Tackling Microplastics in Wastewater: Innovative Removal Strategies

Tackling Microplastics in Wastewater: Innovative Removal Strategies

The Wastewater Crisis: A Multifaceted Challenge

As I flush the toilet, I can’t help but wonder – where does all that waste actually go? It’s not something we often think about, but the truth is, the global wastewater crisis is a pressing environmental and public health issue that demands our attention.

The sheer volume of human waste produced worldwide is staggering – 78 billion people creating an astronomical amount of sewage and wastewater. And it’s not just the raw sewage that’s the problem. These waste streams are also laden with a cocktail of pollutants, from pharmaceuticals to microplastics, collectively destabilizing the Earth’s safe operating systems.

Nutrient overloads, toxic chemicals, and plastic pollution are harming our ecosystems, from coral reefs to seagrass meadows. It’s a multi-headed hydra that’s contributing to the deterioration of at least five planetary boundaries. And as the global population continues to grow, with more people living in cities, the pressure on our sanitation systems is only going to intensify.

Centralized vs. Decentralized Solutions

Historically, the approach to wastewater treatment has been heavily centralized – massive, expensive facilities tasked with processing the waste of entire communities. But this model is increasingly proving inadequate, especially in the face of climate change and extreme weather events.

Combined sewer overflows (CSOs) are a prime example of the limitations of this centralized system. When heavy rains overwhelm the capacity of these facilities, they’re forced to bypass treatment and dump raw or partially treated sewage directly into our waterways. In New York Harbor alone, this results in over 102 million cubic meters of polluted discharge every year.

Upgrading these aging systems to handle increased flows can come with an astronomical price tag – billions of dollars per municipality. And even then, there’s no guarantee they’ll be able to keep up with the pace of climate change.

“It’s a combination of green and gray infrastructure,” says Barry Liner, chief technical officer at the Water Environment Federation. “There’s no one CSO solution, but rather a host of actions that must be taken.”

Nature-Based Solutions to the Rescue

That’s where nature-based solutions (NbS) come in – innovative approaches that harness the power of natural ecosystems to tackle wastewater challenges. These decentralized systems offer a more accessible and affordable alternative to the centralized model.

Constructed wetlands, for example, are affordable, operable, and reliable at both small and large scales, capable of removing pollutants like nutrients, pathogens, and pesticides. And they can be customized to fit the specific needs of urban or rural environments.

One standout example is the Chulalongkorn Centenary Park in Bangkok, Thailand. This watery oasis can collect, treat, and hold up to 3,780 cubic meters of water, providing flood mitigation, habitat creation, and recreational opportunities for city dwellers.

“What we wanted to do was put together something that was quite practical, that would allow different users, especially wastewater utility and municipalities, to understand what the options are for using nature-based solutions,” says Katharine Cross, a senior adviser at Water Cities.

Tackling Microplastics: A Growing Concern

As if the wastewater crisis wasn’t daunting enough, we now have to contend with the insidious threat of microplastics. These tiny plastic particles, often less than 5 millimeters in size, are making their way into our waterways through a variety of sources, including washing machines, personal care products, and even the breakdown of larger plastic items.

Studies have shown that microplastics can accumulate toxic chemicals and transport them through the environment, potentially harming aquatic life and even making their way into the food chain. And with the ubiquity of plastic in modern life, this problem is only going to continue to grow.

But the good news is, researchers are exploring innovative solutions to remove microplastics from wastewater. One promising approach is the Revolving Algal Biofilm system, developed by a startup in Iowa. This technology uses algae-covered conveyor belts to not only remove nitrogen and phosphorus, but also capture microplastics and other contaminants.

We’re then able to harvest the algae, process it, and sell it as a fertilizer,” explains Max Gangestad, COO at Gross-Wen Technologies. “So now we can keep that nitrogen and phosphorus in our ecosystem.”

Closing the Loop: Towards a Circular Economy

As these innovative solutions continue to emerge, the ultimate goal is to transform wastewater from a problem into a valuable resource. This is the essence of the circular economy – capturing, transforming, and reusing all waste, rather than simply discarding it.

Nitrogen and phosphorus, for example, are key nutrients contained within human waste that could potentially replace a significant portion of the synthetic fertilizers used in agriculture. And the water itself can be treated and recycled for non-potable uses, reducing the strain on freshwater resources.

“Properly treated and cleansed water can be reused for many purposes, including as drinking water,” a reality that’s already being implemented in places like Singapore, where an estimated 40% of the population’s water needs are met through recycled sources.

Of course, transitioning to a circular economy for wastewater won’t be easy. It will require a major shift in public perception, overcoming the taboo that often surrounds the topic of human waste. But as Stephanie Wear, senior scientist and strategy adviser at The Nature Conservancy, says, “Behavior is as much a part of the solution as the technology.”

A Call to Action

The wastewater crisis we face is daunting, but the potential solutions are both innovative and inspiring. From nature-based systems that mimic natural ecosystems to advanced treatment technologies that capture valuable resources, we have the tools to tackle this multi-faceted challenge.

But it’s going to take a concerted effort, collaboration between the public and private sectors, and a willingness to break down the societal taboos around waste. As we continue to explore these solutions, I encourage you to visit Alpha Wastewater Services to learn more about how they’re leading the charge in sustainable wastewater management.

Together, we can transform our wastewater systems, protect our environment, and create a more sustainable future. It’s time to stop flushing our resources down the drain and start rethinking the way we manage our waste.