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All Journal CAKRA KIMIA (Indonesian E-Journal of Applied Chemistry) Jurnal Kimia (Journal of Chemistry) Jurnal Sains dan Teknologi Jurnal Penelitian Sains

I. A. Gede Widihati

Department Of Chemistry, University Of Udayana, Jl. Kampus Bukit Jimbaran Bali, Indonesia 80361

Author-ID : 2921132

Chemical Engineering, Chemistry & Bioengineering Chemistry Computer Science & IT Education Electrical & Electronics Engineering Mathematics Physics

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FOTODEGRADASI METILEN BIRU DENGAN SINAR UV DAN KATALIS Al2O3 Ida Ayu Gede Widihati; Ni Putu Diantariani; Yuliana Farhatun Nikmah
Jurnal Kimia (Journal of Chemistry) Vol. 5, No. 1 Januari 2011
Publisher : Program Studi Kimia, FMIPA, Universitas Udayana (Program of Study in Chemistry, Faculty of Mathematics and Natural Sciences, Udayana University), Bali, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (288.412 KB)

The research was conducted to observe the photodegradation of methylene blue by UV light and Al2O3 catalyst. The research determinated the optimum Al2O3 catalyst weight, the optimum pH, the optimum radiation duration and the effectivity of photodegradation at optimum conditions. Degradation of methylene blue were analyzed by UV-Vis spectrophotometer. The results showed that the optimum Al2O3 catalyst weight was 40 mg the optimum of pH was 11, and the optimum of radiation duration was 4 hours. The effectivity of photodegradation was (30.22 ± 1.17)%.

PEMANFAATAN LIMBAH SERBUK KAYU MERBAU (Instia spp.) SEBAGAI PEWARNA KAIN KATUN DENGAN PENAMBAHAN KAPUR SIRIH I Wayan Suirta; Ida Ayu Gede Widihati; I Putu Eka Suwita Hegara
Jurnal Kimia (Journal of Chemistry) Vol. 10, No. 2 Juli 2016
Publisher : Program Studi Kimia, FMIPA, Universitas Udayana (Program of Study in Chemistry, Faculty of Mathematics and Natural Sciences, Udayana University), Bali, Indonesia

Telah dilakukan penelitian mengenai pemanfaatan limbah serbuk kayu merbau (Instia spp.)sebagai pewarna kain katun dengan penambahan mordan kapur sirih. Ekstraksi zat warna limbah serbuk kayu merbau dengan pelarut air perbandingan 1:20 (b/v) (10 gram sampel : 200 mL pelarut) menghasilkan ekstrak berwarna coklat kemerahan yang selanjutnya digunakan untuk mewarnai kain katun dengan variasi penambahan mordan kapur sirih sebanyak 2, 3, 5, 8, dan 12 gram. Ekstrak dapat mewarnai kain katun dengan warna yang bervariasi yakni coklat muda, coklat kemerahan, dan coklat tua. Penambahan mordan kapur sirih mampu membentuk ikatan yang kuat antara zat warna dengan serat pada kain katun serta dapat mempertajam warna pada kain yang dihasilkan. Uji ketahanan warna kain katun dilakukan dengan perendaman menggunakan air deterjen 1% yang dalam waktu 10 menit menunjukkan kain katun yang diwarnai tanpa penambahan mordan mudah luntur, sedangkan pewarnaan dengan penambahan kapur sirih tidak mudah luntur.

KARAKTERISASI KATALIS BATU PADAS LEDGESTONE TERAKTIVASI ASAM DAN APLIKASINYA PADA PEMBUATAN BIODIESEL DARI MINYAK JELANTAH Ika Juliana; Ida Ayu Gede Widihati; Oka Ratnayani
Jurnal Kimia (Journal of Chemistry) Vol. 10, No. 1 Januari 2016
Publisher : Program Studi Kimia, FMIPA, Universitas Udayana (Program of Study in Chemistry, Faculty of Mathematics and Natural Sciences, Udayana University), Bali, Indonesia

