- 學位論文
多用途二氧化氯生成機的開發與加工應用
Development of a multi-purpose chlorine dioxide system and its applications
摘要
二氧化氯 (Chlorine dioxide; ClO2) 是一種被世界衛生組織 (World Health Organization, WHO) 列為A1級的安全高效綠色消毒劑，而且美國環境保護署 (Environmental Protection Agency, EPA) 已批淮用於醫療衛生業儀器設備的消毒。我國現行食品衛生法規也將二氧化氯歸類為食品添加物第二類殺菌劑。過往二氧化氯生成器本身設備體積頗為龐大，且為電解法製程，在空間及電源使用上受到極大限制。本研究分為二大部分；第一部分為多用途二氧化氯生成器的開發與測試。研究中以原實驗室自有之中大型電解式二氧化氯生成器加以模組化與小型化，藉以開發出多用途二氧化氯電解生成器，並探討高純度二氧化氯之生成條件及二氧化氯物化特性等。以透過飽和食鹽水與氯酸鈉鹽類之特定比例，與電解生成操作之電壓、電流及時間，確實可生成高純度二氧化氯。其製備水溶液之特性，為黃綠色清澈液體，pH值在2-4之間，氧化還原電位在1000-1400 mV。並運用於海藻 (Seaweed)、章魚 (Octopus)、丁香魚 (Clove fish)、石斑魚 (Grouper) 及台灣鯛 (Tilapia) 等水產殺菌製程之應用。一般水產品加工製程中極易受污染，與傳統殺菌劑做比較測試。研究發現經清洗後，總生菌數、大腸桿菌群 (Coliform) 及大腸桿菌 (Escherichia coli, E. coli) 的殺菌效果來看，二氧化氯確實比傳統殺菌劑次氯酸鈉來得有效果。且清洗後其總三鹵甲烷殘留的檢測，也比使用次氯酸鈉來得低。第二部份為應用氣態二氧化氯於農產品的消毒和滅菌上，並對草莓 (strawberry)、鱉蛋 (soft-shelled turtle eggs) 評估使用氣體二氧化氯進行氣體殺菌處理成效的探討，分別以二氧化氯氣體 (5-200 ppm)，處理10-60 分鐘，探討對微生物間(總生菌數、大腸桿菌群、大腸桿菌、酵母及黴菌、金黃色葡萄球菌、沙門氏菌等)的殺菌效果。氣態二氧化氯對於草莓、鱉蛋上的酵母菌 (Yeast)、黴菌 (Mold)、大腸桿菌 (E. coli) 及大腸桿菌群 (Coliform)、金黃色葡萄球菌 (Staphylococcus aureus) 及沙門氏桿菌 (Salmonella spp.) ，在20 ppm 處理30 分鐘之條件，可降低至3 個log 值 (CFU/g) ，若延長至50 分鐘後，甚至可達到完全滅菌。若使用100-200 ppm，則可在處理10分鐘下，達到完全滅菌。微生物殺菌反應動力學的結果顯示，較低濃度的二氧化氯處理是傾向於遵循微生物殺菌的線性動力學模式。
並列摘要
Chlorine dioxide (ClO2) has been classified as one of the safe and efficient A1 class green disinfectants by the World Health Organization (WHO). In addition, the United States Environmental Protection Agency (EPA) has approved the application of chlorine dioxide as a bactericide as well as a disinfection agent for equipments used in medical and health industries. Further to this, the Taiwanese Food Hygiene Regulations have also classified ClO2 as a second category fungicides. The volume of the previous chlorine dioxide equipments are quite large, it is extremely limited on space and power usage on the electrolytic process. The present study is divided into two parts. In the first part, this work was in developing and testing of multi-purpose chlorine dioxide generator. This study was aimed to study the generation of high purity ClO2 solution via a small scale electrolytic production, and the study of physical chemistry property of ClO2. Experimental variables for the generation of chlorine dioxide include the voltage, current, and time duration during electrolysis, as well as the temperature. The results showed that the high purity of chlorine dioxide and the yellow solution could be generated in this study. The pH value was 2-4 and oxidation-reduction potential (ORP) was 1000-1400 mV. The process of liquid chlorine dioxide was applied for the sanitation of aquaculture products (seaweed, octopus, clove fish, grouper and tilapia). General aquaculture products processing process vulnerable to pollution, the disinfect effect of aquatic products by chlorine dioxide was compared to that of traditional sodium hypochlorite agent. We found that after cleaning, the bactericidal effects (total plate count and Coliform) of chlorine dioxide better than sodium hypochlorite. Residues in total trihalomethanes (THMs) after cleaning process from chlorine dioxide was much lower than sodium hypochlorite. In the second part, this work was the application of gaseous chlorine dioxide on those agriculture product processings which were not suitable for post-harvest washing. Also the sterilization efficacy of strawberry and soft-shelled turtle eggs by using ClO2 gas was evaluated. Strawberry and soft-shelled turtle eggs were exposing in ClO2 gas (5-200 ppm) , respectively, for 10-60 minutes, for microbial (total plate count, Coliform, E. coli, yeasts and molds count, Staphylococcus aureus and Salmonella spp.) test. The results show that strawberry and soft-shelled turtle eggs samples treated with 20 ppm at 30 min gave microbial counts of less than 3 log (CFU/g ) values (p<0.05); when the treatment was extended to 50 minutes, results for some microbial counts were reduced to non-detectable levels. The same findings can be obtained at a lower treatment duration of 10 min when using 100-200 ppm. The results of experimental kinetics show that lower concentrations tend to follow the linear kinetic model of microbial inactivation.