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Equilibrium Journal of Chemical Engineering
Published by Universitas Sebelas Maret
ISSN : -     EISSN : 26223430     DOI : https://dx.doi.org/10.20961/equilibrium.v4i1.42852
Core Subject : Science, Engineering,
Chemical Engineering, Chemistry & Bioengineering Chemistry Energy Engineering Materials Science & Nanotechnology
Equilibrium Journal of Chemical Engineering (EJChE) publishes communication articles, original research articles and review articles in :. Material Development Biochemical Process Exploration and Optimization Chemical Education Chemical Reaction Kinetics and Catalysis Designing, Modeling, and Process Optimization Energy and Conversion Technology Thermodynamics Process System Engineering and products Membrane Technology Food Technology Bioprocess Technology Chemurgy Technology Waste Treatment Technology Separation and Purification Technology Natural Dyes Technology
Arjuna Subject : Teknik Kimia (semua kategori) - Kimia Proses dan Teknologi
Articles 99 Documents
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Smart-Urea-Controlled-Release-Nitrogen-Fertilizer Menggunakan Plastik Biodegradable Poli Asam Laktat Sebagai Carrier Mujtahid Kaavessina; Chitra Husnabilqis; Meylani Tri Hardiyanti
Equilibrium Journal of Chemical Engineering Vol 1, No 2 (2017): Volume 1 No 2 July 2017
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v1i2.40421

Abstract

Poly lactic acid is a polymer that has been developed as an alternative to substitution of conventional polymers. The properties of this polymer are biodegradable in nature and non-toxic substances. These polymers potentially can be used as a matrix for urea carries. The aim of this research was to synthesize poly lactic acid in a low molecular weight. This product can be used as a matrix that urea release controller during the process of fertilization. The methodology consisted of two stages. The first stage was polycondensation of lactic acid and degradability test. Lactic acid was mixed with SnCl2 catalyst 0.1% and heated to 138oC for 24 hours. The second stage was producing in the form of Smart Urea Controlled Release Nitrogen Fertilizer (CRNF). Urea was dissolved in poly lactic acid through a heating process at 150°C to dissolve urea with variation in urea concentration weight of  0.5%; 0.1%; 0.15%; 0.2%; 0.25%; 0.3% and CRNF granulation processes. Finally, the mixture was granulated in ambient temperature. Chemical analysis was done the molecular weight of poly lactic acid. The relationship between intrinsic viscosity  and  molecular  weight  was  used.  The  IR  spectra  (FTIR)  was  used  to  fine molecular structure. The release testing of urea from the matrix of poly lactic acid uses UV-VIS Spectrophotometer. The results showed that the average molecular weight of poly lactic acid is 1149.49 g /gmol. FTIR spectra of CRNF with variation in urea concentration weight showed the presence of groups owned by poly lactic acid and urea. The peaks are1627.03 to 1629.92 cm-1 for the -NH group and 3478.77 to 3498.06 cm-1 for group -OH. The existence of these groups proves the existence of urea in CRNF. The release of urea from poly lactic acid occurs by diffusion. It can be seen, when urea in CRNF form immersed in water, the concentration of urea in water increase as well as the increasing immersed time.
Tannins Compound In Soga Tingi Bark (Ceriops Tagal) As Natural Dyes Paryanto Paryanto; Sunu Herwi Pranolo; Ari Diana Susanti; Bintang Timur Putrikatama; I. R. Qatrunada; Angga Dwi Wibowo
Equilibrium Journal of Chemical Engineering Vol 5, No 1 (2021): Volume 5, No 1 July 2021
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v5i1.48505

