생물활성탄 재질별 및 안트라사이트 biofilter에서 EBCT 및 수온변화에 따른 aldehyde 4종(formaldehyde, acetaldehyde, glyoxal 및 methylglyoxal)의 생물분해 특성을 조사한 결과 EBCT와 수온을 증가시킬 경우 제거율이 상승하였으며, 수온이 $25^{circ}C$일 때 aldehyde 4종의 제거율은 EBCT의 영향을 크게 받지 않았으나 수온이 $5^{circ}C$일 경우에는 EBCT의 증가가 aldehyde 4종의 제거율 상승에 큰 영향을 미쳤다. 활성탄 재질별 BAC 및 biofilter에서 aldehyde 4종의 제거능은 석탄계-BAC > 야자계-BAC > 목탄계-BAC > biofilter 순으로 조사되었다. 수온 $5^{circ}C{sim}25^{circ}C$, 석탄계- BAC에서 aldehyde류 4종에 대한 생물분해 속도상수(k)와 반감기($t_{1/2}$)를 조사한 결과, formaldehyde는 0.2175~0.7826 $min^{-1}$와 0.89~3.19 min, acetaldehyde는 0.2068~0.9211 $min^{-1}$와 0.75~3.35 min, glyoxal은 0.1468~0.3213 $min^{-1}$와 2.16~4.72 min, methylglyoxal은 0.1794~0.4665 $min^{-1}$와 1.49~3.86 min이었다. Aldehyde 4종에 대한 물질별 생분해율 평가 결과 formaldehyde ${geq}$ acetaldehyde > methylglyoxal > glyoxal 순으로 나타났다.
In this study, the effects of biofilter media type (three different activated carbons and anthracite), empty bed contact time (EBCT) and temperature on the removal of four aldehyde species (formaldehyde, acetaldehyde, glyoxal and methylglyoxal) in BAC filters were investigated. Experiments were conducted at three water temperature (5, 15 and $25^{circ}C$) and four EBCTs (5, 10, 15, and 20 min). The experimental results indicated that the coal based BAC retained more bacterial biomass on the surface of the activated carbon than the other BACs, and increasing EBCT or increasing water temperature also increased the four aldehyde species removal in BAC filters. To achieve above 80% of removal efficiency for four aldehyde species in a BAC filter, above 15 min EBCT at $5^{circ}C$ and 10 min EBCT at above $15^{circ}C$ were required. The kinetic analysis indicated a first-order reaction rate for the biodegradation of four aldehyde species at various water temperatures. Data obtained from the BAC filters at various temperatures were also used to evaluate pseudo first-order rate constants for four aldehyde species. The half-lives evaluated for formaldehyde, acetaldehyde, glyoxal and methylglyoxal in the coal-based BAC ranging from 0.89 to 3.19 min, from 0.75 to 3.35 min, from 2.16 to 4.72 min and from 1.49 to 3.86 min, respectively, could be used to assist water utilities in designing and operating BAC filters.
