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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Jun 25, 2021

UK must stop blundering into high carbon choices warns CCC

Dominic Ellis
5 min
The UK must put an end to a year of climate contradictions and stop blundering on high carbon choices warns the Climate Change Committee

The UK Government must end a year of climate contradictions and stop blundering on high carbon choices, according to the Climate Change Committee as it released 200 policy recommendations in a progress to Parliament update.

While the rigour of the Climate Change Act helped bring COP26 to the UK, it is not enough for Ministers to point to the Glasgow summit and hope that this will carry the day with the public, the Committee warns. Leadership is required, detail on the steps the UK will take in the coming years, clarity on tax changes and public spending commitments, as well as active engagement with people and businesses across the country.

"It it is hard to discern any comprehensive strategy in the climate plans we have seen in the last 12 months. There are gaps and ambiguities. Climate resilience remains a second-order issue, if it is considered at all. We continue to blunder into high-carbon choices. Our Planning system and other fundamental structures have not been recast to meet our legal and international climate commitments," the update states. "Our message to Government is simple: act quickly – be bold and decisive."

The UK’s record to date is strong in parts, but it has fallen behind on adapting to the changing climate and not yet provided a coherent plan to reduce emissions in the critical decade ahead, according to the Committee.

  • Statutory framework for climate The UK has a strong climate framework under the Climate Change Act (2008), with legally-binding emissions targets, a process to integrate climate risks into policy, and a central role for independent evidence-based advice and monitoring. This model has inspired similarclimate legislation across the world.
  • Emissions targets The UK has adopted ambitious territorial emissions targets aligned to the Paris Agreement: the Sixth Carbon Budget requires an emissions reduction of 63% from 2019 to 2035, on the way to Net Zero by 2050. These are comprehensive targets covering all greenhouse gases and all sectors, including international aviation and shipping.
  • Emissions reduction The UK has a leading record in reducing its own emissions: down by 40% from 1990 to 2019, the largest reduction in the G20, while growing the economy (GDP increased by 78% from 1990 to 2019). The rate of reductions since 2012 (of around 20 MtCO2e annually) is comparable to that needed in the future.
  • Climate Risk and Adaptation The UK has undertaken three comprehensive assessments of the climate risks it faces, and the Government has published plans for adapting to those risks. There have been some actions in response, notably in tackling flooding and water scarcity, but overall progress in planning and delivering adaptation is not keeping up with increasing risk. The UK is less prepared for the changing climate now than it was when the previous risk assessment was published five years ago.
  • Climate finance The UK has been a strong contributor to international climate finance, having recently doubled its commitment to £11.6 billion in aggregate over 2021/22 to 2025/26. This spend is split between support for cutting emissions and support for adaptation, which is important given significant underfunding of adaptation globally. However, recent cuts to the UK’s overseas aid are undermining these commitments.

In a separate comment, it said the Prime Minister’s Ten-Point Plan was an important statement of ambition, but it has yet to be backed with firm policies. 

Baroness Brown, Chair of the Adaptation Committee said: “The UK is leading in diagnosis but lagging in policy and action. This cannot be put off further. We cannot deliver Net Zero without serious action on adaptation. We need action now, followed by a National Adaptation Programme that must be more ambitious; more comprehensive; and better focussed on implementation than its predecessors, to improve national resilience to climate change.”

Priority recommendations for 2021 include setting out capacity and usage requirements for Energy from Waste consistent with plans to improve recycling and waste prevention, and issue guidance to align local authority waste contracts and planning policy to these targets; develop (with DIT) the option of applying either border carbon tariffs or minimum standards to imports of selected embedded-emission-intense industrial and agricultural products and fuels; and implement a public engagement programme about national adaptation objectives, acceptable levels of risk, desired resilience standards, how to address inequalities, and responsibilities across society. 

Drax Group CEO Will Gardiner said the report is another reminder that if the UK is to meet its ambitious climate targets there is an urgent need to scale up bioenergy with carbon capture and storage (BECCS).

"As the world’s leading generator and supplier of sustainable bioenergy there is no better place to deliver BECCS at scale than at Drax in the UK. We are ready to invest in and deliver this world-leading green technology, which would support clean growth in the north of England, create tens of thousands of jobs and put the UK at the forefront of combatting climate change."

Drax Group is kickstarting the planning process to build a new underground pumped hydro storage power station – more than doubling the electricity generating capacity at its iconic Cruachan facility in Scotland. The 600MW power station will be located inside Ben Cruachan – Argyll’s highest mountain – and increase the site’s total capacity to 1.04GW (click here).

Lockdown measures led to a record decrease in UK emissions in 2020 of 13% from the previous year. The largest falls were in aviation (-60%), shipping (-24%) and surface transport (-18%). While some of this change could persist (e.g. business travellers accounted for 15-25% of UK air passengers before the pandemic), much is already rebounding with HGV and van travel back to pre-pandemic levels, while car use, which at one point was down by two-thirds, only 20% below pre-pandemic levels.

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