Sources and consequences of Nitrate/Nitrite contamination of fresh water

[Billy T]

In some agricultural areas a significant, if not dominate, source of Nitrates in the water is from fertilizers used for crops. See especially Chapter 6 of this link {I quote start of one sub section now).

6.3 Gulf of Mexico
Production of corn for ethanol may exacerbate existing serious water quality problems in the Gulf of Mexico. Nitrogen fertilizer applications to corn are already the MAJOR source of total nitrogen loadings to the Mississippi River.971 A large area of low oxygen, or hypoxia, forms in the Gulf of Mexico every year, often called the "dead zone". Hypoxia threatens commercial and recreational fisheries in the Gulf because fish and other aquatic species cannot live in the low oxygen waters. The primary cause of the hypoxia is excess nutrients {nitrogen and phosphorus) from the Upper Midwest flowing into the Mississippi River to the Gulf. These nutrients trigger excessive algal growth {or eutrophication) resulting in reduced sunlight, loss of aquatic habitat, and a decrease in oxygen dissolved in the water.
The hypoxic zone in 2008 was the second largest since measurements began in 1985 -- 8,000 square miles, an area larger than the state of Massachusetts, and slightly larger than the 2007 measurement.972 The average size of the hypoxic zone over the past five years has been 6,600 square miles.

The above "already" is 5+ years old.

nitrous oxide (N2O), seems to be emitted when the feedstock crops are grown. This gas is a very powerful greenhouse gas, about 300 times stronger than CO2. There have been investigations* showing a negative potential; that is, bioethanol would be a greater contributor to global warming than regular fossil fuels (gasoline).

SUMMARY of two quotes: Very dumb the US program for corn based gasohol. More pollution than gasoline, more global warming than gasoline's GHGs, more farm subsidy cost to tax payers, higher grocery cost with ~1/2 {See graph at end) of corn crop not used as food {for chickens, etc. and people} but alcohol production that at best has only 10% more energy than the energy used to produce it from corn; But GWB set it up to gain a few, very few, but very rich new big contributors to his campaign funds. {My first of many threads telling this was called "How dumb can US voters be?" which I posted when GWB was campaigning for his second term - I got my question answered by that election.} BTW a well done study by Cornell concluded corn based alcohol had only 90% of the energy used to make it! University of Iowa, disagreed as did several other studies with financial interest in the corn to alcohol program.

* Paul Crutzen, I believe was first widely recognized authority to show this. In cold / short growing season, Iowa, so much nitrogen fertilizer is used to speed corn growth that most of it ends up being converted to NOx by soil bacteria – according to Noble Prize winning Crutzen. Also interesting from Paul Crutzen's 1995 Noble Prize Lecture at: http://www.nobelprize.org/nobel_prizes/chemistry/laureates/1995/crutzen-lecture.pdf
on page 201, is table 1 {which in PDF I can't copy) but it shows how UV light of less than 321nm makes the OH radical that gets into the troposphere as a molar ratio fraction of 4x10^-14 as measured some years earlier (than 1995) or in other words ~10^6 molecules / CM^3.

That table 1 also tell that the OH radial destroys CH4 with 50% chance any CH4 molecule will be oxidixed to water and CO2 within 8 years. i.e. had a half life of 8 years some time before 1995, but now so much CH4 is being released that it is the OH radiacal being destroyed by CH4 faster than OH can be produced, so the half life in 2013 was 12,6 years. Soon to be ~20 years.
During the first decade after its release each gram of CH4 makes the global warming effect of more than 100 grams of CO2 (called its GH “potential”} More referenced details:

A recent study,29 led by the Nobel‐prize‐winning chemist Paul Crutzen, claims that commonly used biofuel crops may in fact lead to increased GHG emissions due to N2O. Corn‐based ethanol was found to cause 0.9–1.5 times GHG emissions, compared to what is saved in CO2 emissions. Sugarcane ethanol was found to be a viable option with a factor of 0.5‐0.9. The study has been criticized for its basic assumptions and numbers
for crop‐to‐ethanol conversion, but a report from OECD24 supports Crutzen’s skepticism.
Ref 29: Corbyn, Z., “Biofuels could boost global warming, finds study,” Chemistry World, 2007. http://www.rsc.org/chemistryworld/News/2007/September/21090701.asp.
Ref24: Doornbosch, R., and Steenblik, R., “Biofuels: Is the Cure Worse than the Disease?” September 2007.

The link's is somewhat old, (May 2009) but a very complete discussion of bio-fuels, their global potential, differences in engines, etc.

One more problem with the new sciforums is that use of parentheses makes the enclosed words all run together with no spaces and be in italic. (why I use this mix}

This graph terminates about 2011 - is from different source.

 

[iceaura]

The nitrate fertilizer runoff and bacterial conversion problem may be reduced by the spread of no-till methods (originally made possible industrially by a GM developed by Monsanto, give the devil their due), but motor fuel from temperate zone corn has more problems yet - landscape destruction and ecological damage large among them. And the transition through the crunch time, when the absurdly shortsighted abuse of glyphosate (herbicide key to the GMOs involved} has burned it out, will be - as they say - interesting.

Meanwhile, the mood in my corner of the midwest is celebratory - gasoline has dropped below $3 per gallon, the KC baseball team is great to watch, Obama's malign powers are about to be curbed in favor of Republican patriotic American Christian family values restored to primacy in national politics, and a bunch of jobs paying around 25k a year have opened up. My neighbors have the memory span of fruit flies, I think.

 

[Billy T]

.. My neighbors have the memory span of fruit flies, I think.

And like fruit flies, a little radiation (from TV political ad) can greatly change their form, belief systems & votes.

 

[iceaura]

The EPA decision comes after the U.S. Department of Agriculture gave final approval last month to Enlist corn and soybeans, which have been altered to tolerate being sprayed with Enlist Duo herbicide. The specialty crops and the herbicide are to be sold as a branded "Enlist Weed Control System".

Like the popular Roundup Ready system developed by rival Monsanto Co, farmers who plant Enlist crops can spray over the crops in their fields with Enlist herbicide and kill weeds but not the crops.

Heavy use of Roundup herbicide triggered an explosion of herbicide-resistant "super weeds" that are hard for farmers to fight and which can choke off crop yields. Such weeds now infest roughly 70 million acres of U.S. farmland, according to Dow.

Enlist Duo combines a 60-year-old herbicide component known as 2,4-D with glyphosate, the chief ingredient in Roundup. Using the 2,4-D in combination with glyphosate should help farmers kill weeds that are resistant to Roundup, Dow officials say.

So glyphosate, among the least dangerous of broad-spectrum herbicides, is burning out under the abuse inherent in the GMO setup - but the agricultural infrastructure built around the GMO setup is embedded, not going away: instead, more toxic and dangerous herbicides are drafted into service.

One term for this: "chasing the dragon".