1. The characteristics of urine, faeces and greywater Course 1 Unit 2 1 Teacher Mariska Ronteltap m.ronteltap@unesco-ihe.org

2. Course 1 Unit 2 The characteristics of urine, faeces and greywater 2 Course 1 Unit 2 Content :  Brief introduction  Part A: Characteristics of urine  Part B: Characteristics of faeces  Part C: Characteristics of greywater

3. CHARACTERISTICS Brief introduction 3

4. 4 composting, anaerobic digestion organic waste soil improvement, biogas Treatment examples Reuse Substance faeces (brown water) anaerobic digestion, drying, composting biogas, soil improvement greywater (shower, washing, etc.) irrigation, groundwater recharge, toilet flushing urine (yellow water) N-rich fertiliser storage filtration, biological treatment rainwater water supply, groundwater recharge Separated „waste“ streams are easier to treat and reuse constructed wetlands, soil filters, membrane technology Source: GTZ-ecosan project, resource book = black water (with small amount of flush water)

5. 5 “Waste” streams discussed in this lecture 1.Urine 2.Faeces 3.Greywater 4.Anal washwater 5.Conventional domestic wastewater – for comparison purposes

6. 6 Nutrients: important component of waste streams!  Macronutrients*: –Nitrogen (N) –Phosphorus (P) –Potassium (K) –Sulphur –Calcium –Magnesium  Micronutrients: –Boron, copper, iron, chloride, manganese, molybdenum and zinc TN = total nitrogen, e.g. urea-N plus ammonia-N (for urine) TP = Total phosphorus A fertiliser which contains these three nutrients is called a “complete” fertiliser Course 1 Unit 2 * The definition of macronutrients and micronutrients for human nutrition is different, see e.g. http://www.fivims.net/glossary.jspx?show_result=true?lang=en#M (or the course glossary) http://www.fivims.net/glossary.jspx?show_result=true?lang=en#M

7. 7 Role of measurement parameters for urine, faeces and greywater ParameterPurpose of measuring Dry mass, moisture content (for faeces) Solids content, mass to be transported Total nitrogen (TN), total phosphorus (TP), potassium (K), ammonia-N Nutrient content for fertiliser value (or for pollution potential if discharged to water course) COD, BOD (chemical / biological oxygen demand) and VS (volatile solids) These parameters determine the organic matter content: most soils will benefit from addition of organic matter (soil conditioner); but organic matter can also be a cause of odour in greywater pHpH around neutral is best for reuse TDS (total dissolved solids)The lower the TDS the better for reuse of water (high TDS means “very salty”) Electrical conductivityProportional to TDS and correlated with ammonia-N Indicator for pathogens (e.g. helminth eggs, E. coli) Assess public health risk (some of these tests may be expensive)

8. CHARACTERISTICS OF URINE C1U2 - Part A 8

9. 9 Human urine quantity facts Human physiology facts: –The body uses urine as a balancing medium for liquids and salts –The kidneys filter urine from the blood –At excretion, the urine pH is normally around 6 but can vary between 4.5 – 8.2 Adults excrete about 0.8 – 1.5 L of urine per day (children about half that amount) depending on time, person and circumstances: –Excessive sweating results in concentrated urine –Comsumption of large amounts of liquid dilutes the urine

10. 10 Nutrients in human urine  Digested nutrients enter the metabolism and are excreted mostly with the urine and the rest in faeces  Urine contains 88% of excreted N, 67% of excreted P and 73% of excreted K; the remainder is in the faeces –This ratio of nutrient split between urine and faeces appears to be more or less the same worldwide

11. 11 Urea facts  Of the nitrogen in fresh urine, 75-90% is in the form of urea; the remainder is in the form of ammonium or creatinine  Urea is (NH 2 ) 2 CO – an organic nitrogen compound (contributing to COD a content of urine)  Urea is easily converted to ammonium by urease (an enzyme excreted by bacteria, that is present everywhere) –In conventional mixed wastewater, about 78% of the total nitrogen is therefore in the form of ammonia already  Urea can be made artificially from ammonia and CO 2 and is a popular fertiliser world-wide –Urea has the highest proportion of N of all liquid fertilisers: 46.4% N in urea a COD = Chemical Oxygen Demand (see also Table 1 later in this presentation)

