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All Journal Konversi Communications in Science and Technology Jurnal Teknik Kimia dan Lingkungan JURNAL ILMIAH EKONOMI, MANAJEMEN, BISNIS DAN AKUNTANSI
Hesti Wijayanti
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Chemical Engineering, Chemistry & Bioengineering Chemistry Decision Sciences, Operations Research & Management Economics, Econometrics & Finance Education Energy Engineering Materials Science & Nanotechnology

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PENGARUH METODE AKTIVASI PADA KEMAMPUAN KAOLIN SEBAGAI ADSORBEN BESI (Fe) AIR SUMUR GARUDA Wulan Sari, Tirta Indah; Muhsin, Muhsin; Wijayanti, Hesti
Konversi Vol 5, No 2 (2016): Oktober 2016
Publisher : Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/k.v5i2.4768

Abstract

Abstrak- Kaolin adalah mineral yang terdapat pada batuan sedimen dikenal dengan nama batu lempung. Kaolin banyak diaplikasikan di industri seperti kertas, keramik, karet, plastik, cat, fibergelas, dan kosmetik. Penelitian ini bertujuan untuk mengetahui pengaruh metode aktivasi terhadap kemampuan kaolin sebagai adsorben. Penelitian dilakukan dengan cara pengaktivasian kaolin secara fisika, kimia, dan kimia-fisika. Aktivasi fisika dilakukan dengan pemanasan kaolin pada suhu 700oC di dalam furnace selama 30 menit dan untuk aktivasi kimia dilakukan penambahan HCl 0,25 M pada kaolin disertai pengadukan dengan kecepatan 200 rpm selama 60 menit sedangkan untuk aktivasi kimia-fisika dilakukan penambahan HCl 0,25 M pada kaolin kemudian dilanjutkan pemanasan di dalam furnace pada suhu 700oC. Pengaktivasian kaolin ini untuk menghasilkan adsorben yang mampu menyerap ion besi (Fe) secara optimum. Dari penelitian ini, aktivasi yang optimum diperoleh untuk kaolin dalam mengadsorpsi Fe adalah aktivasi kimia. Adsorben kaolin yang teraktivasi kimia mempunyai daya adsorpsi yang besar terhadap ion Fe yaitu menghasilkan penurunan kandungan ion besi (Fe) menjadi sebesar 0,04 mg/L.  Kata kunci: Aktivasi, hydrous alumunium silicate, adsorben, besi Abstract- Kaolin is a mineral found in sedimentary rocks known as clay stone. Kaolin widely applied in industries such as paper, ceramics, rubber, plastics, paint, glassfiber, and cosmetics. This study aimed to determine the effect on the ability of kaolin activation methods as adsorbent. The study was conducted by activation of kaolin in physics, chemistry, and chemistry-physics. Physical activation was done by heating kaolin at 700 ° C in a furnace for 30 minutes and for the chemical activation, the addition of 0.25 M HCl in kaolin with stirring speed of 200 rpm for 60 minutes, while the chemical-physical activation, the addition of 0.25 M HCl to the kaolin and continued warming in furnace at 700 ° C. The kaolin activation was to produce an adsorbent that is able to absorb iron (Fe) optimally. From this study, the optimum activation obtained for kaolin in adsorbing Fe is the chemical activation. Chemical activated kaolin adsorbent having a large adsorption capacity of the ion Fe which resulted in decreased content of iron (Fe) to 0.04 mg / L. Keywords : Activation, hydrous alumunium silicate, adsorbent, iron 
PEMANFAATAN ARANG AKTIF DARI SERBUK GERGAJI KAYU ULIN UNTUK MENINGKATKAN KUALITAS MINYAK GORENG BEKAS Wijayanti, Hesti; Nora, Harmin; Amelia, Rajihah
Konversi Vol 1, No 1 (2012): Oktober 2012
Publisher : Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/k.v1i1.106

