Abstract

We regret that incorrect units were used for sludge concentration in the article. Instead of kgTS/L, the correct unit is gTS/L. – Page 178, highlight 3 should say: “Optimal COD solubilization was obtained at 59.3 g TS/L, 30,500 kJ/kg TS and 13 h”.– Page 178, lines 5–6 of abstract should say: “Optimal conditions for chemical oxygen demand solubilization were determined at 59.3 g/L total solids (TS) concentration…”– Page 179, line 109 should say: “SC was fixed at 18.3, 40.7 and 63.1 g TS/L…”– Page 183, lines 40–41 should say: “Solubilization effects were higher at SC values near the central point (40.7 g TS/L)”.– Page 184, line 3–5 should say: “…which corresponded with 41.8 g TS/L SC and 26,450 kJ/kg TS SE and resulted in a predicted f of 7.6%.”– Page 185, line 25–27 should say: “…which corresponded with 59.3 g TS/L SC, 30,500 kJ/kg TS SE and 13 h T and resulted in a predicted f of 18.2%”.– Page 186, line 22–23 should say: “…with optimal operational conditions at 59.3 g TS/L SC, 30,500 kJ/kg TS SE and 13 h T”.Table 1, Fig. 4 and Fig. 5 were corrected and are listed below: