EKSTRAKSI FENOL DAN ASAM ASKORBAT DARI DAUN SIRIH (Piper betle L.) DAN PEMANFAATANNYA UNTUK FOTOREDUKSI ION Ag(I) DALAM LIMBAH FOTOGRAFI; EXTRACTION OF PHENOL AND ASCORBIC ACID FROM BETEL LEAF (Piper betle L.) AND ITS OF Ag(I) ION PHOTOGRAPHIC WASTEWATER

Apriyani, Nani, Endang Tri Wahyuni

2015 | Disertasi | FMIPA

Photoreduction of Ag(I) ion from photographic wastewater using phenol and ascorbic acid extracted from betel leaf (Piper betle L.) in water solvent has been studied. The study was began by optimization of time, temperature and mass of betel leaf in extraction process to obtain the maximum phenol and ascorbic acid. The organic substances in betel leaf extract were analysed by alkalimetric titration for determination of total acid, permanganometric for determination of reductic acid and Folin-Ciocalteu method for determination of total phenols in the extract. The photoreduction was carried out by irradiation of photographic wastewater that contain [Ag(S2O3)2]3- and betel leaf extract with UV light. In this process, the influence of betel leaf extract volume, time of irradiation and volume of N2 gas were also studied. The quantity of reduced Ag(I) ion is presented as a percentage based on the difference between the initial quantity of Ag(I) ion and the quantity of unreduced Ag(I) ion. The unreduced Ag(I) ion was determined by Atomic Absorption Spectroscopy (AAS) instrument. The solid result of photoreduction was analysed using X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) instrument. The results showed that the optimal dissolution conditions of betel leaf at temperature was 80 °C for 120 min and using 7 g of betel leaf on 100 mL of water that obtained concentration of total acid was 1.10 mmol g-1, reductic acid was 0.59 mmol g-1 and total phenols was 538.03 mg L-1. The maximal photoreduction results of 86.49% was obtained from the optimal condition of betel leaf extract volume of 50 mL, time of irradiation was 4 hours and N2 gas volume was 90 L. The result of XRD and TEM analysis showed that the solid resulted from the photoreduction in addition to contain Ag metal also mixed with Ag2S, Ag2O3, Ag3O4.

Kata Kunci : Ag(I); ascorbic acid; photographic wastewater; photoreduction; phenol.