Skip to main content
SpringerLink
Log in

Dewaterability of faecal sludge and its implications on faecal sludge management in urban slums

Faecal sludge pre-treatment by dewatering

  • Original Paper
  • Published:
International Journal of Environmental Science and Technology Aims and scope Submit manuscript

Abstract

The current practices of faecal sludge management in urban slums pose risks to public health and environmental pollution. Given that faecal sludge contains high water content, dewatering it presents an important step of managing it effectively. This paper therefore explores the applicability of dewatering as the first step in decentralized treatment of faecal sludge (FS) generated from pit latrines, the commonest sanitation technology used in urban slums. A total of 22 and 10 FS samples were collected from lined and unlined pit latrines, respectively. The high moisture content of 92.4 and 83.4 % of FS from lined and unlined pit latrines, respectively, depicted a need for dewatering. Dewaterability extent and rate were measured in terms of per cent cake solids and capillary suction time, respectively. The average dewaterability extent of FS from unlined pit latrines (31.8 %) was significantly higher than that of lined latrines (18.6 %) (p = 0.000) while the dewaterability rate (1122 and 1485 s of FS from lined and unlined pits, respectively) was not significantly different (p = 0.104), although very low compared to sewage sludge. To obtain high dewaterability extent of FS from lined pit latrines, volatile solids should be reduced and sand content increased. To maintain high dewaterability extent of FS from unlined pit latrines, the particle sizes should be ≤1 mm. The results from this study suggest that FS from pit latrines in Kampala can be conveniently dewatered without thickening, thereby reducing costs of FS management.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5

Similar content being viewed by others

References

  • Amuda OS, Amoo IA, Ajayi OO (2006) Performance optimization of coagulant/flocculant in the treatment of wastewater from a beverage industry. J Hazard Mater 129:69–72. doi:10.1016/j.jhazmat.2005.07.078

    Article  CAS  Google Scholar 

  • APHA/AWWA/WEF (2012) Standard methods for the examination of water and wastewater, 22nd edn. Washington DC, USA

  • Blackett I, Hawkins P, Heymans C (2014) The missing link in sanitation service delivery: a review of fecal sludge management in 12 cities. WSP-World Bank Research Brief, Washington DC

    Google Scholar 

  • Broadbent T (2001) Centrifuges: the choice. Filtr Sep 38:30–33

    Article  Google Scholar 

  • Burton CH (2007) The potential contribution of separation technologies to the management of livestock manure. Livest Sci 112:208–216. doi:10.1016/j.livsci.2007.09.004

    Article  Google Scholar 

  • Chen GW, Lin WW, Lee DJ (1996) Capillary suction time (CST) as a measure of sludge dewaterability. Water Sci Technol 34:443–448. doi:10.1016/0273-1223(96)00610-5

    Article  CAS  Google Scholar 

  • Chen C, Melia CRO, Hahn MW (1997) Some effects of particle size in separation processes involving colloids. Water Sci Technol 36:119–126

    Article  Google Scholar 

  • Chindaprasirt P, Homwuttiwong S, Sirivivatnanon V (2004) Influence of fly ash fineness on strength, drying shrinkage and sulfate resistance of blended cement mortar. Cem Concr Res 34:1087–1092. doi:10.1016/j.cemconres.2003.11.021

    Article  CAS  Google Scholar 

  • Chu CP, Lee DJ (2001) Experimental analysis of centrifugal dewatering process of polyelectrolyte flocculated waste activated sludge. Water Res 35:2377–2384. doi:10.1016/S0043-1354(00)00539-X

    Article  CAS  Google Scholar 

  • Cofie O, Agbottah S, Strauss M et al (2006) Solid-liquid separation of faecal sludge using drying beds in Ghana: implications for nutrient recycling in urban agriculture. Water Res 40:75–82. doi:10.1016/j.watres.2005.10.023

    Article  CAS  Google Scholar 

  • Cofie O, Koné D, Rothenberger S et al (2009) Co-composting of faecal sludge and organic solid waste for agriculture: process dynamics. Water Res 43:4665–4675. doi:10.1016/j.watres.2009.07.021

