Periodic Table Nitrogen is in the Nonmetals/BCNO Group
Where is nitrogen found in the environment?
The largest single source of nitrogen is in the atmosphere. Nitrogen makes up 78% of our air!
It is one of nature’s great ironies… Nitrogen is an essential component of DNA, RNA, and proteins—the building blocks of life. Although the majority of the air we breathe is nitrogen, most living organisms are unable to usenitrogen as it exists in the atmosphere!
How does atmosphericnitrogen get changed into a form that can be used by most living organisms? N N
By traveling through one of the four processes in the Nitrogen Cycle! (1) Nitrogen Fixation (4) Denitrification Nitrogen Cycle (3) Nitrification (2) Ammonification
Nitrogen in the air animal protein nitrogen fixing plant eg pea, clover plant made protein dead plants & animals urine & faeces denitrifying Pseudomonas denitrificans root nodules (containing Rhizobium) decomposition by bacteria & fungi nitrates absorbed ammonia nitrates nitrites Azobacter Nitrobacter (nitrifying bacteria)
Yourtask! Imagine you are a nitrogenatom! Sendpostcardtoyournitrogenfriendsexplainigthefollowing: -Whereyouwere… -Whereyou are now…. -Whereyou are goingnext…. Don´tforgettoexplainanymeetingswith bacteria orhowyouhavechanged as a molecule!
Sewage IB Biology
Flushed with success? To draw attention to the people who do not have toilets or proper sanitation Built by Sim Jae-Duck, involved with World Toilet Association Seoul, South Korea Why? 2 billion
Sewage What is it? Untreated raw sewage is waste which has come from our toilets, sinks, baths etc. What does it contain? examples
Faeces, food fragments, enzymes, soap, gel, hair Phosphates, nitrates Some from detergents & washing powders Food poisoning, disease-causing
Environmental damage 14 July 07 14 Sept 07
In rivers can cause algal blooms (as sewage is a good food source for them), killing animals and plants living in water.
May release methane and ammonia gases (foul smelling).
Eutrophication Sussex River Ouse Sea trout nursery
Eutrophication High concentrations of inorganic substances can cause algal blooms Substances encourage rapid growth of algae and blue-green bacteria
Biological Oxygen Demand Sample of water measured at 20˚C over 5 days 2. Increase in organic pollutants increases number of bacteria BOD will increase Copy the steps above and give a reason as to why each step is occurring -use your handout to help!
Sewage treatment works
Why treat it?
May cause disease if it contaminates drinking water, due to harmful bacteria present.
Examples of diseases which may be spread by untreated sewage. dysentery, typhoid, cholera
Sewage treatment process 0 Untreated raw sewage enters the sewage works 1a 1b Aerobic conditions Sedimentation tank 2 3 Anaerobic conditions 4 5 Sewage water to: Screening (coarse filter) Metal grids strain out large objects Grit tank Stones and heavy solids sink to the bottom Lighter solids such as faeces sink to the bottom and form a sludge
Anaerobic conditions Aerobic conditions 3 4 5 6 *or biobeads Sludge digestion tank Bacteria feed on sludge, producing methane. Can be used as a fuel. Activated sludge tank Sludge mixed with extra air (oxygen), stirred, bacteria produce harmless liquids. Biological filter tank Fluid from tank sprinkled over stones* coated with microbes. Bacteria produce harmless liquids Treated waste emptied into rivers
Now complete yourSewageTreatmentcut and paste sheet!
Increasing energy levels Biofuels The main fuels which can be obtained from biomass:
Methane (biogas) production occurs naturally by fermentation (anaerobic respiration) when animal or plant material decays. Both are products of fermentation
Generation of methane from biomass Fermentation of faeces -aerobic bacteria hydrolysecarbs, proteins, fats Oxygenused up -acetogenic bacteriaconvertsugarsto short chainfattyacids (e.g.acetate), CO2 and H2 -acetogenesisstage Methanogenesis -final stageisanaerobicand involvesmethanogenic bacteria -conversion of actetatetomethane Temp: 30-40˚C