Research Faecal Sludge Treatment

Background

Gap Analysis in Emergency Water, Sanitation and Hygiene Promotion (HIF 2013)1. Latrines in locations where no pits are possible

(urban, high watertable/flooding)2. Latrine emptying and desludging3. Faecal sludge disposal options after desludging

and treatment !!MOST CHALLENGING GAP!!4. Urban alternatives for excreta disposal

Problem

• Lack of space for treatment (urban area)• High water table (no digging possible)• No off site treatment/disposal site, no skilled

labour• Security• Faecal sludge source of disease (Cholera Haiti)• Raised latrine full after 1 week

Objective

• Sanitization Faecal Sludge• Simple & rapid & easy to put

in place• Easy to operate & maintain

& reliable• Demonstrate feasibility at

scale and document the whole process

• Process to be incorporated in the Oxfam and/or IFRC catalogue

• From Speed to Seed

Field testing Malawi

• 5 Students from Unesco-IHE & TUD

• 3 Treatment Methods for Centralised Treatment : – Lime, Ammonia, Lactic Acid

• 3 Decentralised Treatment (SEED)- on-going research: – Worm Toilet, Terra Preta

Toilet, Anaerobic Digester

Emergency Faecal Sludge Treatment Methods:

Preliminary Field Testing Results

Treatment

• Treatment Time

• Final Concentration of E-coli, Salmonella and Faecal Coliform

• pH

• Quantities of Chemical Addition for Treatment

Ammonia

• 4-8 days

• <1000 cfu/ 100ml

• pH 9

• 2% Urea w/w (20g urea/kg Sludge =9g TAN/kg Sludge)

Lime

• 2 hours

• <1000 CFU/ 100ml

• pH 11

• 12-16g Lime per kg Sludge ( The buffer capacity varied considerably between sludges)

Lactic Acid

• 7-9 days

• <1000 cfu/ 100ml

• pH 4

• 20-30 g/L Lactic acid concentration (using 10%w/w preculture, 2g simple sugar/kg sludge)

Lactic Acid Experiments

• 3 Log removal for E-coli 7-9 days

• 10% w/w milk preculture, 10% w/w molasses ( 2kg simple sugar/1000kg sludge)

• 20-30g/L lactic acid• pH: 3.8-4.2 • Next Phase –

knowledge applied to Terra Preta Toilet

UREA EXPERIMENTS

• 3 Log removal 4-8 days after addition of urea

• 2% Urea observed to be the most effective

• pH 9 – 9.5• Reactors must be sealed • High temperature can

enhance treatment• Next Phase – upscale to

Bladder

LIME EXPERIMENTS - MALAWI

• 50L Drum Experiments• pH Control - Addition of

Hydrated Lime ( CaOH) & 10’ mixing

• > pH 10.2 to <1000 CFU/100ml within 1 hour

• No distinct reduction in COD and TS or VS within

• Further research upscaling

ControlpH 7

pH 9 pH 10 pH 11 pH 12

0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.51.00E+00

1.00E+01

1.00E+02

1.00E+03

1.00E+04

1.00E+05

1.00E+06

1.00E+07

E-coli RemovalControl ( no mix)

Control ( mixing

pH 9

pH 10,2

pH 11

pH 12

Time elapsed since Lime addition (hours)E-

coli

Conc

entr

ation

( CF

U/10

0ml)

Future Work

Additional Research is essential to ensure that a robust method which safeguards public health can be established for faecal sludge treatment in an emergency context

(De) Centralized:• Lime Treatment• Urea Treatment On site:• Self-mixing Anaerobic

Digester• Worm Toilet• Terra Preta Sanitation Toilet

.

Future work

(De-) centralized treatment:• Upscale options, test robustness of process on different

sludge types & in different settings• Investigate sanitization, stabilization, costs• Devise the process conditions required for Faecal Sludge

Treatment to achieve the WHO guideline sanitation requirements.

On-site systems:• Compare and contrast each of the on-site sanitation systems• Investigate the functionality of the on-site sanitation systems• Investigate sanitization, stabilization, costs, useful byproducts

Thank you for your input!

www.emergencysanitationproject.orgwww.speedkits.eu

emergencysanitation@waste.nl