12. 12 Urine storage Fresh (24 March 06) One month old (24 April 06) Fresh (24 March 06) One month old (24 April 06) Three months old (28 June 06) Note the change in colour, increasing cloudiness, sediments (precipitates) Course 1 Unit 2

13. 13 Main processes during urine storage The nitrogen in fresh urine is mostly in the form of urea (75- 90%), with very little ammonia Upon storage, the urea is quickly degraded to ammonia (NH 3 ) by the enzyme urease, and hence the ammonia concentration increases Higher ammonia concentrations result in a pH increase to 9 - 9.3 The increased pH value causes a precipitation of certain crystals and precipitates (precipitation of P, Mg, Ca and NH 4 occurs) Sludge/ precipitates Ammonia (gas)

14. 14 Other comments on processes during urine storage  There is a risk of losing N in the form of ammonia with the ventilated air  The colour of the urine changes from bright yellow to orange/red  Sludge forms where urine usually stands for a while –This sludge largely consists of struvite and apatite –It is formed because the pH of the urine increases to 9-9.3 and at this high pH, precipitation of P, Mg, Ca and NH 4 occurs  Urine is very corrosive (use plastic or high quality concrete for storage, not metals) – see also Course 2 Unit 3 (Storage and transport logistics) Sludge/ precipitates Ammonia (gas)

15. 15 Pathogens in urine  Pathogen types: bacteria, viruses, parasitic protozoa and helminths  Number of pathogens in urine is very low  One pathogen of concern is Schistosoma haematobium (causing bilharziasis), where eggs can be excreted in the urine  In areas where this pathogen is endemic, urine should not be used on fields near freshwater sources  Hygiene risks associated with diverted urine are mainly a result of contamination by faeces  Urine use in agriculture is “pretty safe” – see more details in Course 2 Unit 1 Part A (Treatment aspects for urine, faeces and greywater)

16. 16 Chemical contaminants in urine  Heavy metals (Cu, Zn, Cr, Ni, Pb, Cd):  Levels of heavy metals in urine are very low because only substances that have entered the metabolism are contained in urine  Hormones (endocrine disrupters) and pharmaceuticals:  A large proportion of the hormones produced by our bodies and the pharmaceuticals that we consume are excreted with the urine  As a rule of thumb, an average of 64% of a substance ingested is excreted in the urine (Escher et al., 2007)  It is considered better to recycle urine to arable land than to flush the hormones and pharmaceuticals into recipient waters because: Hormones and pharmaceuticals are degraded in natural environments with a diverse microbial activity Urine is mixed into the active topsoil and retained for months (see Course 3 “Reuse of ecosan products in agriculture”)

17. 17 Pharmaceutical residues in urine (continued from previous slide) The load of pharmaceutical residues from animal manure which is freely spread on land has never concerned anyone Some research is ongoing in Europe on this aspect (e.g. ozonation of urine to degrade pharmaceutical residues), but it is not a very important research question for the field of low-cost sanitation (see also Course 2 Unit 1 “Treatment aspects of urine, faeces and greywater”) What is your opinion on this? You can answer on the forum!

18. 18 Nutrient excretion by humans is directly linked to diet  Diet is the main factor for amount of nutrients excreted  Relationship to calculate the amount of nutrients excreted (in total) from the food intake:  N = 0.13 x total food protein  P = 0.011 x (total food protein + vegetal food protein)  FAO statistics are available for food supply for different countries (see www.fao.org) N N P P Diet Excreta Course 1 Unit 2

19. 19 Estimated excretion of nutrients per capita in different countries based on diet (using data and correlation mentioned on previous slide) Source: Jönsson et al. (2004), page 6

