Positive Progress: 3 Trends in Wastewater Treatment

By Ralph Exton

Water has become one of the foremost challenges affecting the world today. In developing countries, millions of people lack access to clean, safe water. Weather extremes, such as drought are creating dangerous situations; meanwhile, a new released report predicts that by year 2060, more than a billion people worldwide will live in cities at risk of major flooding as a result of climate change.

Then there’s the rapid population growth and economic development in regions, such as the Middle East, where water resources are being pushed well beyond natural limits. And as cities’ aging piping and distribution infrastructure continues to crumble, trillions of gallons of water are lost.

Municipalities in particular are taking the brunt of these challenges. Yet, I believe some of the greatest opportunities for solving the problems exist within their wastewater treatment plants. Last month, leaders in the global water sector convened in Munich, Germany, for the 50th anniversary of IFAT – an influential conference for innovation in water, sewage, waste and raw materials management. Three wastewater treatment trends – and solutions – dominated the discussion.

Water reuse: Closing the gap between treatment and reuse

It is critical that we seek to spur increased adoption of water reuse – a strategy that allows the world to take advantage of a water source constantly replenished every day regardless of drought or climate change. Treated municipal wastewater is a virtually untapped resource. In North America, 75 percent of wastewater is treated (16 trillion gallons of water every day), but less than 4 percent of that water is reused. It’s a gap that needs to be closed.

The vast majority of treated municipal effluent is discharged into a local receiving stream. Technology exists to take this wastewater and treat it to a quality suitable for other, non-potable purposes: agricultural needs, groundwater recharge, industrial applications. In fact, wastewater can be treated to a quality suitable for drinking (if we can get past the “ick” factor of the toilet-to-tap water recycling concept).

Historically, policy has focused on effluent quality, pushing for discharge limits to protect the environment. This is important – and necessary. However, policy and regulation need to catch up with the growing acceptance of water reuse and begin to structure guidance around its implementation. It’s starting to happen in several corners of the world. For example, Saudi Araba increased its water tariff to encourage water reuse. The United Arab Emirates is opting for stronger conservation and reuse rather than investing in desalination technologies, which are effective but expensive.

But resource recovery goes beyond water reuse. It also means we can capture other valuable byproducts from wastewater. Energy is one of them.

Energy neutrality: Harnessing the power of water

The water-energy nexus is real. Without water, you can’t create energy; without energy, you can’t treat water. Consider that municipal wastewater contains two to four times more energy within it than it takes to treat it. Innovative technologies are critical to finding new ways to reduce plants’ energy consumption. Energy-efficient treatment options are gaining ground, such as the MABR (Membrane Aerated Biofilm Reactors) and advanced anaerobic digesters. Advanced digestion can be used to create biogas and reciprocating gas engines can turn that biogas into electricity, creating a pathway to becoming energy neutral or even energy positive.

It’s a revolution in water resource recovery – and it’s underway. Some utilities are already energy neutral; many more are in some stage of planning, designing and constructing water resource recovery systems.

The benefits of energy neutrality extend beyond the individual wastewater facilities. Water resource recovery is a vision and a strategy that is encouraging greater adoption of water reuse around the world. And as a result, water resource recovery is helping to propel a circular economy where water is a valued, well-managed resource sustained by advances in science and technology.

Water quality: Tackling the micro pollutants challenge

Municipal wastewater contains a diverse array of biological solids, nutrients and pathogens; all very common and treatable. More recently, however, a new crop of contaminants are challenging the treatment capabilities of conventional wastewater treatment plants: micro pollutants.

Micro pollutants – commonly originating from sources such as pharmaceutical residues, personal care products, various household chemicals, and biocides/pesticides, these pollutants – are a group of more than 10,000 substances with various chemical properties affecting the environment. The impact of the contaminants’ release into the environment, where they may cause adverse effects on aquatic ecosystems (reproduction issues in fish, among other things), depends on how they are treated within wastewater treatment plants. Many facilities, however, aren’t adequately equipped to handle them.

There is a growing focus, mainly in Europe, on removing micro pollutants from wastewater streams. Switzerland and Germany are two such countries leading the way. Certain regions of Germany, for example, have adopted targets for removal and are providing significant funding for research, feasibility studies and plant upgrades. Advanced technologies like GE’s MBR with MACarrier, which combines membrane bioreactor (MBR) technology with powdered activated carbon (PAC), may be a simplistic, stable and cost-effective process scheme for the removal of micro pollutants. This technology is also proving beneficial for the treatment of other contaminants of emerging concern.

Up until just a few years ago, water-related challenges and solutions such as those above interested only specialists and scientists. They’re now a central concern for many more, including public and private operators, elected officials, associations, and even the general population of involved and concerned citizens. As a society, we’re now recognizing that water management affects us all.

Image credit: Pixabay

Ralph Exton is the chief marketing officer for GE Power, Water & Process Technologies. Ralph also serves as the business program manager for the GE Experienced Commercial Leadership Program (ECLP). Follow Ralph on LinkedIN and GE Water on Twitter.