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Wasting less wastewater

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Ultra-pure water is essential for multiple industries, for example semiconductors, batteries, and pharmaceuticals, as well as food and beverage companies.  Such water is produced by various processes including desalination plants that use reverse osmosis.  The byproduct of the processing is industrial brine:  salty wastewater.

The brine produced by desalination is generally dumped into the ocean if the desalination plant is located at the seashore, but if the plant is inland, such as in places like Arizona, that isn’t an option.

Nestle runs a water desalinating plant near Phoenix that generates more than 50,000 gallons of brine every day.  Concentrated brines must be carefully managed and disposed of. 

Researchers at Arizona State University are developing a mobile, closed-loop water recovery demonstration system that aims to recover 50%-90% of previously unusable water from industrial brine and reduce the remainder to solid salt. 

The team’s approach involves pretreating Nestle’s brine to remove larger particles.  It then goes through a reverse osmosis process that results in a stream of high-quality water and a salty concentrate.  The salty concentrate goes through a special membrane that recovers even more pure water.  The highly concentrated brine is then dried and crystalized into a solid salt product.  Atmospheric water harvesters capture any remaining water vapor during the drying process.

In places like Arizona where freshwater is a scarce commodity, finding sustainable ways to separate water from salt is both a scientific challenge and an economic necessity.

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Squeezing every last drop out of wastewater

Photo courtesy of the Global Center for Water Technology.

Earth Wise is a production of WAMC Northeast Public Radio

Reducing methane from cattle

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Livestock is responsible for almost 15% of global greenhouse gas emissions.  Most of that is in the form of methane that cattle release when they burp.  Grazing cattle produce more methane than feedlot cattle or dairy cows because they eat more fiber from grass.  There are 9 million dairy cows in the U.S. but more than 64 million beef cattle.

Beef cattle spend most of their lives grazing in pastures and producing methane.  Controlling the food of pasture-raised cattle is difficult because they often graze far from ranches for extended periods of time.  During the winter and during times when grass is scarce, ranchers supplement the diet of cattle.

A new study by researchers at the University of California – Davis has found that feeding grazing cattle a seaweed supplement in pellet form reduced their methane emissions by nearly 40% without affecting their health or weight.  There have been previous studies that showed seaweed cut methane emissions by 82% in feedlot cattle and over 50% in dairy cows.  But this is the first study to test the effects of seaweed on grazing beef cattle.

The seaweed pellets were made available to grazing cattle and they ate the supplement voluntarily.  Compared to a group of cattle who didn’t receive the supplements, the seaweed eaters had a 40% reduction in methane emissions.

Other research studies to reduce methane emissions using feed additives have taken place in controlled environments with daily supplements.  This method provides a way to make a seaweed supplement easily available to grazing animals.  It could even be introduced through a lick block for cattle.

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Feeding Grazing Cattle Seaweed Cuts Methane Emissions by Almost 40%

Photo, posted February 18, 2016, courtesy of Beverly Moseley/NRCS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Solar Power And Water | Earth Wise

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Solar power is a prime example of clean energy, but it does not come without complications and potential problems.  One problem that has arisen in the Californian desert is the effect on scarce water supplies.  Solar farms don’t use up water when they are operating but they consume it when they are being built.

One of the densest areas of solar development in North America is in a corridor along Interstate 10 near Palm Springs, California.  Multiple utility-scale solar projects are underway near the small town of Desert Center.  The projects are being built on public land overseen by the Department of Interior’s Bureau of Land Management.  The location is ideal for solar power projects:  endless sunshine, nearby transmission lines to distribute power, and a major highway for easy transportation of construction materials.

The problem is that during construction of the solar farms, the law requires developers to reduce the amount of dust being generated that can otherwise spread health problems like Valley Fever.  Preventing dust from flying requires water and lots of it.

The water comes from groundwater and building the solar farms is drying up local wells and emptying the aquifer that is part of the Chuckwalla Valley Groundwater Basin.  For the people who live in Desert Center and adjacent areas, this is a serious problem. It is also a problem for the desert ecosystem that supports palo verde and ironwood trees as well as endangered desert tortoises.

This isn’t an easy problem to solve. Seven approved new utility-scale solar projects in the area will provide enough electricity to power 2 million homes. But having enough water to build those projects won’t be easy.

