Yuxiang Fang and his team at East China Normal University have just published a critical review that could reshape how the water industry—and energy sector—tackle one of the most insidious challenges of our time: the invisible war against emerging biological contaminants in wastewater. Their findings, published in *Energy & Environmental Protection*, don’t just describe a problem—they map the frontlines of a growing crisis that threatens both public health and industrial sustainability.
Emerging biological contaminants—pathogenic bacteria, antibiotic-resistant bacteria (ARB), antibiotic resistance genes (ARGs), and viruses—are not your typical pollutants. Unlike chemical contaminants that degrade over time, these agents can replicate, mutate, and spread genetic resistance. Fang explains, “These contaminants don’t just persist—they evolve. And wastewater treatment plants, which are designed to remove organic matter and nutrients, are now becoming reservoirs for these invisible threats.” The implications are far-reaching: treated effluent released back into rivers or reused in agriculture may still carry viable pathogens or resistance genes, potentially seeding new outbreaks or accelerating the global spread of antimicrobial resistance.
The review systematically evaluates how conventional and advanced wastewater treatment processes perform against these threats. Fang and his team found that traditional secondary biological processes—like oxidation ditches and A/A/O systems—can reduce microbial loads by 2 to 5 logs through biodegradation and sludge adsorption. But here’s the catch: resistant genes and viruses often survive. “We’re treating the symptoms,” Fang notes, “but not the genetic footprint of resistance.” That means even after treatment, effluent can still contain ARGs capable of being taken up by other bacteria downstream—a process known as horizontal gene transfer.
Membrane technologies offer a stronger shield, physically blocking resistant bacteria and intracellular ARGs. However, they fall short against extracellular ARGs and tiny viruses like adenoviruses or noroviruses, which slip through even nanofiltration. Fang emphasizes the physical limitation: “Membranes act like sieves, but genes and viruses can be slippery. They pass through or remain intact unless inactivated.”
Enter advanced oxidation processes (AOPs)—chemical and photochemical treatments that generate reactive oxygen species to attack DNA and viral structures. AOPs can achieve 5 to 7 log inactivation of pathogens and ARB, degrade ARGs by 2 to 8 logs, and reduce viruses by 2 to 4 logs. But there’s a trade-off: high operational costs and instability under varying water conditions. “AOPs are powerful,” says Fang, “but they’re not a silver bullet. They require precise control, energy input, and careful integration into existing infrastructure.”
The energy sector should take note. Wastewater treatment plants are energy-intensive, and retrofitting them with advanced oxidation or membrane systems could significantly increase electricity demand. Yet, failing to adapt could lead to higher public health risks, regulatory penalties, and reputational damage. Fang suggests that future-proofing wastewater infrastructure will require “multi-barrier strategies”—layered defenses combining biological, physical, and chemical treatments tailored to local contaminant profiles.
He also points to a growing need for smart monitoring. “We’re flying blind without real-time data,” Fang argues. He envisions a future where online biosensors and machine learning models predict contaminant spikes, enabling plants to adjust operations dynamically. “Digital twins and AI-driven control aren’t just futuristic—they’re necessary,” he says. “The influent is changing. Selective pressures from antibiotics and heavy metals are shifting. We need systems that can adapt in real time.”
For energy companies involved in water reuse, desalination, or district heating, this research signals a shift in priorities. Investing in resilient, data-driven wastewater treatment isn’t just about compliance—it’s about safeguarding water supplies, protecting ecosystems, and securing long-term operational licenses. As Fang’s review makes clear, the cost of inaction could far outweigh the price of innovation.
Published in *Energy & Environmental Protection* (translated from *能源环境保护*), this work doesn’t just advance science—it challenges industries to rethink how they manage water as a shared resource in an era of rising biological threats. The next generation of wastewater treatment won’t be judged solely on how clean the effluent is, but on how well it prevents the next pandemic from spreading through our pipes.