    Article  CAS  Google Scholar 

  • Dodane P, Bassan M (2014) Settling-Thickening Tanks. In: Strande L, Ronteltap M, Brdjanovic D (eds) Faecal sludge management—systems approach implementation and operation. IWA Publishing, London, pp 123–139

    Google Scholar 

  • Dodane P-H, Ronteltap M (2014) Unplanted Drying Beds. In: Strande L, Ronteltap M, Brdjanovic D (eds) Faecal sludge management: systems approach for implementation and operation. IWA Publishing, London, pp 141–154

    Google Scholar 

  • Evans JD (1996) Straightforward statistics for the behavioral sciences. Brooks/Cole Publishing, Pacific Grove

    Google Scholar 

  • Gebauer R, Eikebrokk B (2006) Mesophilic anaerobic treatment of sludge from salmon smolt hatching. Bioresour Technol 97:2389–2401. doi:10.1016/j.biortech.2005.10.008

    Article  CAS  Google Scholar 

  • Ghafari S, Aziz HA, Bashir MJK (2010) The use of poly-aluminum chloride and alum for the treatment of partially stabilized leachate: a comparative study. Desalination 257:110–116. doi:10.1016/j.desal.2010.02.037

    Article  CAS  Google Scholar 

  • Gold M, Niang S, Niwagaba CB, et al (2014) Results from FaME (Faecal Management Enterprises)—can dried faecal sludge fuel the sanitation service chain? In: Sustainable water and sanitation services for all in a fast changing world. 37th WEDC international conference. Hanoi, Vietnam, pp 1–6

  • Gold M, Dayer P, Faye MCAS et al (2016) Locally produced natural conditioners for dewatering of faecal sludge. Environ Technol. doi:10.1080/09593330.2016.1165293

    Google Scholar 

  • Han YW, Anderson AW (1975) Semisolid fermentation of ryegrass straw. Appl Microbiol 30:930–934

    CAS  Google Scholar 

  • Heinss U, Larmie SA, Strauss M (1998) Solids separation and pond systems for the treatment of septage and public toilet sludges in the Tropics—Lessons learnt and recommendations for preliminary design. EAWAG/SANDEC Report No. 05/98

  • Heinss U, Larmie SA, Strauss M (1999) Characteristics of Faecal Sludges and their Solids-Liquid Separation. EAWAG/SANDEC, Janeiro

    Google Scholar 

  • Houghton JI, Burgess JE, Stephenson T (2002) Off-line particle size analysis of digested sludge. Water Res 36:4643–4647

    Article  CAS  Google Scholar 

  • Jin B, Wilén B-M, Lant P (2004) Impacts of morphological, physical and chemical properties of sludge flocs on dewaterability of activated sludge. Chem Eng J 98:115–126. doi:10.1016/j.cej.2003.05.002

    Article  CAS  Google Scholar 

  • Kabouris JC, Tezel U, Pavlostathis SG et al (2009) Mesophilic and thermophilic anaerobic digestion of municipal sludge and fat, oil, and grease. Water Environ Res 81:476–485. doi:10.2175/106143008X357192

    Article  CAS  Google Scholar 

  • Karr PR, Keinath TM (1978) Influence of particle size on sludge dewaterability. Water Pollut Control Fed 50:1911–1930. doi:10.1177/03063127067078012

    Google Scholar 

  • Kengne IM, Akoa A, Koné D (2009) Recovery of biosolids from constructed wetlands used for faecal sludge dewatering in tropical regions. Environ Sci Technol 43:6816–6821

    Article  CAS  Google Scholar 

  • Klingel F, Montangero A, Koné D, Strauss M (2002) Fecal sludge management in developing countries. A planning manual. Duebendorf, Switzerland

  • Koné D, Strauss M (2004) Low-cost options for treating faecal sludges (FS) in developing countries—challenges and performance. In: 6th international IWA specialist group conference on waste stabilisation ponds. Avignon, France

