Tag: wastewater treatment plant

Searching for New Bio-Diesel Source

The U.S. is looking for ways to depend less on foreign oil and reduce greenhouse
gas emissions. A popular method is so-called bio-fuels. Those are fuels, such as
ethanol or bio-diesel, made from plants. Cleaner burning bio-diesel has been billed
as an environmentally-friendly replacement for our 60 billion gallon a year thirst for
diesel oil. But there aren’t enough crops or land to produce enough bio-diesel to
replace fossil fuel-based diesel. Amy Quinton reports new research is looking at
another way to make bio-diesel: using algae:

Transcript

The U.S. is looking for ways to depend less on foreign oil and reduce greenhouse
gas emissions. A popular method is so-called bio-fuels. Those are fuels, such as
ethanol or bio-diesel, made from plants. Cleaner burning bio-diesel has been billed
as an environmentally-friendly replacement for our 60 billion gallon a year thirst for
diesel oil. But there aren’t enough crops or land to produce enough bio-diesel to
replace fossil fuel-based diesel. Amy Quinton reports new research is looking at
another way to make bio-diesel: using algae:


Bio-diesel is made primarily from plant oils: soybean, canola, rapeseed. Ihab Farag
is a chemical engineering professor at the University of New Hampshire. He climbs
up scaffolding to demonstrate a processor that turns waste oil from the University’s
cafeteria into bio-diesel. Farag says this is more environmentally-friendly than diesel:


“It’s coming from vegetable oil, so therefore it’s cleaner… it doesn’t have the sulfur in it so you
don’t get acid rain issue that you get from diesel, it doesn’t do particulates which are suspect[ed] to be cancer-
causing.”


Almost any diesel engine built in the last 15 years can use bio-diesel, but Farag says
there’s a major drawback: it takes an acre of most crops to produce only 100 gallons
of bio-diesel per year:


“I think it has been estimated that if we are using just something like soybean[s] and want to
produce bio-diesel for the whole country, we need almost an area of land that’s about
two and a half to three times the area of Texas.”


That would be an environmental nightmare because bio-fuels require a lot of fossil
fuels to plant, harvest and process them. They only produce a bit more energy than
the energy needed to make them. It also would put the nation’s fuel needs in conflict
with its food needs. That could drive the price of both sky-high.


So Farag and Master Chemical Engineering student Justin Ferrentino are looking at
another plant. One that’s capable of producing much more oil : algae.
Inside the University’s bio-diesel lab, Ferrentino holds up a glass jar filled with a sea-
green powder:


“This is freeze-dried cells that we’ve grown up in our photo-bioreactor.”


He’s testing different ways of extracting oil from these single-celled algae plants to
produce the most bio-diesel:


“People have projected with micro-algae you can grow somewhere between five and 15,000
gallons per acre per year, so it’s a big difference.”


Compared to 100 gallons per acre of soybeans, it’s a very big difference. Ferrentino
has built a contraption of two small fiberglass tanks, surrounded by florescent lights
and reflectors. It’s called a photo-bioreactor. With the right amount of light, the algae
here grows rapidly:


“When I fill these with growth medium and then add the cells to them and they just
multiply, they divide… they double every ten to 15 hours, when they’re growing
exponentially.”


The more cells, the more oil, and the more bio-diesel. Ferrentino’s photo-bioreactor
is small, producing only a tenth of a gram of bio-diesel. But build one on a larger
scale where there’s lots of sunlight, like the desert Southwest, and it could potentially
produce thousands of gallons on just an acre of land.


And Farag says because carbon is needed to fertilize algae growth, the potential
exists to remove greenhouse gases while simultaneously producing bio-diesel:


“If we can connect it with a wastewater treatment plant, where they have a lot of
waste coming in with lots of carbon in it then you can consume the carbon to grow
the algae and at the same time clean up the wastewater.”


But skeptics say one of the biggest challenges is making algae production
economical. Commercial production would initially yield fuel that could cost between
20 and 50 dollars a gallon. Ferrentino recognizes the drawbacks, but says their
research is worth pursuing:


“I think that our energy needs are not necessarily going to be solved with a magic
bullet, but I think this is certainly one part of it, being that you don’t need arable land
you have the added benefit of maybe being able to use the carbon from flue gases
from power plants, maybe being able to treat wastewater. So, it has some significant
added benefits so it could be one piece of the energy picture.”


But growing algae in the desert or anywhere else doesn’t have the kind of political
appeal that subsidizing farmers to grow soybeans for soy-diesel does. So finding
funding for a commercial-sized algae bio-reactor will face significant obstacles.


For the Environment Report, I’m Amy Quinton.

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Ten Threats: Sewage in the Lakes

  • Workers build Toledo's wet weather treatment system. The system is expected to go online next fall. It will treat water in the event of a storm. (Photo by Mark Brush)

Point source pollution means just that. It’s pollution that comes from a
single point; usually out the end of a pipe. It’s easy to identify. Since
the passage of the Clean Water Act more than 30 years ago, most of that kind
of pollution has been cleaned up, but today, there are still some pipes dumping
pollution into lakes and rivers, but Mark Brush reports stopping that remaining
pollution isn’t that easy:

Transcript

We’re continuing our look at Ten Threats to the Great Lakes. Lester Graham
is our guide through the series. He says the next report is part of coverage
of a threat called point source pollution.


