Intercalation Of Bio-enzyme/LDH And Its Application In Treatment Of Wastewater

In this paper, layer double hydroxide is synthesized by two different methods and used as carrier to immobilize enzyme. Glucose oxidase and laccase were intercalated through the methods of convalent binding and ion exchange. The properties of intercalate was investigated by X-ray diffractioin, FT-IR spectroscopy, and SEM measurements. The objective of this thesis is to apply bio-enzyme/LDH in treatment of wastewater, the detailed works can be summarized as follows:1. NiAl-LDH nanoparticles were synthesized by using Ni:Al=2:1, pH=6.5, together with N₂ via unsteadystate coprecipitation. The XRD revealed that pure crystal structure of NiAl-LDH was formed, and its interlamellar spacing d=8.0367 (?). V_c/LDH nanocoposite was synthesized by using method of ion exchange, and the concentration of V_c:LDH was optimized. The results displayed that V_c was intercalated into LDH successfully, V_c/LDH nanocoposite had highest crystallinity when the concentration of V_c was 1:1, and the nanocoposite inerlamellar spacing changed to 9.2053 (?).2. In-situ LDH were synthesized by usingα-Al₂O₃ as basement, pH=6.5, together with N₂ via coprecipitation. The optimized synthesis time was 12h, and the results was characterized by X-ray diffractioin revealed that in-situ LDH had formed well crystal structure, and its Ni:Al=3:1, interlamellar spacing d=8.1077 (?). The V_c/in-situ LDH nanocoposite and SDS/in-situ LDH nanocoposite were synthesized via coprecipitation, and SDS/in-situ LDH nanocoposite inerlamellar spacing was broadened to 25.6 (?).3. GOD/in-situ LDH was synthesized via coprecipitation, the results displayed that the GOD was intercalated into in-situ LDH successful, the nanocoposite interlamellar spacing changed to 20.5 (?). GOD/in-situ LDH was used into MFC as anode, GCE for the control experiment. The polarization curve revealed that the performance of MFC discharge of GOD/in-situ LDH as anode was improved significantly than GCE as anode. Under the same voltage drop, the output current of GOD/in-situ LDH was higer than GCE as anode. After running of MFC 15 days, the output current of GCE dropped to 29%, though the output current of GOD/in-situ LDH was 58%.4. Laccase/LDH was synthesized via ion exchange, the characterization results revealed that Laccase was intercalated into LDH successfully, the nanocoposite interlamellar spacing changed to 20.5 (?). The maximum intercalation efficiency was 65% when the intercalation temperature was 55℃. The phenols wastewater were dealt with free Laccase and Laccase/LDH nanocomposite simultaneously, the activity of free enzyme was dropped to 59%, but the Laccase/LDH nanocomposite was retained 70%. It was noted the Laccase/LDH nanocomposite still kept a high operational stability of about 70% after having recycled for 10 times. The results showed that the stability and repetition rate of Laccase/LDH nanocomposite enhanced.