This research aims to improve characteristics of ledgestone catalyst by using acid activation with various concentrations. The acid used for activation was H2SO4 with concentrations of 1, 2 and 3M. The characterization of catalysts was carried out by acid-base titration method to determine the surface acidity, methylene blue adsorption to measure the spesific surface area of ??the catalyst, and the NH4OAc extraction method to measure the value of cation exchange capacity of the catalyst. Ledgestone catalyst with the best character was applied to convert waste cooking oil into biodiesel. The characterization of biodiesel was carried out by densitometry to determine the density of biodiesel, Oswald viskosimetry to measure the viscosity, and Gas Chromatography-Mass Spectrometry (GCMS) to determine the composition of chemical compounds of the biodiesel. The results showed that the concentration of acid used to activate ledgestone catalyst with the best character was 1M. This acid-activated ledgestone (catalyst A1) had a value of surface acidity, surface area, active sites number, and high cation exchange capacity were 0.3530 ± 0.0011 mmol / gram and35.7581 m2/gram, 2.1258 x 1020 atoms/gram, and 5.88 me/100 g, respectively. The concentration of catalyst A1 producing the highest biodiesel yield was 1% w/v. The produced biodiesel was 74,71% with 0.02% FFA, acid value of 0.0438 mg KOH/gram biodiesel, density of 0.7850 g/mL, kinematic viscosity of 0.4650 cSt. Two major compounds of the biodiesel were methyl hexadecanoate with area of 71.84% and cis methyl-9-octadecenoate with area of 28.16%.

FOTODEGRADASI METILEN BIRU DENGAN SINAR ULTRAVIOLET DAN KATALIS ZnO Ni Putu Diantariani; Ida Ayu Gede Widihati; I G. A. A. Ratih Megasari
Jurnal Kimia (Journal of Chemistry) Vol. 8, No. 1 Januari 2014
Publisher : Program Studi Kimia, FMIPA, Universitas Udayana (Program of Study in Chemistry, Faculty of Mathematics and Natural Sciences, Udayana University), Bali, Indonesia

Study on photodegradation methylene blue with ultra violet light and catalyst ZnO has been carried out. This study include determination of quantity of catalyst ZnO optimum with radiation and without radiation, the optimum of pH, the optimum UV light radiation time, and the effectivity of photodegradation at optimum condition. The results of the research showed that percentage of degradation highly influence by the quantity of catalyst, pH of the methylene blue solution, and time of ultra violet radiation. In this study, quantity of catalyst ZnO optimum of degradation methylene blue with UV light radiation was 40 mg, whereas degradation methylene blue without UV light radiation was 50 mg. The optimum pH of fotodegradation methylene blue occurs at pH 12 and the optimum UV light radiation time was 5 hours. The effectivity photodegradation methylene blue at optimum condition was (94,67 ± 0,35) %.

PEMANFAATAN SILIKAT BENTONIT TERSUSPENSI NaCl, MgCl2, DAN CaCl2 UNTUK ISOLASI DNA METAGENOMIK DARI TANAH HUTAN MANGROVE Luh De Dwi Jayanthi; Ida Ayu Gede Widihati; I Nengah Wirajana
Jurnal Kimia (Journal of Chemistry) Vol. 9, No. 2 Juli 2015
Publisher : Program Studi Kimia, FMIPA, Universitas Udayana (Program of Study in Chemistry, Faculty of Mathematics and Natural Sciences, Udayana University), Bali, Indonesia

The aim of this study was to compare the isolated metagenomic DNA of mangrove soil in Suwung Kauh Beach, Bali by utilizing suspended bentonite of NaCl, MgCl2 and CaCl2. The metagenomic DNA isolation was performed by directly lysis method from soil with lysis buffer and heat-shock, and then continued by DNA extraction with suspended bentonite of NaCl, MgCl2 and CaCl2. Preparation of suspended bentonite was done in 1 M NaCl, MgCl2 and CaCl2. The results of metagenomic DNA isolation were analysed by gel agarose electrophoresis and spectrophotometer Nano at wave length 230, 260, and 280 nm. The results of gel agarose electrophoresis showed that DNA was not detected in the first elution from all suspended bentonite, but DNA was only detected in the first supernatant before elution from Na-bentonite and Mg-bentonite suspended. The DNA bands were most thick in the supernatant before the elution of Na-bentonite. This result indicated that Na-bentonite adsorption to metagenomic DNA was lower than the other bentonite suspended. The DNA band was not detected in the first supernatant and the first elution from Ca-bentonite that indicated that DNA adsorption was stronger than the other and was not breakable from this suspended. The results of spectrophotometer nano showed that the metagenomic DNA isolated by suspended bentonite of NaCl, MgCl2 and CaCl2 were contaminated by humic acid and protein.