Abstract

Abstrak - Penelitian ini bertujuan untuk mengetahui sejauh mana kemampuan arang aktif dari serbuk gergaji kayu ulin dalam proses adsorpsi minyak goreng bekas. Tujuan lainnya adalah untuk mengetahui waktu adsorpsi yang paling baik diantara range waktu yang digunakan untuk proses adsorpsi minyak goreng bekas dengan menggunakan arang aktif dari serbuk gergaji kayu ulin. Arang aktif dibuat dengan membakar serbuk gergaji kayu dan diaktivasi menggunakan ZnCl2 0,1 N. Arang aktif yang diperoleh digunakan untuk mengadsorpsi minyak goreng bekas dengan variasi jumlah arang sebanyak 5, 10 dan 15 gram. Selanjutnya minyak goreng bekas dan arang aktif yang sudah dicampurkan dalam Erlenmeyer tersebut diadsorpsi dengan variasi waktu 40, 60 dan 80 menit menggunakan shaker. Setelah disaring, minyak goreng bekas tersebut dianalisa angka asam, bilangan peroksida dan bilangan penyabunannya.Hasil penelitian yang didapatkan yang mememenuhi standar SNI 01- 3741-2002 dan hasil yang paling bagus adalah dengan berat arang aktif 15 gram dan dengan lama waktu pengadukan selama 80 menit. Dengan nilai angka asam sebesar 0,224 mgKOH/gram, bilangan peroksida sebesar 10 mg eq/gram, sedangkan untuk bilangan penyabunan yang memenuhi standar adalah dengan arang aktif 10 gram dan lama waktu pengadukan 40 menit yaitu sebesar 200,09 mg KOH/gram. Keywords : adsorpsi, minyak goreng bekas, arang aktif Abstract - This research conducted to investigate the ability of activated carbon from sawdust ulin wood for waste cooking oil adsorption and to get the best adsorption time from the used time range in this research. Activated carbon was gotten by carbonizing sawdust before activated it with 0.1 N ZnCl2. This activated carbon was used in adsorption waste cooking oil with weight variation of 5,10 and 15 gram that put into shaker for  40, 60 and 80 minute adsorption. After being filtered, this proceeded waste cooking oil would be analyzed in order to measure acid number, peroxide number and saponification number.As the result, the best dose for adsorption regarding SNI 01- 3741-2002 standard was 15 gram activated carbon in 80 minute adsorption which gave acid number was 0,224 mgKOH/gram, peroxide number was 10 mg eq/gram while the best dose to get saponification number that meet SNI 01- 3741-2002 standard was 10 gram in 40 minute adsorption which gave 200,09 mg KOH/gram. Keywords: adsorption, waste cooking oil, activated carbon
PEMBUATAN ARANG AKTIF DARI CANGKANG KELAPA SAWIT DENGAN AKTIVASI SECARA FISIKA, KIMIA DAN FISIKA-KIMIA Meisrilestari, Yessy; Khomaini, Rahmat; Wijayanti, Hesti
Konversi Vol 2, No 1 (2013): April 2013
Publisher : Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/k.v2i1.136

Abstract

Penelitian ini bertujuan untuk mengetahui karakteristik produk hasil pembuatan arang aktif dari cangkang kelapa sawit secara aktivasi fisika, kimia dan fisika-kimia dan mengetahui kemampuan adsorpsi arang aktif dari cangkang kelapa sawit dalam uji adsorpsi dengan asam asetat 0,5 N. Proses aktivasi dilakukan secara kimia, fisika, dan fisika-kimia. Pada aktivasi secara fisika dilakukan dengan pemanasan pada suhu tinggi menggunakan furnace yaitu pada suhu 750oC selama 3 jam. Pada aktivasi secara kimia menggunakan ZnCl2 sebagai aktifator dan direndam selama 24 jam. Aktivasi secara fisika-kimia merupakan penggabungan dari aktivasi fisika dan aktivasi kimia. Kemudian dilakukan pengujian untuk mengetahui karakteristik arang aktif dan uji kemampuan daya adsorben arang aktif terhadap asam asetat. Berdasarkan hasil penelitian arang aktif yang dibuat dari cangkang kelapa sawit dengan proses aktivasi secara fisika-kimia mempunyai daya jerap yang paling baik di antara arang aktif lain yang diaktivasi dengan proses fisika dan kimia. Pada waktu penjerapan 4 jam, arang aktif berdiameter 355 µm dengan aktivasi fisika-kimia mampu menjerap sebanyak 34,4% bagian dari larutan asam asetat 0,5 N.Keywords: Arang aktif, asam asetat, aktivasi, adsorpsiThis study was carried out to investigate the characteristics of activated carbon from coconut palm shell and also the performance of activated carbon for adsorption 0.5 N acetic acid solution. Activated carbon obtained from coconut palm shell was activated by chemical, physical and combination of physical and chemical methods. Physical activation was performed by heating the carbon at 750oC for 3 hours while chemical activation process was exhibited by immersing the carbon in ZnCl2 solution for 24 hours. Furthermore, the combination of physical-chemical activation was gained by heating carbon at 750oC for 3 hours and then immersing in ZnCl2 solution for 24 hours.The adsorption performance of activated carbon was investigated by immersing activated carbon in 0.5 N acetic acid solution for specific time. The result showed that activated carbon which was obtained by combination of physical and chemical process was the best among the other methods that mentioned earlier. The highest adsorption capacity for 0.5 N acetic acid solution was achieved 34,4% for 4 hours by using355 µm of particle size..Keywords: activated carbon, acetic acid, activation,adsorption
PENGARUH PENGGUNAAN NANAS DAN UMBI POHON GADUNG SEBAGAI KOAGULAN TERHADAP KUALITAS BAHAN OLAHAN KARET RAKYAT Praharnata, Praharnata; Sulistyo, Joko; Wijayanti, Hesti
Konversi Vol 5, No 1 (2016): April 2016
Publisher : Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/k.v5i1.4776

