Nav: Home

Where there's waste there's fertilizer

May 15, 2019

May 15, 2019 - We all know plants need nutrients, especially nitrogen and phosphorus. To give crops a boost, they are often put on fields as fertilizer. But we never talk about where the nutrients themselves come from.

Phosphorus, for example, is taken from the Earth, and in just 100-250 years, we could be facing a terrible shortage. That is, unless scientists can find ways to recycle it.

Scientists at Tel Hai College and MIGAL Institute in Israel are working on a way to make phosphorus fertilizer from an unlikely source -- dairy wastewater.

Additionally, they are taking the element from the wastewater with another unlikely character. They are using the leftovers that comes from making clean drinking water, which contain the element aluminum.

"The material left after purification, called aluminum water treatment residue, is normally taken to a landfill to be buried," says Michael "Iggy" Litaor, who led this work. "We changed this material by mixing it with dairy wastewater rich with phosphorus and organic matter. We then found it can be just as good as common fertilizers."

The benefits of the practice could go beyond recycling the element. Putting too much of the commercially available fertilizers on fields can hurt the quality of water nearby.

"Phosphorus is an important nutrient needed by most crops," Litaor explains. "However, it is a non-renewable resource. If we continue with the current rate of use, what we have may be depleted in 100 to 250 years. There are also side-effects of too much fertilizer. Hence, scientists around the world are searching for simple and affordable ways to recycle the element without lowering crop yield."

In their study, Litaor and his team mixed the aluminum water treatment residue with dairy wastewater. Dairy wastewater comes from washing cow udders before milking and from cooling cows during hot summer days. It is high in phosphorus because of detergents used while cleaning the sheds that house the cows as well as runoff from cows' urine.

What allows the mixture to become fertilizer is the magic of chemistry. Reactions occur between the phosphorus, aluminum, and organic matter that result in it being a possible fertilizer.

Litaor and his team then put the potential fertilizer on lettuce to see how well it worked. They found it did just as well as common fertilizers.

"This experiment clearly showed that we can use aluminum refuse to recapture phosphorus from dairy wastewater and use it as fertilizer," he says. "We showed that the water treatment residue can take phosphorus from the wastewater and put it in soil that doesn't have much phosphorus. This may offset somewhat the mining of this non-renewable resource."

If this method of making fertilizer were to become widely practiced, Litaor sees the possibility of building plants next to dairies with lots of cattle. This would give a large supply of phosphorus. A company could bring in the leftovers from water treatment systems to produce fertilizer. It could be used by large farms or sold to others.

He says the next step in this research is to look at the use of water treatment leftovers that contain iron, because many soils also lack this element. The scientists must also show that no unwanted material such as hormones and antibiotics are in the fertilizer.

"I also want to find an investor who will support us taking this idea to the marketplace," he adds. "After many years of research on phosphorus in wetlands, streams, and rivers, I decided to look for an efficient means to recycle the element using wastes we were already producing."
-end-
Read more about this research in the Soil Science Society of America Journal. This research was supported by the United States-Israel Binational Agricultural Research and Development Fund and the Israel Department of Agriculture.

American Society of Agronomy

Related Wastewater Articles:

Plant research could benefit wastewater treatment, biofuels and antibiotics
Chinese and Rutgers scientists have discovered how aquatic plants cope with water pollution, a major ecological question that could help boost their use in wastewater treatment, biofuels, antibiotics and other applications.
Predicting earthquake hazards from wastewater injection
ASU-led geoscientists develop a method to forecast seismic hazards caused by the disposal of wastewater after oil and gas production.
Stronger earthquakes can be induced by wastewater injected deep underground
Earthquakes are getting deeper at the same rate as the wastewater sinks.
Harnessing sunlight to pull hydrogen from wastewater
Hydrogen is a critical component in the manufacture of thousands of common products from plastic to fertilizers, but producing pure hydrogen is expensive and energy intensive.
Tracking sludge flow for better wastewater treatment and more biogas
Study finds the flow behaviour of sewage sludge can be used as a tool to gauge how quickly organic matter is dissolving at high temperatures, paving the way for online monitoring
Wastewater reveals the levels of antibiotic resistance in a region
A comparison of seven European countries shows that the amount of antibiotic resistance genes in wastewater reflects the prevalence of clinical antibiotic resistance in the region.
Fracking wastewater accumulation found in freshwater mussels' shells
Elevated concentrations of strontium, an element associated with oil and gas wastewaters, have accumulated in the shells of freshwater mussels downstream from fracking wastewater disposal sites, according to researchers from Penn State and Union College.
Irrigating vegetables with wastewater in African cities may spread disease
Urban farmers growing vegetables to feed millions of people in Africa's ever-growing cities could unwittingly be helping to spread disease by irrigating crops with wastewater, a new study reveals.
Study: Human wastewater valuable to global agriculture, economics
It may seem off-putting to some, but human waste is full of nutrients that can be recycled into valuable products that could promote agricultural sustainability and better economic independence for some developing countries, says a new study by University of Illinois researchers.
Wastewater treatment plants are key route into UK rivers for microplastics
Water samples from UK rivers contained significantly higher concentrations of microplastics downstream from wastewater treatment plants, according to one of the first studies to determine potential sources of microplastics pollution.
More Wastewater News and Wastewater Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.