Abstract

In general, natural dyes for textile materials are obtained from extracts part of the plants such as roots, wood, leaves, seeds, and flower. Textile industry especially batik craftsman, have known many plants that can dye textile materials, such as indigo (indigofera), soga tingi bark (Ceriops tagal), tegeran wood (Cudraina javanensis), turmeric (Curcuma), tea (The), noni root (Morinda citrifelia), soga jambal bark (Pelthophorum ferruginum), kesumba (Bixa orelana), and guava leaf (Psidiumguajava). Soga tingi bark chosen because it can produce tannins which can be used as natural dyes. The purpose of this research was to obtained tannin content in soga tingi bark as qualitatively and quantitatively. The analysis carried out is FTIR and HPLC method. FTIR analysis carried out to determine of the compounds contained in the soga tingi bark extraction. Based on FTIR analysis it can be seen that there are O-H and N-H group in the wavenumber 3375,13 cm-1. C=O bond at wavenumber 1739,16 cm-1. C=C bond at wavenumber 1624,31 cm-1. C-H bond at wavenumbers 2970,72 cm-1, 1456,39 cm-1, and 1365,74 cm-1. NO2 bond at wavenumber 1365,74 cm-1. C-N bond at wavenumbers 1228,69 cm-1 and 1217,34 cm-1. And C-O bond at wavenumbers 1228,69 cm-1, 1217,34 cm-1, and 1052,3 cm-1. While HPLC analysis carried out to determine contains tannin level in the soga tingi bark extraction. HPLC conditions used are Flowrate: 1 mL/min, Mobile phase: MeOH : H2O (50:50), λ: 271 nm and Column: C18, 250 mm. Based on HPLC analysis it is known that the contains tannin level in the soga tingi bark extraction is 22,44 ppm.
Biosorption of Chromium from Textile Wastewater Using Mimosa pudica Tannin Gel Yanuar Bekti Ramadhan; Aida Nur Sabrina; Endang Kwartiningsih
Equilibrium Journal of Chemical Engineering Vol 5, No 1 (2021): Volume 5, No 1 July 2021
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v5i1.54012

Abstract

Abstract. The heavy metal content is very dangerous because it can pollute the environment. One of the heavy metals waste commonly found in the textile industry is chromium (Cr). Mimosa pudica is a weed plant and its availability is very abundant. However, it also contains tannin which can be developed into tannin gel biosorbent to adsorption heavy metal content in the wastewater. The purpose of this research is to study Mimosa pudica tannin as a Cr biosorbent from textile wastewater. There are two steps to synthesis tannin gel biosorbent. They are the tannin extraction and the condensation polymerization process. Tannin is easily soluble in water so the condensation polymerization process is needed to make it insoluble in water. The extraction of Mimosa pudica tannin was done using water solvent. The condensation polymerization process was done by the reaction of tannin extract and formaldehyde. The Cr content of textile industry wastewater in the Pasar Kliwon, Surakarta was 4 ppm. The results of the biosorption of Cr heavy metal using Mimosa pudica tannin gel showed that the remaining Cr heavy metal was 0.7098 ppm. It was already below the threshold which was 1 ppm. Keywords: biosorption, condensation polymerization, extraction, Mimosa pudica, tannin gel
Kinetic Study on Hydrothermal Decomposition of Glucose in NaOH Solution With ZnO as Catalyst Bregas Siswahjono Tatag Sembodo; Addiva Febrioka; Adistya Hilga Pratiwi Aprilia
Equilibrium Journal of Chemical Engineering Vol 5, No 1 (2021): Volume 5, No 1 July 2021
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v5i1.53407

