Large-scale Faecal Sludge Biochars: Agronomic Properties and Tomato Growth Experiments
Larissa Nicholas a
a Swansea University, Singleton Park, Swansea, United Kingdom
Proceedings of SUNRISE September Symposium 2021 ‘Powering Green Recovery’ (SUNRISEIII)
Online, Spain, 2021 September 20th - 22nd
Organizers: Hari Upadhyaya, Adrian Walters, James Durrant, Sara Walters and Georgia Bevan
Poster, Larissa Nicholas, 041
Publication date: 14th September 2021

In developing nations, the disposal of untreated faecal sludge (FS) from onsite sanitation facilities to surrounding water bodies is damaging to both the local environment and public health.

Pyrolysis is a safe method of disposing of faecal sludge since the process eliminates pathogens within the sludge and produces biochar which can be used as a soil amendment.  FS biochar produced from three operational sludge treatment facilities in India (WAI-BC, WGL-BC, NSP-BC) was characterized with regards to the biochars potential as a soil amendment. The biochars were studied systematically by X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), BET specific surface area, electrophoretic light scattering, elemental analysis, proximate analysis, and pH, and Electrical conductivity (EC) measurements.

Results showed that all three biochars had high ash content, alkaline pH values, low specific surface area and negative zeta potentials. FTIR spectra of all three biochars were very similar indicating the presence of the same surface functional groups. XRD indicated slightly different mineral composition of the biochars which may be related to different mineral composition of the faecal sludge. SEM analysis showed the biochars complex porous structure with a honeycomb-like morphology.

The effect of faecal sludge biochars on soil quality, growth, yield, and water runoff in micro-tomatoes were investigated by a pot experiment carried out in an outdoor greenhouse environment. Four different treatments were used consisting of control soil, soil with biochar, soil with fertilizer, and soil with fertilizer and biochar. The soil used was acidic, low in nutrients and poorly draining. Biochar was applied at 10 t ha−1.


This study shows that large -scale faecal sludge biochar addition to an acidic soil can increase crop yield, fruit number, plant height and plant biomass in micro-tomatoes.

All parameters: plant height, leaf length, number of micro-toms and yield were highest when biochar was applied in combination with the fertilizer.

Biochar addition alone produced plants with significantly greater number of tomatoes, longer leaves, greater biomass and greater fruit yield compared to Control.

My supervisors Ian Mabbett and Aisling Devine, Bill and Melinda Gates Foundation, Tom Dunlop for XRD analysis, Gabriel Sigmund for the elemental analysis and Tide Technocrats for supplying the biochars

© Fundació Scito
We use our own and third party cookies for analysing and measuring usage of our website to improve our services. If you continue browsing, we consider accepting its use. You can check our Cookies Policy in which you will also find how to configure your web browser for the use of cookies. More info