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PENGGUNAAN METODE PRESIPITASI UNTUK MENURUNKAN KADAR Cu DALAM LIMBAH CAIR INDUSTRI PERAK DI KOTAGEDE Handoko, Chanel Tri; Yanti, Tri Budi; Syadiyah, Halimatus; marwati, siti
Jurnal Penelitian Saintek Vol 18, No 2 (2013): OKTOBER 2013
Publisher : Jurnal Penelitian Saintek

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Abstract

Penelitian ini bertujuan untuk mengetahui pH optimal penurunan kadar logam Cu menggunakan metode presipitasi serta efektivitas aplikasi penurunan kadar logam Cu menggunakan agen  pengendap  larutan  kapur. Penelitian  dilakukan  dengan  mengum- pulkan sampel limbah cair industri perak di Kotagede dari 3 sumber yang berbeda, menganalisis kandungan awal logam Cu,  perlakuan presipitasi terhadap sampel, dan menganalisis kandungan akhir logam Cu. Proses presipitasi dilakukan dengan cara mereaksikan sampel limbah cair dan larutan Ca(OH)2 0,2 M pada variasi pH 7, 8, 9, 10, dan 11, kemudian didiamkan selama 24 jam. pH optimal dari percobaan tersebut digunakan sebagai pH pada proses presipitasi menggunakan larutan kapur 5%. Analisis kandungan logam Cu pada penelitian ini menggunakan alat AAS. pH sampel C = 10,3 (basa), sehingga tidak dilakukan proses presipitasi lebih lanjut terhadap sampel C. pH optimal  presipitasi  untuk  menurukan  kadar  logam  Cu  adalah  8.  Kadar  Cu  setelah perlakuan presipitasi menggunakan   larutan kapur 5% pada pH 8 adalah 0,6583 ppm untuk sampel A dan 0,4697 ppm untuk sampel B. Jika dibandingkan dengan kadar awal Cu untuk sampel A sebesar 28132,7430 ppm dan sampel B sebesar 11233,467 ppm, maka metode  presipitasi  menggunakan larutan  kapur  efektif  digunakan  untuk  menurunkan kadar Cu.
RECOVERY OF GOLD (Au) AND SILVER (Ag) METALS IN THE ELECTRONIC WASTE THROUGH MULTILEVEL PRECIPITATION PROCESS Marwati, Siti; Padmaningrum, Regina Tutik; Sunarto, Sunarto
Jurnal Sains Dasar Vol 4, No 2 (2015): Jurnal Sains Dasar
Publisher : Yogyakarta State University

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Abstract

This research aims to determine the percent recovery of gold (Au) and silver (Ag) in the electronic waste such as CD-RW and determine the purity of gold and silver metals in the electronic waste such as CD-RW that through multilevel precipitation process. The first step was the optimization of the concentration of thiourea and time dissolution of gold and silver in the sample. The concentration of thiourea and the time dissolution optimum obtained from conentration of gold and silver maximum. By The percent recovery of gold and silver are determined by comparing the concentration of gold and silver between in the solution sample and in the sample without dissolution that be analyzed by XRF. The scond step was the multilevel precipitation process and calcination. Precipitation and calcination of the filtrat was dissolution results in the optimum condition. Reagent used was a solution of hydrochloric acid and potassium carbonate. The precipitation gold and silver produced from the precipitation of dissolution again and then be analyzed by atomic absorption spectrophotometry. The purity was determined by comparing the weight of gold and silver between in the precipitate and in the solution.  The results of this research showed that the percent recovery of the silver in the CD-RW through the process dissolution with thiourea 10 g/L and 4 hours soaking time were 21.09 %. The purity silver preipitate were 0.15 %. The percent recovery and the purity of gold can  not be determined because the gold contained in the sample were not detected or below the limit of detection equipment. Keywords: recovery, gold, silver, electronic  waste
VALIDATION OF CYCLAMATE ANALYSIS METHOD WITH SPECTROPHOTOMETRY AND TURBIDIMETRY Padmaningrum, Regina Tutik; Marwati, Siti
Jurnal Sains Dasar Vol 4, No 1 (2015): Jurnal Sains Dasar
Publisher : Yogyakarta State University

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Abstract

This research aims to validate methods of analysis by spectrophotometry and turbidimetry cyclamate in the sample drink mango-flavored jelly drink  by spectrophotometry with hypochlorite reagent, ultraviolet spectrophotometry (without reagent) and turbidimetry. The object of research was the validity parameters spectrophotometric method were linearity, linear range, the limit of detection, limit of quantitation, precision, and accuracy. The calibration curve of standard solution of sodium cyclamate in the spectrophotometric method with hypochlorite reagent, UV spectrophotometry (without reagent), and turbidimetry are linear. Linear range each method respectively at a concentration were (211.36-747.08); (16.000-146.434); and (1.8521-6.1717) ppm. The detection limit of each method successively were 53.6028; 0.5833; and 0.2723 ppm. Limit of quantitation each method successively were 66.9948; 1.9443; and 0.8068 ppm. Spectrophotometric analysis method cyclamate with hypochlorite reagent had good precision and accuracy. Ultra violet  spectrophotometric analysis method of cyclamate have a good precision but the accuracy was not good. Turbidimetric methods  analysis of cyclamate had  precision and accuracy were not good.Keywords:   method validation, spectrophotometry, turbidimetry, cyclamate