Corrigendum: Water Practice and Technology 14 (1), 43–54: Clogging limitations of nitrifying biofilters: BiosytrDuo® process study, Vincent Rocher, Romain Mailler, Perrine Mèche, Sébastien Pichon, Jean Bernier, Sabrina Guérin, Olivier Ferro, Anthony Augé, Lina Boursaud, Geneviève Bord, Jean-François Bulteau and Sam Azimi

The authors regret that there were some errors in the text and Figure 5 of their original paper and apologise for any inconvenience caused. The corrected text is given below.

Clogging sensitivity

Page 51

Figure 5 should be shown as

The initial headloss has been normalized with the volume of beads and K5-media and with the water rising velocity. It varies from 1 to 3.6 cm H₂O/m/m.h⁻¹ for the K5-media equipped biofilter (Figure 5(a)). For the reference biofilter, excluding two results under 1 cm H₂O/m/m.h⁻¹, the initial headloss ranged from 2.3 to 6.1 cm H₂O/m/m.h⁻¹ and is always above those of the K5-media equipped biofilter. Figure 5(b) shows the same results under boxplot form. This form, introduced by Tukey (1977) consists of a box extending from the first quartile (Q1) to the third quartile (Q3); a...