Abstract

Abstrak- Prakoagulasi lateks merupakan penggumpalan spontan lateks yang biasanya disebabkan oleh pengaruh asam, enzim dan bakteri. Bahan yang digunakan untuk mempercepat prakoagulasi sering dikenal sebagai koagulan. Beberapa penduduk di Kalimantan Selatan menggunakan beberapa koagulan alami yang tidak banyak dikenal seperti umbi akar pohon gadung dan tongkol nanas, sehingga dalam penelitian ini kami ingin mengkaji lebih dalam mengenai penggunaan koagulan alami ini, mengamati dan membandingkan kualitas karet yang dihasilkan. Percobaan dilakukan dengan melakukan pengamatan pada sampel lateks yang telah dicampurkan dengan koagulan yang telah divariasi, penelitian ini mencoba meniru cara pengolahan karet remah kering, sehigga sampel karet yang dibuat memiliki sifat teknis yang dapat diuji. Adapun uji yang dilakukan dalam penelitian ini antara lain; uji prakoagulasi dengan koagulan yang bervariasi, uji prakoagulasi dengan dosis koagulan yang divariasikan, uji prakoagulasi lateks dengan air sisa prakoagulasi awal dan uji sifat teknis karet. Dari hasil analisa sampel gadung diperoleh kadar nitrogen karet sebesar 0,22 %, Po 31, dan PRI 76, pada sampel nanas diperoleh kadar nitrogen sebesar 0,24%, Po 21,5 dan PRI 56. Kata kunci: Prakoagulasi, lateks, koagulan, enzim, bakteri Abstract- Latex precoagulation is a spontaneous clot of latex that is usually caused by the effects of acids, enzymes and bacteria. Materials used to make precoagulation faster known as a coagulant. Some people in South Kalimantan using some natural coagulant that is not widely known as a gadung tree root and pineapple cob, so in this study we wanted to examine more deeply about the use of this natural coagulant, observe and compare the quality of rubber produced. The experiments were performed by making observations on a sample of latex was mixed with a coagulant which has been varied, this study tried to imitate the dry crumb rubber processing, so the rubber samples that created has technical properties that can be tested. The tests performed in this study were precoagulation test with varying coagulant, precoagulation test with coagulant dose varied, latex precoagulation test with waste water of early precoagulation and test of the technical properties of the rubber. From the analysis of gadung sample  obtained rubber nitrogen content of 0.22 %, Po 31, and the PRI 76, the pineapple samples obtained rubber nitrogen content of 0.24 %, 21.5 Po and the PRI 56. Keywords: Precoagulation, latex , coagulants , enzymes , bacteria  
Corncob residue as heterogeneous acid catalyst for green synthesis of biodiesel: A short review Mardina, Primata; Wijayanti, Hesti; Tuhuloula, Abubakar; Hijriyati, Erita; Sarifah
Communications in Science and Technology Vol 6 No 2 (2021)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.6.2.2021.460

Abstract

The utilization of an appropriate catalyst in biodiesel production depends on the free fatty acid content of vegetable oil as a feedstock. Recently, heterogeneous acid catalysts are widely chosen for biodiesel production. However, these catalysts are non-renewable, highly expensive and low stability. Due to the aforementioned drawbacks of commercial heterogeneous acid catalyst, a number of efforts have been made to develop renewable green solid acid catalysts derived from biomass. Published literature revealed that the application of the biomass derived solid acid catalysts can achieve up to 98% yield of biodiesel. This article focused on corncob as raw material in solid acid catalyst preparation for biodiesel production. The efficient preparation method and performance comparation are discussed here. The corncob derived heterogeneous acid catalysts provides an environmentally friendly and green synthesis for biodiesel production.
Evaluation of stirring rate and pH on phenolic compounds recovery from palm kernel shell heavy phase bio-oil Wijayanti, Hesti; Mardina, Primata; Tuhuloula, Abubakar; Tri Ananda, Lidya; Aulia Rauf, Zahwa Syafa; Lutfi, Auliyani; Fadil Riyadi, Syahril
Communications in Science and Technology Vol 8 No 1 (2023)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.8.1.2023.1119

