Stanford University engineers are transforming wastewater from a costly burden into a valuable resource. Their groundbreaking project, “From Wastewater to Wealth,” redefines wastewater treatment using advanced synthetic polymers known as resource-recovery resins.
Led by Eric Appel, associate professor of materials science and engineering, this work promotes sustainability and unlocks new economic opportunities by recovering essential nutrients and energy from treated water.
Let’s see how this technique works.
Addressing the Global Water Crisis
With the United Nations projecting a 40% global freshwater shortfall by 2030, Stanford’s initiative offers a timely and scalable solution. The research team designs selective ion-exchange resins that capture high-value compounds like ammonia and phosphorus while filtering out harmful pollutants. This approach supports circular economy goals and allows municipalities to turn wastewater into an asset rather than a liability.
Here is a table summarizing the most relevant and recent estimates for global wastewater volumes, compiled from various sources:
| Category | Volume | Source |
|---|---|---|
| Total global municipal wastewater produced annually | 380 billion m³ (approx.) | UNESCO WWAP, UN Water Development Report 2017 |
| Treated municipal wastewater | 20–30% of total | United Nations World Water Development Report 2017 |
| Untreated wastewater discharged | ~80% of all wastewater globally | UN-Habitat / World Bank |
| Global average water footprint | 1,240 m³ per capita per year | “Sustainability: A Comprehensive Foundation”, A.Y. & Chapagain, A.K., 2007, Water Footprints of Nations: Water Use by People as a Function of Their Consumption Pattern |
Important notes:
- 380 billion cubic meters of municipal wastewater is produced each year globally. This is roughly 10,000 cubic kilometers per decade, enough to fill 152 million Olympic swimming pools.
- Only about 20% of wastewater is currently treated to a safe level globally; 80% is discharged untreated, especially in lower-income and fast-growing urban regions.
- Wastewater production is expected to rise significantly by 2030 and 2050 due to population growth and urbanization.
- The water footprint figure includes all freshwater used in producing goods and services, but gives context to overall water use that ultimately contributes to wastewater volumes.
- Most sources focus on municipal wastewater or specific countries, with only a few providing global estimates. The figure of ~380 billion m³ annually for total or municipal wastewater is consistently cited across multiple sources. However there are data gaps. Industrial wastewater data is scarce, with only 22 countries (8% of global total) reporting treatment data, per UN Water (2024).
Stanford’s resource-recovery resins
Stanford’s resource-recovery resins function like high-precision filters. Inspired by natural biological receptors, these synthetic polymers extract useful chemicals while targeting specific pollutants such as PFAS. Eric Appel explains, “We design polymers based on organisms that naturally filter water, tailoring them to remove or recover key substances.”
The resins help wastewater treatment plants transition into Water Resource Recovery Facilities (WRRFs), where they purify water and extract fertilizer precursors. The resins integrate seamlessly with existing treatment infrastructure, reducing barriers to adoption.
Eliminating PFAS with Precision
PFAS compounds—found in nonstick cookware and textiles—persist in water systems and pose serious health risks. Stanford’s resins, engineered with tailored chemical affinities, offer a scalable method to remove these so-called “forever chemicals” from water supplies.
Interdisciplinary Innovation Accelerates Results
The project brings together experts from multiple fields. William Tarpeh, assistant professor of chemical engineering, focuses on extracting marketable compounds like ammonia. Polly Fordyce, associate professor of bioengineering and genetics, uses microfluidics to test thousands of resin formulas rapidly and cost-effectively. This team-based approach dramatically reduces the time needed to develop new, effective resins.
Environmental and Public Health Risks
While resource recovery offers clear advantages, wastewater treatment still poses environmental and health concerns. Communities near treatment plants face risks from airborne pollutants like chlorine and ammonia. Noise from equipment also threatens residents’ well-being. The World Health Organization advises keeping ambient nighttime noise below 40 decibels in residential areas.
Public acceptance remains a major hurdle, particularly for potable reuse of treated water. Cities like San Diego and Amsterdam have encountered resistance. Building public trust through clear regulations and education campaigns will be essential.
Enabling Equitable Adoption Through Policy
Robust regulatory frameworks and community-focused planning are key to scaling these innovations. Policies must support fair access, especially for low-income communities often burdened by environmental risks. Transparent communication and local partnerships can foster equitable distribution of benefits.
Unlocking Economic and Agricultural Gains
Recovered nutrients like phosphorus and ammonia boost agricultural sustainability. Treated wastewater can irrigate crops and supplement protein production through nitrogen-based animal feed. Managed correctly, these applications reduce environmental impacts and improve food security.
Energy Recovery: Promise and Barriers
Energy recovery technologies like bioelectrochemical systems (BES) can convert organic wastewater matter into electricity. However, current systems face high costs and performance limitations. Scaling these technologies will require more research and better integration with existing infrastructure.
Advancing the Circular Economy in Water Management
Stanford’s resin-based approach is a big step toward circular water systems. Instead of treating wastewater as waste, these systems recover materials, reduce emissions, and generate revenue. The initiative supports goals like carbon neutrality and energy efficiency in utility operations.
Resource-recovery resins offer a path forward. They increase treatment efficiency, lower costs, and create sustainable byproducts. With strong policy support and public engagement, these innovations could completely change global water management for decades to come.
