Comments on Managing the Nitrogen Cycle

Cecile Gonzalez
Cecile Gonzalez

PostedFebruary 14, 2008

What are the "low-hanging fruit" produced by excess nitrogen that engineering could tackle first?  Which aspects of this problem are most noticible to you?

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  • Kartik Chandran
    Kartik Chandran

    Posted 4 years and 2 months ago

    Kartik Chandran from Columbia University, New York comments on Where to reduce nitrogen first?
    Wastewater streams are an example of low-hanging fruit from which nitrogen can be removed. These are far more controlled than 'diffuse' nitrogen sources such as agricultural runoff. An additional benefit of removing nitrogen from the aqueous phase is that gaseous emissions of nitrous oxide (a greenhouse gas 300 times more potent than CO2) can be also reduced concurrently. A link to a recent article on this topic is as follows:

    http://pubs.acs.org/doi/abs/10.1021/es200419h
  • Philip H.
    Philip H.

    Posted 8 years and 3 months ago

    Philip H. from Silver Spring, MD comments on Where to reduce nitrogen first?
    I saw this on the Science Cheerleader, and I have to say that the Nirotgen Cycle challenge is probably one of the most interesting to me as an oceanographic scientists. I'm a little concerned, however, that you are looking for solutions to nitorgen issues without mapping the interactions between nitrogen, carbon, silicon, and the hydrologic cycles. If you make an intentional perturbation in the nitrogen cycle to address changes in denitrofying microbes, you may well upset the carbon fixing portion of those microbes lifecycles. That sort of disruption can well lead to other disruptions to a complex system. Not what I think you are after.
  • E.M. van Wingerden
    E.M. van Wingerden

    Posted 8 years and 9 months ago

    E.M. van Wingerden from Netherlands, E.U. comments on Where to reduce nitrogen first?

    Unfortunately, we seem to have lost control of all the elements on the table, with nitrogen perhaps not even the most acute of problems (plutonium probably tops the list in Washington). The Netherlands in North-west Europe, is by far the most nitrogen-intensive economy in the world. As such many studies have been conducted and engineering innovations are at a very high level. (We have here what is called ´food-valley´ centered around the agricult. university of Wageningen). In general I wish there would be more student-exchanges for young engineers, and more cooperation on matters such as intellectual property rights, agricultural policy, between the U.S., the E.U. and most importantly: China. Because China is definitely the lowest hanging fruit: it will have a huge future problem with its nitrogen run-offs. From a nitrogen viewpoint there are 3 main routes towards a more sustainable, durable food-chain:


    1 incease of the N-efficiency of production. By the use of better genetically modified races. By adjustments in agricultural management (mineral bookkeeping, guided fertilizing machinery, manure-processing installations on the premise of diaries and cattle farms combined with power production, more use of biological N-binding). By the growth of vegetables without the use of soil: hydroponics by computer controlled greenhouses that recycle the watersoluble fertilizers constanly.


    2 A relocation of food production to regions that because of their climate and physical environment allows higher N-efficiencies to be achieved. In practice this means an end to all agricultural subsidies eg such as those for corn-ethanol.


    3 Increase of the N-efficiency of consumption. By less protein consumption: U.S. citizens and North, East-Europeans are 30-50% above the daily recommended levels. By more consumption of proteins that can be produced with a higher N-efficiency, mainly vegetables, poultry, cheeses (an excellent way to store fat) and cultured fish at the cost of beef consumption. Here I see a great future for algae-based aquaculture (see: algaelink.com). Agriculture + Aquaculture = more Culture. Algae mass DOUBLES from 0.3 to 3 times a day, depending on strain selection. This means exponential growth, and by modular bioreactor expansion at ethanol fermentation plants, breweries, and clean powerplants, local markets everywhere in the world (where there is pure CO2) can be flooded with FRESH uncontaminated tuna, clams, lobster, trout, shrimp, mussels, salmon, carp, catfish, tilapia and of course: oysters. Enjoy your lunch.