Abstract

This study aims to develop an efficient separation method for phenolic compounds derived from the heavy phase of bio-oil produced by the pyrolysis of palm kernel shell. Two variables were investigated during phenolic compound extraction using dichloromethane, i.e., stirring rate and pH of the solution. In both variables, the composition, yield, and distribution coefficient of the extracted phase were investigated. The results showed that the phenolic compounds' extraction favors high stirring rate and it obtained more results at more acidic conditions (lower pH). The best conditions for phenolic compounds were at 300 rpm of stirring rate and pH 4, which resulted in 77.88 % of yield and a 1.13 distribution of coefficient for the total phenols. The findings of this research will contribute to the better separation of phenolic compounds in bio-oil for improving its fuel characteristics as well as producing value-added chemicals.
MASA DEPAN TEORI AKUNTANSI: TANTANGAN, INOVASI, DAN PELUANG Hesti Wijayanti; Suciati; Arifa Ilmiyati; Gunawan Aji
JURNAL ILMIAH EKONOMI, MANAJEMEN, BISNIS DAN AKUNTANSI Vol. 1 No. 2 (2024): Juli
Publisher : CV. KAMPUSA AKADEMIK PUBLISING

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.61722/jemba.v1i2.153

Abstract

This research discusses the future of accounting theory on the innovations, challenges, and opportunities that arise in the digital era. Recent technological developments, such as artificial intelligence, blockchain, and big data, have significantly changed the accounting landscape. This article has explored how these innovations can affect traditional accounting theories and open up new opportunities for more efficient and transparent accounting practices. On the other hand, it has also identified challenges, including ethical issues, data security, andregulatory changes. By analyzing the impact of technological developments, this research is able to provide insights into how the accounting profession can adapt and evolve in the future.
Kinetic Study of Co-pyrolysis of Kelakai (Stenochlaena palustris) and Low-rank Coal (Lignite) Fadhillah, Hilda Nur; Wijayanti, Hesti; Mardina, Primata; Juwita, Rinna; Nata, Iryanti Fatyasari; Putra, Meilana Dharma; Madani, Zikri Daffa Aulia; Hendrawan, Rangga Dwi
Jurnal Teknik Kimia dan Lingkungan Vol. 9 No. 2 (2025): October 2025
Publisher : Politeknik Negeri Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33795/jtkl.v9i2.7195

Abstract

Recently, fossil fuels have still become a main source of energy and chemicals. Biomass conversion has become a promising technology to convert biomass into bio-energy and bio-chemicals. Kelakai, as a potential biomass, is abundant in wetland areas such as Kalimantan (Indonesia) and many other Asian regions, so that low-rank coal (lignite). Co-pyrolysis, the combined pyrolysis of biomass and lignite, is an attractive technique considering to its potential to enhance the efficiency of pyrolysis products. In this study, the thermal decomposition behavior and kinetic of co-pyrolysis of kelakai and lignite at various mass ratio composition (1:0, 3:1, 1:1, 1:3, and 0:1) were investigated. The experiments were performed on a thermogravimetric analyzer (TGA). The TGA result indicated that the kelakai highly decomposed at 257-400℃, while lignite was 286-500℃. Their blends were in between. In addition, thermogravimetric data were subsequently applied to a kinetic analysis based on the Arrhenius equation, with a first-order reaction. The kinetic analysis results, including activation energy and pre-exponential factor, were determined for the kelakai and lignite mixture were found to be in the range of 10.22-10.98 kJ/mol and 0.0651-0.1351 min-1, respectively. Knowledge of thermal decomposition characteristics of kelakai and its kinetics is essential for optimizing pyrolysis design. The co-pyrolysis kelakai and lignite resulted in the highest bio-oil yield of  26.86 wt% at the ratio of  0:1 and the lowest yield of 12.51 wt% for the ratio of 1:0, when using mixed ratios of kelakai and lignite, the highest yield was 24.60% (1:3) and the lowest yield was 21.18 wt% (1:1).
Co-Authors Abubakar Tuhuloula Arifa Ilmiyati Aulia Rauf, Zahwa Syafa Fadhillah, Hilda Nur Fadil Riyadi, Syahril Gunawan Aji Harmin Nora Hendrawan, Rangga Dwi Hijriyati, Erita Iryanti Fatyasari Nata, Iryanti Fatyasari Joko Sulistyo Lutfi, Auliyani Madani, Zikri Daffa Aulia Meilana Dharma Putra Muhsin Muhsin Praharnata, Praharnata Primata Mardina Rahmat Khomaini Rajihah Amelia Rinna Juwita Sarifah Suciati Tri Ananda, Lidya Wulan Sari, Tirta Indah Yessy Meisrilestari