Strengthen effects of dominant strains on aerobic digestion and stabilization of the residual sludge

• Published in: Bioresource technology 2017-07, Vol.235, p.202-210
• Main Authors: Liu, Yongjun, Gao, Min, Zhang, Aining, Liu, Zhe
• Format: Article
• Language: English
• Subjects: Aerobic digestion of sludge; Aerobiosis; Bioreactors; Dominant strains; Nitrogen; Phosphorus; Sewage; Stabilization; Strengthen; Waste Disposal, Fluid
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2017.03.060

•Strains which have obvious tolerance to the dissolved oxygen were isolated.•Addition of dominant strains has a significant role on the sludge reduction.•The stabilization time of sludge was shortened considerably.•Accumulation of nitrogen and phosphorus in sludge supernatant was increased. In order to strengthen the aerobic digestion of residual sludge, shorten the time of sludge stabilization and further reduce operating costs, 3 dominant strains identified as Pseudomonas sp. L3, Acinetobacter sp. L16 and Bacillus sp. L19 were isolated from long-term aerobic digestion sludge. Results showed that the sludge stabilization time were reduced by 3–4days compared with the control when the dominant strains were added to the process of sludge aerobic digestion. The addition of dominant strains accelerated the accumulation of TOC, nitrate nitrogen and ammonia nitrogen in the digestive solution at different levels, and it was beneficial to the dissolution of phosphorus. Controlling DO 3–5mg/L, pH 6.5, the strains of Pseudomonas sp. L3 and Bacillus sp. L19 were combined dosing with the dosage of 2% in the process of sludge aerobic digestion, compared with the control, digestion rates of TOC and MLSS were increased about 19% and 16%, respectively.