Table 1.

Experimental design for biodegradability testing (Dil, dilution).

S0	Temperature (°C)	Cell density	Inoculum
Low S0 conc. (μg/L)	10	X0opt 6xdilX0	3 Activated sludges
	25	X0opt 6xdilX0	2 Soils
High S0 conc. (mg/L)	10	X0opt 6xdilX0	2 River waters
	25	X0opt 6xdilX0	3 Marine waters

X0, initial total cell density; X0opt, optimal cell density; 6xdilX0, series of 6 dilutions of the inoculum.