20. 20 Table 1: Excreted mass of nutrients in urine per year (typical values for Sweden) Wet masskg/cap/yr550 VolumeL/cap/yr550 Dry masskg/cap/yr21 Total nitrogen (TN)kg/cap/yr4 Total phosphorus (TP)kg/cap/yr0.37 Potassium (K)kg/cap/yr1 CODkg/cap/yr3.6 BODkg/cap/yr1.8 Useful for calculating crop demand or area required for application. Source: Jönsson et al. (2004), and Otterpohl (2003) for COD data; BOD assumed to be half of COD COD and BOD are measures of organic content; see lecture on “Fundamentals of conventional biological wastewater treatment” Values are country-specific or diet-specific (treat as guideline only!) cap = capita = person

21. 21 Table 2: Urine data - same data as in Table 1 but per day Wet massg/cap/d1507 VolumeL/cap/d1.5 Dry massg/cap/d57.5 Total nitrogen (TN)g/cap/d11.0 Total phosphorus (TP)g/cap/d1.0 Potassium (K)g/cap/d2.7 CODg/cap/d9.9

22. 22 Table 3: Urine data - same data as in Table 1 but given as concentrations Dry massmg/L38200 Total nitrogen (TN)mg/L7300 Total phosphorus (TP)mg/L670 Potassium (K)mg/L1800 CODmg/L6500 BODmg/L3250 pH-6 (4.5 – 8.2) Own determinations: CODmg/L5,200 – 10,300 VS (volatile solids) content%16-32 Electrical conductivity (EC)  S/cm 10,600 – 25,100 TDS (total dissolved solids)mg/L7,800 – 18,000 Concentrations are useful when working with urine of unknown number of people Results from lab session on 20 Sept 06 with 18 MSc students Urine is highly saline (see next slide)

23. 23 Some additional information on TDS and EC  For conventional wastewater, the following relationship holds (Metcalf and Eddy, page 56)  TDS (mg/L) ~= EC (mS/cm) x (0.55 – 0.70) or  EC (mS/cm) ~= 1.6 x TDS (mg/L)  Pure urine is not to be used as irrigation water, but as a fertiliser  Nevertheless, the classification of water in regards to saltiness is shown below for comparison purposes: Name of waterTDS (mg/L) Non-saline< 500 Slightly saline> 500 – 1,500 Moderately saline> 1,500 – 7,000 Highly saline> 7,000 – 15,000 Very highly saline> 15,000 – 35,000 Seawater> 35,000 Urine

24. 24 Differences between fresh and stored urine (data set 1) Source: Novaquatis research project, published in Eawag News (March 2007) http://www.eawag.ch/services/publikationen/eanews/news_63/en63e_maurer.pdf The main difference is the much higher ammonium + ammonia concentration in stored urine The table does not include data for ortho-P, but it would be lower in the stored urine than in the fresh urine (soluble P is precipitating to form various crystals)

25. 25 Differences between fresh and stored urine (data set 2) ParameterUnitOld UrineFresh Urine pH -9.88.2 TNmg/L57306060 NH 4 -N (includes NH 3 -N)mg/L5780630 TPmg/L940400 CODmg/L69007300 ConductivitymS/cm2300019200 TDSmg/L- 14800 Ratio conductivity/TDSmS/cm / (mg/L)- 1.30 Source: Determinations at UNESCO-IHE laboratory with class during Ecosan Summer School in Sept. 2006. Values are averages of 6 groups (old urine sample was 7 months old; fresh urine samples were different for each group (taken on same day)). How about letting your own students do some determinations? It is a good experience…

26. CHARACTERISTICS OF FAECES C1U2 - Part B 26

27. 27 Faeces quantity and content  Faeces consist mainly of non-metabolised material combined with some metabolised material  Undigested nutrients are excreted with the faeces  The lower the digestibility of the diet, the higher the mass of faeces excreted per day, e.g.:  Average person in Sweden: 51 kg/cap/yr (wet mass)  Average person in China: 115 kg/cap/yr  Average person in Kenya: 190 kg/cap/yr  Extremely high number of many different pathogens  Heavy metal content in faeces is higher than in urine (heavy metals pass through the intestine unaffected)  Concentrations of contaminating substances in faeces are usually lower than in chemical ferilisers (e.g. cadmium) and farmyard manure Course 1 Unit 2

28. 28 What does it look like when faeces dry out? Children have no problem with faeces… This is actually a bucket latrine for children This is one of the daughters of Elisabeth

29. 29 Air drying of faeces Fresh faeces (14 May 06) 2 days old (16 May 06) 2 weeks old (1 June 06) 6 weeks old (28 June 06)

30. 30 After two weeks of drying: appears totally dry, Trial # 1 Faeces of a 2.5 year old girl Dead flies: container was covered but holes in lid, flies could not get out (??)