  • Kulabako N, Nalubega M, Wozei E, Thunvik R (2010) Environmental health practices, constraints and possible interventions in peri-urban settlements in developing countries—a review of Kampala, Uganda. Int J Environ Health Res 20:231–257

    Article  CAS  Google Scholar 

  • Lee CH, Liu JC (2000) Enhanced sludge dewatering by dual polyelectrolytes conditioning. Water Res 34:4430–4436. doi:10.1016/S0043-1354(00)00209-8

    Article  CAS  Google Scholar 

  • Levine AD, Tchobanoglous G, Asano T (1991) Size distributions of particulate contaminants in wastewater and their impact on treatability. Water Res 25:911–922

    Article  CAS  Google Scholar 

  • Liu H, Fang HHP (2002) Extraction of extracellular polymeric substances (EPS) of sludges. Biotechnology 95:249–256

    CAS  Google Scholar 

  • Metcalf and Eddy (2003) Wastewater engineering: treatment and reuse, 4th edn. McGraw Hill, New York

    Google Scholar 

  • Mikkelsen LH, Keiding K (2002) Physico-chemical characteristics of full scale sewage sludges with implications to dewatering. Water Res 36:2451–2462. doi:10.1016/S0043-1354(01)00477-8

    Article  CAS  Google Scholar 

  • Møller HB, Sommer SG, Ahring BK (2002) Separation efficiency and particle size distribution in relation to manure type and storage conditions. Bioresour Technol 85:189–196

    Article  Google Scholar 

  • Murray Muspratt A, Nakato T, Niwagaba C et al (2014) Fuel potential of faecal sludge: calorific value results from Uganda, Ghana and Senegal. J Water Sanit Hyg Dev 4:223–230. doi:10.2166/washdev.2013.055

    Article  Google Scholar 

  • Murthy SN, Novak JT, Holbrook RD, Surovik F (2000) Mesophilic aeration of autothermal thermophilic aerobically digested biosolids to improve plant operations. Water Environ Res 72:476–483

    Article  CAS  Google Scholar 

  • Murungi C, van Dijk MP (2014) Emptying, Transportation and Disposal of feacal sludge in informal settlements of Kampala Uganda: the economics of sanitation. Habitat Int 42:69–75. doi:10.1016/j.habitatint.2013.10.011

    Article  Google Scholar 

  • Nakagiri A, Kulabako RN, Nyenje PM et al (2015) Performance of pit latrines in urban poor areas: a case of Kampala, Uganda. Habitat Int 49:529–537. doi:10.1016/j.habitatint.2015.07.005

    Article  Google Scholar 

  • Nakagiri A, Niwagaba CB, Nyenje PM et al (2016) Are pit latrines in urban areas of Sub-Saharan Africa performing? A review of usage, filling, insects and odour nuisances. BMC Public Health 16:1–16. doi:10.1186/s12889-016-2772-z

    Article  Google Scholar 

  • Neyens E, Baeyens J (2003) A review of thermal sludge pre-treatment processes to improve dewaterability. J Hazard Mater 98:51–67. doi:10.1016/S0304-3894(02)00320-5

    Article  CAS  Google Scholar 

  • Niu M, Zhang W, Wang D et al (2013) Correlation of physicochemical properties and sludge dewaterability under chemical conditioning using inorganic coagulants. Bioresour Technol 144:337–343. doi:10.1016/j.biortech.2013.06.126

    Article  CAS  Google Scholar 

  • Novak JT, O’Brien JH (1975) Polymer conditioning of chemical sludges. Water Pollut Control Fed 47:2397–2410

    CAS  Google Scholar 

  • Pan JR, Huang C, Cherng M et al (2003) Correlation between dewatering index and dewatering performance of three mechanical dewatering devices. Adv Environ Res 7:599–602. doi:10.1016/S1093-0191(02)00052-7

    Article  CAS  Google Scholar 

  • Peng G, Ye F, Li Y (2011) Comparative investigation of parameters for determining the dewaterability of activated sludge. Water Environ Res 83:667–671