Point source pollution means just that. It’s pollution that comes from a
single point; usually out the end of a pipe. It’s easy to identify. Since
the passage of the Clean Water Act more than 30 years ago, most of that kind
of pollution has been cleaned up, but today, there are still some pipes dumping
pollution into lakes and rivers, but Mark Brush reports stopping that remaining
pollution isn’t that easy:


(Sound of the Maumee)


We’re on the banks of the Maumee River near Toledo, Ohio. Sandy Binh
brought us here to describe what she saw in the river several years ago when
she was out boating with some friends.


“When there was a heavy rain maybe five years or so ago this is where we saw
a sea of raw sewage in this whole area. It was like, I mean it was like chunks
everywhere. It was just disgusting.”


Binh reported it and found that the city couldn’t do anything about it. That’s
because Toledo’s sewage treatment plant is at the end of what’s called a combined
sewer system. These systems carry both storm water from city streets, and raw
sewage from homes and businesses. If too much water comes into the plant, a
switch is flipped, and the sewage goes straight into the river.


(Sound of treatment plant)


Steve Hallett manages engineering at the wastewater treatment plant for the
city of Toledo. He says a rainstorm can bring twice as much water as the
plant can handle.


“And when hydraulically you can only take about 200 million of it – where’s
the other 200 hundred million go?”


“Where does it go?”


“Uh, it’s by-passed. Limited treatment possibly and then it would be
by-passed to the Maumee River”


Toledo is not alone. More than seven hundred cities across the country have
combined sewer systems that often overflow, cities such as Milwaukee,
Detroit, Buffalo, Chicago, and Cleveland. Every year billions of gallons of
raw sewage are dumped into the Lakes from cities with these old combined systems.


The sewage can cause problems for the environment, but the biggest concern
is that people might get sick. Some of the bugs found in sewage can cause
liver problems, heart disease, and can even cause death.


Dr. Joan Rose is a microbiologist with Michigan State University. She’s
been studying sewage in water for more than 20 years. She says sewage
contains viruses and other nasty microorganisms that can hang around in the
environment.


“Up here in the Great Lakes region with the cool temperatures we have –
these organisms can survive for months, and also these organisms
accumulate.”


Rose says what’s unique about the microorganisms in sewage is that it only
takes a few of them to cause diseases in humans, and once contracted they
can be contagious.


The Ohio EPA sued the city of Toledo. It wanted the city to clean up its
act. After a long battle, the city and the state reached a settlement, and
officials agreed to spend more than 450 million dollars to try to do
something about the problem.


(Sound of construction)


Back at the wastewater treatment plant we’re standing on the edge of a deep
pit. Down at the bottom sparks are flying as welders climb over towers of
green rebar. They’re building a new system that’s designed to treat water
quickly when there’s a heavy rainstorm. The water won’t be fully treated,
but the solids will be settled out and the water will be chlorinated before it’s
released into the river. It’s a compromise the city and the state EPA agreed
upon.


Steve Hallett says to fully treat every drop of water that comes to the
treatment plant in a big storm would require a project four times this size.


“You’d need massive amounts of storage to hold every drop here. You know, that’s
extremely costly and I think, uh, is deemed not feasible.”


Toledo’s project will mostly be paid for by a steady hike in water and sewer
rates over the next fifteen years. The increase was approved by voters
three years agom, and officials plan to go after federal grants and loans
to help defray the costs, but federal dollars are getting scarce. Big cuts
have been made to the federal low interest loan program many cities use to
finance these projects.


The demand for financing is likely to increase. The cost of upgrading the
nation’s combined sewer systems will cost hundreds of billions of dollars.
The question is, who will pay to stop one of the biggest sources of water
pollution left in the country?


For the GLRC, I’m Mark Brush.

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Researchers Seek to Reduce Fertilizer Pollution

New research could reduce the amount of fertilizer pollution coming from farms. After manure is spread onto farm fields, nutrients like phosphorus can run off into nearby lakes and streams. Too much phosphorus in the water leads to excessive plant growth, which can eventually choke out fish and other aquatic species. The Great Lakes Radio Consortium’s Erin Toner reports:

Transcript

New research could reduce the amount of fertilizer pollution coming from farms. After manure is spread onto farm fields, nutrients like phosphorus can run off into nearby lakes and streams. Too much phosphorus in the water leads to excessive plant growth, which can eventually choke out fish and other aquatic species. The Great Lakes Radio Consortium’s Erin Toner reports:


A researcher at Michigan State University found that treating liquid dairy manure with certain chemical compounds reduced the phosphorus load in the manure by 80 percent. The phosphorus binds to the compounds and then settles out in a solid form. Researcher Dana Kirk says the process is common at wastewater treatment plants. He says it could be expensive technology for farmers.


“The upfront costs are generally very high. If we can find ways to sell this product or put an better economic value on manure, it potentially could, you know, at least be a
break-even venture.”


Kirk says he’s working with a company to test the manure-treatment system at two farms in Michigan. He says using this treatment process to remove phosphorus from manure would have to be tailored to each individual farm.


For the Great Lakes Radio Consortium, I’m Erin Toner.