31. 31 Data of own faeces drying trials StartEnd Trial # 1 (drying time 14 days) Weight (g)6015 Water lost (g)45 g Moisture (calculated) (%)75 Dimensions (cm)4 x 6 x 2.53 x 4.5 x 2 Volume (mL)6027 Density (kg/L)1.170.55 Trial # 2 (drying time 12 days) Weight7020 Moisture (calculated) (%)71

32. 32 Table 4: Excreted mass of nutrients in faeces per year (typical values for Sweden) Wet masskg/cap/yr51 Volume (at excretion i.e. before drying) L/cap/yr51 Dry masskg/cap/yr11 Total nitrogenkg/cap/yr0.55 Total phosphoruskg/cap/yr0.18 Potassiumkg/cap/yr0.4 CODkg/cap/yr14 BODkg/cap/yr7 Useful for calculating crop demand or area required for application Source: Jönsson et al. (2004), and Otterpohl (2003) for COD BOD assumed to be half of COD Values are country- specific or diet-specific (treat as guideline only!) Course 1 Unit 2

33. 33 Table 5: Faeces data - same data as in Table 4 but per day Wet massg/cap/d140 Volume (at excretion)L/cap/d0.1 Dry massg/cap/d30 Total nitrogeng/cap/d1.5 Total phosphorusg/cap/d0.5 Potassiumg/cap/d1.1 CODg/cap/d39 this is the mass of wet faecal matter excreted per person per day this is the mass of faeces after drying, per person per day For comparison: solid waste production is 200 – 500 g/cap/d in cities in India (Source: Rothenberger et al., 2006, page 93)

34. 34 Table 6: Faeces data - same data as in Table 4 but given as concentrations in g/kg wet mass Dry mass (at excretion) g/kg216 Total nitrogen (TN)g/kg11 Total phosphorus (TP)g/kg4 Potassiumg/kg8 Moisture content%78 Dry matter content (at excretion) %22 pH - 7 – 9 (?) Useful when working with faeces of unknown number of people How to measure the organic content (COD and BOD were developed for liquids)?  Volatile solids content or ignition loss; TOC How to measure pH?  Dilution with water + shaking, or pH meter for soil

35. 35 Main differences between fresh and old (dried) faeces (collected without flush water) The old, dried faeces has:  Less moisture, volume, weight, density  Much fewer pathogens (note: of all the pathogens, the helminth eggs are most resilient)  No attractiveness for flies anymore  A much less offensive appearance to the human eye Note: These points do not apply for old faeces which is stored together with water and urine!

36. CHARACTERISTICS OF GREYWATER C1U2 - Part C 36

37. 37 Greywater - definition  Greywater is domestic wastewater with no or minimal human excrements  Sources are kitchens, baths, showers, laundry, washing  Some faecal matter enters if nappies are washed in the laundry for example (households with pit latrines automatically have a “source separation” of greywater)

38. 38 Greywater quantities generated  Range: 60 – 275 L/cap/d (depending on country and wealth/attitude of user)  Some new houses in Germany, Norway, Sweden: less than 100 L/cap/d  Rural Jordan example: 20 L/cap/d (water is precious, so is used several times)  Note: Basic lifeline water requirement: 25 or 50 L/cap/d (Gleick, 1998)  For comparison: Drinking water requirement: 3-5 L/cap/d

39. 39 Greywater characteristics: organic matter, nutrients, pollutants  Organic matter (BOD): High concentrations of easily degradable organic material, e.g. fat, oil and other organic substances from cooking, residues from soap, shampoos and tensides from detergents  Nutrients: –Nitrogen levels low –Phosphorus input from washing and dish-washing powder (for water softening) – some countries, e.g. Norway, have banned washing powder containing P  Metals and other toxic pollutants: Metals originating from water itself, corrosion of pipe system, dust, cutlery, dyes, shampoos (similar to conventional wastewater) Source: Ridderstolpe (2004)

