The document discusses nutrients and their role in ecosystems. When organisms first conquered land, nutrients were recycled through their waste returning to the soil and sea. However, as populations grew and centralized in cities, nutrients were exported away from farmlands, decreasing harvests. The issues were addressed through artificial fertilizers but caused pollution problems. Modern sewage systems and treatment plants remove phosphorus but accumulate it in sludge near cities, risking future leakage and negating water treatment benefits. Long-term sustainability requires recycling nutrients through improved infrastructure instead of accumulation and leakage.

2. What happened when the living organisms conquered land ? Nutrients in food Nutrients in urine 2 The situation after the first animals had conquered land

3. After just a few tousand years:

4. Where are the green fields my ancestors were bragging about?

6. Nutrients Without gaseous phases — must be transported as solids or liquids More common in the Earth crust than in the body The constituents of an animal (or vegetable) body: H O C N S P Na K Ca … 64 P H O C N S Na K Ca … 64 With gaseous phases — can be transported by the air – phosphorus is the most important nutrient ! P 10 times more common in the body than in the Earth crust

7. Nutrients are essential for life -- but phosphorus is the most crucial

8. We need a method to use the phosphorus molecules several times, without losses, so we can retain phosphorus on land! !

9. If we could transfer the phosphorus seamless from organism to organism without losses to sea, we might solve it !

10. PO 4 DNA Urine Consumption Recycling Reconstruction The regenerative cycle, basic for living systems -- ecosystem level: A seamless transport of phosphorus from organism to organism!

11. Petrified newspaper found in the Cretaceous – Devon geosynclinal

12. PO 4 DNA Urine Consumption Recycling Reconstruction The regenerative cycle High exergy Low exergy

14. Present times

15. In preindustrial times, the farmland nutrients came from the meadows Meadows PO 4 N A certain amount of meadows were needed to feed the farmland Manure Feed Food Farmland PO 4 Phosphorus and nitrogen were collected by the meadow plants

16. During industrialisation, people moved into cities

17. PO 4 N The nutrients that went away to the cities never came back Manure Feed Food PO 4 These nutrients were collected by the meadow plants In the cities, they also needed food, food from the farms The food contained nutrients The export led to an impoverishment of the agricultural land Food PO 4

18. The impoverished land produced insufficient harvests This triggered emigration The industrialisation process might have been halted by the loss of nutrients from farmland PO 4 Food

19. The situation was solved by the invention of artificial fertilizers By that, the nutrients from the meadows became unnecessary Even more food could be produced PO 4 Food PO 4 Food

20. But in the cities, the situation was becoming problematic PO 4 Food PO 4 Pollu-tion PO 4 Pollu-tion PO 4 Pollu-tion PO 4 Pollu-tion PO 4 Pollu-tion

21. But the invention of the piping system eased the problems PO 4 Food PO 4 Pollu-tion PO 4 Pollu-tion PO 4 Pollu-tion PO 4 Pollu-tion PO 4 Pollu-tion

22. However, at the end of the pipe, new problems were encountered Plancton algae multiplied gladly from the new phosphorus PO 4 Pollu-tion PO 4 Pollu-tion PO 4 Pollu-tion PO 4 Pollu-tion PO 4 Pollu-tion

23. Already 50 years after the introduction of the process, it was realised that it was the phosphorus that caused the problems in the water Therefore, the politicians asked the technicians for a way to remove the phosphorus from the waste water PO 4 Pollu-tion PO 4 Pollu-tion PO 4 Pollu-tion PO 4 Pollu-tion PO 4 Pollu-tion

24. Naturally, they solved the problem in their usual expedient way Large particle filtration Sedimentation Sedimentation Aeration Flocculation Rotation Filtering Air Aluminum sulphate Sludge The problem Problem solved!

25. The problem to be solved was: ” How to get (moderately) clean water from the polluted water?” This problem was solved . The problem Problem solved!

26. Sludge However, the question not asked was: ” How to recycle the phosphorus to avoid the problem?” A large part of the phosphorus is contained in the sludge

27. Food Food Food PO 4 PO 4 PO 4 Most of the food to the city comes from very large distances ..while the phoshorus in the sludge is placed on a much smaller area City

28. Food Food Food PO 4 PO 4 PO 4 This means that there will be an accumulation of phosphorus around the city PO 4 PO 4 PO 4 PO 4 After some time, the leakage from this heap will equal what is put on The larger the amount accumulated, the larger the leakage

29. Food Food Food PO 4 PO 4 PO 4 PO 4 PO 4 PO 4 PO 4 At that time, the investment in water purification plants becomes meaningless

30. Food Food PO 4 PO 4 PO 4 PO 4 PO 4 PO 4 PO 4 PO 4 PO 4 PO 4 The HEAP-effect, in a saturated system When saturated, the system leaks at the same rate as it is loaded With effiecient waste water treatment methods (P precipitation), this state is attained faster City