Presentation on theme: "1 We and Nitrogen: Explosives to Eutrophication Jawed Hameedi Center for Coastal Monitoring and Assessment National Centers for Coastal Ocean Science National."— Presentation transcript:
1 We and Nitrogen: Explosives to Eutrophication Jawed Hameedi Center for Coastal Monitoring and Assessment National Centers for Coastal Ocean Science National Ocean Service, NOAA NOAA Central Library Brown Bag Seminar 26 June 2008
2 Four aspects 1.Explosives and warfare 2.Agriculture 3.Nutrition 4.Contemporary
3 Stating the obvious! Nitrogen in the Earth’s atmosphere – 78% Nitrogen in the Earth’s crust – 20 ppm –[P=1,000 ppm] Nitrogen in the human body – 4 th most abundant element Human Body (70 kg) Oxygen: 43 kg Carbon: 16 kg Hydrogen: 7 kg Nitrogen: 2 kg Calcium: 1 kg Phosphorus Potassium Sulfur Sodium Chlorine
4 Dr. Jekyll and Mr. Hyde – split personality Building block for life’s essential molecules (nucleic acids, enzymes, pigments); deadly poison (cyanides, azides), anesthetic (nitrous oxide), key ingredient of nearly all antibiotics, and used in regulating heart function (nitric oxide, nitroprusside) Nearly all explosives are based on nitrogenous chemicals (e.g., TNT, nitroglycerine, nitrogen triiodide); nitrogen gas is used as a safeguard against certain liquid explosives. Hydrazine is used as a rocket fuel; nitrogen gas is used to prevent fire in spacecraft chambers. Nitrous oxide is approved as a food additive (aerosol propellant – whipped cream); alkyl nitrite (or “poppers”) taken with nitrous oxide causes hallucinations and “surfing;” some alkyl nitrites were used as antidote for cyanide poisoning.
5 I. Green Bamboo Fireworks First “fireworks” may have been caused by burning green bamboo shoots [when dry wood ran out] – Han Dynasty (200 BC) –Fast growing – traps air pockets –Various PAHs, alcohols and phenolic compounds Created sizzling sounds, little sparkles, and mini- explosions Nurtured a belief that the sounds and flames warded off the evil spirit “Nian,” which ate crops and people –Exploding bamboos became a ritual during the Lunar New Year festivals, and then extended to weddings, births and other occasions
6 Black Powder Explosions May have been discovered from accidental ignition of chemicals used to synthesize an “elixir” for life Initial ingredients in such experiments included chemicals of know medicinal value: mercury, arsenic, honey, and salts of various kinds by mixing or cooking various combinations of them Many noblemen died after tasting different potions, and a few laboratories were destroyed during “experiments” – until the “fire chemical” [or huo yao] was identified (500 to 900 AD) The fire chemical was potassium nitrate [saltpeter or saltpetre or stone salt] It was isolated and used in bamboo stems – first to ward off evil spirits, then to scare off enemy soldiers.
