Monday January 21, 2019
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Researchers Look for Alternatives To Chemical Fertilizers for a Cleaner Environment

Too many nutrients in the water leads to poor water quality by causing hazardous algal blooms.

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Fertilizers
A farming woman spreads fertilizer in a paddy field. Flickr

Fertilizer is made of nutrients like nitrogen and phosphorus. Chemical fertilizers require huge amounts of energy to produce. But there are other, natural and more readily available sources.

The University of Michigan, with support from the National Science Foundation, is working at making our water cleaner, and our agriculture more sustainable, by capturing one of those sources, rather than flushing it down the toilet.

On a hot summer afternoon near Brattleboro, Vermont, farmer Dean Hamilton has fired up his tractor and is fertilizing his hay field — with human urine.

It takes a bit of time to get used to, says environmental engineer Nancy Love.

“I’ve been surprised at how many people actually get beyond the giggle factor pretty quickly,” she said, “and are willing to listen.”

Fine-tuning the recycling

Rich Earth Institute, a nonprofit, is working with Love and her team. Abraham Noe-Hays says they are fine-tuning new methods to recycle urine into fertilizer.

“There’s a great quote by Buckminster Fuller about how pollution is nothing but the resources that we’re not harvesting, and that we allow them to disperse because we’ve been ignorant of their value,” he said.

Harvesting the resource of urine — which is, after all, full of the same nutrients as chemical fertilizer — will fix two problems at once: eliminate waste and create a natural fertilizer.

The Rich Earth Institute has been using urine as fertilizer since 2012. Kim Nace says they collect about 26,000 liters a year, thanks to a loyal group of dedicated donors.

“We now have people who have some source-separating toilets in their homes. We also have people who have 55 gallon (200-liter) barrels where they collect and then we transport to our farms, and we’ve also got a large urine depot,” Nace said.

`fertilizers
Fertilizers. Wikimedia Commons

They pasteurize the urine to kill any microbes, and then it is applied directly onto hay fields like Hamilton’s.

Next level of project

Now that they’ve partnered with the University of Michigan, Love says they’re looking to take their project to the next level.

“There are three things we really are trying to do with the urine in this kind of next phase. We’re trying to concentrate it. We’re trying to apply technologies to reduce odor, and we’re trying to deal with trace contaminants like the pharmaceuticals,” she said.

Dealing with pharmaceuticals is an important issue. Heat urine kills germs but has no effect on chemicals like drugs that pass through our bodies.

“We know pharmaceuticals are a problem for aquatic organisms and water systems,” Love said. “It’s debatable about the impact on human health at very, very low levels. Independent of that, I think most people would prefer that they not be in their food.”

Fertilizers
Farmer Scott Halpin is facing another year of high prices for seed and fertilizer, and low prices for the corn and soybeans his family is planting on farmland outside Morris, Illinois.

21st century infrastructure

For Love, this is all about redesigning our wastewater infrastructure for the 21st century. Too many nutrients in the water leads to poor water quality by causing hazardous algal blooms.

“Our water emissions are going into very sensitive water bodies that are vulnerable to these nutrient loads,” she said. “We need to change that dynamic. And if we can capture them and put them to a beneficial use, that’s what we’re trying to do.”

Also Read: Common Plastic Chemical May Increase Breast Cancer Risk

Their efforts could make agriculture greener and our waterways cleaner. (VOA)

Next Story

New Technology That Can Clean Water Twice As of Now

more than one in 10 people in the world lack basic drinking water access, and by 2025, half of the world's population will be living in water-stressed areas.

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Novel technology cleans water using bacteria

Researchers, led by one of Indian-origin, have developed a new technology that can clean water twice as fast as commercially available ultrafiltration membranes, an advance that brings hope for countries like India where clean drinking water is a big issue.

According to a team from the Washington University in St. Louis, more than one in 10 people in the world lack basic drinking water access, and by 2025, half of the world’s population will be living in water-stressed areas.

The team led by Srikanth Singamaneni, Professor at the varsity, developed an ultrafiltration membrane using graphene oxide and bacterial nanocellulose that they found to be highly efficient, long-lasting and environment-friendly.

The membrane technology purifies water while preventing biofouling, or build up of bacteria and other harmful micro-organisms that reduce the flow of water.

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The membrane technology purifies water while preventing biofouling. VOA

For the study, published in the journal Environmental Science and Technology, they used bacteria to build such filtering membranes.

The Gluconacetobacter hansenii bacteria is a sugary substance that forms cellulose nanofibres when in water.

The team then incorporated graphene oxide (GO) flakes into the bacterial nanocellulose while it was growing, essentially trapping GO in the membrane to make it stable and durable.

They exposed the membrane to E. coli bacteria, then shone light on the membrane’s surface.

After being irradiated with light for just three minutes, the E. coli bacteria died. The team determined that the membrane quickly heated to above the 70 degrees Celsius required to deteriorate the cell walls of E. coli bacteria.

While the bacteria are killed, the researchers had a pristine membrane with a high quality of nanocellulose fibres that was able to filter water twice as fast as commercially available ultrafiltration membranes under a high operating pressure.

When they did the same experiment on a membrane made from bacterial nanocellulose without the reduced GO, the E. coli bacteria stayed alive.

The new technology is capable of identifying and quantifying different kinds of cyanobacteria, or blue-green algae, as a threat to shut down water systems when it suddenly proliferates. Pixabay

While the researchers acknowledge that implementing this process in conventional reverse osmosis systems is taxing, they propose a spiral-wound module system, similar to a roll of towels.
Also Read: India Gets Assistance of Rs 3,420 Crore From Japan
It could be equipped with LEDs or a type of nanogenerator that harnesses mechanical energy from the fluid flow to produce light and heat, which would reduce the overall cost.

If the technique were to be scaled up to a large size, it could benefit many developing countries where clean water is scarce, the researchers noted. (IANS)