Influence of the thermochemical sludge pretreatment on the nitrification of A/O reactor with the removal of phosphorus by simultaneous precipitation

• Published in: Biotechnology and bioprocess engineering 2013, 18(2), , pp.313-320
• Main Authors: Do, Khac-Uan, Rajesh Banu, J., Kaliappan, S., Yeom, Ick-Tae
• Format: Article
• Language: English
• Subjects: Analysis; Biomass; Biotechnology; Caustic soda; Chemical precipitation; Chemistry; Chemistry and Materials Science; Civil engineering; Denitrification; Efficiency; Effluents; Industrial and Production Engineering; Laboratories; Liquor; Membrane reactors; Nitrification; Nitrogen; Nitrogen removal; Nutrient removal; Phosphorus removal; Reactors; Recycling; Research Paper; Sludge; Studies; Temperature; Water treatment; 생물공학
• ISSN: 1226-8372; 1976-3816
• DOI: 10.1007/s12257-012-0492-5

In the present study, a laboratory scale anoxic/oxic (A/O) reactor is used for the removal of nutrient and sludge reduction. Phosphorus removal was achieved through simultaneous precipitation, and sludge production was reduced through thermochemical pretreatment. The main objective of the study was to investigate the influence of sludge pretreatment on the nitrification rate. Total phosphorus in the effluent was maintained around 0.5 ∼ 1.0 mg/L by simultaneous precipitation, using coagulant alum at 2.2 mole ratio. Before simultaneous precipitation, the nitrification rate of the A/O reactor was found to be 0.050 g N-NH 4 + /g MLVSS.d. The thermochemical sludge pretreatment began on the 120 th day at pH 11 and 80°C. The initiation of sludge pretreatment brought about a significant reduction of the A/O reactor nitrification rate, which fell to 0.038 g N-NH 4 + /g MLVSS/day. The effect of sludge pretreatment was reflected in the reduction of the nitrogen removal efficiency from 85 to 74%. Recycling of the thermochemically pretreated sludge accounted for 57% sludge reduction, which had an adverse influence on the nitrification rate of the system.