Management of Non-Point Source Pollution CE 296B

1. Management of Non-Point Source PollutionCE 296B Department of Civil Engineering California State University, Sacramento Lecture #7, February 19, 1998 Sources of Pollutants - Part III

2. Recall that we were looking at the six categories of pollutants: 1. Toxic inorganics - e.g. metals 2. Synthetic organics - e.g. solvents 3. Biostimulants - BOD, nutrients 4. Sediment - clay, silt, sand, gravel 5. Pathogenic organisms - viruses, bacteria, protozoa 6. Trash - use your imagination

3. And the framework for acquiring knowledge about each category: • 1. What are the sub-categories in each category and what are representative members? • 2. What are the origins of pollutants? • 3. How pollutants are introduced to the flow stream? • 4. How pollutants behave in water?

4. IV. The third category of pollutant to examine is biostimulants. A. Define what a biostimulant is: A biostimulant is a substance, that when added to a receiving water, allows primary members of the food chain to increase their metabolic activity. 1. Primary members of the food chain: • Bacteria • Fungi • Protozoa • Algae

5. IV. The third category of pollutant to examine is biostimulants. (cont.) • A. Define what a biostimulant is: (cont.) • A biostimulant is a substance that when added to a receiving water allows primary members of the food chain to increase their metabolic activity. (cont.) 2. Increase in metabolic activity means: • Microorganism reproduce faster, which in turn- • Contributes to the process of eutrophication • Leads to an increased rate of resource consumption such as dissolved oxygen

6. IV. The third category of pollutant to examine is biostimulants. (cont.) • A. Define what a biostimulant is: (cont.) • A biostimulant is a substance that when added to a receiving water allows primary members of the food chain to increase their metabolic activity. (cont.) 3. To be living healthy receiving waters, some input of biostimulatory substances is required. The problem is when more than is required is added to a receiving water.

7. IV. The third category of pollutant to examine is biostimulants. (cont.) B. Categories of biostimulants: Each category is based on an element that contributes to nutritional requirements. To survive, living organisms require a wide variety of elements. Most, such as copper, selenium, arsenic, are provided in excess in most receiving waters. The amount of three elements, carbon, nitrogen, and phosphorous typically control the amount of biological activity.

8. IV. The third category of pollutant to examine is biostimulants. (cont.) • B. Categories of biostimulants: (cont.) 1. Carbon: Defining element for organic compounds. The oxidation of organic compounds, increasing the oxidation number of the carbon atom, is the energy source for most organisms.

9. IV. The third category of pollutant to examine is biostimulants. (cont.) • B. Categories of biostimulants: (cont.) Carbon metabolism can be either: • Aerobic: Respiration - organic compounds are oxidized and oxygen serves as the terminal electron acceptor. • Anaerobic: Respiration - organic compounds are oxidized and an inorganic compound other than oxygen serves as the terminal electron acceptor. Fermentation - organic compounds are oxidized and organic compounds serves as terminal electron acceptor.

10. IV. The third category of pollutant to examine is biostimulants. (cont.) • B. Categories of biostimulants: (cont.) • 1. Carbon: (cont.) a. Like virtually all other elements, carbon is cycled. Without a cycle, the worlds carbon would all end up in one form or another.

11. Organic Compounds H2O O2 Micro-organisms Animals Plants CO2 Carbon Cycle Oxygenic photosynthesis Aerobic Respiration, Combustion of Organic Material

12. Oxidation Oxidation of Organic Compounds

13. IV. The third category of pollutant to examine is biostimulants. (cont.) • B. Categories of biostimulants: (cont.) • 1. Carbon: (cont.) b. Measures of organic carbon in water samples: • BOD - The oxygen demand required to biologically oxidize the readily biodegradable carbon present. • COD - The oxygen demand required to chemically oxidize virtually all the carbon present to CO2. • TOC - The amount of organic carbon present, measured by pyrolosis.

14. IV. The third category of pollutant to examine is biostimulants. (cont.) • B. Categories of biostimulants: (cont.) • 1. Carbon: (cont.) c. As noted, not all organic compounds are readily biodegradable. A good example is lignin, a common substance in all plant material. It degrades very slowly. What if we analyze a sample for BOD5 and COD look at the ratio: The closer this number is to one, the more biodegradable the organic material in the sample is.

15. IV. The third category of pollutant to examine is biostimulants. (cont.) • B. Categories of biostimulants: (cont.) • 1. Carbon: (cont.) d. Because it is a carrier for fallen leaves and twigs, non-point source run-off often has a ratio of less than 0.2. BOD5 values are typically less than 20 mg/L and COD values are often above 80 mg/L. Substaintial concentrations of volatile suspended solids (VSS) help confirm the plant material connection.

