부산시 도심하천 퇴적물의 오염도 평가 및 BMP test에 의한 최종메탄 및 이산화탄소발생량 산정

Abstract

The main objective of this study was to offer informations about conditions of stream sediments and to evaluate biochemical methane potentials of stream sediments from the urban streams in Busan city using conventional BMP test. So we first select 14 urban streams and collect sediment samples. Then, pH, COD, proximate analysis, volatile solid, organic carbon content, elemental analysis and analysis for heavy metal concentrations were conducted to determine characteristics of the sediments. Results show that COD, organic carbon content, volatile solid content and heavy metal concentration of sediments are determined in range of 1.20∼75.07 mg L, 0.19∼11.54 %, 0.23∼34.21 % and 0.4∼732.6 mg kg, respectively. Using the above experimental results, we evaluated the correlations between sediment COD and moisture contents, ash contents, volatile solid, total organic carbon, total nitrogen and total carbon using linear model with a least-squares algorithm. As a result, linear model was well fitted to each data with good values of the correlation coefficient(r=0.9664∼0.8501). Also, Analysis data of sediments were compared with USEPA sediment quality standards and ontario sediment quality guidelines. As a result, when compared with USEPA sediment quality standards, total 9 samples were evaluated as heavily polluted and total 3 samples were evaluated as moderately polluted. But when compared with ontario sediment quality guidelines, total 3 samples were evaluated as severe effect level and total 10 samples were evaluated as lowest effect level. Finally, to evaluate biochemical methane potential of stream sediments using BMP test, we select total 5 urban streams and several biochenmical methane potential tests were performed in a laboratory. As a result, pH values of the reactors generally increased and then stabilized at 7.11∼7.35. In addition, C/N ratio, ultimate methane and carbon dioxide yield(mL /g VS) and biodegradability(%)were determined to 1.05∼10.27, 10.1∼179.4, 10.3∼34.4 and 4.0∼30.1, respectively. Also, in a similar manner linear model was fitted to each data for determination of the correlations between ultimate methane yield and ultimate carbon dioxide yield, C/N ratio, COD, volatile solid and total organic carbon content. As a result, except for COD(R=0.7586) and volatile solid(R=0.7876), linear model was well fitted to each data with good values of the correlation coeffcient(R=0.9795∼9858). Through these results, we propose empirical equations, which contain C/N ratio or TOC, for the prediction of ultimate methane yield for the ulban streams in Busan city.