7 Ingredients for an explosive 1.Fuel – anything that would burn Charcoal, alcohol, fuel oil, honey, powdered aluminum 2.An oxidant – e.g., saltpeter, ammonium nitrate, perchlorate, etc. 3.Reaction stabilizer or catalyst – e.g., sulfur to help form potassium sulfide or potassium sulfate 10KNO 3 + 3S + 8C → 2K 2 CO 3 + 3K 2 SO 4 + 6CO 2 + 5N 2 2KNO 3 + S + 3C → 3CO 2 + K 2 S + N 2
8 Evolving pyrotechnology Add more saltpeter – bigger and faster burn Concept of “fuse” Inventing “fire arrows” Paper firecrackers [instead of bamboos] When open at one end, escaping gas would propel the device – a “rocket” was invented! Firework technology further evolved in Europe, notably Italy ( )
9 Explosives in Europe Introduced by the Mongols, who brought the explosives technology from China by way of the Silk Road – perhaps the Northern Route (13th Century) First “pipe bomb” – black powder in bamboos Technology advancement by putting gunpowder in bronze metal bells (from cathedrals) – ultimately inventing the cannon (14th and 15th Centuries) – capable of hurling massive stones and destroying castle walls and enemy frontlines
10 Quest for Saltpeter The ingredient of choice for weapons and wars but Europe had no minerals deposits of potassium nitrate –only source being rotting organic matter, notably urine. Thus dung heaps became a resource – creating artificial “nitre beds” to extract potassium nitrate crystals. –In 1626, King Charles declared an edict for conserving and contributing wastes from humans and animals, and that edict was enforced by a police known as “Petermen.” The Golden Age of Guano – Peru ( ): more than 20 million tons was excavated from arid (no rain) islands off Peru – largely under English monopoly The War of the Pacific ( ) was fought to control Chilean saltpeter (sodium nitrate) mines – the world’s largest
11 Haber-Bosch Process – Nitrogen fixation Fritz Haber -- professor of physical chemistry and electrochemistry – demonstrated (1909) a process of converting atmospheric nitrogen to liquid ammonia Carl Bosch – a pioneer in high- pressure physics and manufacturing – at BASF -- agreed to investigate large scale production
12 Haber-Bosch Process Within years (1913), commercial production of ammonia was feasible, and Germany was producing 60,000 tons of ammonia – making it self-sufficient in the production nitrogen compounds (for example ammonium nitrate) for use in making bombs and explosives during World War I.
13 II. Nitrogen Limitation in Agriculture Recognized in the earliest recorded times! Adaptations to this deficiency –Enriching the farm with crop residues and animal manure –“Resting” the soil between crops –Importing plants, e.g., sorghum from Africa, that would “fertilize” the field
14 The Age of Agricultural Revolution (8th to 13th Centuries) Rashid, Umayyad, Abbasid, and Fatimid dynasties Introduced crop rotation system – 4 different crops in a two-year cycle Planted fast-growing vegetables and grains in between the main crops Imported foreign crops [citrus, sugarcane, rice, herbs, etc.] Installed a pump-operated irrigation systems and canals Introduced a “cash market” for crops to assure supplies and pricing stability The “Fertile Crescent” became the most productive patch of land in the world.
15 Four Crop Rotation – England (18th Century) Wheat, barley, clover, and turnips – assured food and fodder [for livestock] on a year-round basis Crop fertilization – use of minerals
16 Haber-Bosch Process The process is now producing nearly 100 million tons of nitrogen fertilizers each year (ammonium sulfate, ammonium phosphate, ammonium nitrate, and urea) 27 million tons used in China 11 million tons used in US 11 million tons used in India
17 There is no imminent shortage of nitrogen- based fertilizers The Haber-Bosch Process has been termed the “Detonator of the Human Population Explosion” implying that the current human population and its lifestyles could not have been supported by the naturally occurring nitrogen cycle.
18 III. We need nitrogen! Nitrogen is essential to life: it is needed for construction of life’s basic building blocks, i.e., DNA and RNA molecules, and is also required to make proteins and enzymes that are crucial to the functioning of our bodies
19 There is no substitute for nitrogen intake! Our medical doctor friends tell us: Nitrogen deficiency can result in growth retardation in children; wasting of muscles, changes in skin pigmentation, reduced mental capacity, fatigue, and susceptibility to infections.
