Abstract

The main objective of this study was to analyze sediments in 14 urban streams in the city of Busan, South Korea, and to evaluate their biochemical methane potentials (BMP) by use of conventional BMP tests. Then chemical oxygen demand (COD), proximate analysis, volatile solids (VS), organic carbon content and elemental analysis were conducted to determine sediment characteristics. The results showed that COD, VS and organic carbon contents were 15.2 ∼ 75.1 mg/g, 2.3 ∼ 11.5% and 1.3 ∼ 34.2%, respectively. From BMP tests, the ultimate methane and carbon dioxide yield (mL/g VS) and biodegradability (%) were determined to be 10.1 ∼ 179.4, 10.3 ∼ 34.4, and 4.0 ∼ 30.1, respectively. To determine the correlations between ultimate methane yield, C/N ratio, COD, and VS and organic carbon content, a linear model was fitted to the data using a least-squares algorithm. Except for COD (r = 0.7586) and VS (r = 0.7876), the linear model was well fitted to each data point with good correlation coefficient values (r = 0.9795 ∼0.9858). A multivariate regression analysis was also performed to find multiple effects of factors on the ultimate methane yield. From these findings, empirical equations are provided that contain C/N or VS ratios for the prediction of ultimate methane yields from urban stream sediments in Busan.

Key words: Sediments, urban streams, C/N ratio, chemical oxygen demand (COD) , biochemical methane potentials (BMP) test, volatile solids.