduce emissions.
Instead of expanding freshwater supply alone, cities can use advanced treatment, membrane separation, reclaimed-water networks, sludge digestion and renewable energy to extract additional value from existing wastewater flows.
For industrial parks, the approach can also provide a more resilient source of process water while reducing the environmental burden associated with wastewater discharge.
The project therefore sits at the intersection of water security, industrial sustainability, circular economy development and low-carbon infrastructure.
Sources:
Activated Carbon (Powder) - China
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