Siti Sulastri
Universitas Negeri Yogyakarta

Published : 2 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 2 Documents
Search

EFFECT OF MALELO SANDAL SALT WITH HN03 TO THE EFFICIENCY OF CRYSTAL IMPLEMENTATION Siti Sulastri; Susila Kristianingrum; Retno Arianingrum
Jurnal Penelitian Saintek Vol 9, No 1: April 2004
Publisher : Institute of Research and Community Services, Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (12814.019 KB) | DOI: 10.21831/jps.v9i1.5553

Abstract

The  objective   of  this  study   was  to  investigate    the  effect  of  soaking nitrate  acid  of Malelo  sand  to adsorption   efficiency   of chromium  (Cr). The Malelo  sand  was prepared   by soaking   in nitric  acid with variation of  concentration     were   17,5:  35  and   70%  for    24  hours   at  room temperature.    The  adsorption   efficiency   of  chromium   was  determined based  on concentration    of chromium   residue   after  adsorption.   which measured  using Atomic Absorption  Spectrophotometer    (AAS). The characterization    of Malelo  sand  determined   using  FTIR  and XRD.  The result  indicated  that the mean  ofadsorption    efficiency   of chromium  on Malelo   sand   without   preparation    and  soaking   in  nitrate   acid  with variation   concentration    17.5:  35 and  70%  were  91,36:  92,40:  92,72 and 94,004%  respectively.
THE EFFECT OF pH ON THE ADSORPTION OF MICRONUTRIENT CATIONS OF Ca 2+ AND K + BY SILICA FROM LAPINDO MUD Jaslin Ikhsan; Siti Sulastri; Erfan Priyambodo
Jurnal Penelitian Saintek Vol 20, No 1: April 2015
Publisher : Institute of Research and Community Services, Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1406.394 KB) | DOI: 10.21831/jps.v20i1.5603

Abstract

The aim of this research was to determine the effect of pH on the adsorption of micronu- trients of Ca 2+  and K . by silica from lapindo mud. Data were collected by the adsorption experiments, on which 3 grams of silica separated from Lapindo mudwere dissolved in 300 mL of 0.0001 or 0.001 M Ca + 2+ or K ., and stirred for 2 hours. The pH of suspension was varied and left for equilibrate for 2 hours, and a sample was taken and measured for free concentration of K + + .cation  using Flame Atomic Emission Spectroscopy and of Ca  using Atomic Absorption Spectroscopy (AAS). The pH ranges were from 3 to 10. Temperature o  30 C and contact time of 2 hours were maintained. The research showed that both cations were adsorbed in sigmoid curve, increased with increasing pH values. In entire ranges of observed pH, the percentage of cations adsorbed by silica was not different signifi cantly. The adsorbent of silica formed silanol (SiOH) in water. The –OH groups of silica were protonated forming SiOH o at lower pH and deprotonated forming SiO¯ at higher pH. Wether Ca 2+  or K + 2 + . cations were bound to silica surfacesvia cation exchange reactions, on which Ca2+ or K + . exchanged H of SiOH using one charge of the cations, forming [SiO(CaO)] for Ca 2+ , and [SiO-K] for K