Keywords: swim–bed technology, nitrification, protozoa, latex wastewater, acryl–fibre biomass carrier biofringe, COD removal, chemical oxygen demand, wastewater treatment
Study of swim–bed technology for COD removal and nitrification for latex wastewater treatment
COD removal and nitrification by swim–bed technology using a novel carrying acryl–fibre biomass carrier (biofringe) was conducted to investigate its effectiveness for latex wastewater treatment. The influent taken from a rubber factory contained 2,000 to 3,500 mg/l COD, 150 to 300 mg/l ammonia–N and 250 to 500 mg/l TKN. The quality of latex wastewater is unstable, depending on seasonal latex production. The results showed that COD removal and nitrification efficiency were high at the volumetric loading rates (VLRs) equal and less than 1.0 kg COD/m³/d, corresponding to 0.13 kg N/m³/d. COD removal and nitrification efficiency were above 90% and 73%, respectively. At the VLR of 2 kg COD/m³/day (0.24 kg N/m³/d), nitrification efficiency was reduced to 56%, while COD removal were still above 90%. At the VLR as high as 3 kg COD/m³/d (0.4 kg N/m³/d), low COD removal and nitrification efficiency were observed, 86% and 20%, respectively. Biomass concentration increased as the increase of VLRs. Total biomass was 6,800 mg/l and 7,900 mg/l at VLRs of 2 and 3 kg COD/m³/d, respectively.