20 “Protein Paranoia” The US recommended daily allowance is less than one-half of a quarter pounder each day (or roughly 50 lb per year) Americans consume the most: roughly 275 lb per person each year Western European, Brazil, Argentina, New Zealand: lb/year
21 Other countries China – meat consumption is on a rampant increase having steadily gone up: –20 lb/year in the 1970s –120 lb/year in recent years Pakistan – 27 lb/year India – 12 lb/year These figures do not include seafood consumption, which in the US is about 16 lb/year
22 Meat Production Because of this voracious (and increasing) appetite for meat: We are sharing the Earth’s natural resources with more than a billion cows, about a billion pigs, nearly 2 billion sheep and goats, and 14 billion chickens Yearly meat production amounts to more than 200 million tons: –China million –US – 37 million –Brazil – 13 million –France – 6 million
23 IV. So, what’s the big problem? Only about 14 percent of nitrogen used as fertilizers results in crops and even lesser amount in human food. The remaining amount is lost: –during food production, including transportation and application of fertilizers, spoilage and waste –seepage to groundwater and surface water streams –as crop residue, animal waste –via escape of gaseous chemicals to the atmosphere. Nitrate in particular does not bind well with soil; it can be readily transported over long distances, typically ending up in large waterbodies
25 [Guess] estimates of sources and amounts (mt) of reactive nitrogen (1890 and1990) Terrestrial (natural)10089 Terrestrial (cultivation- induced) 1535 to 40 Lightning55 Guano-derived0.02 Nitrate minerals0.13 Marine140 (?) Nitrogen oxides emissions0.620 (30) Haber-Bosch Process90 (100) TOTAL to 404
26 Effects of nitrogen overload on land Nitrogen saturation of watersheds, i.e., more nitrogen is deposited than plants can use or bacteria can transform – causing excessive algal growth even in the most remote alpine lakes Lakes, streams and soils are becoming acidic, resulting in fundamental changes in ecosystems Nitrogen in groundwater contaminates drinking water; in some areas much above the criterion (400 vs. 10 mg NO 3 -N/L Nitrogen oxides promote formation of fine particulate matter in the air (respiratory problems) Nitrous oxide is an important greenhouse gas [it has a global warming potential 329 times greater than that of carbon dioxide]
27 A Global Environmental Issue– subject of conferences, research initiatives and declarations The direct and indirect delivery of fertilizers (reactive nitrogen) into coastal bays and estuaries has increased tremendously in recent years, and there are indications that the problem will worsen globally In nearly all parts of the world, the effects of excessive nutrient enrichment in coastal waters are obvious: –Unwanted and excessive algal growth that cannot be utilized by animals –Accumulation of large amounts of dead and decaying plant matter, and that sucks up dissolved oxygen in the water –“Dead zones” have now been documented all over the world –Coral reefs are surrounded by murky green, not azure blue, waters, with 40% of the world’s reefs in jeopardy of being lost.
28 CAFOs –animal meat producing factories In a book entitled “This Steer’s Life,” (Michael Pollan, NY Times: March 31, 2002), it was noted that “we have … transformed what was once a solar-powered ruminant into the very last thing we need: another fossil fuel machine.” It has been estimated that annual production of cows in the US requires 158 million barrels of crude oil equivalents – or more energy per cow than I use as gasoline each year! There is a general lack of management of manure from these operations; the argument is that you will not be allowed to put untreated human waste from a town of 120,000 people on a farmland but you can do that if you had a CAFO farm with 4,000 cows.
29 Trends in national and utility-only NO X and SO 2 emissions from 1985 to 2006 and projected to 2015 Burning of fuel at high temperature (automobiles, power plants, electric utilities, other industries) Escape from fertilized fields
30 Journey and fate of atmospheric nitrogen deposition Would the transport of nitrogen from the watershed to rivers and streams be minimal if atmospheric deposition were less than 8 kg/ha/year (as was shown in a northeast forest)?
31 Relative contribution of nitrogen sources to different estuaries on the US East Coast
32 Maumee River watershed – a poster child! Once a forested swampland – now nearly all farmland and Toledo –Tile drainage; poor soil and water management –Watershed loses millions of tons of soil to Lake Erie –Approximately, 850,000 cubic yards [85,000 dump truck loads] of sediment is dredged from Toledo Harbor each year Total phosphorus loading of about 100,000 kg/day [Detroit River: 2,250 kg/day]
33 Nitrogen and HABs Largely due to greatly increased inputs of reactive nitrogen to coastal bays and increased number of harmful algal bloom observations in recent years, nitrogen-related issues in coastal waters are stated or implied to include HABs. A direct relation between nitrogen over-enrichment, nearly always reported as concentration of dissolved inorganic nitrogen (DIN), and the onset and magnitude of HABs has remained difficult to quantify.