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Solar Is Booming in the California Desert, if Water Issues Don’t Get in the Way

Photo, posted October 16, 2017, courtesy of UC Davis College of Engineering via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Chatbots Are Thirsty | Earth Wise

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We hear a lot about artificial intelligence these days.  ChatGPT has found its way into education, technology, and many other aspects of life.  It and its brethren are a source of fascination, enthusiasm, and even fear.  Many of us have given queries to the bot to see what kind of results we can obtain.  But a recent study has found out something about AI systems that we probably didn’t know – they use up lots of fresh water.

According to researchers at the University of California, Riverside, running a few dozen queries on ChatGPT uses up about half a quart of fresh water from already overtaxed reservoirs.

Running artificial intelligence systems like ChatGPT relies on cloud computations done in racks of servers in warehouse-sized data processing centers.  Google’s data centers in the U.S. alone consumed nearly 3.5 billion gallons of fresh water in 2021 in order to keep their servers cool.

Data processing centers consume water in two ways.  They often draw much of their electricity from power plants that use large cooling towers that convert water into steam emitted into the atmosphere.  In addition, the servers themselves need to be cooled to keep running and are typically connected to cooling towers as well.

It isn’t going to be easy for AI systems to reduce their water use.  The study’s authors noted that people make use of AI at all hours of the day and night.  But a significant amount of AI activity is actually the training of the systems.  That could be scheduled for the cooler hours, when less water is lost to evaporation.

In an era of scarce fresh water and droughts, it is important to make AI less thirsty.

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AI programs consume large volumes of scarce water

Photo, posted May 22, 2023, courtesy of Jernej Furman via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Ivory-Billed Woodpecker | Earth Wise

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The ivory-billed woodpecker was the largest woodpecker in the US.  They were once relatively common, stretching from the Carolinas through the southeast and across to Texas.  Their numbers started to drop sharply in the 19th century because of habitat loss and overhunting.  Many were taken as valuable specimens; some were even eaten by poverty-stricken people.

The last widely accepted sighting was way back in 1944.  For years, the birds were listed as critically endangered with only infrequent and entirely anecdotal reports of sightings.  Last year, the U.S. Fish and Wildlife Service finally declared the species extinct.

A multiyear field study by avian researchers from multiple institutions has recently reported that the ivory-billed woodpecker may in fact still exist in a remote swampy region of Louisiana. 

The three-year effort to find the woodpecker involved scientists trudging through the remote site to observe birds and take audio recordings.  Unmanned trail cameras taking time-lapse photos and a drone were used to capture images.  Several members of the team report that they observed the birds.  Some photographic images and videos appear to show ivory bills.  Based on characteristic markings visible in some of the photos, the birds do appear to be the ivory bill and not, for example, the fairly common but similar looking pileated woodpecker.

The birds are scarce, live in a tough, swampy habitat, and actively avoid getting near people.  They live high in trees and are very difficult to spot, much less get clear photographs of.  From all indications, however, reports of the demise of the ivory-billed woodpecker may have been premature.

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Back from the dead? Elusive ivory-billed woodpecker not extinct, researchers say

Photo, posted May 3, 2008, courtesy of Michael McCarthy via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Lake Tuz Is Disappearing | Earth Wise

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Lake Tuz is Turkey’s second-largest lake and one of the world’s largest hypersaline lakes.  Its high salt content makes it an ideal breeding ground for some migratory bird species, including flamingos, which are often present there in huge numbers in the spring and summer.

Now, Lake Tuz rarely spans an area much larger than a puddle. In some summers, it completely dries up.  It did so this past summer, which resulted in the deaths of thousands of flamingos.

According to experts, Lake Tuz is a victim of climate change-induced drought, which has hit the region hard, and decades of harmful agricultural policies that exhausted the underground water supply.

Water in this region has become increasingly scarce.  The Mediterranean Basin has already seen more frequent and intense droughts, and is considered a climate change hotspot. 

According to new research, which was recently published in the journal Regional Environmental Change, Lake Tuz generally contained enough water in August for the lake to be considered permanent up until 2000.  But between 2001 and 2016, something shifted.  Water spanned less than 20% of the lake in every August except for one, and droughts became more frequent and intense. And in some years, the lake completely dried up.   

