Improvement of the assimilable organic carbon （AOC） analytical method for reclaimed water

• Published in: 中国环境科学与工程前沿：英文版 2013 (4), p.483-491
• Main Author: Xin ZHAO Hongying HU Shuming LIU Feng JIANG Xiaolei SHI Mingtang LI Xueqiao XU
• Format: Article
• Language: English
• Subjects: AOC; 再生水; 可同化有机碳; 培养时间; 培养温度; 生长潜力; 荧光假单胞菌; 试验菌株
• ISSN: 2095-2201; 2095-221X

Microbial growth is an issue of concern that may cause hygienic and aesthetic problems during the transportation and usage of reclaimed water. Assimilable organic carbon （AOC） is an important parameter which determines the heterotrophic bacterial growth potential of water. Pseudomonas fluorescens P17 and Spirillum sp. NOX are widely used to measure AOC in drinking water. The AOC values of various reclaimed water samples determined by P 17 and NOX were compared with those determined by the new strains isolated from reclaimed water in this study. It showed that the conventional test strains were not suitable for AOC measurement of reclaimed water in certain cases. In addition to P17 and NOX, Stenotrophomonas sp. Z J2, Pseudomonas saponi- phila G3 and Enterobacter sp. G6, were selected as test strains for AOC measurement of reclaimed water. Key aspects of the bioassay including inoculum cell density, incubation temperature, incubation time and the pH of samples were evaluated for the newly selected test strains. Higher inoculum density （104 CFU.mL-1） and higher incubation temperature （25℃） could reduce the time required for the tests. The AOC results of various collected samples showed the advantages of the method proposed based on those five strains in evaluating the biologic stability of reclaimed water.