Abstract

Abstrak. Likuifaksi hidrotermal adalah proses konversi biomassa, di mana struktur biomassa diubah menjadi komponen cair dalam kondisi super kritis dengan suhu tinggi. Dalam penelitian ini, glukosa digunakan sebagai biomassa. Tujuan dari penelitian ini adalah mempelajari kinetika reaksi dan menentukan dekomposisi hidrotermal glukosa dalam larutan NaOH. Percobaan ini menggunakan 10 gram glukosa dan dilarutkan dalam 80 mL larutan NaOH kemudian dimasukkan ke dalam autoklaf. Percobaan dilakukan dengan memvariasikan suhu pemanasan yang dilakukan dalam autoklaf dengan pengaduk magnet. Setelah dipanaskan pada berbagai suhu, autoklaf segera didinginkan. Bahan yang diproses disaring untuk memisahkan padatan yang tidak larut dari fase cair. Residu padat yang telah dipisahkan dari fase cairnya kemudian dikeringkan dalam oven pada suhu 105°C selama 24 jam. Komposisi filtrat dianalisis menggunakan metode GC-MS dan konsentrasi glukosa dianalisis menggunakan metode Lane Eynon. Sebelum analisis GC-MS, filtrat didistilasi pada tekanan atmosfer sampai residu padat tetap. Sampel yang dianalisis merupakan hasil destilasi dengan suhu di atas 100 °C untuk memastikan tidak ada air dan sisa glukosa dalam sampel. Hasil analisis GC-MS sampel produk dari proses dekomposisi hidrotermal memiliki 3 puncak. Puncak pertama menunjukkan senyawa 1,3 Dipalmitin yang memiliki luas 14,74%, puncak kedua menunjukkan senyawa Olealdehida yang memiliki luas 32,35%, dan puncak ketiga menunjukkan senyawa 1,2-Epoxyhexadecane yang memiliki luas 52,91%. Hasil kinetika hidrotermal dekomposisi glukosa pada percobaan ini diperoleh orde reaksi 2 dengan energi aktivasi (Ea) sebesar 15,91 KJ/mol dan faktor pra-eksponensial sebesar 66,12.Abstract. Hydrothermal liquefaction is a biomass conversion process, where the structure of the biomass is convert into liquid components under super critical conditions with a high temperature. In this study, glucose is used as biomass. The purpose of this study was to study the reaction kinetics and determine the hydrothermal decomposition of glucose in NaOH solution. This experiment used 10 grams of glucose and dissolve it in 80 mL of NaOH solution then put it in an autoclave. Experiments were carried out by varying the heating temperature carried out in an autoclave with a magnetic stirrer. After heating at various temperatures, the autoclave is immediately cooled down. The processed material is filtered to separate insoluble solids from the liquid phase. The solid residue that has been separated from the liquid phase is then dried in an oven at 105°C for 24 hours. The composition of the filtrate was analyzed using the GC-MS method and the glucose concentration was analyzed using the Lane Eynon method. Prior to GC-MS analysis, the filtrate was distilled at atmospheric pressure until a solid residue remained. The sample analyzed is the result of distillation with a temperature above 100°C to ensure that there is no water and residual glucose in the sample. The results of GC-MS analysis of product samples from the hydrothermal decomposition process had 3 peaks. The first peak shows the compound 1,3 Dipalmitin which has an area of 14.74%, the second peak shows the Olealdehyde compound which has an area of 32.35%, and the third peak shows the 1,2-Epoxyhexadecane compound which has an area of 52.91%. The kinetics results in hydrothermal decomposition of glucose in this experiment obtained a reaction order of 2 with an activation energy (Ea) of 15.91 KJ / mol and a pre-exponential factor of 66.12. 
Konduktivitas Listrik Poly(Lactic Acid) dengan Variasi Bahan Isian Karbon: Review Gabrella Efendy; Indah Dwi Handayani; N Fauziatul Husni; Siti Habibah; Mujtahid Kaavessina
Equilibrium Journal of Chemical Engineering Vol 5, No 1 (2021): Volume 5, No 1 July 2021
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v5i1.54195

