Data-driven Environmental Laboratory for Technology and AnalyticsHong Kong PolyU

Research

We develop AI tools and models to understand water systems and improve how they operate. Our research spans water treatment, reuse and resource recovery, from the performance of individual processes to the energy use and emissions of entire systems. We study how to make these tools reliable in practice, alongside water technologies that can support the growing demands of AI infrastructure.

01 / Net-zero water

Multiscale modeling of water sector electrification and decarbonization

We leverage geospatial, thermodynamic and techno-economic modeling to understand the opportunities and implications of water sector electrification and decarbonization. By putting the "science of where" into the core of environmental modeling, we derive solutions that are adaptive to local conditions.

02 / Smart water

Generative and agentic AI for water, and water technology for sustainable AI

Frontier AI including large language models, chemical language models, and machine learning algorithms are changing how we interact with information. The water sector is information-rich yet slow toward adopting AI. We study how to implement trustworthy AI systems that minimize hallucination, streamline automation, and bring expert-level knowledge to every operator, engineer, and decision-maker. The nexus runs both ways: AI is a thirsty sector with ever-growing water needs, and using AI for sustainability means AI development itself should put sustainability at its core. We develop and assess technologies for securing alternative water sources that alleviate the competition between AI's water demand and existing freshwater supplies.

03 / Circular water

Water reuse, resource recovery, and unconventional water sources

Used water is a resource in the wrong place. We study de facto and planned water reuse to understand where recycled water already sustains our supplies and where it can go further, and we analyze treatment processes that recover energy and resources from wastewater instead of discarding them. Beyond reuse, we explore unconventional sources to diversify supply where conventional infrastructure falls short.

Featured study · Net-zero water

Reclaimed water for renewable hydrogen: treated water from a water resource recovery facility flows through additional treatment into an electrolyzer, renewable electricity from solar and wind powers it, and hydrogen comes out.

Environmental Science & Technology · 2024

Water resource recovery facilities empower the electrolytic hydrogen economy

Electrolytic hydrogen needs water as well as electricity. We examine where treated wastewater can meet that demand—and what it could save in freshwater use and cost.

Featured study · Smart water

Regulatory limits from the U.S., China, the EU and WHO, each drawn as a row around its true value. Answers recalled from model memory land off the limit, some by more than tenfold, most often for non-U.S. standards; once the regulation text is retrieved, nearly all answers move back onto the limit.

Environmental Science & Technology · 2026

Patterns and Mitigation of Large Language Models’ Hallucinations on Environmental Regulatory Facts

How often do language models get environmental limits wrong? Across 505 water, air and solid-waste regulatory facts, open-weight models hallucinated on 50–70% and commercial models on 7–15%, with errors concentrated on non-U.S. standards and Chinese prompts. Causal tracing located the recall of these limits in early-to-middle layers, and editing those layers could correct a limit—but often rewrote its neighbors in the same standard. Grounding answers in the regulation text was the safer route, bringing even small open-weight models close to commercial accuracy.

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Featured study · Smart water

A general-purpose language model forms the foundation. Three pillars rise from it one by one: domain perception (understanding inputs), knowledge grounding (trustworthy evidence) and action capability (safe decisions and tool use). A trust and safety roof with human oversight then settles on top, completing an ESE-LLM for environmental science and engineering.

Environmental Science & Technology · 2026

Putting Large Language Models into Environmental Context

What does a language model need to work reliably on environmental problems? Our perspective connects three capabilities—understanding environmental data, grounding answers in traceable evidence, and using tools—with evaluation, physical constraints and human oversight.

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Featured study · Circular water

Environmental Science & Technology · 2026

What reaches our drinking water?

Our work on de facto reuse traces how treated wastewater contributes to surface drinking-water supplies.