Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/4985
標題: 加氯量對自來水不鏽鋼管線生物膜消長影響之研究
The effect of different chlorine levels in controlling bioflm formation on stainless steel surfaces in distribution systems
作者: 蔡長憲
Tasi, Chang-Hsien
關鍵字: biofilm;生物膜;drinking water;distribution system;自來水;配水管線
出版社: 環境工程學系
摘要: 
隨著科技的進步,依目前的淨水處理技術而言,水源經過淨水廠處理後的出流水,大都能夠符合自來水法規標準,然而在民眾的反應上,對於自來水水質滿意度方面,卻不甚理想。造成此現象主要是因為自來水經常在輸送的過程中,受到二次污染所致。而生物性污染一直被公認為是配水管線二次污染最主要的問題,其中更以生物膜累積的問題最嚴重且難以解決。
本研究的目的即在探討不同加氯濃度對自來水不鏽鋼管線生物膜生長的影響。研究中採用異營菌平板計數、ATP biomass、濾膜法測大腸菌以及菌種的分離及觀察等方法,同時配合模式模擬,評估加氯對於管線生物膜消長的影響,作為未來自來水廠控制微生物污染的參考依據。
由試驗結果顯示,在異營菌計數方面,不加氯的情況下,培養14週後生物膜密度可達最大值8.7×105 CFU/cm2,且隨著培養時間增長,生物膜會愈趨於穩定。在加氯的試程中,高加氯濃度對生物膜累積的速率比低濃度慢,但隨著培養時間的增加會愈接近。在ATP biomass方面,不加氯情況下平均生物膜形成速率(biofilm formation rate, BFR)為325.2 ATP pg/cm2day,低加氯濃度與高濃度試程則分別為159及118.4 ATP pg /cm2day。在大腸菌方面,加氯對大腸菌的抑制作用僅開始培養時有效,而不同加氯濃度在抑制大腸菌效果上,並無明顯差異。另外,在菌種分離方面,生物膜中分離出的菌種種類較原水中多,且以革藍氏陰性桿菌居多。
由模式模擬的結果顯示,本研究所建立的模式能夠有效地模擬生物膜中附著性微生物的消長情形。由不同進流條件模擬方面,隨著自來水進流餘氯濃度的降低、懸浮性細菌濃度的增加、DOC與BDOC濃度的增加,配水管線中附著性細菌的密度會隨之增高。在靈敏度分析方面,隨著細菌對基質的利用速率及轉換率提高、自然死亡速率減慢、附著性細菌對氯殺菌力的阻抗作用增大,附著性細菌的密度會隨之愈大,生長至穩定所需的時間也愈長。

Generally speaking , most the effluents of the water treatment plant can fill drinking water prescripts now . But it is frequent that consumers complain the quality of drinking water . According to the references , this phenomenon results from the recontamination of transport processes . And biological contamination is regarded as the primary problem , furthermore the problem of biofilm accumulation is especially tough and difficult to be treated .
The purpose of this research is to study the effect of different chlorine levels in controlling bioflm formation on stainless steel surfaces in distribution systems . For evaluating the effect of chlorination , including heterotrophic plate counts , ATP biomass analysis , coliform measurement with membrance method and separation and observation of biofilm bacteria was applied to the experiment , then a water quality model was used to simulate the result all together . Furthermore the results can apply to the operation of the water treatment industries .
The results of experiments indicated that maximum heterotrophic plate counts levels of the biofilm was 8.7×105 CFU/cm2 after 14 weeks of exposure for non-chlorine water and the biofilm became steadier with cultivated time extending . The accumulation rate of biolilm for high-chlorine level water was lower than low-chlorine level water , but the contrast diminished with cultivated time extending . Average biofilm formation rates was 325.2 ATP pg/cm2day for non-chlorine water , 159 and 118.4 ATP pg /cm2day for low-chlorine and high-chlorine level water . Chlorination showed a bit of effects in controlling attached coliform in cultivated incipiency , and there are no difference between chlorine levels . The bacterial species separated from biofilm were more than from original water , and most of these species were Gram-negative bacteria .
The theoretical results showed that the propose model could predict the experimental data well . The accumulative rate of attached bacteria in the distribution system increased with the decrease of the chlorine level and the enhance of the concentration of free bacteria , DOC , and BDOC . From a sensitivity analysis , The concentration of attached bacteria was higher under the conditions of higher utilized rate of substrates , lower natural decayed rate , higher resistive ability to chlorine , and took more time to grow into stabilized condition .
URI: http://hdl.handle.net/11455/4985
Appears in Collections:環境工程學系所

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