Abstract

Abstrak. Conductive Polymer Nanocomposites (CPC) merupakan material yang banyak digunakan sebagai sensor, sel fotovoltaik, kapasitor, dioda, dan perangkat energi yang sangat mudah meregang. CPC memiliki beberapa sifat unggul, diantaranya konduktivitas elektrik yang tinggi, ringan, tahan korosi, dan memiliki karakteristik mekanis yang bagus. Konduktivitas elektrik pada polimer diperoleh dan diatur dengan menambahkan bahan isian berbasis karbon seperti: Carbon Black (CB), Carbon Nano Tube (CNT), Graphite maupun Graphene. Metode panambahan bahan isian dapat dilakukan dengan Melt blending dan Solvent blending. Metode melt blending memiliki beberapa keunggulan, diantaranya mudah, praktis, murah, serta dapat diaplikasikan pada berbagai bahan. Selain itu, metode melt blending termasuk  ramah lingkungan karena tidak ada pelarut organik. Sedangkan kelebihan metode Solvent Blending adalah campuran yang lebih kuat dikarenakan disperse yang terjadi merata dan lebih baik. Pada review, penulis mengulas tentang sifat elektrik dari CPC berbasis poli asam laktat dan berbagai bahan isian  karbon, yaitu CNT, graphene, dan CB. Hasil studi literatur menunjukkan bahwa konduktivitas elektrik CPC meningkat seiring bertambahnya komposisi bahan isian. Pada metode solvent blending faktor yang berpengaruh adalah komposisi PLA dan filler, suhu operasi, kecepatan pengadukan, waktu pengadukan, dan solvent yang digunakan. Sedangkan metode melt blending faktor yang berpengaruh adalah komposisi PLA dan filler, suhu operasi, kecepatan, dan waktu.Kata kunci: Poli Asam Laktat, CNT, CB, Graphene, CPC Abstract. Conductive Polymer Nanocomposites (CPC) are materials that are widely used as sensors, photovoltaic cells, capacitors, diodes, and highly flexible energy devices. CPC has several superior properties, including high electrical conductivity, lightweight, corrosion resistance, and good mechanical characteristics. The electrical conductivity of the polymer is obtained and adjusted by adding carbon-based fillers such as: Carbon Black (CB), Carbon Nano Tube (CNT), Graphite, and Graphene. The method of adding fillers can be conducted by Melt blending and Solvent blending. The melt blending method has several advantages, including being easy, practical, inexpensive, and can be applied to various materials. In addition, the melt blending method is environmentally friendly because there is no organic solvent used. Meanwhile, the advantage of the Solvent Blending method is more homogeneous dispersion. In the review, the author reviews the electrical properties of CPC based on poly(lactic acid) and various carbon filling materials, namely CNT, graphene, and CB. The literature study shows that the electrical conductivity of CPC increases as the increase of fillers composition. In the solvent blending method, the main influencing factors are the composition of PLA and filler, operating temperature, stirring speed, stirring time, and solvent used. While the melt blending method, the influencing factors are the composition of PLA and filler, operating temperature, speed, and blending time. Keywords: Poli(lactic acid), CNT, CB, Graphene, CPC 
Training of Electric Bike Assembly with Lithium Batteries at SMK Muhammadiyah 6 Karanganyar Tika Paramitha; Endah Retno Dyartanti; Hendri Widiyandari; Arif Jumari; Adrian Nur; Inayati Inayati; Anatta Wahyu Budiman; Agus Purwanto
Equilibrium Journal of Chemical Engineering Vol 5, No 1 (2021): Volume 5, No 1 July 2021
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v5i1.53965

Abstract

With the increasing development of the battery and electric vehicle industry, student's and teacher's understanding of lithium batteries and skills in assembling electric bikes are very important in competing for jobs in these fields. Educational activities regarding batteries and training on assembling electric bike are carried out at SMK Muhammadiyah 6 Karanganyar, because there were no facilities that support the learning and teaching process about electric vehicles and batteries. The method used in this training is lecture, discussion and practice method. The material presented was about the technology of making lithium batteries and electric bike components. While practical activities include the stages of converting conventional bikes into electric bikes with energy from lithium batteries. This activity shows that participants can understand batteries and can apply batteries to electric vehicles, especially electric bikes.
Pengaruh Ekstrak Daun Kecibeling (Strobilanthes crispa), Kayu Manis (Cinnamon), dan Kersen (Muntingia calabura) Terhadap Indeks Glikemik pada Pengolahan Beras Metode Pratanak Margono Margono; Louise Louise; Laila Zulhijah Choirudina; Ameilia Ayu Safitri; Fawnia Hanifah
Equilibrium Journal of Chemical Engineering Vol 5, No 1 (2021): Volume 5, No 1 July 2021
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v5i1.53229