What caused this change?  According to the research team, Lake Tuz’s decline coincided with the excessive use of groundwater and surface water resources responsible for feeding the lake.  Some streams were rerouted for agricultural purposes, while others were dammed.  And when surface water sources dwindled, people turned to groundwater that historically fed the springs in Lake Tuz. 

Lake Tuz may be on the brink of extinction. 

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Impact of climate variability on the surface of Lake Tuz (Turkey), 1985–2016

Disappearing Lake Tuz

Photo, posted August 16, 2021, courtesy of Godot via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Electronic Waste On The Decline | Earth Wise

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A new study published in the Journal of Industrial Ecology has found that the total mass of electronic waste generated by Americans has been declining since 2015.  Given that electronic devices are playing an ever-growing role in our lives, this finding seems rather surprising.  It also seems like pretty good news, but the underlying facts should dampen our level of enthusiasm.

The main reason for the decline is the disappearance of large, bulky cathode-ray tube televisions and computer monitors.  Since about 10 years ago, CRT displays have been on the decline in the waste stream, thereby leading to an overall decline in total e-waste mass.

Many state regulations with respect to e-waste recycling have targets based on product mass.  The regulations were typically designed to keep electronics with high levels of lead and mercury out of landfills.

At present, the more pertinent concern is how to recover valuable elements like cobalt (from lithium-ion batteries) and indium (from flat-panel displays).  These elements are not so environmentally toxic, but rather are relatively scarce in the earth’s crust. 

The main conclusion to be drawn from the declining mass of electronic waste is not that we are necessarily winning the battle against generating it but rather that e-waste is changing and regulations concerning it need to be rethought.  Focusing regulations on capturing critical elements not only would have significant economic benefits but also would be important in addressing geopolitical uncertainties that potentially could threaten what could be termed the mineral security of the U.S.

E-waste recycling is regulated at the state level and only half the states have e-waste recycling laws.  It may be time for more uniform policies across the country.

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Electronic Waste on the Decline, New Study Finds

Photo, posted January 22, 2013, courtesy of Thorsten Hartmann via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Blue Acceleration | Earth Wise

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The oil and gas sector is the largest ocean industry.  It’s responsible for about one third of the value of the ocean economy.  Sand and gravel, destined for the construction industry, are the most mined minerals in the ocean.  And during the past 50 years, approximately 16,000 desalination plants have popped up around the world to help supply people with an increasingly scarce commodity: freshwater. 

As a result of these and other human pressures, the world’s oceans have suffered a lot over time.  But according to a comprehensive new analysis on the state of the ocean, human pressure on the world’s oceans, driven by a combination of technological progress and declining land-based resources, sharply accelerated at the start of the 21st century.  Scientists have dubbed this dramatic increase, which shows no signs of slowing down, the “Blue Acceleration.”

A  research team from Stockholm University analyzed 50 years of data from aquaculture, bioprospecting, shipping, drilling, deep-sea mining, and more.  Their findings were recently published in the journal One Earth.

While claiming ocean resources and space is not new, lead author Jean-Baptiste Jouffray from the Stockholm Resilience Centre says “the extent, intensity, and diversity of today’s aspirations are unprecedented.”

The researchers also highlight how not all human impacts on the ocean are negative.  For example, offshore wind farm technology has reached commercial viability allowing the world to reduce reliance on fossil fuels.

But how can the Blue Acceleration be slowed?  Since only a handful of multinational companies dominate sectors like the seafood industry, oil and gas exploitation, and bioprospecting, one idea is to have banks and other investors adopt more stringent sustainability criteria for making ocean investments. 

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Human pressure on world’s ocean shows no sign of slowing

Photo, posted October 29, 2008, courtesy of Silke Baron via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Desalination On The Rise

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Desalination has been regarded for decades as a solution for providing fresh water to places where it is scarce.  With drought becoming more common around the world – sometimes even in places where water supplies were thought to be ample – there is increasing pressure to bring new desalination plants online.

San Diego gets only 12 inches of rain a year and has no groundwater.  It gets half its water from the distant Colorado River, and that source is becoming increasingly unreliable.  Thus, it is no surprise that America’s largest desalination plant is in Carlsbad, about 30 miles north of San Diego.  That plant provides about 10% of the fresh water needs of the region’s 3.1 million people.