  • Richard Rogala
    Richard Rogala

    Posted 8 years and 11 months ago

    Richard Rogala from L'Anse,MI comments on Where to reduce nitrogen first?
    A U.S. Patent has been awarded on Feb. 5, 2008 for a new type of Electric Generator that may soon be developed into an alternative energy source which the inventor hopes may soon replace the need for all combustion, as well as all other energy sources. The Nullgrav Corporation was founded by Richard Rogala to develop the Rogala Electric Generator. The Nullgrav team will develop this new device for two distinct purposes: 1. To improve the efficiency of the electric generator as is used in all coal burning and nuclear power plants, wind generators and portable generators 2. To prove the viability of extracting so much electricity from magnetism to allow the generator to spin itself with a net output of "free" electricity. The first purpose will strive to use Rogala's new Patented generator design to yield above the 85% efficiency ceiling common to conventional electric generators. This may result in more electricity being generated by a ton of coal or conversely produce the same amount of electricity from less coal than today and therefore less greenhouse gas. The second purpose may take the efficiency above 100% enabling a net output of electricity 24/7, without the use of any fuel or combustion. The simple fact is that current generators have inherent opposing forces when put under load which result in a limit to the amount of power that can be extracted from the magnets. This characteristic is seen when you hear a typical portable gas generator slow down when you suddenly put the power it's producing to use. By eliminating the features that cause this opposition the Rogala generator may be able to extract far more electricity from the same magnets. This has no relation to the myth of perpetual motion since the source of the power is the naturally occurring phenomenon of magnetism. This power has always been hidden in magnetism, but conventional methods of generating could not tap it fully. Rogala's Nullgrav team will work to develop this into a product which may prove to power homes and cars without the use of any fuel or combustion. This development may use the proven patented method to make all combustion obsolete. While the first purpose may only cut greenhouse gas production, the second purpose may address the vast need for energy and elimination of all greenhouse gas production. Even the global emergency of inadequate pure drinking water could be addressed by teaming up the Rogala generator with Reverse Osmosis Seawater Desalination to make pure drinking water from that which covers 7/8 of the planet. Eventually Nullgrav may license the manufacture of their generators to the automakers so that fully electric fuel free cars can be produced. These cars could be made to allow the power they produce to be used when the car is at home to power your house, in addition to units that would permanently provide household power. When all of humanity gets the energy it needs from a decentralized generator such as this, our lifeblood will no longer be tapped to make the owners of petroleum and municipal electric companies wealthy. We will no longer pay "rent" for energy, for we may now be able to get it directly from nature.
  • Ernest Rogers
    Ernest Rogers

