Tag Archives: United Nations University

Desalination and toxic brine

Have you ever wondered about the possible effects and impact of desalinating large amounts of ocean water? It seems that some United Nations University (UNU) researchers have asked and are beginning to answer that question. The following table illustrates the rise in desalination plants and processes,


Today 15,906 operational desalination plants are found in 177 countries. Almost half of the global desalination capacity is located in the Middle East and North Africa region (48 percent), with Saudi Arabia (15.5 percent), the United Arab Emirates (10.1 percent) and Kuwait (3.7 percent) being both the major producers in the region and globally. Credit: UNU-INWEH [downloaded from http://inweh.unu.edu/un-warns-of-rising-levels-of-toxic-brine-as-desalination-plants-meet-growing-water-needs/]

A January 14, 2019 news item on phys.org highlights the study on desalination from the UNU,

The fast-rising number of desalination plants worldwide—now almost 16,000, with capacity concentrated in the Middle East and North Africa—quench a growing thirst for freshwater but create a salty dilemma as well: how to deal with all the chemical-laden leftover brine.

In a UN-backed paper, experts estimate the freshwater output capacity of desalination plants at 95 million cubic meters per day—equal to almost half the average flow over Niagara Falls.
For every litre of freshwater output, however, desalination plants produce on average 1.5 litres of brine (though values vary dramatically, depending on the feedwater salinity and desalination technology used, and local conditions). Globally, plants now discharge 142 million cubic meters of hypersaline brine every day (a 50% increase on previous assessments).

That’s enough in a year (51.8 billion cubic meters) to cover Florida under 30.5 cm (1 foot) of brine.

The authors, from UN University’s Canadian-based Institute for Water, Environment and Health [at McMaster University], Wageningen University, The Netherlands, and the Gwangju Institute of Science and Technology, Republic of Korea, analyzed a newly-updated dataset—the most complete ever compiled—to revise the world’s badly outdated statistics on desalination plants.

And they call for improved brine management strategies to meet a fast-growing challenge, noting predictions of a dramatic rise in the number of desalination plants, and hence the volume of brine produced, worldwide.

A January 14, 2017 UNU press release, which originated the news item, details the findings,

The paper found that 55% of global brine is produced in just four countries: Saudi Arabia (22%), UAE (20.2%), Kuwait (6.6%) and Qatar (5.8%). Middle Eastern plants, which largely operate using seawater and thermal desalination technologies, typically produce four times as much brine per cubic meter of clean water as plants where river water membrane processes dominate, such as in the US.

The paper says brine disposal methods are largely dictated by geography but traditionally include direct discharge into oceans, surface water or sewers, deep well injection and brine evaporation ponds.

Desalination plants near the ocean (almost 80% of brine is produced within 10km of a coastline) most often discharge untreated waste brine directly back into the marine environment.

The authors cite major risks to ocean life and marine ecosystems posed by brine greatly raising the salinity of the receiving seawater, and by polluting the oceans with toxic chemicals used as anti-scalants and anti-foulants in the desalination process (copper and chlorine are of major concern).

“Brine underflows deplete dissolved oxygen in the receiving waters,” says lead author Edward Jones, who worked at UNU-INWEH, and is now at Wageningen University, The Netherlands. “High salinity and reduced dissolved oxygen levels can have profound impacts on benthic organisms, which can translate into ecological effects observable throughout the food chain.”

Meanwhile, the paper highlights economic opportunities to use brine in aquaculture, to irrigate salt tolerant species, to generate electricity, and by recovering the salt and metals contained in brine — including magnesium, gypsum, sodium chloride, calcium, potassium, chlorine, bromine and lithium.

With better technology, a large number of metals and salts in desalination plant effluent could be mined. These include sodium, magnesium, calcium, potassium, bromine, boron, strontium, lithium, rubidium and uranium, all used by industry, in products, and in agriculture. The needed technologies are immature, however; recovery of these resources is economically uncompetitive today.

“There is a need to translate such research and convert an environmental problem into an economic opportunity,” says author Dr. Manzoor Qadir, Assistant Director of UNU-INWEH. “This is particularly important in countries producing large volumes of brine with relatively low efficiencies, such as Saudi Arabia, UAE, Kuwait and Qatar.”

“Using saline drainage water offers potential commercial, social and environmental gains. Reject brine has been used for aquaculture, with increases in fish biomass of 300% achieved. It has also been successfully used to cultivate the dietary supplement Spirulina, and to irrigate forage shrubs and crops (although this latter use can cause progressive land salinization).”

“Around 1.5 to 2 billion people currently live in areas of physical water scarcity, where water resources are insufficient to meet water demands, at least during part of the year. Around half a billion people experience water scarcity year round,” says Dr. Vladimir Smakhtin, a co-author of the paper and the Director of UNU-INWEH, whose institute is actively pursuing research related to a variety of unconventional water sources.

