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Effects of Calcination Temperatures on The Catalytic Activities of Alumina Supported Cobalt and Chromium Catalysts Mardwita Mardwita; Eka Sri Yusmartini; Nidya Wisudawati
Bulletin of Chemical Reaction Engineering & Catalysis 2019: BCREC Volume 14 Issue 3 Year 2019 (December 2019)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.14.3.4673.654-659

Abstract

Catalysts properties are important for catalytic reactions. The interaction between support and metal in a catalyst is resulted from catalyst preparation. In this study, gamma-alumina (Al2O3) supported cobalt (Co) and chromium (Cr) catalysts were prepared by impregnation method and calcined at two different temperatures, they are 400 °C for 4 hours and 800 °C for 4 hours. The resulted catalysts contained 10 wt.% of metal and denoted as Co/Al2O3(400), Co/Al2O33(800), Cr/Al2O3(400), and Cr/Al2O3(800) catalysts. The surface and state of the catalysts were examined by using x-ray diffraction (XRD), x-ray photoelectron spectrometer (XPS) and transmission electron microscopy (TEM). The XRD result reveals that strong interaction between Co and Al2O3 due to a formation of higher cobalt oxide. The XRD result further indicates aggregation and strong support metal interaction between Co and Al2O3 during calcination. On the other hand, TEM result showed that large Co particle was observed on Al2O3. The Cr/Al2O3 catalysts were characterized by using XPS. The XPS results showed that Cr/Al2O3(800) catalyst was dominated by Cr6+ species at binding energy 579.04 eV, indicating high dispersion of Cr on Al2O3. Moreover, Cr metal particle was not observed on XRD and TEM image. All the characterization results provide information that the impregnated metal on Al2O3 showed different properties. Co metal particle tends to be more oxidized and formed large particle, however it was not observed on Cr metal particle. 
Effects of Cobalt and Chromium Loadings to The Catalytic Activities of Supported Metal Catalysts in Methane Oxidation Mardwita Mardwita; Eka Sri Yusmartini; Nidya Wisudawati
Bulletin of Chemical Reaction Engineering & Catalysis 2020: BCREC Volume 15 Issue 1 Year 2020 (April 2020)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.15.1.6320.213-220

Abstract

A series of alumina supported cobalt and chromium catalysts with different metal loadings were prepared by impregnation method. Six types of alumina supported cobalt and chromium catalysts contained 5 wt%, 10 wt%, and 15 wt% loadings were produced and tested in methane oxidation. The catalysts were characterized by using x-ray diffraction (XRD) and carbon monoxide chemisorption (CO chemisorption). The XRD results do not confirmed any features of cobalt and chromium metal. The metal sizes for both catalysts were larger in high loading as shown by CO chemisorption results. Methane conversion results showed that the conversion increases with increasing the metal loading, however supported chromium catalysts were higher in activities compared to supported cobalt catalysts. Thermal stability tests on 15 wt% Co/Al and 15 wt% Cr/Al catalyst showed that supported chromium catalyst is more stable and maintain the particle size due to its strong interaction with support, while supported cobalt catalyst decrease in methane conversion due to deactivation of the catalyst. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 
Egg Shells as an Adsorbent for the Adsorption of Lead (Pb) and Iron (Fe) Metals Eka Sri Yusmartini Yusmartini; Mardwita Mardwita; Atikah Atikah; Suli Cahaya Kaswari
AJARCDE (Asian Journal of Applied Research for Community Development and Empowerment) Vol. 8 No. 1 (2024)
Publisher : Asia Pacific Network for Sustainable Agriculture, Food and Energy (SAFE-Network)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29165/ajarcde.v8i1.349

