Screening and Identification of Two Heterotrophic Nitrifiers and Growth Characteristic Research

摘要

The superiority of heterotrophic nitrifiers over the traditional autotrophic nitrifiers makes heterotrophic nitrifiers become the focus in actual wastewater treating processes. The primary objetives of this study were: (ⅰ) to screen out heterotrophic nitrifiers from bio-ceramic reactor which can effectively remove the ammonium; (ⅱ) to identify strains through method of morphology and phylogenies analysis; (ⅲ) to study the strains' characteristic of growth, the ammonia nitrogen removal, the COD degeneration. Through the strain morphology and the phylogenetic analysis, the isolated strain Z5 was preliminarily identified as the Pseudomonas aeruginosa, and Z8 was identified as the Acinetobacter sp. They all grow quickly .The Generation time G(Z5)=3.33h ,the specific growth rate μ(Z5)=0.30 h-1, G(Z8)=3.65h, μ(Z8)=0.274 h-1.The COD degeneration rate of Z5 was 56.45 mg/(L·h), and the COD degeneration rate of Z8 was 86.78 mg/(L·h). According to the high growth speed and high COD degeneration ability, Z5 and Z8 were supposed to be heterotrophic nitrifiers. The isolated strains Z5 and Z8 could quickly remove the ammonia nitrogen. After 28h cultivation, their ammonia nitrogen removal rate achieved 86.49% and 86.75%, respectively .They both achieved good heterotrophic nutrition effect. Z5 and Z8 have extensive appliance and wide foreground in actual wastewater treating processes.