34 Nitrogen control strategy Standards, criteria and strategy are required under Clean Water Act amendments (1977), and the Great Lakes Critical Programs Act (1990) EPA -- concept of “ecoregions” –Adopt 25 th percentile of historically reported nitrogen data –Develop your own
35 Delaware River Basin Commission None of the states accepted the Ecoregion criteria Delaware River flows through 5 aggregate “ecoregions: with N criteria of 0.54, 0.38, 0.31, 0.69, and 0.71 mg/L (from upstream to downstream) Dischargers question “no measureable change” policy or capping nutrient discharge at some derived value of the dataset [17 year long for the bay] – effects? Nothing for the bay: 1-2 mg/L: very high ambient values
36 No numerical criteria for nitrogen control None for coastal bays and estuaries Just a handful of states have “approved” ones for entire classes of rivers and streams No toxicological benchmarks for protection of coastal and estuarine organisms; in Canada, an interim guideline exists (but not from impacts of eutrophication): 18 mg NO 3 /L National Estuaries Experts Workgroup (2006) – report due?
37 V. Take Home Messages -- I Excessive, unprecedented and increasing amounts of reactive nitrogen are entering the biosphere, almost entirely due to the Haber-Bosch process. Environmental concerns associated with nutrient enrichment are quite varied and potentially severe – ranging from low or non-existent dissolved oxygen in waterbodies, to smog and greenhouse effects, to eutrophication and altered ecosystems, and jeopardy of coral reefs. There are no environmental or toxicological criteria for protection of coastal and estuarine organisms and ecosystems.
38 Take Home Messages -- II Knowledge of nitrogenase Carbon sequestration on land Nitrogen fixation in the sea Effects of nitrogen deposition on the inorganic carbon cycle in the sea – ocean acidification Increased release of carbon dioxide from peat bogs under increased nitrogen deposition
39 Thank You! Photographs: Free downloads from the Internet, NOAA, cited documents, and the author
40 Nitrogenase The highly complex structure of the nitrogenase enzyme and its molybdenum-iron co- factor continue to “surprise” scientists Biosynthesis and catalytic roles; also where and how the substrates bind (Smith, 2002) One implication is relative to the role of iron in oceanic nitrification.
41 Carbon sequestration on land Many carbon sequestration scenarios for terrestrial ecosystems project hundreds of billion metric tons of carbon bound in trees and other plants; where would thousands of million tons of nitrogen come from? (Gruber and Galloway, 2008).
42 Nitrogen fixation in the sea What really is the global distribution of nitrogen fixation in the sea? Recent data indicate that it is quite variable spatially, and the supply of iron may not be the primary limiting factor for marine nitrogen fixation (Deutsch, et al., 2007) The figure in my table – 140 million metric tons – is an often-repeated but still a crude estimate (Galloway and Cowling, 2002)
43 Nitrogen deposition and ocean acidification The significance of 37 million tons of nitrogen deposition to the coastal and open ocean environments is yet to be determined, particularly in terms of ocean acidification and the inorganic carbon system Wet deposition of nitrate is acidic, and the dry deposition of ammonia is alkaline (Doney, et al., 2007)
44 Nitrogen deposition on peat bogs High level of nitrogen input can make bogs – such as peat bogs -- give off more carbon dioxide, thereby aggravating greenhouse effect. A huge amount of carbon is stored in peat layers, which consist of organic substances, such as polyphenols, that are difficult to break down. Bog mosses growing in nitrogen-enriched soils produce smaller amount of polyphenols; also grass and sedge plants tend to proliferate – this results in a net increase of carbon dioxide emissions (Uppsala University data).