There are 11 desalination plants in California, and 10 more are proposed. Desalination is huge in Saudi Arabia, Australia and Israel.  Globally, more than 300 million people get their water from desalination.

But there are problems.  Desalination is expensive and energy-intensive.  If the process is powered by fossil fuels, it contributes to global warming.  There are ecological impacts as well since it takes two gallons of sea water to make a gallon of fresh water, and the gallon left behind is extremely briny and potentially harmful to dump back into the sea.  The intake systems of desalination plants are also harmful to fish and other aquatic creatures.

The cost of desalination has dropped by more than half over the last 30 years but water from it still costs about twice as much as that from other main sources.  The technology is getting better and cheaper, but the industry must confront and solve serious environmental and economic problems in order for desalination to be able to meet the needs of an increasingly thirsty world.

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As Water Scarcity Increases, Desalination Plants Are on the Rise

Photo, posted January 12, 2011, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Collecting Clean Water From The Air

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Clean water is an essential requirement for human life and there are many places where it is a scarce commodity.   In the world’s deserts, getting water to people requires feats of engineering and irrigation that can be cumbersome and expensive.

Researchers at Ohio State University have produced a couple of new studies that explore options for gathering water from fog and condensation that are based on principles of biomimicry:  copying strategies already in use by plants and animals.

The researchers looked at how cactus, beetles and desert grasses all collect water condensed from nighttime fog, gathering droplets from the air and filtering them to roots or reservoirs.

The cactus they studied collects water on its barbed tips before guiding droplets down conical spines to the base of the plant. They learned that conical shapes gather more water than do cylindrical shapes.  This is because of a physics phenomenon called the Laplace pressure gradient.

The beetles they studied collect drops of water on waxy, water-repellent bumps on their backs.  The water then slides towards the beetle’s mouth on the flat surface between the bumps.  Based on this, the researchers experimented with structures that include multiple hydrophilic cones with spaces in between where water droplets can coalesce.

From grasses, they learned that grooved surfaces move water more quickly than ungrooved surfaces – in fact, about twice as much.

The work so far has been on a laboratory-level, but the researchers envision scaling up to structures in the desert that can gather water from fog or condensation and supplement public systems or wells either on a house-by-house basis or on a community-wide basis.  Copying cacti, beetles and grasses could supply clean water to people in the desert.

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Collecting clean water from air, inspired by desert life

Photo, posted February 7, 2010, courtesy of Remko van Dokkum via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Sustainable Plastics

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According to the United Nations, plastic accounts for up to 90% of all the pollutants in the ocean. Conventional plastics take hundreds of years to decay, so all the plastic that gets into the oceans piles up and endangers marine life and pollutes the environment. Unfortunately, there are few comparable, environmentally friendly alternatives.  

An often-proposed solution is bioplastics, which are not made from petroleum and degrade quickly.  The downside of bioplastics is that growing the plants or bacteria used to make the plastic requires fertile soil and fresh water, which are scarce commodities in many places.

One such place is Israel.  So, researchers there at Tel Aviv University have developed a process to make a bioplastic polymer that doesn’t require land or fresh water.  The new polymer is derived from microorganisms that feed on seaweed.  It is biodegradable, produces zero toxic waste and recycles into organic waste.

The polymer is called polyhydroxyalkanoate, or PHA for short.  The raw material is multicellular seaweed, cultivated in the ocean.  These algae are eaten by single-celled microorganisms, which also grow in salty seawater and produce a polymer that can be used to make bioplastic.  PHA is already produced in commercial quantities, but it is currently made from plants that require agricultural land and fresh water.  The new process would enable countries with limited fresh water, such as Israel, China and India, to switch from petroleum-based plastics to biodegradable plastics.

Plastics from fossil sources are one of the world’s biggest pollution problems.  The new study shows that it is possible to produce bioplastic completely based on marine resources in an environmentally-friendly process. 

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Sustainable ‘plastics’ are on the horizon

Photo, posted March 14, 2015, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Solar Plus Storage In The Caribbean

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The Caribbean is home to nearly 30 island nations and more than 7,000 individual islands with a combined population of around 40 million.  All of the islands are susceptible to disasters such as hurricanes that can leave residents without electrical power for extended periods of time.

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