    Article  CAS  Google Scholar 

  • Reddy M (2013) Standard operating procedures. Durban, South Africa

  • Rudolfs W, Heukelekian H (1934) Relation between drainability of sludge and degree of digestion. Sewage Work J 6:1073

    CAS  Google Scholar 

  • Semiyaga S, Okure MAE, Niwagaba CB et al (2015) Decentralized options for faecal sludge management in urban slum areas of Sub-Saharan Africa: a review of technologies, practices and end-uses. Resour Conserv Recycl 104:109–119. doi:10.1016/j.resconrec.2015.09.001

    Article  Google Scholar 

  • Still D, Foxon K (2012) Tackling the challenges of full pit latrines. Volume 1: understanding sludge accumulation in VIPs and strategies for emptying full pits. South Africa

  • Strande L (2014) The global situation. In: Strande L, Ronteltap M, Brdjanovic D (eds) Faecal sludge management—systems approach implementation and operation. IWA Publishing, London, pp 1–14

    Google Scholar 

  • Tumwebaze IK (2014) Increasing cleaning behaviour of shared toilet users in Kampala’ s urban slums, Uganda. University of Zurich

  • UN-HABITAT (2006) State of the World’s cities 2006/2007: 30 years of shaping the Habitat Agenda. United Nations Human Settlements Programme. Nairobi, Kenya

  • Wakeman RJ (2007a) The influence of particle properties on filtration. Sep Purif Technol 58:234–241. doi:10.1016/j.seppur.2007.03.018

    Article  CAS  Google Scholar 

  • Wakeman RJ (2007b) Separation technologies for sludge dewatering. J Hazard Mater 144:614–619. doi:10.1016/j.jhazmat.2007.01.084

    Article  CAS  Google Scholar 

  • WSP (2009) Strategic guidelines for improving water and sanitation services in Nairobi’ s informal settlements. Nairobi, Kenya

Download references

Acknowledgments

This research was carried out as part of the project titled “Stimulating Local Innovation on Sanitation for the Urban Poor in Sub-Saharan Africa and South-East Asia”, which is funded by the Bill and Melinda Gates Foundation, USA, through UNESCO-IHE in partnership with Makerere University. Grant Number is OPP1029019. The authors are grateful for the assistance provided by Mr. Muhammad Ssemwanga in analysis of faecal sludge samples, Dr. Joel R. Kinobe and Mr. Alfred Ahumuza in field collection of faecal sludge samples. The authors would also like to thank Mr. Moritz Gold and Dr. Linda Strande from SANDEC (the Department of Water and Sanitation in Developing Countries), EAWAG (the Swiss Federal Institute of Aquatic Science and Technology) in Switzerland for their helpful guidance in conducting this study and allowing us to use their equipment.

Author information

Authors and Affiliations

  1. Department of Civil and Environmental Engineering, College of Engineering, Design, Art and Technology, Makerere University, P.O. Box 7062, Kampala, Uganda

    S. Semiyaga, C. B. Niwagaba & P. M. Nyenje

  2. Department of Mechanical Engineering, College of Engineering, Design, Art and Technology, Makerere University, P.O. Box 7062, Kampala, Uganda

    M. A. E. Okure

  3. Department of Environmental Management, College of Agricultural and Environmental Sciences, Makerere University, P.O. Box 7062, Kampala, Uganda

    F. Kansiime

Authors
  1. S. Semiyaga
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. M. A. E. Okure
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. C. B. Niwagaba
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. P. M. Nyenje
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. F. Kansiime
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to S. Semiyaga.

Ethics declarations

Conflict of interest

The authors declare that they have no conflict of interest.

Additional information

Editorial responsibility: M. Abbaspour.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Supplementary material 1 (PDF 324 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Semiyaga, S., Okure, M.A.E., Niwagaba, C.B. et al. Dewaterability of faecal sludge and its implications on faecal sludge management in urban slums. Int. J. Environ. Sci. Technol. 14, 151–164 (2017). https://doi.org/10.1007/s13762-016-1134-9

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s13762-016-1134-9

Keywords

Search

Navigation