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ADSORPSI ZAT WARNA TEKSTIL PADA ZEOLIT ALAM DARI BAYAH Hilyati Hilyati; BAMBANG WIDIHASTONO
Jurnal Kimia Terapan Indonesia Vol 1, No 2 (1991)
Publisher : Research Center for Chemistry - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3480.237 KB) | DOI: 10.14203/jkti.v1i2.304

Abstract

Adsorption equilibrium of a dye stuff (Basacryl Red X. GRL 300% of BASF) on a natural zeolite from Bayah was investigated by studying the effects of dye concentrations, panicle sizes of adsorbent, agitation rates and adsorption temperatures. The experimental results indicated that adsorption follows the Langmuir and Freundlich equations. Adsorption of dye stuff into the zeolite increased by decreasing the adsorbent panicle size and by increasing both temperature and agitation rate. The adsorption ability of the natural zeolite could be increased up to 5-7 % higher than inactroated zeolite via an aktivation proces by treating it with H2SO4, HCL, HNO3, NaOH or heating seperately. It is found that the maximum adsorption by zeolite occured at the base or acid concentration of 0,05 N, or at temperature of 100°C.
BIOSENSOR UNTUK ANALISIS UREA BERDASARKAN PADA APLIKASI ENZIM UREASE DAN ELEKTRODA TUNGSTEN Bambang Widihastono
Jurnal Kimia Terapan Indonesia Vol 3, No 1 (1993)
Publisher : Research Center for Chemistry - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (4013.436 KB) | DOI: 10.14203/jkti.v3i1.298

Abstract

This study describes the development of a potentiometric biosensor for the determination of urea. The sensor was constructed by combining a tungsten wire with an enzyme, urease, physically immobilized in polyvinylchloride (PVC). The fabrication of the sensor was carried out by coating a tungsten wire with the immobilized urease. The changes in pH resulted from the enzyme-catalyzed hydrolysis of urea is measured with the tungsten electrode and shown to be proportional to the log of concentration of urea in sample solutions over a limited concentration range. Urea Sensor prepared in this study gives an almost linear response with the log of concentration in the range of 0.1 - 10.0 mM, and the calibration slope wasfound to be 52 mV Vper decade change in urea concentration.