SPESIASI DAN BIOAVAILABILITAS LOGAM BERAT Cu DAN Zn DALAM TANAH PERTANIAN ORGANIK DI DAERAH BEDUGUL Tri Rahayu; I Made Siaka; Ida Ayu Gede Widihati
Jurnal Kimia (Journal of Chemistry) Vol. 9, No. 2 Juli 2015
Publisher : Program Studi Kimia, FMIPA, Universitas Udayana (Program of Study in Chemistry, Faculty of Mathematics and Natural Sciences, Udayana University), Bali, Indonesia

A research on heavy metal speciation and bioavailability of Cu and Zn in soil of organic agriculture in Bedugul area has been carried out. This study aimed to determine the total metal content, speciation, and bioavailability of Cu and Zn in the soil of organic agriculture aged 5 and 4 years in Bedugul area. The total metal content was performed by the used of a digestion method with a mixture of HNO3 and HCl (3:1) in the ultrasonic bath and followed by heating on the hotplate. Speciation and bioavailability of Cu and Zn was conducted using SET (Sequential Extraction Technique). The content of Cu and Zn in the total sample was analyzed using the Atomic Absorption Spectrophotometer (AAS) with a calibration curve method. The total metal concentrations of Cu in the organic agricultural land of aged 5 and 4 years and were 41.8808-49.1060 mg/kg and 22.8544-41.6616 mg/kg whereas the concentrations of Zn in the organic agricultural land of aged 5 and 4 years were 62.9273-73.3729 mg/kg and 58.0970-73.9987 mg/kg respectively. The speciation of Cu obtained in in the organic agricultural land of aged 5 and 4 years was ranged from 6-17% and 3-14% in the EFLE fraction, from 9 to 37% and 6 to 24% in the Fe/Mn oxides fraction, and ranged from 27 to 53% and 41 to 69% in the resistant fraction (non bioavailable). The Zn speciation found in the organic agricultural land of aged 5 and 4 years was ranged from 6 to 9% and 7 to 10% the EFLE fraction (bioavailable), from 15 to 22% and 11 to 25% in the Fe/Mn oxides and organic (potentially bioavailable) fractions and ranged from 46 to58% and 40 to 53% in the silicate fraction (non bioavailable).

KARAKTERISASI KEASAMAN DAN LUAS PERMUKAAN TEMPURUNG KELAPA HIJAU (Cocos nucifera) DAN PEMANFAATANNYA SEBAGAI BIOSORBEN ION Cd2+ I. A. G. Widihati; Oka Ratnayani; Yunita Angelina
Jurnal Kimia (Journal of Chemistry) Vol. 4, No. 1 Januari 2010
Publisher : Program Studi Kimia, FMIPA, Universitas Udayana (Program of Study in Chemistry, Faculty of Mathematics and Natural Sciences, Udayana University), Bali, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (92.605 KB)

The characterization of surface acidity and area of green coconut shell (Cocos nucifera) and the applicationof the shell as biosorbent of Cd2+ have been conducted in this study. The physico-chemical characterization of thebiosorbent was observed by surface acidity measurement using gravimetry, acid base titration, and infraredspectrofotometry, and the surface area was determined by spectrofotometer UV-Vis using methylen blue method.The use of this shell as biosorbent of Cd2+ was studied by the equilibrium time, the adsorption isotherms, theadsorption capacity, and the influence of pH on adsorption capacity.The result showed that the acidity surface of the green coconut shell determined using gravimetric and acidbase titration was 39.2647 mmol/g and 39.8843 mmol/g. The surface area was 36.5961 m2/g. The adsorption capacityof green coconut shell (Cocos nucifera) as biosorbent of Cd2+ was 2.5135 mg/g at 4 hours equilibrium time with Cd2+and initial concentration (adsorption isotherms) of 50 ppm. At pH 11.00 the adsorption capacity of biosorbent onCd2+ increased to 2.7857 mg/g.

SINTESIS NANOKOMPOSIT LEMPUNG BENTONIT-ASAM SALISILAT DENGAN METODE SOL-GEL DAN KARAKTERISASINYA DENGAN XRD DAN IR-FTIR Ida Ayu Gede Widihati; Ni Putu Diantariani; Ni Made Puspawati
Jurnal Kimia (Journal of Chemistry) Vol. 11. No.2 Juli 2017
Publisher : Program Studi Kimia, FMIPA, Universitas Udayana (Program of Study in Chemistry, Faculty of Mathematics and Natural Sciences, Udayana University), Bali, Indonesia