Abstract

Abstrak. Diabetes melitus merupakan penyakit mematikan yang masuk dalam lima besar di Indonesia. Pola makan yang sehat dengan mengkonsumsi makanan rendah gula sangat dianjurkan untuk mencegah penyakit diabetes melitus. Beras sebagai sumber utama karbohidrat di Indonesia dikategorikan sebagai makanan dengan indeks glikemik tinggi. Penelitian ini merupakan eksperimen beras dengan indeks glikemik rendah yang layak dikonsumsi oleh penderita diabetes mellitus. Berbagai ekstrak digunakan dalam pembuatan beras indeks glikemik rendah seperti strobilanthes crispus, kayu manis, dan muntingia calabura. Beras direndam dengan ekstrak 1% selama 2 jam dan dilanjutkan pemasakan dalam autoklaf selama 15 menit dengan suhu 116°C. Beras kemudian dikeringkan dalam oven pada suhu 50°C selama 24 jam sebelum dimasak dalam rice cooker dan dapat dikonsumsi. Hasil penelitian menunjukkan bahwa beras strobilanthes crispus dan ekstrak kayu manis memiliki indeks glikemik yang lebih rendah dibandingkan beras biasa. Abstract. Diabetes mellitus is a top five deadly disease in Indonesia. A healthy diet with consuming low sugar index food is suggested to prevent diabetes mellitus. Rice as the main source of carbohydrate in Indonesia is categorized as food with a high glycemic index. This study is experimenting rice with a low glycemic index that suitable to be consumed by diabetes mellitus sufferer. Various extracts are used in the making of low glycemic index rice such as strobilanthes crispus, cinnamon, and muntingia calabura. The rice is marinated with 1% extract for 2 hours and continued to cook in an autoclave for 15 minutes with temperature 116°C. The rice then dried in an oven at 50°C for 24 hours before it cooked in a rice cooker and can be consumed. The result shows that strobilanthes crispus and cinnamon extract rice has lower glycemic index than common rice.
Adsorbsi Zat Warna Alami Buah Mangrove Jenis rhizophora stylosa dan Kulit Kayu Tingi ke dalam Kain dengan Pengunci Tunjung dan Tawas Paryanto Paryanto; Ayu Mustika Wijaya; Dwi Bagas Ongko Widodo; Sonia Waluya; Wahyu Daut Utomo
Equilibrium Journal of Chemical Engineering Vol 5, No 1 (2021): Volume 5, No 1 July 2021
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v5i1.50359

