Table 2.

The functional diversity indices for the contaminated with DTZ and control activated sludge at the beginning (start), 30th and 100th day of exposition to different concentrations of diatrizoate (0.2; 2.0 and 20 mg/L). The numbers in captions after underlying means the sampling day.

	G	H’	R	AWCD
Start	0.43 ± 0.05	1.38 ± 0.01	28.60 ± 0.55	1.46 ± 0.04
Control_30	0.67 ± 0.06*	1.17 ± 0.05a*	23.67 ± 4.51a	0.94 ± 0.19ab
0.2 mg/L_30	0.69 ± 0.01*	1.11 ± 0.01a*	24.67 ± 1.15a	0.80 ± 0.04a*
2 mg/L_30	0.69 ± 0.01*	1.01 ± 0.07b	18.67 ± 1.53b	1.03 ± 0.03b*
20 mg/L_30	0.69 ± 0.01	1.09 ± 0.03ab	23.67 ± 1.53a	1.26 ± 0.09c*
Control_100	0.54 ± 0.01A*	1.27 ± 0.02A*	26.33 ± 0.58A	0.84 ± 0.02A
0.2 mg/L_100	0.62 ± 0.01B*	1.18 ± 0.02A*	26.67 ± 1.15A	0.44 ± 0.07B*
2 mg/L_100	0.65 ± 0.02C*	1.15 ± 0.11A	22.67 ± 2.08B	0.23 ± 0.04C*
20 mg/L_100	0.69 ± 0.01D	0.96 ± 0.16B	20.33 ± 1.53B	0.07 ± 0.02D*

G—Gini coefficient; H’—Shannon index; R—substrate richness; AWCD—average well colour development. The plus/minus values represent SD. The means with different letters in each column are significantly different (p < 0.05, LSD test) considering the effect of DTZ concentration on the 30th day (lowercase letters) or the 100th day (higher case letters). The means without any letters did not differ among others on the adequate sampling day. In each column, the pairs of means with the same concentration of DTZ marked with an asterisk are significantly different (p < 0.05, the independent samples t-test) considering the effect of time.