Decentralised wastewater treatment can deliver clean water, energy efficiency, new resources and cost savings. Exploring space-age technology and examples closer to home, Paul O’Callaghan, chief executive, BlueTech Research, investigates.

Traditional wastewater treatment facilities are finding it increasingly challenging to meet the demands of contemporary regulatory and sustainability targets. They are faced with processing highly complex influent, comprising domestic sewage, stormwater, and industrial wastewater to increasingly high standards. It is then returned to the natural environment only to be abstracted downstream for treatment for municipal supply.

Water stress is also a challenge for communities across the globe, but rarely is treated wastewater effluent used as a water source, even though this has been technologically possible for decades. One way to help solve both of these challenges is decentralized water reuse.

Wastewater can be treated at smaller plants closer to its source and in some applications can re-enter the processing cycle as clean water or be put to greywater uses in cleaning and landscaping. An immediate benefit is the energy and infrastructure savings that come from removing wastewater pumping over long distances.

Financial incentive

However, the rewards of decentralized water reuse go much further and may provide significant financial incentives to manufacturers. The extraction of reusable energy, organics, minerals, metals and even acid is also made easier by containing the concentrated waste stream.

Further, decentralized water reuse offers a route to efficient regulatory compliance through the targeted removal of a range of toxic substances and microcontaminants at the point where they first emerge. The multiple cost and environmental benefits should play very strongly to companies’ corporate sustainability strategies and to the ears of their financial directors.

To date, North America and the Caribbean have seen the greatest take-up of decentralized reuse, especially within hotel complexes. Located close to the source of production, the plants can target the most highly concentrated solids and pathogens from black water and greywater sources such as bathrooms, kitchens, and laundries. The treated water can then be reused at the same site for toilet flushing and landscape irrigation.

Jim Hotchkies, a member of BlueTech’s Technology Assessment Group, who will lead an interactive roundtable on decentralized water reuse at BlueTech Forum in Vancouver this June, says that better quality and lower cost technologies are what allow phosphorus recovery to happen at the local level now.

“You can reuse the water in a potato processing plant, for example, and also extract the phosphorus and put it straight back on the nearby field, which creates a very tight loop.”

Energy saving

There are multiple inspiring examples of energy and water reclamation by large corporations in Europe and North America, such as a dairy plant in New York state which generates 1,000m3/d wastewater. The site is now completely water and energy neutral and the project had a payback of less than two years.

Global cosmetics company L’Oréal has introduced the ‘dry factory’ approach into its processing operations worldwide in order to meet one of its 2020 corporate sustainability goals – reducing consumption of water from municipal supply by 60 percent. Hans-Ulrich Buchholz, L’Oréal’s environmental compliance director will deliver a keynote speech at BlueTech Forum 2018 and says the journey was as much about changing the corporate culture as introducing new technology.

Research scientist Michael Flynn, NASA’s principal investigator in water recycling technology development at the Ames Research Centre, will present a keynote speech at BlueTech Forum on how water reuse technologies being developed for astronauts traveling to Mars could change water management back on Earth.

Regulatory compliance

While the cost-benefit of recovery of water and other resources is a very large part of the case for decentralized water reuse, compliance with environmental regulation can often be much easier to achieve where wastewater is treated at source. Menno Holterman, chief executive of Nijhuis Industries says,

If you keep dirtiest wastewater streams isolated, then the treatment is much more cost-effective overall. In Europe, the 7th Water Framework Directive is forcing industry and utilities to remove pesticides, hormones, pharmaceutical residues and other microcontaminants from wastewater. They have the choice of doing that at scale in a centralized wastewater treatment facility or investing at the source.

“Looking closely at the market it is clear that the clean water and wastewater cycles are unifying, bringing some very interesting opportunities for different technologies and facilities. Decentralised reuse is expected to grow apace, but alternative design principles that are more integrated and connected also need to be developed and applied and that will certainly be under discussion at BlueTech Forum in Vancouver this June.”

Continue the discussion on decentralised water reuse at BlueTech Forum

The core theme of BlueTech Forum, which takes place in Vancouver on 6-7 June 2018, is managing water risk in the circular economy. It will bring together the industry leaders, emerging water tech companies, end-users, researchers, and investors to address key topics and leading trends in water.

Michael Flynn, principal investigator in water recycling technology development at NASA Ames Research Center shares experience of managing water in a closed-loop environment in a keynote address.

Hans-Ulrich Buchholz, Environmental Compliance, Corporate QEHS Group, L’Oréal reveals the journey from linear to circular in cosmetics and manufacturing at the company’s first dry factory in Spain.

Menno Holterman, chief executive, Nijhuis Industries will give the opening address for the thought-leadership roundtables.

James Hotchkies, BlueTech Technology Assessment Group member, and Robert Kennedy, chief technology officer, Newterra, host a roundtable on decentralised water reuse as an enabler for the circular economy.