Microbiological Evaluation of the Effectiveness of Sewage Sludge Sanitization with Solar Drying Technology

Table 4

Number of indicator bacteria in particular determination times.

Cycle	Bacteria number [MPN × g^−1]			Drying time (days)
		0	7	14	21	28
Sludge from carriers placed on the turner frame
	Salmonella Senftenberg W775	4.5 × 10^7	3.83 × 10^6	9.97 × 10^7	4.83 × 10^5	2.8 × 10^5
Summer	Escherichia coli	4.33 × 10^7	6.83 × 10^6	3.17×10^4	6.83 × 10^3	4.5 × 10^3
	Enterococci	6.13 × 10^7	5.5 × 10^6	4.15 × 10^7	2.13 × 10^5	1.87 × 10^5
	Salmonella Senftenberg W775	2.13 × 10^9	3.83 × 10^8	1.38 × 10^9	1.73 × 10^7	3.83 × 10^6
Winter	Escherichia coli	3.83 × 10^7	3.83 × 10^7	1.51 × 10^8	6.17 × 10^4	1.83 × 10^5
	Enterococci	9.0 × 10^7	1.82 × 10^9	1.25 × 10^9	1.07 × 10^9	3.25 × 10^8
Sludge from carriers placed on the turner shovels
	Salmonella Senftenberg W775	4.5 × 10^7	6.5 × 10^6	2.86 × 10^5	4.9 × 10^3	4.67 × 10^2
Summer	Escherichia coli	4.33 × 10^7	4.33 × 10^5	7.83 × 10^6	2.65 × 10^4	7.65 × 10^3
	Enterococci	6.13 × 10^7	2.15 × 10^8	4.37 × 10^8	5.17 × 10^6	5.5 × 10^6
	Salmonella Senftenberg W775	2.13 × 10^9	1.38 × 10^9	1.73 × 10^8	2.83 × 10^6	1.72 × 10^7
Winter	Escherichia coli	3.83 × 10^7	7.17 × 10^7	9.67 × 10^5	9.33 × 10^4	1.55 × 10^5
	Enterococci	9.0 × 10^7	6.17 × 10^8	2.38 × 10^8	3.17 × 10^8	1.07 × 10^9
Sudge from carriers placed in the sludge pile
	Salmonella Senftenberg W775	4.5 × 10^7	3.17 × 10^6	1.77 × 10^6	6.17 × 10^5	3.17 × 10^5
Summer	Escherichia coli	4.33 × 10^7	2.84 × 10^7	3.8 × 10^5	3.26 × 10^4	7.17 × 10^2
	Enterococci	6.13 × 10^7	3.75 × 10^8	2.48 × 10^7	5.98 × 10^4	7.17 × 10^3
	Salmonella Senftenberg W775	2.13 × 10^9	2.13 × 10^9	5.58 × 10^8	7.83 × 10^6	6.83 × 10^6
Winter	Escherichia coli	3.83 × 10^7	2.5 × 10^7	7.83 × 10^5	1.2 × 10^6	3.17 × 10^6
	Enterococci	9.0 × 10^7	9.17 × 10^8	1.67 × 10^8	1.13 × 10^9	1.67 × 10^9