    Posted 8 years and 11 months ago

    Ernest Rogers from Pleasant Grove, Utah comments on Where to reduce nitrogen first?
    NOx and N2O are quite separate issues. I will talk about one, NOx. Here is my breakdown on where the NOx is coming from in the U.S. (data about seven years old) Gasoline engines..........18% Diesel engines...............35 Power plants.................22 Process heat.................16 I think gasoline engines (mostly cars) are making great progress, and we can expect less use of gasoline engines in the future. So this matter is under control. I will offer ideas on the remaining sources. DIESEL ENGINES Thermodynamics created the problem (the heat engine) and I think we should look to thermodynamics for the solution. Above about 2200 deg K, NOx forms. Below 1900 K, it doesn't. It's generally believed that high temperature is needed to obtain high energy efficiency and good combustion efficiency. Going back and checking the thermodynamics, we see that it is not the source temperature that is essential, but the ratio of source temperature to sink temperature. And, this in turn is closely connected to the compression ratio. From this viewpoint, solving the NOx emissions of diesel engines seems simple-- keep the compression ratio high but devise to keep the local flame temperature low everywhere. The other issue is to maintain efficient combustion with a lower flame temperature. There are many possibilities here. (HCCI is sometimes mentioned.) I suggest reconsidering the type of fuel that is burned in diesel engines. Diesel engines can be operated on gaseous fuels (such as methane) with essentially no NOx emissions. But, I would hope that another fuel could be found, dimethyl ether being one possibility. In summary, the performance of the diesel engine can be maintained very high, but with very low NOx emissions, by redesigning the engine-fuel system. POWER PLANTS AND PROCESS HEAT At least for coal power plants, great efforts are being made to clean them up, and I can't see to add much there. But, maybe there is another approach. Could it be practical to work on capturing ALL of the remaining pollutants after they leave the plant? Why not? A couple of ideas-- We are having trouble finding enough productive land to meet our agricultural needs. Could we use the plant exhaust to provide a nutrient-rich "produce factory?" Here, you have heat, fixed nitrogen, moisture, and elevated CO2, just what every farm crop dreams of having. Some sunshine and minerals complete the farm requirements. Maybe biologists could work out an aquatic system that thrives on the plant exhaust. Growing algae for biofuel has been suggested, but there may be better possibilities. Most of what I've said about power plants could apply to process heat. Additionally, most process heat requirements are for temperatures below the NOx formation temperature of 1900 deg. K, suggesting research toward "very low NOx" burners.. Further, with some imagination, many process heat requirements might be met by solar heat. I appreciate what you are doing with this web site. GOOD JOB! Ernie Rogers
  • Brad Morton
    Brad Morton

    Posted 8 years and 11 months ago

    Brad Morton from Cupertino Ca comments on Where to reduce nitrogen first?
    Switchgrass, Switchgrass, Switchgrass ! Rotating crops intermittently with this warm season grass, rebuilds soil without the need for fertilizer. It doesn't require alot of water, and as much as 15 tons (dried) can be grown annually per acre for up to ten years without the need to replant it annually. Farmers can bank on it as a bio-fuel in the future, but we don't have to wait for the new and improved ethanol plants. Pelletizing it and burning it in highly efficient gasifying multi-fuel furnaces for heating homes can be done RIGHT NOW ! Just ask Vinod Khosla. b 408 887-8466
  • Evan Larson
    Evan Larson

    Posted 8 years and 11 months ago

    Evan Larson from Arroyo Grande, CA comments on Where to reduce nitrogen first?
    From the article: "In addressing the nitrogen cycle problem, experts must remember that fertilizers and farming have played a central role in boosting worldwide food production," Boosting food production provides more food at a discounted price. This low price and increased production creates hidden costs to society. We have more children because food is remains cheap and we are relatively oblivious to the costs imparted to the Earth, which it will not pay (we will later & highly taxed at that). I believe the lowest hanging piece of fruit is population control (education). This may not produce the quickest results, but the longer this is not addressed...the worse it will be....exponentially. I do not believe technology will have a chance to compete with the effects of growth and consumption. We are already well past the point of continuing our existence on the supplies the Earth has to offer. It will be "fun" and "interesting" to see what we, as a scientific community, create in coming years. Sadly, the destruction of the Earth due to overconsumption and destruction will overcome scientific novelties. Evan Larson, PE B.S. / M.S. Civil & Environmental Engineering 2003 Cal Poly SLO
  • John LaRue
    John LaRue

    Posted 8 years and 11 months ago

    John LaRue from Mason, Michigan comments on Where to reduce nitrogen first?
    Regarding the manure issue. Although transporting is sometimes difficult and costly, perhaps a tangible solution would be to centralize locations for manure to be processed, either liquified or reduced to dried material. This centralization has worked very well in other commercialized endeavors. Taking my location for instance. Haulers could remove manure from farms, feed lots, etc from around the state and then transport it to centralized processing plants, take for example, Grand Rapids, Lansing, Detroit suburbs, Sault Ste Marie, Gaylord, Bay City, Escanaba. These facilities could be run in an evironmentally safe and clean manner. The threat of stench and the NIMBY attutude would be reduced. Then the processed items could be retransported out to farms for distribution to grow more plants. It offers a possibility of recycling as well as efficient use of a nitrogen based item. Although this may seem far fetched, the possibilities are there. They would also offer employment opportunities especially in areas where that is a needed situation. And this could be manifested worldwide.
  • Fred Moore
    Fred Moore

