Jiang Zhanpeng

INT-dehydrogenase activity test for assessing anaerobic biodegradability of organic compounds.

This study assessed anaerobic biodegradability of organic compounds from microorganism activity. Dehydrogenase activity can be a good parameter characterizing the microorganism activity. A modified method of 2-(p-iodophenyl-3-(p-nitrophenyl)-5-pheny tetrazolium chloride-dehydrogenase activity determination was proposed in anaerobic biodegradability assessment. Cubic spline curves were adopted to link the data points. This curve was integrated twice to calculate areas. The microorganism activity index in anaerobic biodegradability assessment was calculated by standardizing the integral. According to the results of the activity index, 14 kinds of organic compounds were classified into readily, partially, and poorly biodegradable under anaerobic conditions, respectively. As a result, some conclusions for anaerobic biodegradability of organic compounds were reached, based on the activity index value.

Integrated assessment for anaerobic biodegradability of organic compounds using the analytical hierarchy process

Anaerobic biodegradability of organic compounds can be assessed from the changes in organic compounds, the end products, and the activity of microorganisms. In this study, all three of these variables were considered to integrate assessment of the anaerobic biodegradability of organic compounds. The analytical hierarchy process (AHP) was introduced to integrate the assessment. Real values between 0 and 10 were determined in the pairwise comparison matrix according to the values of assessment indices of the three variables. A new adjustment method, which can obtain minimum adjustment of the values in matrix, was proposed to reach the acceptable consistency of the matrix. Finally, the anaerobic biodegradability of 14 organic compounds was assessed using AHP.

Biodegradability of organic substances by ATP test

The aerobic biodegradability of organic substances in water is characterized by determination of energy change ‐ ATP content in microbial cells during biodegradation. A satisfactory result is obtained under the following conditions: the initial concentration of tested substance is 100mg/l (as DOC), the amount of the inoculum in the biological medium is 500mg/l (as MLSS), and the duration of test time is 14 days. The evaluating system (peak time, peak height and IA index) is proposed to assess the biodegradability of 46 organic compounds and 7 wastewaters.