| Summary: | 碩士 === 國立暨南國際大學 === 土木工程學系 === 94 === Abstract
This research utilized five annular reactor (AR) systems to conduct the experiments. Three ARs were PVC materials, the other two were casting iron and stainless steel materials, respectively. All systems were controlled under the same condition during the period of biofilms acclimating in the initial stage for about 40 days. Five ARs were divided into two categories. Firstly, experiments conducted under controlled temperature (20℃) to compare the effect of material (PVC, casting iron and stainless steel) on biofilm formation. Secondly, experiments conducted under controlled material (PVC) to compare the effect of temperature (6, 20 and 30℃) on biofilm formation.The experimental results showed that biofilm HPC quantity could be reduced for casting iron system only at the condition of higher disinfection time (30 days) and higher chlorine concentration (0.7 mgl-1). And, the biofilm HPC quantity of casting iron system was significantly larger than those of PVC and stainless steel systems. The chlorine treatment increased the TOC concentration, although the HPC, TDCs and ATP of the biofilm and effluent bulk water could be reduced. All the chlorine added into casting iron systems were disappeared and it resulted the regrowth of microorganisms. It revealed that the consumption rate of chlorine depends on the material and dose. The residual chlorine concentration (RCC) was highest and the chlorine consumption rate (kb) was lowest at the 6℃ system. A reverse result occurred at the 30℃ system.
Keywords: drinking water distribution system, biofilm, residual chlorine, TOC, pipe material, temperature, annular reactors
|
|---|
