Abstract
Recycled paper mill wastewater is currently treated and irrigated on site at Amcor Fibre Packaging Mill Spearwood, in Western Australia . The residual organics in wastewater create odour and filter fouling problems. In this study, parameter spaces of the following potential treatments were investigated: enzymes (cellulase mixtures), microbial digestion, and wet oxidation (150°C and 540- 560kPa with combinations of NaOH, H20 21 and CH3COOH). The success of treatments was assessed by comparing the chemical oxygen demand (COD) and filterability before and after treatment. The enzyme treated wastewater samples showed no significant difference to the control, possibly due the presence of in situ bacterial populations or cooked starch. Aerobic bacterial digestion reduced filterability and COD reduction (maximum 17%) was unsatisfactory. Wet oxidation significantly increased the filterability and COD reduction of wastewater. Cooking time was a significant factor. Up to 79% reduction in COD was achieved after 30 minutes of wet oxidation. Acetic acid and 10 minutes of wet oxidation removed 83% of COD, but also corroded the test apparatus. In this pilot study, wet oxidation was the most effective wastewater treatment tested, but further investigation into the process parameters are needed.