“There is an urgent need to make desalination technologies more affordable and extend them to low-income and lower-middle income countries. At the same time, though, we have to address potentially severe downsides of desalination — the harm of brine and chemical pollution to the marine environment and human health.”

“The good news is that efforts have been made in recent years and, with continuing technology refinement and improving economic affordability, we see a positive and promising outlook.”

¹The authors use the term “brine” to refer to all concentrate discharged from desalination plants, as the vast majority of concentrate (>95%) originates from seawater and highly brackish groundwater sources.

Here’s a link to and a citation for the paper,

The state of desalination and brine production: A global outlook by Edward Jones, Manzoor Qadir, Michelle T.H.van Vliet, Vladimir Smakhtin, Seong-mu Kang. Science of The Total Environment Volume 657, 20 March 2019, Pages 1343-1356 DOI: https://doi.org/10.1016/j.scitotenv.2018.12.076 Available online 7 December 2018

Surprisingly (to me anyway), this paper is behind a paywall.

Earth Day, Water Day, and every day

I’m blaming my confusion on the American Chemical Society (ACS) which seemed to be celebrating Earth Day on April 15, 2014 as per its news release highlighting their “Chemists Celebrate Earth Day” video series  while in Vancouver, Canada, we’re celebrating it on April 26, 2014 and elsewhere it seems to be on April 20, this year. Regardless, here’s more about how chemist’s are celebrating from the ACS news release,

Water is arguably the most important resource on the planet. In celebration of Earth Day, the American Chemical Society (ACS) is showcasing three scientists whose research keeps water safe, clean and available for future generations. Geared toward elementary and middle school students, the “Chemists Celebrate Earth Day” series highlights the important work that chemists and chemical engineers do every day. The videos are available at http://bit.ly/CCED2014.

The series focuses on the following subjects:

  • Transforming Tech Toys– Featuring Aydogan Ozcan, Ph.D., of UCLA: Ozcan takes everyday gadgets and turns them into powerful mobile laboratories. He’s made a cell phone into a blood analyzer and a bacteria detector, and now he’s built a device that turns a cell phone into a water tester. It can detect very harmful mercury even at very low levels.
  • All About Droughts – Featuring Collins Balcombe of the U.S. Bureau of Reclamation: Balcombe’s job is to keep your drinking water safe and to find new ways to re-use the water that we flush away everyday so that it doesn’t go to waste, especially in areas that don’t get much rain.
  • Cleaning Up Our Water – Featuring Anne Morrissey, Ph.D., of Dublin City University: We all take medicines, but did you know that sometimes the medicine doesn’t stay in our bodies? It’s up to Anne Morrissey to figure out how to get potentially harmful pharmaceuticals out of the water supply, and she’s doing it using one of the most plentiful things on the planet: sunlight.

Sadly, I missed marking World Water Day which according to a March 21, 2014 news release I received was being celebrated on Saturday, March 22, 2014 with worldwide events and the release of a new UN report,

World Water Day: UN Stresses Water and Energy Issues 

Tokyo Leads Public Celebrations Around the World

Tokyo — March 21 — The deep-rooted relationships between water and energy were highlighted today during main global celebrations in Tokyo marking the United Nations’ annual World Water Day.

“Water and energy are among the world’s most pre-eminent challenges. This year’s focus of World Water Day brings these issues to the attention of the world,” said Michel Jarraud, Secretary-General of the World Meteorological Organization and Chair of UN-Water, which coordinates World Water Day and freshwater-related efforts UN system-wide.

The UN predicts that by 2030 the global population will need 35% more food, 40% more water and 50% more energy. Already today 768 million people lack access to improved water sources, 2.5 billion people have no improved sanitation and 1.3 billion people cannot access electricity.

“These issues need urgent attention – both now and in the post-2015 development discussions. The situation is unacceptable. It is often the same people who lack access to water and sanitation who also lack access to energy, ” said Mr. Jarraud.

The 2014 World Water Development Report (WWDR) – a UN-Water flagship report, produced and coordinated by the World Water Assessment Programme, which is hosted and led by UNESCO – is released on World Water Day as an authoritative status report on global freshwater resources. It highlights the need for policies and regulatory frameworks that recognize and integrate approaches to water and energy priorities.

WWDR, a triennial report from 2003 to 2012, this year becomes an annual edition, responding to the international community’s expression of interest in a concise, evidence-based and yearly publication with a specific thematic focus and recommendations.

WWDR 2014 underlines how water-related issues and choices impact energy and vice versa. For example: drought diminishes energy production, while lack of access to electricity limits irrigation possibilities.

The report notes that roughly 75% of all industrial water withdrawals are used for energy production. Tariffs also illustrate this interdependence: if water is subsidized to sell below cost (as is often the case), energy producers – major water consumers – are less likely to conserve it.  Energy subsidies, in turn, drive up water usage.

