Remediation and toxicity removal from Kraft E1 paper mill effluent by ozonization

The degradation of Kraft El pulp mill effluent was studied by four different ozonization oxidation systems (O-3/pH3, O-3/pH11, O-3/pH11/H2O2, O-3/pH11/UV). The investigation was focused on the reduction of total organic carbon (TOC), total phenols, color and acute toxicity (monitoring by inhibition of Escherichia coli respiration). For a reaction time of 90 minutes, the O-3/pH11/UV was the most effective process for decoloration (45%).The O-3/pH11/H2O2, O-3/pH11/UV and O-3/pH11 processes showed the best results for total phenols reduction (congruent to 90%). None of the studied processes showed a significant TOC reduction. The O-3/pH11/UV and O-3/pH11 processes were effective for the acute toxicity reduction. Different kinetic parameters were also determined in order to quantify the reactivity of the effluent towards the applied oxidation systems.