Mar 24, 2017

Wastewater recycling technology: the answer to water scarcity

Prabir Chetia
4 min
Wastewater recycling technology: the answer to water scarcity
Over 663 million people across the world don’t have access to clean drinking water. We’ll have 40 percent less potable water than what...

Over 663 million people across the world don’t have access to clean drinking water.

We’ll have 40 percent less potable water than what we’ll need in 2030.

With growing populations relying on shrinking freshwater sources, it’s imperative that we, as a species, get serious about sustainability and prudent use of our dwindling water reserves.

While we’ll need to do whatever we can to stretch existing sources, recycling the copious amounts of wastewater we’re producing right now could go a long way toward addressing our growing demand for clean water. 

The emergence of viable and scalable technologies that can do just that has made it a serious possibility, within our lifetime.

Several countries across the world are doing more than just dabbling in wastewater recycling right now. Singapore, Israel, Spain, a few Scandinavian countries, as well as the United States recycle a significant portion of the wastewater they generate. Recycled wastewater is generally disposed of in larger bodies of water (seas, rivers, ponds, etc.) or used for gardening, cleaning, as well as for industrial applications.

Israel is a world leader in wastewater treatment; around 85 percent of their wastewater is treated and recycled for ruse in sectors like agriculture.

Singapore, Australia and the US (especially California) generate significant amounts of portable water though wastewater recycling.

Still, very little (probably less than two percent) of recycled wastewater is used as potable water.

Is recycled water safe to drink?   

While a scarcity of potable water sources across the globe is certainly spurring efforts, recycling initiatives in play right now aren’t able to treat wastewater to an extent that’s fit for direct human consumption.

Low-cost water treatment technologies have several inefficiencies that need to be addressed, while advanced (more successful) technologies aren’t viable right now due to the high upfront investment and operational costs associated with them.

Current research is trying to address these issues by modifying existing wastewater technologies to make them more efficient. Tweaks to existing wastewater treatment technologies include advanced anaerobic digesters, biofilm sheets and dry cycle biofilms, multistage aerated biofilms, as well as Membrane Aerated Biofilm Reactors (MABR).

While they’ve been reasonably successful, the hunt is on for new and improved technologies that could supersede existing processes that are still somewhat inefficient.

Future technologies

Besides modifications to existing technologies, a series of new wastewater technologies have been developed as viable alternatives to older, less feasible options.

These new wastewater recycling technologies aren’t just improving the quality of recycled water significantly; they’re also doing it at lower costs.

Besides reducing initial setup costs, upcoming wastewater technologies are focusing on lowering their operational costs by lowering their energy consumption.

There’s also growing interest in generating electricity from sludge (waste materials generated during the treatment process) in order to reduce operational cost further, besides reducing the amount of leftover (unusable) sludge byproducts.

Most new and advanced wastewater treatment and recycling technologies are still in their trial phase, and could take another four to five years before they’re anywhere close to being commercialized.

Future adoption

The adoption of advanced wastewater treatment and recycling technologies is limited to a few countries, principally due to limited government initiatives supporting wastewater treatment and recycling.

While plenty of countries across the world have policies in place that focus on the quality of discharged effluents (wastewater) in order to protect the environment, few, if any,  have one in place governing the reuse of recycled wastewater.

Adoption of more holistic wastewater treatment policies and technologies is expected to increase significantly in the future, driven by growing environmental awareness, improvement in technologies, as well as policies and regulations focused on wastewater reuse.

An inevitable rise in the demand for potable water as well as dwindling fresh water resources will also spur aggressive adoption of such technologies in the long run. Developing countries are likely to record double-digit growth in the adoption of wastewater treatment technologies over the next five years, driven predominantly by a growing scarcity of fresh water.

With operational costs sufficiently minimized, the commercialization and mass adoption of advanced wastewater treatment technologies such as Bio-electrochemical Systems (BES), nanoparticle water filtration systems, and Nanofiltration (NF) Hollow Fiber Membrane technology are likely to pick up in the future.


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May 13, 2021

All but two UK regions failing on school energy efficiency

Dominic Ellis
2 min
Yorkshire & the Humber and the North East are the only UK regions where schools have collectively reduced how much they spend on energy per pupil

Most schools are still "treading water" on implementing energy efficient technology, according to new analysis of Government data from eLight.

Yorkshire & the Humber and the North East are the only regions where schools have collectively reduced how much they spend on energy per pupil, cutting expenditure by 4.4% and 0.9% respectively. Every other region of England increased its average energy expenditure per pupil, with schools in Inner London doing so by as much as 23.5%.

According to The Carbon Trust, energy bills in UK schools amount to £543 million per year, with 50% of a school’s total electricity cost being lighting. If every school in the UK implemented any type of energy efficient technology, over £100 million could be saved each year.

Harvey Sinclair, CEO of eEnergy, eLight’s parent company, said the figures demonstrate an uncomfortable truth for the education sector – namely that most schools are still treading water on the implementation of energy efficient technology. Energy efficiency could make a huge difference to meeting net zero ambitions, but most schools are still lagging behind.

“The solutions exist, but they are not being deployed fast enough," he said. "For example, we’ve made great progress in upgrading schools to energy-efficient LED lighting, but with 80% of schools yet to make the switch, there’s an enormous opportunity to make a collective reduction in carbon footprint and save a lot of money on energy bills. Our model means the entire project is financed, doesn’t require any upfront expenditure, and repayments are more than covered by the energy savings made."

He said while it has worked with over 300 schools, most are still far too slow to commit. "We are urging them to act with greater urgency because climate change won’t wait, and the need for action gets more pressing every year. The education sector has an important part to play in that and pupils around the country expect their schools to do so – there is still a huge job to be done."

North Yorkshire County Council is benefiting from the Public Sector Decarbonisation Scheme, which has so far awarded nearly £1bn for energy efficiency and heat decarbonisation projects around the country, and Craven schools has reportedly made a successful £2m bid (click here).

The Department for Education has issued 13 tips for reducing energy and water use in schools.

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