Off-Site Lime Stabilisation as an Option to Treat Pit Latrine Faecal Sludge for Emergency and Existing On-Site Sanitation Systems

Table 3

Average E. coli reduction for small-scale trials.

Treatment time (hrs)	Small-scale field trial
	Escherichia coli (CFU/100 mL)
	Control	pH 10	pH 10.5	pH 11	pH 11.5	pH 12
0	7.7 ± 2.3 × 10^7	7.2 ± 3.3 × 10^7	5.9 ± 2.7 × 10^7	5.7 ± 1.2 × 10^7	7.8 ± 0.6 × 10^7	7.2 ± 0.3 × 10^7
0.1	Not tested	4.9 ± 0.5 × 10^6	4.3 ± 2.8 × 10^7	1.9 ± 1.2 × 10^6	Not detected	Not detected
1	Not tested	2.2 ± 0.8 × 10^6	4.1 ± 0.6 × 10^6	Not detected	Not detected	Not detected
2	Not tested	1.9 ± 0.3 × 10^6	1.4 ± 0.6 × 10^6	Not detected	Not detected	Not detected
5	Not tested	2.6 ± 0.3 × 10^5	Not detected	Not detected	Not detected	Not detected
24	4.7 ± 2.9 × 10^7	1.6 ± 1.1 × 10^5	Not detected	Not detected	Not detected	Not detected
48	8.2 ± 4.5 × 10^7	Detected	Detected	Not detected	Not detected	Not detected
72	7.1 ± 3.2 × 10^7	Detected	Detected	Not detected	Not detected	Not detected
96	6.0 ± 2.6 × 10^7	Detected	Detected	Not detected	Not detected	Not detected
120	6.1 ± 5.1 × 10^7	Detected	Detected	Not detected	Not detected	Not detected
144	4.7 ± 2.9 × 10^7	Detected	Detected	Not detected	Not detected	Not detected
169	4.0 ± 0.3 × 10^7	Detected	Detected	Not detected	Not detected	Not detected

Not detected: detection limit 10⁴ CFU/100 mL.
Detected: detected but below viable range limit.