Removal of para-chloronitrobenzene in water by FeOOH/H ₂O ₂

Synthetic goethite(FeOOH) prepared in laboratory was evaluated for FeOOH/H ₂O ₂ catalytic activity removing para-chloronitrobenzene(p-CNB) in water. The pathway of degradation was deduced from the effect of tert-butanol on the catalytic reaction and the performance comparison with some related reactions. Effects of catalyst and oxidant doses, as well as the factors associated with water quality such as initial pH of solution, HCO ₃ ^- alkalinity and humic acids, on p-CNB removal in FeOOH/H ₂O ₂ system were also examined. The results show that FeOOH has high catalytic activity on H ₂O ₂ decomposition for removing p-CNB in water. Tert-butanol could effectively inhibit the oxidation of p-CNB in FeOOH/H ₂O ₂ system, indicating the catalytic oxidation reaction follows a hydroxyl radical pathway. Under the optimal reaction conditions of pH value in the range of 4.0-6.0, dosage of 333 mg·L ^-1 FeOOH and 6.6 mg·L ^-1 of H ₂O ₂, the removal efficiency of p-CNB is more than 80% after 30 minutes in this experiment. Both bicarbonate and humic acid have inhibitory effect on p-CNB removal, and the higher bicarbonate and humic aid concentration are, the stronger the inhibitory effect is.