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Treatment technologies for human faeces and urine

Niwagaba, Charles (2009). Treatment technologies for human faeces and urine. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis agriculturae Sueciae, 1652-6880 ; 2009:70
ISBN 978-91-576-7417-3
[Doctoral thesis]

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Abstract

This thesis examines simple, cheap, environmentally friendly and resource efficient technologies for the treatment of source-separated human faeces and urine to enable safe recycling of their plant nutrients for plant production in developing countries. Composting of faeces-to-food waste (F:FW) in wet weight mix ratios of 1:0, 3:1 and 1:1 was studied in 78 L reactors insulated by 25 mm styrofoam; and of F:FW in wet volume/weight ratios of 1:0, 1:1 and 1:3 in 216 L reactors insulated by 75 mm styrofoam. At both scales, composting without insulation produced temperatures that differed from the ambient by ≤15 °C. A sanitised compost product was produced when the temperature was maintained above sanitising levels (>50 °C) for a sufficiently long time (at least 2 weeks). High moisture levels (>60%) led to low pH (<6), which impeded composting and the attainment of sanitising temperatures. Incineration of well prepared source-separated faeces with ash as cover material produced high temperatures (800-1000 °C). This process decreased the organic matter, total N and plant-available P by 70->90%. Mass decrease was 15-36% due to high ash content of the incoming material. Incinerating faeces/ash mixtures with DM<90% resulted in a strong smell that lessened when DM was higher. The ash produced by incineration can be used as cover material for faeces during toilet use, which is advantageous in urban areas of developing countries where access to ash is limited. In urine treatment, a breakpoint concentration of ammonia was found at approximately 40 mM NH3 (e.g. 2.1 g NH3-N L-1 and pH 8.9 at 24 °C), below which all studied organisms, except Salmonella Typhimurium (S. Typhimurium), persisted considerably longer irrespective of treatment temperature, showing that urine dilution rate is highly important for pathogen inactivation. The time to no detection in urine stored in the sun (Uganda; mean temperature±amplitude 24±7.5 °C, NH4-N of 4±1.5 mg L-1 and pH 9) for E. coli, Salmonella and Ascaris suum was 11 hours, 14 hours and 40 days respectively. Under similar conditions, Enterococcus spp. reached non-detection levels in 50 days, while the phages studied persisted considerably longer. The t90 for MS2, Φx 174 and S. Typhimurium 28B was 8.2, 37 and 55 days respectively. Fluctuating temperatures in combination with ammonia were shown to inactivate pathogens in urine faster than the same average steady temperature.

Authors/Creators:Niwagaba, Charles
Title:Treatment technologies for human faeces and urine
Year of publishing :2009
Volume:2009:70
Number of Pages:91
Papers/manuscripts:
NumberReferences
ALLI. Niwagaba, C., Nalubega, M., Vinnerås, B., Sundberg, C. & Jönsson, H. (2009). Bench-scale composting of source-separated human faeces for sanitation. Waste Management 29(2), 585-589. II. Niwagaba, C., Nalubega, M., Vinnerås, B., Sundberg, C. & Jönsson, H. (2009). Substrate composition and moisture in composting source-separated human faeces and food waste. Environmental Technology 30(5), 487-497. III. Niwagaba, C., Nalubega, M., Vinnerås, B. & Jönsson, H. (2006). Incineration of faecal matter for treatment and sanitation. Water Practice and Technology 1(2). doi10.2166/wpt.2006.0042. IV. Vinnerås, B., Nordin, A., Niwagaba, C. & Nyberg, K. (2008). Inactivation of bacteria and viruses in human urine depending on temperature and dilution rate. Water Research 42(15), 4067-4074. V. Nordin, A., Niwagaba, C., Jönsson, H. & Vinnerås, B. (2009). Inactivation of indicators and pathogens in source-separated human urine at varying temperatures. (Manuscript).
Place of Publication:Uppsala
ISBN for printed version:978-91-576-7417-3
ISSN:1652-6880
Language:English
Publication Type:Doctoral thesis
Full Text Status:Public
Agrovoc terms:faeces, urine, sanitation, separating, recycling, composting, waste incineration, pathogens, bacteria, viruses, temperature, uganda, developing countries
Keywords:composting, faeces, sanitation, treatment, urine, pathogens, temperature
ID Code:2177
Department:(NL, NJ) > Dept. of Energy and Technology
Deposited By: Charles Niwagaba
Deposited On:25 Nov 2009 00:00
Metadata Last Modified:02 Dec 2014 10:16

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