40. 40 Greywater characteristics: pathogens  Proportion of pathogens is low (some faecal contamination possible) –Greywater has lower pathogen content than treated effluent from most conventional wastewater treatment plants (unless they include tertiary treatment for disinfection)  Amount of faeces in greywater: –Based on measured faecal sterols, the estimate is that about 0.04 g/cap/d of faeces is mixed into the greywater (compared to 30 g/cap/d of faeces produced, i.e. 0.1%) –Note: use of indicator bacteria to measure the amount of faeces in greywater might be misleading because of their growth on organic matter that is contained in greywater Source: Ridderstolpe (2004)

41. 41 Table 7: Greywater characteristics VolumeL/cap/d 60 - 275 Total suspended solids (TSS) mg/L365 Total nitrogen (TN)mg/L6 Total phosphorus (TP)mg/L3 Potassiummg/L15 CODmg/L562 BODmg/L281 pH -7-8 Only to provide an idea – highly variable and dependent on water use patterns Concentrations are based on Otterpohl (2003) mass flows, and flowrate of 60 L/cap/d Course 1 Unit 2

42. 42 Anal cleansing materials used world-wide  Toilet paper: collect in faeces compartment of UDD toilet if material to be composted or incinerated, otherwise store separately  Water (see next slide)  Vegetable materials: collect in faeces compartment  Stones or rags: collect separately  Newspaper, card board: treat same as toilet paper Note: absence of available anal cleansing material next to the toilet can lead to higher incidence of diarrhoea (Herbst (2006) proved this correlation for a case study area in Uzbekistan)

43. 43 Anal washwater  Origin: Practise of many cultures (e.g. Muslims and Buddhists) to wash anal area after defecating and after urinating*  = Water with a low level of faecal matter  Treatment methods for anal washwater similar to those for greywater, e.g. constructed wetlands, soil infiltration  Poorly characterised (few studies)  Should not be mixed with urine; can be mixed with greywater * Therefore, there are no public free-standing urinals for men in muslim countries – only in cubicles

44. 44 Table 8: Summary table of mass of nutrients in urine, faeces and greywater ParameterUnitUrineFaecesTotal % in urin e Grey- wat er Wet masskg/cap/yr5505160192%21900 Volume (before drying) L/cap/yr5505160192%21900 Dry masskg/cap/yr21113266%8 Total nitrogenkg/cap/yr40.554.5588%0.14 Total phosphoruskg/cap/yr0.370.180.5567%0.08 Potassiumkg/cap/yr10.41.471%0.32 CODkg/cap/yr3.61417.720%12 BODkg/cap/yr1.878.8520%6.2 For greywater used 60 L/cap/d (quite low consumption) Source: Jönsson et al. (2004), and Otterpohl (2003) for greywater data and COD. BOD assumed to be half of COD

45. 45 Source: Otterpohl (2003) Volume of greywater, urine and faeces Course 1 Unit 2 24,000 – 100,000 L/cap/yr 500 L/cap/yr 50 L/cap/yr Mind that there is a large variation in volume (related to country and standard of living) – 66 to 274 L/cap/d L/cap/year Can be a good source of irrigation water if managed safely Greywater urine faeces

46. 46 N P K Mass of nutrients greywaterurine faeces Source: Otterpohl (2003) kg/cap/year This is a „complete“ fertiliser (= containing N, P, K)

47. 47 Mass of organic matter (measured as COD) Source: Otterpohl (2003) kg/cap/year greywaterurine faeces Highly beneficial when applied to soil as soil conditioner (see Course 3 Unit 1 „Reuse of ecosan products in agriculture)

48. 48 For comparison: conventional domestic wastewater  Conventional domestic wastewater is wastewater from households connected to a sewer system, without any separation of waste streams  Polluted water with high levels of pathogens  Large volumes that need treatment  Industrial effluent (untreated or pre-treated) is mostly mixed together with domestic wastewater  Rainwater and sewage are mixed intentionally (combined sewer) or mixed partially (separate sewer) – it is difficult to keep rainwater completely out of sewers, unless they are brand new

