Data normality and homoscedasticity were verified using the
Shapiro–Wilk and Levene’s tests, respectively. We performed a
statistical comparison (SPSS 21 IBM software package) between
tests carried out with and without mussels in the pilot-plant,
where the dependent variable is the ME concentration in the
wastewater and the
fixed factors are the treatment and the
exposure time. For all these cases, we conducted the comparison
using the two-way analysis of variance (two-way ANOVA;
*p < 0.05; **p < 0.01).