Abstract: For the treatment of wastewater with low carbon and high nitrogen, the indispensable and effective manner is to launch carbon and microbial inoculum. In this study, investigations were performed into the water purifying capacity of a novel and comprehensive management strategy, which integrated sustained-release carbon source and water purification bacteria-embedded solid capsules. Sodium acetate was used as the carbon source and embedded with carrier materials. Scanning electron microscopy (SEM) was carried out to analyze micro-morphological changes to the entrapments before and after release of the carbon source. The released carbon source (sodium acetate) was detected using high performance liquid chromatography (HPLC). The bacteria-embedded solid capsules were divided into W-capsule and B-capsule, which included Pseudomonas stutzeri ADH1, Enterobacter sp. AOZ1 and Bacillus subtilis BSK9. Experiments were performed on river sewage in buckets with intermittent aeration to investigate the change to some routine indexes covering ammonia nitrogen, total nitrogen (TN) and chemical oxygen demand (COD), etc. Sewage treated using instant/sustained-release carbon source and bacteria with/without embedding were tested as comparable controls. Untreated sewage was also tested as a negative control (NC). It was shown that extensive wood shaving-like structures formed inside the entrapments after the release of sodium acetate. TN remove rate of the sewage treated with sustained-release carbon source was 60.2%, and the COD kept less than 20 mg·L^-1. For the sewage treated with W-capsule and the combination of sustained-release carbon source and bacteria-embedded capsules, the TN remove rate was 39.1% and 85.2%, respectively, which indicated high performance of the novel combinatorial strategy in nitrogen removal of river sewage.

Key words: sodium acetate, biological denitrification, denitrifying bacteria, nitrifying bacteria