49. 49 Table 9: Overview of characteristics of “waste” streams Parameter (concentrations) UrineFaecesGrey-waterConvent. domestic ww Organic solid waste TSSLN/AMM Nitrogen H MLMM PhosphorusHM M ML Organic matter (COD, BOD) LH M HH PathogensL H LHL Heavy metalsLLMML L Low M Medium H High N/A Not applicable Toxic substances: heavy metals, pesticides, chlorinated organic compounds etc. Course 1 Unit 2

50. 50 Table 10: Comparison with conventional domestic wastewater ParameterUrineFaecesGreywaterConvent. domestic ww a Volume, L/cap/year5505124,000 – 100,00095,000 Nitrogen, kgN/cap/year 4.00.550.145.8 Phosphorus, kgP/cap/year 0.370.180.080.5 Organic matter, kgCOD/cap/year 3.6141255 Source: Otterpohl (2003)(for faeces, urine and greywater data) a For US conditions: 260 L/cap/d, 16 gN/cap/d, 1.5 g P/cap/d, 68 gBOD/cap/d, 150 gCOD/cap/d cap = capita = person

51. 51 “Water footprint” of an individual or a nation  So far, we have only looked at the greywater production resulting from domestic activities  If you want to investigate your total water consumption, you also need to consider water used to produce the food that you eat and the industrial products you consume  Vegetarians have a much lower water consumption for their food production than meat eaters  Poor people also have a much lower water footprint than wealthy people (typically)  A water footprint calculator is available here: http://www.waterfootprint.org/index.php?page=files/home

52. 52 Average national water footprint per capita (m3/cap/yr) Green means that the nation's water footprint is equal to or smaller than the global average. Countries with red have a water footprint beyond the global average. Period: 1997-2001. Source: http://www.waterfootprint.org/index.php?page=files/WaterFootprints

53. 53 References  Escher, B. (2007) Can NoMix help to prevent environmental problems caused by medicines? Eawag News: Mix or NoMix? A closer look at urine source separation, 63(March), 23-25. http://www.eawag.ch/services/publikationen/eanews/news_63/en63e_escher.pdf  Gleick, P. H. (1998) The human right to water, Water Policy 1, p. 487-503 *  Herbst, S. (2006) Water, sanitation, hygiene and diarrheal diseases in the Aral Sea area (Khorezm, Uzbekistan). PhD thesis, University of Bonn, Germany *  Jönsson, H, Richert Stinzing, A., Vinneras, B., Salomon, E. (2004) Guidelines on the Use of Urine and Faeces in Crop Production, Stockholm Environment Institute (get from www.ecosanres.org) *www.ecosanres.org  Otterpohl, R. (2003) New technological development in ecological sanitation. Proceedings of 2nd international symposium on ecological sanitation, April 2003, Lübeck, Germany, p. 455 (http://www.gtz.de/de/dokumente/en-ecosan-symposium-luebeck-session-e-2004.pdf) *http://www.gtz.de/de/dokumente/en-ecosan-symposium-luebeck-session-e-2004.pdf  Ridderstolpe, P. (2004) Introduction to greywater management, Stockholm Environment Institute, Sweden (get from www.ecosanres.org) *www.ecosanres.org  Rothenberger, S., Zurbrügg, C., Enayetullah, I., and Maqsood Sinha, A. H. M. (2006) Decentralised composting for cities of low- and middle-income countries - A users' manual, Eawag/Sandec (Switzerland) and Waste Concern (Bangladesh), Dübendorf, Switzerland. http://www.eawag.ch/organisation/abteilungen/sandec/publikationen/publications_swm/downloads _swm/decomp_Handbook_loRes.pdf http://www.eawag.ch/organisation/abteilungen/sandec/publikationen/publications_swm/downloads _swm/decomp_Handbook_loRes.pdf  Tchobanoglous, G., Burton, F.L., Stensel, H.D. (2003) Wastewater Engineering, Treatment and Reuse, Metcalf & Eddy, Inc., McGraw-Hill, 4th edition. Good book on conventional wastewater treatment * This publication is available on the I-LE for this unit (either assigned reading or extra materials)