Abstract

An eggshell is estimated to have around 10,000–20,000 pores; this condition created a chance for the eggshells to be used as an adsorbent. This research aims to activate egg shells used as an adsorbent. Egg shells were applied as an adsorbent in solutions of lead (Pb) and iron (Fe). Test parameters for adsorption capacity were carried out on the optimum mass and absorption contact time with lead (Pb) and iron (Fe) while using the eggshell waste as an adsorbent. The adsorbent quality of egg shells was tested using parameters such as ash content, water content, and adsorption capacity towards methyl blue. This research aims to utilize egg shells as an adsorbent to absorb lead (Pb) and iron (Fe) content using an adsorption process. There are 3 stages of a method for this research to establish: adsorbent preparation, adsorbent activation, and the adsorption process. The adsorption process was carried out with variations of the mass sample, which are 0.75 grams, 1 gram, 1.25 grams, 1.50 grams, and 2 grams and time variations when contact occurred in 20, 30, 40, 50, and 60 minutes. The outcome of this research showed that the highest adsorption capacity at the optimum mass of Pb metal was 1.5 grams at 98.914% and for Fe metal at 96.386%. The highest adsorption capacity results were influenced by Pb metal contact time in 40 minutes, which was 99.30%, and the best capacity for adsorption of Fe metal was at a contact time in 50 minutes, which was 99.82%.
Simulation Study of Propylene Glycol Formation from Propylene Oxide and Water: Effect of Reactor Type, Reactant Ratio, Temperature, and Reactor Configuration Ariyanto, Eko; Yusmartini, Eka Sri; Robiah, Robiah; Ardianto, Feby
IJFAC (Indonesian Journal of Fundamental and Applied Chemistry) Vol 9, No 1 (2024): February 2024
Publisher : IJFAC (Indonesian Journal of Fundamental and Applied Chemistry)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24845/ijfac.v9.i1.26

Abstract

This study investigates the influence of reactor type, reactor configuration, reactor temperature, and reactant ratio on the formation of propylene glycol from propylene oxide and water using HYSYS simulation software. The examined reactor types include Continuous Stirred Tank Reactors (CSTR) and Plug Flow Reactors (PFR). The impact of reactant ratio is explored by varying the mole ratio of propylene oxide to water. The effect of temperature is studied by altering the reaction temperature from 24 to 40 °C. HYSYS simulation results reveal that PFR yields the highest conversion compared to CSTR. Furthermore, consecutive CSTR configuration produces higher conversion than parallel CSTR configuration. Additionally, an increase in reaction temperature from 24 to 40 °C enhances the conversion of propylene oxide to propylene glycol. The reactant ratio 1:1 (propylene oxide to water) yields the highest conversion compared to other reactant ratios. The implications of these findings are to provide insights into more efficient and economical propylene glycol processes. The study suggests that PFR configuration, consecutive CSTR configuration, elevated reactor temperatures, and optimal reactant ratios can significantly improve the efficiency of propylene glycol formation.Keywords: Propylene Glycol, CSTR, PFR, Conversion, HYSYS Simulation
Proses Pembentukan Struvite Kristal Menggunakan Sampah Organik Melalui Proses Anaerobik Ariyanto, Eko; Septiaranisi, Eci Dwi; Martini, Sri; Yusmartini, Eka Sri
Prosiding Semnastek PROSIDING SEMNASTEK 2024
Publisher : Universitas Muhammadiyah Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Penelitian ini bertujuan untuk mengevaluasi pengaruh penambahan Effective Microorganisms-4 (EM-4) pada proses anaerobik limbah organik terhadap peningkatan konsentrasi ammonium (NH4) serta mengevaluasi penambahan ion Magnesium (Mg) dan Pospat (PO4) terhadap penurunan konsentrasi ion NH4 dalam proses pembentukan struvite. Meskipun telah ada penelitian sebelumnya mengenai pengaruh penambahan ion Mg dan PO4 dalam pembentukan struvite, namun penelitian yang secara khusus memperhatikan pengaruh penambahan EM-4 masih terbatas. Penelitian ini menggunakan limbah organik, kotoran sapi, dan EM-4 dalam proses anaerobik untuk menghasilkan peningkatan konsentrasi NH4, yang kemudian digunakan untuk pembentukan struvite dengan penambahan ion Mg dan PO4, serta dianalisis menggunakan SEM dan EDX. Hasil penelitian menunjukkan bahwa penambahan EM-4 sebesar 60 ml dalam proses anaerobik limbah organik menghasilkan peningkatan konsentrasi NH4 yang signifikan dari 97 mg/L hingga 350 mg/L. Pada Proses pembentukan struvite kristal menunjukkan bahwa penambahan ion Mg dan ion PO4 memiliki efek yang signifikan dalam penurunan konsentrasi NH4 hingga mencapai 53,6 mg/L dan meningkatkan kemurnian struvite yang dihasilkan yaitu 65%. Analisis Scanning Electron Microscope (SEM) dan Energy Dispersive X-Ray Analysis EDX memberikan gambaran tentang hasil pembentukan struvite dan keberadaan pengotor dalam struvite. Penelitian ini memberikan kontribusi dalam pemahaman tentang pengaruh penambahan EM-4, ion Mg, dan ion PO4 dalam pembentukan struvite melalui proses anaerobik limbah organik, serta menekankan pentingnya penelitian lebih lanjut untuk pemahaman yang lebih baik dalam pengolahan limbah organik secara efektif dan berkelanjutan.Kata kunci: Anaerobik, limbah organik, Effective Microorganisms-4 (EM4), struvite
Optimization of Coal Fly Ash Heating Temperature as an Adsorbent to Improve Acid Mine Water Quality Ridhowan, Thoufiq; Yusmartini, Eka Sri; Kharismadewi, Dian
IJFAC (Indonesian Journal of Fundamental and Applied Chemistry) Vol 9, No 3 (2024): October 2024
Publisher : IJFAC (Indonesian Journal of Fundamental and Applied Chemistry)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24845/ijfac.v9.i3.139