16. IV. The third category of pollutant to examine is biostimulants. (cont.) • B. Categories of biostimulants: (cont.) • 1. Carbon: (cont.) e. Although carbon does have the potential to be a biostimulatory substance in non-point source run-off it is typically not considered a major problem. Note: The plant material itself, as a mass loading effect, can certainly become a nuisance.

17. Discussion Break As a biostimulatory substance, does organic carbon have a concentration pollution effect or a mass loading pollution effect?

18. IV. The third category of pollutant to examine is biostimulants. (cont.) • B. Categories of biostimulants: (cont.) 2. Nitrogen: For most organisms nitrogen is the second most required nutritional element, on a molar basis, after carbon. It is also the energy supply for nitrifying bacteria. These bacteria are present in all reasonable receiving waters. As with carbon, nitrogen has a cycle associated with it.

19. Nitrogenous organic compounds (e.g., amino acids) Microorganisms, plants, animals NH3 NO3- N2 NO2- Nitrogen Cycle Ammonification (microorganisms) Assimilation of nitrate Nitrogen Fixation (microorganisms) Assimilation of ammonia Nitrate Reduction Denitrification (microorganisms) Nitrification (aerobic) Nitrification (aerobic)

20. Oxidation Nitrogen Oxidation States

21. IV. The third category of pollutant to examine is biostimulants. (cont.) • B. Categories of biostimulants: (cont.) • 2. Nitrogen: (cont.) As can be seen from the nitrogen cycle, nitrogen in non-point source run-off can have a wide range of biostimulatory effects: a. Assimilation of ammonia Assimilation of nitrate Can, if nitrogen is the rate limiting nutrient, stimulate the growth of primary members of the food chain.

22. IV. The third category of pollutant to examine is biostimulants. (cont.) • B. Categories of biostimulants: (cont.) • 2. Nitrogen: (cont.) • As can be seen from the nitrogen cycle, nitrogen in non-point source run-off can have a wide range of biostimulatory effects: b. Through the process of nitrification the growth of nitrifying bacteria is stimulated and more importantly oxygen is consumed. c. Through the process of ammonification the growth of microorganisms is stimulated.

23. IV. The third category of pollutant to examine is biostimulants. (cont.) • B. Categories of biostimulants: (cont.) • 2. As can be seen from the nitrogen cycle, nitrogen in non-point source run-off can have a wide range of biostimulatory effects: (cont.) d. Through the process of denitrification and nitrate reduction the growth of microorganisms is stimulated.

24. Discussion Break The decay of plant material releases ammonia through the process of ammonification. How would a low BOD5 / COD ratio in a non-point source run-off lead to concern about mass loading problems with respect to nitrogen?

25. IV. The third category of pollutant to examine is biostimulants. (cont.) • B. Categories of biostimulants: (cont.) 3. Phosphorous: After carbon and nitrogen, the element next in line for the greatest requirement on a molar basis for balanced nutrition is phosphorous. Like carbon and nitrogen, phosphorous is cycled. Unlike carbon and nitrogen, no valence change takes place when phosphorous is cycled. Rather phosphorous is cycled between organic and inorganic forms.

26. Phosphorous Compounds

27. IV. The third category of pollutant to examine is biostimulants. (cont.) C. What are the sources of biostimulants in non-point source run-off: 1. Carbon: Excess plant material such as grass clippings, fallen leaves, used Christmas trees, etc. 2. Nitrogen: Excess plant material, fertilizers and, incomplete combustion. 3. Phosphorous: Excess plant material, and fertilizers.

28. Discussion Break The substantial imports of water from Northern California and Arizona to Southern California has allowed a far greater amount of plant material to grow in Southern California than would be possible under natural conditions. Could those water imports be considered biostimulatory non-point source pollution? How?

29. Discussion Break How could perfectly immaculate application of fertilizer, i.e., no excess fertilizer run-off, yield biostimulant non-point source pollution with respect to: Nitrogen? Phosphorous? Carbon?

30. IV. The third category of pollutant to examine is biostimulants. (cont.) D. How are biostimulants introduced into the non-point source pollution flow. 1. Atmospheric scrubbing, wetfall. Nitrogen There are places, where, for example the use of automobiles is heavy, the amount of nitrogen compounds in rainfall is significant. Examples: • The Los Angeles Basin • The Industrial Eastern U.S. • Lake Tahoe (The largest source of nitrogen is raindrops hitting the lake)

31. IV. The third category of pollutant to examine is biostimulants. (cont.) • D. How are biostimulants introduced into the non-point source pollution flow. (cont.) 2. Excess fertilizer run-off. Both an urban and rural problem. Nitrogen and Phosphorous Think about golf courses. 3. Run-off rich in animal excrement. Carbon, Nitrogen, and Phosphorous Stockyards, pig farms, Central Park in New York (all the dogs). 4. Excess plant material. Could be urban or rural. Carbon, Nitrogen, and Phosphorous