Dalam penelitian ini dilakukan sintesis nanokomposit lempung bentonit-asam salisilat dengan metode sol gel melalui mekanisme interkalasi. Pada proses interkalasi ini, asam salisilat harus dibuat dalam bentuk senyawa kompleks dengan ion Fe(III) agar asam salisilat dapat masuk ke ruang antar lapis lempung. Pada proses interkalasi tahap pertama, konsentrasi interkalat divariasikan dengan tujuan mendapatkan nanokomposit yang memliki karakter kimia fisik yang terbaik. Sifat kimia fisik nanokomposit lempung bentonit-asam salisilat dikarakterisasi dengan menggunakan metode difraksi sinar X, FTIR. Pada tahap kedua dilakukan proses interkalasi dengan waktu reaksi yang bervariasi. Dari data XRD didapatkan bahwa variasi konsentrasi interkalat tidak menyebabkan perubahan kristalinitas yang signifikan. Ketiga komposit yang terbentuk menunjukkan puncak difraktogram yang sama dengan bentonit awal. Interkalasi asam salisilat ke dalam ruang antar lapis lempung bentonit menyebabkan peningkatan jarak antar lapis (d basal spacing) menjadi 16-17Å. Dari spektra IR dapat dilihat beberapa pita absorpsi yang karakteristik untuk lempung dan modifikasinya. Pita serapan pada bilangan gelombang 3620 cm-1 menunjukkan vibrasi stretching dari –OH untuk Al-OH pada montmorillonit. Bilangan gelombang 1640 cm-1 mengindikasikan adanya –OH bending dari air yang terabsorpsi. Pada ketiga spektra di atas terjadi pergeseran bilangan gelombang ke, (a). 1631,78 cm-1 (b). 1635,64 cm-1 dan (c). 1633,7 cm-1. Pita serapan pada bilangan gelombang 1115 cm-1 mengindikasikan adanya Si-O stretching untuk lapisan-lapisan silikat. Pada nanokomposit yang dihasilkan terjadi pergeseran bilangan gelombang tersebut ke 1109,7 cm-1(a), 1111cm-1 (b dan c). Pita serapan pada bilangan gelombang 1633,71 cm-1, 1631,78 cm-1dan 1635 cm-1 pada ketiga spectra di atas menunjukkan adanya vibrasi dari gugus C=O yang berasal dari asam salisilat. Adanya pita serapan pada bilangan gelombang 920 cm-1 mengindikasikan vibrasi bending dari Al-Al-OH. Karakterisasi dengan FTIR menunjukkan bahwa pemanasan dari 120°C hingga 250°C tidak mengakibatkan perubahan struktur yang ditunjukkan dengan tidak adanya pergeseran pita vibrasi yang dimilki oleh masing-masing gugus fungsi dari nanokomposit lempung bentonit asam salisilat

FRAKSINASI DAN BIOAVAILABILITAS LOGAM BERAT Fe DAN Mn PADA SEDIMEN DI PELABUHAN BENOA Emmy Sahara; Ida Ayu Gede Widihati; I Gede Darma Putra
Jurnal Kimia (Journal of Chemistry) Vol. 9, no. 1 Januari 2015
Publisher : Program Studi Kimia, FMIPA, Universitas Udayana (Program of Study in Chemistry, Faculty of Mathematics and Natural Sciences, Udayana University), Bali, Indonesia

A research on metal fractionation and bioavailability of Fe and Mn in sediments collected from the area of Benoa Bay at Bali has been carried out. The purpose of this study was to determine the fraction of Fe and Mn in the sediments and their bioavailabilities. Fractionations were achieved by the Sequential Extraction methods during which various solutions were employed. Measurement of the concentration of both metals was done by using Atomic Absorption Spectrofotometer with a calibration curve method. The concentrations of total Fe and Mn in the sediment obtained were of 668.2948 mg/kg and 321.5761 mg/kg, respectively. The results of Fe and Mn fractionations in sediments were as follow: the fraction of freely, leachable and exchangeable (EFLE) were of 27.74% and 24.31%, the fractions of Fe/Mn-oxides were of 23.55% and 19.99%, organic and sulfide fraction were of 25.14% and 26.11% while the resistant fraction were of 23,57% and 29,59%, respectively. It Therefore, the results showed that the bioavailable and the resistant fractions for Fe in the sediment were of 76.43% and 23,57%, respectively while for Mn were of 70.41% and 29,59%, respectively

KARAKTERISASI LEMPUNG BENTONIT TERMODIFIKASI SURFAKTAN DAN PEMANFAATANNYA SEBAGAI ADSORBEN LOGAM Cr DAN Pb PADA LIMBAH CAIR INDUSTRI TEKSTIL I. A. G. Widihati; N. P. A. H. Saraswati; I G. A. K. S. P. Dewi
Jurnal Kimia (Journal of Chemistry) Vol. 15, No.1, Januari 2021
Publisher : Program Studi Kimia, FMIPA, Universitas Udayana (Program of Study in Chemistry, Faculty of Mathematics and Natural Sciences, Udayana University), Bali, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/JCHEM.2021.v15.i01.p05