Abstract

Abstrak. Industri tekstil di Indonesia berkembang pesat, hal ini ditegaskan oleh data Badan Pusat Statistik (BPS) yang menunjukkan produksi industri sandang mengalami pertumbuhan yang signifikan sebesar 15,29 persen pada tahun 2019. Penggunaan pewarna tekstil akan menimbulkan limbah. masalah di lingkungan. Sehingga diperlukan pewarna alami sebagai alternatif yang lebih aman dan ramah lingkungan. Tujuan dari penelitian ini adalah untuk memperoleh analisis data dan menentukan nilai kesetimbangan adsorpsi larutan pewarna alami kulit batang pohon bakau Rhizophora stylosa dan tingi dengan variasi jumlah pencelupan pada kain primisima dengan membandingkannya dengan persamaan Langmuir dan Freundlich serta mengetahui peran tunjung dan tawas dalam proses pengikatan zat warna menjadi kain. Penelitian ini menggunakan metode ekstraksi padat-cair kemudian diuji dengan spektrofotometri untuk mendapatkan data konsentrasi awal. Selanjutnya, tuangkan zat warna yang telah diuji kandungan taninnya ke dalam gelas ukur dan masukkan kain sebagai media perpindahan massa tanin dari cair ke padat. Sampel diambil untuk setiap pencelupan dan diuji kandungan tanin secara spektrofotometri dan diperoleh nilai Ca. pengujian pola isoterm. Uji adsorpsi proses penyerapan tanin pada zat warna alam oleh kain dilakukan dengan menghitung menggunakan persamaan Langmuir dan Freundlich. Selanjutnya kain yang telah diwarnai difiksasi dengan tunjung dan tawas. Penentuan kapasitas adsorpsi kain yang paling sesuai terhadap pewarna alam Rhizopora stylosa dan kulit kayu tingi adalah dengan menggunakan persamaan adsorpsi Freundlich dibandingkan dengan persamaan Langmuir. Hal ini dibuktikan dengan nilai error persamaan Freundlich lebih kecil dari pada persamaan Langmuir dengan menunjukkan nilai R2 yang mendekati angka 1. Nilai konstanta persamaan Langmuir kulit tingi selama tiga kali pencelupan diperoleh nilai b sebesar 0,2338 mg/gr dan nilai k adalah 0,00517 L/gr. Untuk lima kali pencelupan diperoleh nilai b sebesar 0,10817 mg/gr dan nilai k sebesar 0,00421 L/gr. Untuk tujuh kali pencelupan diperoleh nilai b sebesar 0,0670 mg/gr dan nilai k sebesar 0,003899 L/gr. Sedangkan pada persamaan Freundlich untuk kulit kayu tingi untuk tiga kali pencelupan diperoleh nilai n sebesar 0,4312 mg/g dan nilai k sebesar 0,36374 x 103 L/gr. Untuk lima kali pencelupan nilai n sebesar 0,30114 mg/g dan nilai k sebesar 0,99586 x 105 L/g. Untuk tujuh kali pencelupan nilai n sebesar 0.2424 mg/g dan nilai k sebesar 0.9354 x 107 L/g. Nilai konstanta persamaan Langmuir Rhizopora stylosa untuk tiga kali pencelupan, nilai b 0,15635 mg/gr dan nilai k 0,005224 L/gr. Untuk lima kali pencelupan diperoleh nilai b sebesar 0,08141 mg/gr dan nilai k sebesar 0,004415 L/gr. Untuk ketujuh pencelupan diperoleh nilai b sebesar 0,04909 mg/gr dan nilai k sebesar 0,00408 L/gr. Sedangkan pada persamaan Freundlich untuk Rhizopora stylosa untuk tiga kali pencelupan diperoleh nilai n sebesar 0,3862 mg/g dan nilai k sebesar 0,1090 x 104 L/g. Untuk lima kali pencelupan nilai n sebesar 0,2733 mg/g dan nilai k sebesar 0,4355 x 106 L/g. Untuk tujuh kali pencelupan diperoleh nilai n sebesar 0,2126 mg/g dan nilai k sebesar 0,1545 x 109 L/g. Dapat disimpulkan bahwa semakin banyak pewarnaan maka daya serap kain terhadap tanin semakin kecil. Perubahan warna fiksasi kain pada pencelupan ekstrak Rhizopora stylosa dengan tunjung adalah dari coklat menjadi coklat keabu-abuan, sedangkan dengan tawas dari coklat menjadi coklat tua. Perubahan warna fiksasi kain pada pencelupan ekstrak kulit tingi dengan tawas adalah dari coklat menjadi hitam, sedangkan dengan tawas dari coklat menjadi coklat tua. Abstract. The textile industry in Indonesia is growing rapidly, this is confirmed by data from the Badan Pusat Statistik (BPS) which shows that the production of the clothing industry has experienced a significant growth of 15.29 percent in 2019. The use of textile dyes will cause waste problems in the environment. So we need natural dyes as a safer and environmentally friendly alternative. The purpose of this study was to obtain data analysis and to determine the adsorption equilibrium value of the natural dye solution of mangrove Rhizophora stylosa and tingi bark with variations in the amount of dyeing in primisima cloth by comparing it with the Langmuir and Freundlich equations and knowing the role of tunjung and alum in the process of fixing dyes into cloth. This study used a solid-liquid extraction method and then tested by spectrophotometry to obtain initial concentration data. Next, pour the dye that has been tested for its tannin content into a measuring cup and insert the cloth as a medium for mass transfer of tannins from liquid to solid. Samples were taken for each dyeing and tested for tannin content by spectrophotometry and the Ca value was obtained. Isotherm pattern testing. The adsorption test for the absorption process of tannins in natural dyes by cloth was carried out by calculating using the Langmuir and Freundlich equation. Furthermore, the cloth that has been dyed is fixed by tunjung and alum.The most suitable determination of the adsorption capacity of the cloth against natural dyes Rhizopora stylosa and tingi bark is by using the Freundlich adsorption equation compared to the Langmuir equation. This is evidenced by the error value of the Freundlich equation is smaller than the Langmuir equation by showing the value of R2 which is close to number 1. The constant value of the Langmuir equation tingi bark for three times of dyeing obtained the b value is 0.2338 mg/gr and the k value is 0.00517 L/gr. For five of dyeing, the b value is 0.10817 mg/gr and the k value is 0.00421 L/gr. For the seven times of dyeing, the b value is 0.0670 mg/gr and the k value is 0.003899 L/gr. Whereas in the Freundlich equation for tingi bark for three times of dyeing, the n value is 0.4312 mg/g and the k value is 0.36374 x 103 L/gr. For five of dyeing, the n value is 0.30114 mg/g and the k value is 0.99586 x 105 L/g. For seven of dyeing, the n value is 0.2424 mg/g and the k value is 0.9354 x 107 L/g. The constant value of the Langmuir Rhizopora stylosa equation for three times of dyeing, the b value is 0.15635 mg / gr and the k value is 0.005224 L/gr. For five of dyeing, the b value is 0.08141 mg/gr and the k value is 0.004415 L/gr. For the seven of dyeing, the b value is 0.04909 mg/gr and the k value is 0.00408 L/gr. Whereas in the Freundlich equation for  Rhizopora stylosa for three times of dyeing, the n value is 0.3862 mg/g and the k value is 0.1090 x 104 L/g. For five of dyeing, the n value is 0.2733 mg/g and the k value is 0.4355 x 106 L/g. For seven of dyeing, the n value is 0.2126 mg/g and the k value is 0.1545 x 109 L/g. It can be concluded that the more dyeing, the less the absorbency of the cloth on tannins. The color change of fixation the cloth in the dyeing of Rhizopora stylosa extract with tunjung is from brown to grayish brown, while with alum from brown to dark brown. The color change of fixation the cloth in the dyeing of tingi bark extract with alum is from brown to black, while with alum from brown to dark brown.
Pengaruh Konsentrasi Aktivator Asam Fosfat (H3PO4) pada Pembuatan Karbon Aktif dari Sabut Kelapa terhadap Adsorpsi Logam Kromium Hamida Ishmatu Sholikhah; Hartika Rahma Putri; Inayati Inayati
Equilibrium Journal of Chemical Engineering Vol 5, No 1 (2021): Volume 5, No 1 July 2021
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v5i1.53572