Abstract

Fly ash, a fine dust from coal combustion in steam power plants, is an unused waste material that can be repurposed as a low-cost adsorbent. One type of adsorbent that can be synthesized from fly ash is zeolite-like material (ZLM), which has a porous structure capable of absorbing molecules smaller than or equal to its cavity size. In this study, untreated and heat-activated fly ash at 100, 200, and 300°C was used as an adsorbent for acid mine water. Adsorbent mass varied between 6, 8, 10, 12, and 14 g, mixed with 130 mL of mine water and stirred at 150 rpm for 60 minutes. The results showed that heat activation increased the surface area of the fly ash adsorbent, reaching 22.658 m²/g at 300°C. Heat-treated fly ash at 200 and 300°C showed a more significant reduction in Fe and Mn levels, especially with 8 g of adsorbent. Additionally, all adsorbents, whether heated or not, raised the pH of the acid mine water. The total suspended solids (TSS) were reduced to meet quality standards using 14 g of adsorbent heated to 300°C. These results indicate that coal fly ash adsorbent can be effectively applied for treating acid mine water
PENYULUHAN PEMBUATAN KOMPOS DARI LIMBAH RUMAH TANGGA MENGGUNAKAN KOMPOSTER DI KELURAHAN KEBUN BUNGA PALEMBANG Mardwita, Mardwita; Yusmartini, Eka Sri; Kalsum, Ummi; Rifdah, Rifdah; Angkasa, Zuber
JURNAL WIDYA LAKSANA Vol 7 No 2 (2018)
Publisher : Universitas Pendidikan Ganesha

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23887/jwl.v7i2.12897

Abstract

Meningkatnya jumlah sampah dilingkungan masyarakat memberikan dampak negatif bagi kesehatan masyarakat, seperti masalah kesehatan dan polusi udara (bau) yang dihasilkan oleh sampah. Sampah organik seperti sayur-sayuran dan buah-buahan yang telah membusuk dan banyak dihasilkan dari rumah tangga dapat diolah menjadi pupuk kompos. Tujuan dari pengabdian masyarakat ini adalah untuk mengajarkan pada masyarakat khususnya ibu rumah tangga untuk dapat memisahkan antara sampah organik dan anorganik dan selanjutnya dapat mengolah sampah organik tersebut menjadi pupuk kompos. Pengomposan sampah organik tersebut menggunakan komposter dan Effective Microorganism 4 (EM4). Hasil pengomposan berupa pupuk kompos padat dan cairan lindi. Cairan lindi dapat digunakan kembali sebagai biang dan dapat digunakan sebagai pupuk cair tanaman. 
SOSIALISASI PENGOLAHAN LINDI MENJADI PUPUK CAIR DI TPS-3R KELURAHAN TALANG KELAPA KECAMATAN ALANG-ALANG LEBAR PALEMBANG SUMATERA SELATAN Yusmartini, Eka Sri; Mardwita, Mardwita; Fahmi, Innike Abdillah
JURNAL WIDYA LAKSANA Vol 10 No 1 (2021)
Publisher : Universitas Pendidikan Ganesha