Penelitian mengenai karakterisasi lempung bentonit termodifikasi surfaktan dan pemanfaatannya sebagai adsorben logam Cr dan Pb pada limbah cair industri tekstil telah dilakukan. Modifikasi dilakukan melalui metode interkalasi dengan menambahkan 2,9155 gram surfaktan heksadesil trimetil amonium bromida per 10 gram bentonit kemudian ditambahkan dengan 2,0480 gram asam palmitat. Bentonit yang telah termodifikasi dimanfaatkan sebagai adsorben ion Cr3+ dan Pb2+. Penelitian ini bertujuan untuk mengetahui karakteristik bentonit termodifikasi, waktu optimum dan kapasitas adsorpsi terhadap ion Cr3+ dan Pb2+ . Hasil penelitian menunjukan bahwa interkalasi hekasdesil trimetil amonium bromida ke dalam antar lapis lempung bentonit tidak menyebabkan perubahan kristalinitas bentonit. Ikatan antara surfaktan dengan kisi kristal bentonit ditunjukkan dengan vibrasi pada bilangan gelombang 2922,16 dan 2850,97 cm-1 yang merupakan vibrasi dari gugus CH2 amina. Luas permukaan spesifik bentonit termodifikasi ditentukan dengan metode adsorpsi metilen biru dan didapatkan luas permukaan spesifik sebesar 46,180 m2/g. Waktu optimum adsorpsi bentonit termodifikasi untuk ion Cr3+ dan Pb2+berturut-turut 20 dan 10 menit, dengan kapasitas adsorpsi untuk ion Cr3+ dan Pb2+berturut-turut sebesar 0,0277 (84,575%) mg/g dan 0,1350 (87,455%) mg/g. Kata kunci: adsorpsi, bentonit, interkalasi, limbah cair, logam berat This paper discusses the characterization of surfactant-modified bentonite clays and its application as the adsorbent of Cr dan Pb in textile industry wastewater. The modifications were made through intercalation by the addition of 2.9155 grams of hexadecyl trimethyl ammonium bromide per 10 grams of bentonite and 2.0480 grams of palmitic acid. The aims of the research were to determine the characteristics of modified bentonite, optimum contact time and adsorption capacity of Cr3+ and Pb2+ ions. The results showed that the intercalation of hexadecyl trimethyl ammonium bromide into the interlay of bentonite clay did not cause changes in the bentonite crystallinity. The bond between the surfactant and the bentonite crystal lattice was shown by the vibration at wave numbers of 2922.16 and 2850.97 cm-1 indicating the vibration of the CH2 amine. The specific surface area of ??the modified bentonite determined by the blue methylene adsorption method was of 46,180 m2/g. The optimum adsorption time of modified bentonite for Cr3+ and Pb2+ ions were of 20 and 10 minutes, respectively with the adsorption capacity of Cr3+ and Pb2+ ions of 0.0277 mg/g (84.58%) and 0.1350 mg/g (87.46%), respectively. Keywords: adsorption, bentonite, heavy metals, intercalation, wastewater

Co-Authors Asih, I. A. R. A. Cahyanti, N. N. A. T. Emmy Sahara G. S. U. Mahaputra I G. A. A. Ratih Megasari I G. A. K. S. P. Dewi I Gede Darma Putra I Gusti Agung Gede Bawa I Made Siaka I Nengah Wirajana I Putu Eka Suwita Hegara I Wayan Suarsa I Wayan Suirta I. A. R. Astiti Asih I. Apriliyanto Ida Bagus Putra Mahardika Ika Juliana Iryanti Eka Suprihatin James Sibarani Juniari, Tjokorda Istri Trisna K. R. Pangestu Luh De Dwi Jayanthi M A Yohanita Nirmalasari Manuntun Manurung N. P. A. H. Saraswati N. P. A. J. S. Putri Nanik Wijayanti Ni G. A. M. Dwi Adhi Suastuti Ni Made Puspawati Ni Putu Diantariani Ni Wayan Sekarini Novita Rambu Atandawu Oka Ratnayani P. Suarya Sari, A. A. D. P. Tri Rahayu Widia Purwaningrum Yuky Astary Hermanto Yuliana Farhatun Nikmah Yunita Angelina

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