    Posted 8 years and 11 months ago

    Fred Moore from Australia comments on Where to reduce nitrogen first?
    Thermodynamics: Engineers know that a statistical interpretation of the 2nd Law of Thermodynamics implies that increasing the per capita ENERGY input to ANY system of entities (including human populations) results in increased ORDER or lower ENTROPY of that system. By this analysis the ONLY engineering solutions required for the N-Cycle problem are to use hot rock GEOTHERMAL power as the major metropolitan and industrial human power source, stabilise global population to between 6 & 7 billion people and use engineered wetlands to reduce raw wastes entering coastal seas by 75% of current levels, all within a decade. These INPUT, PROCESSING and WASTE initiatives all work synergistically to lower per capita ENTROPY. This is effectively a BRAIN BOOST for all mankind that will see the brain boost from the internet revolution pale. Although the term 'brain boost' is literary and widely derided, thermodynamic considerations dictate the reality of its existence. Simply put, the lower the entropy the units within a system are the longer the system takes to decay. The only way that can be in thinking units like hamans within civil populations is if INTELLIGENCE is correspondingly increased. I submit that this is at the root of the N-cycle problem and the only engineering solution required for the N-cycle problem to be solved within a decade. Geothermal considerations: Until direct extraction of energy from close orbits to the Sun is possible Geothermal power can be shown by thermodynamic analyses based on EMERGY (see dieofforg.com) to be THE ONLY SUSTAINABE power source. Power station construction times (@ 5Km depth) of between 6-9 months should be targetted within a decade. Laser drilling technologies MUST be used and perfected and any resistance to their use from competing OIL interests must be quashed. Population control: The concept of rights for the unborn must be reevaluated in light of the imminence of a PEAKOIL2025 chaotic meltdown possibly reducing human numbers to 2 billion impoverished people within 6 months of a PEAKOIL crisis commencing. A one child per woman policy Engineered wetlands: the final and perhaps the most important step in the Thermodynamic Cycle is the waste elimination. Engineered wetlands can replace all the wetlands destroyed in the last 200 years with less than 100th the acreage and many times the efficiency of using INSOLATION to slow-time convert wastes at BMP(Best Management Practice) to easily transportable waste streams, most of which will be reuseable. This is the most direct solution to the N-cycle problem as it will potentially capture through waterway ENDPOINTS nearly all of humanity's fixed-nitrogen waste. Plug the inequities of free enterprise capitalism: Inequities in existing capitalism models actively resist solutions to all 14 engineering challenges because those solutions present challenges to staus quo monopolies that have been carefully crafted over the decades since WWII. Unfortunately America is at the forefront of these ineqiuities and the aroma of straw(man) hangs over this engineering challenge accordingly. In short all CEOs of US companies must have salaries and remunerations legislated to be no more than twice that of elected government officials. This will allow free enterprise to thrive whilst removing corruption, monopoly, collusion and inequities that are holding back engineering and scientific breakthroughs in all 14 engineering challenges. Rather than reducing competition for talented executives, this US initiative would send a message to the rest of the world that corruption, the breeding of future Adolph Hitler CEOs beyond all government control and ensuing global warfare a la 'Omega Man' and 'Soylent Green' scenarios is the most serious threat to the sustainability of the human race over the next 2 decades. I chose the N-Cycle challenge to draw out this Thermodynamic Cycle approach because as a CYCLE it fits well with the entire concpt of life, death, preserving the collective historical OUTPUT of humanity and its future sustainability both on this planet and beyond.