ANAEROBIC TREATMENT OF KENAF STEM WOOD APMP WASTE-WATER

The characteristics, pollution load and anaerobic biodegradability of the wastewater from an alkaline peroxide mechanical pulping (APMP) process using kenaf stem wood as raw material were investigated. The wastewater had a high anaerobic biodegradability, although it contained peroxide which is toxic to anaerobic bacteria. A biological preacidogenic reactor was used to eliminate peroxide toxicity and acidify the wastewater, which then entered a UASB reactor. The results showed that the wastewater could be treated efficiently using the two-phase UASB system. At 36 +/- 1-degree-C and an average loading rate of 12 kg COD m-3d-1, 84% COD removal, 96% BOD removal and a methane yield of 0.30 Nm3 kg-1 COD removed were achieved.