The report stresses the imperative of coordinating political governance and ensuring that water and energy prices reflect real costs and environmental impacts.

“Energy and water are at the top of the global development agenda,” said the Rector of United Nations University, David Malone, this year’s coordinator of World Water Day on behalf of UN-Water together with the United Nations Industrial Development Organization (UNIDO).

“Significant policy gaps exist in this nexus at present, and the UN plays an instrumental role in providing evidence and policy-relevant guidance. Through this day, we seek to inform decision-makers, stakeholders and practitioners about the interlinkages, potential synergies and trade-offs, and highlight the need for appropriate responses and regulatory frameworks that account for both water and energy priorities. From UNU’s perspective, it is essential that we stimulate more debate and interactive dialogue around possible solutions to our energy and water challenges.”

UNIDO Director-General LI Yong, emphasized the importance of water and energy for inclusive and sustainable industrial development.

“There is a strong call today for integrating the economic dimension, and the role of industry and manufacturing in particular, into the global post-2015 development priorities. Experience shows that environmentally sound interventions in manufacturing industries can be highly effective and can significantly reduce environmental degradation. I am convinced that inclusive and sustainable industrial development will be a key driver for the successful integration of the economic, social and environmental dimensions,” said Mr. LI.

Rather unusually, Michael Bergerrecently published two Nanowerk Spotlight articles about water (is there theme, anyone?) within 24 hours of each other. In his March 26, 2014 Spotlight article, Michael Berger focuses on graphene and water remediation (Note: Links have been removed),

The unique properties of nanomaterials are beneficial in applications to remove pollutants from the environment. The extremely small size of nanomaterial particles creates a large surface area in relation to their volume, which makes them highly reactive, compared to non-nano forms of the same materials.

The potential impact areas for nanotechnology in water applications are divided into three categories: treatment and remediation; sensing and detection: and pollution prevention (read more: “Nanotechnology and water treatment”).

Silver, iron, gold, titanium oxides and iron oxides are some of the commonly used nanoscale metals and metal oxides cited by the researchers that can be used in environmental remediation (read more: “Overview of nanomaterials for cleaning up the environment”).

A more recent entrant into this nanomaterial arsenal is graphene. Individual graphene sheets and their functionalized derivatives have been used to remove metal ions and organic pollutants from water. These graphene-based nanomaterials show quite high adsorption performance as adsorbents. However they also cause additional cost because the removal of these adsorbent materials after usage is difficult and there is the risk of secondary environmental pollution unless the nanomaterials are collected completely after usage.

One solution to this problem would be the assembly of individual sheets into three-dimensional (3D) macroscopic structures which would preserve the unique properties of individual graphene sheets, and offer easy collecting and recycling after water remediation.

The March 27, 2014 Nanowerk Spotlight article was written by someone at Alberta’s (Canada) Ingenuity Lab and focuses on their ‘nanobiological’ approach to water remediation (Note: Links have been removed),

At Ingenuity Lab in Edmonton, Alberta, Dr. Carlo Montemagno and a team of world-class researchers have been investigating plausible solutions to existing water purification challenges. They are building on Dr. Montemagno’s earlier patented discoveries by using a naturally-existing water channel protein as the functional unit in water purification membranes [4].

Aquaporins are water-transport proteins that play an important osmoregulation role in living organisms [5]. These proteins boast exceptionally high water permeability (~ 1010 water molecules/s), high selectivity for pure water molecules, and a low energy cost, which make aquaporin-embedded membrane well suited as an alternative to conventional RO membranes.

Unlike synthetic polymeric membranes, which are driven by the high pressure-induced diffusion of water through size selective pores, this technology utilizes the biological osmosis mechanism to control the flow of water in cellular systems at low energy. In nature, the direction of osmotic water flow is determined by the osmotic pressure difference between compartments, i.e. water flows toward higher osmotic pressure compartment (salty solution or contaminated water). This direction can however be reversed by applying a pressure to the salty solution (i.e., RO).

The principle of RO is based on the semipermeable characteristics of the separating membrane, which allows the transport of only water molecules depending on the direction of osmotic gradient. Therefore, as envisioned in the recent publication (“Recent Progress in Advanced Nanobiological Materials for Energy and Environmental Applications”), the core of Ingenuity Lab’s approach is to control the direction of water flow through aquaporin channels with a minimum level of pressure and to use aquaporin-embedded biomimetic membranes as an alternative to conventional RO membranes.

Here’s a link to and a citation for Montemagno’s and his colleague’s paper,

Recent Progress in Advanced Nanobiological Materials for Energy and Environmental Applications by Hyo-Jick Choi and Carlo D. Montemagno. Materials 2013, 6(12), 5821-5856; doi:10.3390/ma6125821

This paper is open access.

Returning to where I started, here’s a water video featuring graphene from the ACS celebration of Earth Day 2014,

Happy Earth Day!