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (493.682 KB) | DOI: 10.23887/jwl.v10i1.27968

Abstract

Meningkatnya pertumbuhan penduduk  dan aktifitasnya, memberi kontribusi significan pada peningkatan sampah. Bank Sampah merupakan usaha masyarakat bersama dengan pemerintah memiliki fungsi sebagai media edukasi bagi masyarakat bagaimana memelihara lingkungan dan mengelola sampah Metode yang digunakan dalam program kemitraan masyarakat (PKM) adalah dengan pendekatan terhadap mitra untuk memberikan pandangan tentang perlunya diversifikasi produk untuk pengolahan lindi. Diversifikasi produk dengan memberikan sosialisasi mengolah lindi yang dihasilkan dari proses pengomposan menjadi pupuk cair yang juga dapat dimanfaatkan sebagai EM4 dalam proses pengomposan. Pemasangan alat yang sudah diterapkan pada TPS 3 – R, lindi yang dihasilkan terkumpul dengan baik dan akan dapat digunakan untuk pemrosesan lanjut menjadi pupuk cair.
Pendampingan dan Pelatihan Web Pemasaran Berbasis On-Line Di SMA Negeri I Tanjung Raja Yusmartini, Eka Sri; Mardwita; Aseptianova
JURNAL WIDYA LAKSANA Vol 11 No 2 (2022)
Publisher : Universitas Pendidikan Ganesha

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (512.012 KB) | DOI: 10.23887/jwl.v11i2.40041

Abstract

Menumbuhkan minat dan jiwa entrepreneur dapat ditanam sejak di bangku sekolah. Dengan mendaur ulang sampah organik yang dihasilkan oleh sekolah menjadi pupuk kompos dan menjualnya menjadi salah satu upaya melahirkan entrepreneur muda. Tim Pengabdian UM Palembang bermitra dengan SMA Negeri 1 Tanjung Ogan Ilir dalam memberikan keterampilan dasar menjadi entrepreneur, tidak hanya kepada siswa tetapi juga guru pendamping, yaitu keterampilan dalam membuat website sebagai sarana promosi dan penjualan serta keterampilan mendesain label produk agar mampu menarik perhatian pembeli. Metode pelaksanaan kegiatan pengabdian ini adalah pra-pelaksanaan, pelaksanaan dan evaluasi. Hasil dari kegiatan ini adalah peningkatnya pengetahuan siswa dan guru pendamping terhadap pembuatan website untuk memasarkan produk, pelabelan produk serta adanya website SMANTRA01 dengan menggunakan platform Google Site dan label produk SMANTRA 01 Kompos sebagai hasil pendampingan.
Harnessing Electrochemical Processes for Enhanced Struvite Crystallization: A Comprehensive Review Ariyanto, Eko; Yusmartini, Eka Sri; Gusmiatun, Gusmiatun; Fatimah, Fatimah; Purwoko, Mitayani
IJFAC (Indonesian Journal of Fundamental and Applied Chemistry) Vol 10, No 1 (2025): February 2025
Publisher : IJFAC (Indonesian Journal of Fundamental and Applied Chemistry)

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

The recovery of nutrients from contaminated water and wastewater can effectively mitigate both the nutrient burden on water resources and the associated environmental issues affecting aquatic ecosystems. This approach presents a valuable solution towards achieving environmental and societal sustainability. Consequently, struvite crystallization technology has emerged as a promising method for nutrient recovery, as the resulting precipitate can be recycled as a natural fertilizer. This review aims to elucidate the characteristics of struvite and provide insight into the fundamental process of crystallization. Furthermore, it comprehensively discusses the various variables that influence struvite crystallization, with a special focus on its application in urine-contaminated water using electrochemical methods. The review also highlights the advantageous on environmental and economic aspects. In addition, the limitations of struvite crystallization technology are examined, and future research prospects are explored, particularly in the context of electrochemical techniques which offer innovative solutions for controlled nutrient extraction. Ultimately, this work serves as a foundational resource for the future utilization of struvite crystallization technology in nutrient recovery, in response to the escalating environmental challenges and depletion of natural resources.Keywords: Struvite formation, electrochemical process, magnesium anode, struvite crystallization, natural fertilizer