| 摘要: | 氯酚化合物具頑抗、難分解之特性，常見處理方式有物理、化學、生物等，利用酵素去除氯酚被認為對環境較為友善。本研究藉由添加酵素至受氯酚污染土壤中，將小分子具毒性之氯酚化合物偶合成分子量大且特性穩定之產物。選取市售Peroxidase及Laccase分別與氯酚於水溶液及土壤中進行催化偶合反應，探討酵素活性、外在環境因子與反應時間對氯酚化合物去除之影響，並鑑定偶合產物及其相對產量。
研究結果發現以相同酵素活性催化偶合反應後，當土壤有機質含量越高時，土壤中氯酚剩餘濃度由高至低為：紗帽山>彰化表土>台中土>林口土。土壤含水率越高，對酵素催化偶合氯酚化合物有明顯助益。酵素催化土壤中氯酚化合物，所產生之偶合產物不盡相同，利用Laccase分別與含2,4-二氯酚及2,4,6-三氯酚之台中、紗帽山土反應所產生之偶合產物分子量皆為339.1(m/z)，但因土壤中複雜之有機、無機質交互作用而使偶合產物相對產量與添加酵素活性並無相關趨勢，但其隨催化反應時間增長，氯酚濃度下降並伴隨偶合產物產生。
Peroxidase及Laccase催化氯酚化合物，可去除氯酚並同時產生偶合產物。添加不同酵素催化氯酚化合物時會產生多種不同之偶合產物，於酵素催化2,3,4,5-四氯酚及五氯酚水溶液會產生七種偶合產物。Peroxidase去除氯酚化合物之效率較Laccase高，酵素催化偶合同種氯酚化合物，在土壤所產生之偶合產物分子量不同於氯酚水溶液。
;Chlorophenols (CPs) pollution of the soil has become a major concern. The pollution of soil has been treated using physical and chemical processes that have proven to be much more expensive. By changing the traditional methodology, biodegradation has been used as a new methodology in which enzymes are used (peroxidase and laccase) to promote oxidative-coupling reaction between recalcitrant organic pollutants (e.g. 2,4-DCP, 2,4,6-TCP, 2,3,4,5-TeCP, PCP) and soil organic matter (SOM), which produce stable incorporated polymers.
In this study, the soils from Shamao Mountain, Changhua topsoil, Linkou and Taichung were collected and studied. The soil organic matter (SOMs) was determined. The SOMs and reaction time will affect enzyme activity in the environment. 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and catalyzing in aqueous medium are the optimizations to find the best activity reaction conditions with enzyme. Dissociated enzymes on the oxidative-coupling reaction in the difference phase (water and soil) will be discussed. The presence of microorganisms and organic matter in the soil as a coupling product , can promote the coupling reaction. The chlorine monomer (CPs in the soil) can be transfered into dimers, trimers of macromolecular products, which are stable incorporated polymer.When the content of organic matter is higher, the residual concentration of chlorophenols are also higher. Additionally, the moisture(%) of soil favors for oxidative-coupling reaction, and the effect of removal of chlorophenol is as follows; 100%>60%>30%. Relative quantitiy of coupling products is different in sterilization and unsterilization. When samples 2,4-DCP and 2,4,6-TCP of Taichung.; Shamao Mountain are catalyzed by laccase, their products which molecular weight were the same (339.1m/z). The oxidative-coupling reaction in soil is complicated so the trends can’t be correlated. Taking advantage of enough activity, enzyme can reduce chlorophenols and produce lots of coupling products in the same time. The effect of catalysts to chlorophenols is observed as that peroxidase showed better activity than laccase. Moerover, if numbers of chlorine in chlorophenols is higher, it will be more difficulty to remove. |
