中文摘要 本研究分別將三種酚類衍生物：3,4-dihydroxy benzoic acid (DBA) ， 3,4-dihydroxyphenyl acetic acid (PA) ，以及dihydrocaffeic acid (CA)在酪胺酸酵素催化下進行接枝反應於幾丁聚醣，而後以FTIR光譜驗證接枝反應確已發生，並以Amaranth (acid red27) 計算其接枝量。以此種改質之幾丁聚醣為吸附劑，研究其在工業廢水處理上，本實驗用於討論其去除水中染料、酚類與酪胺酸酵素之效果。 幾丁聚醣原為極佳的酸性染料吸附劑，但對於鹼性染料則毫無吸附力可言。接枝carboxyl group之幾丁聚醣，則同時具有對酸性及鹼性染料之吸附能力。以酪胺酸酵素進行去酚反應時，轉化出之quinone 化合物，可以幾丁聚醣吸附移除，而水溶液中殘餘的酪胺酸酵素，則可以用carboxyl group改質之幾丁聚醣吸附去除。 為比較不同carboxyl group對於鹼性染料吸附能力之影響，將改質後之幾丁聚醣對二種鹼性染料crystal violet (CV)及Bismarck brown Y (BB)作吸附實驗，發現pH值會影響吸附量，最適pH值分別為pH 7 (CV) 及 pH9 ( BB)。實驗數據顯示改質後之幾丁聚醣對二種鹼性染料之吸附行為遵循Langmiur type，而對二種鹼性染料之最大吸附量依下列順序減少CTS-CA > CTS-PA > CTS-DBA。與羧基接枝量大小順序相同。 改質之幾丁聚醣吸附酪胺酸酵素，於低濃度酪胺酸酵素時，依循一級吸附模式；高濃度酪胺酸酵素下則遵循二級吸附模式。比較不同溫度下的吸附效果，35℃下的吸附速率較4℃大，且吸附量也較大。在相同溫度下，三種改質幾丁聚醣對酪胺酸酵素的最大吸附量依序為CTS-DBA>CTS-PA>CTS-CA。 Abstract Phenolic compounds and dyes are commonly found in wastewaters. This study explores an enzymatic method for removal phenol and dyes from the wastewater. Three kinds of phenol derivatives: 3,4-dihydroxy benzoic acid (DBA), 3,4- dihydroxyphenyl- acetic acid (PA), hydrocaffeic acid (CA) were used individually as substrates of tyrosinase to graft onto chitosan (CTS). FTIR analysis provided supporting evidence of phenol derivatives being grafted. The grafting conversion of these phenolic reactants on chitosan was examined by the adsorption of an anionic dye: acid red 27. Time course of enzymatic grafting reaction showed a saturated grafting extent of carboxyl groups onto chitosan. The highest content of carboxyl groups on modified chitosan beads was CTS-CA. In this study, these modified beads were used in experiments on uptake of cationic dyes such as Crystal violet (CV) and Bismarck brown (BB). Adsorption of the cationic dyes onto modified chitosan gels is studied by batch adsorption technique at optimal pH (pH 7 for CV and pH9 for BB) under 30℃. Langmiur type adsorption was found for both dyes, and the maximum adsorption capacities were decreased with the following order CTS-CA > CTS-AA > CTS-DBA > CTS-BA. Tyrosinase converted p-cresol to polyquinones, and polyquinones was removed by adsorbing onto chitosan beads and tyrosinase was adsorbed by those carboxyl groups modified chitosan beads. Under low concentration , tyrosinase adsorbed by modified chitosan fitted pseudo-first order kinetic model; while at high level of tyrosinase, the adsorption fitted pseudo-second order kinetic model. The maximun adsorbed capacity and adsorbed rate constant were decreased with CTS-DBA > CTS-PA > CTS-CA.