Abstract

Abstrak. Kromium merupakan salah satu logam berat berbahaya yang terkandung dalam air limbah industri. Hal ini dapat dikurangi dengan berbagai metode, seperti adsorpsi. Penelitian ini bertujuan untuk menginisialisasi karbon aktif dari sabut kelapa dengan berbagai konsentrasi aktivator asam fosfat (H3PO4) (0,1M; 0,5M; 1M; 1,5M; 2M) dan variasi waktu kontak (30; 60; 90 ; 120; 150; 180 menit) untuk mendapatkan kapasitas adsorpsi krom yang optimum. Analisis karbon sabut kelapa aktif dengan SAA diperoleh luas permukaan 53,39 m2/g. Larutan kalium kromat (K2CrO4) diadsorpsi oleh adsorben kemudian dianalisis dengan Spektrofotometer UV-VIS untuk mengukur kandungan kromium. Penelitian ini membuktikan bahwa adsorpsi kromium oleh karbon aktif sabut kelapa semakin meningkat dari waktu ke waktu hingga mencapai kondisi optimum. Peningkatan kapasitas adsorpsi berbanding lurus dengan semakin pekatnya aktivator asam fosfat. Kapasitas adsorpsi maksimum yang diperoleh adalah 3.464 mg/g dan kondisi optimum pada waktu kontak 150 menit dengan konsentrasi aktivator asam fosfat 2M. Abstract. Chromium is one of the hazardous heavy metal contained in the industrial wastewater. It can be reduced by various methods, such as adsorption. The purpose of this study was initialized an activated carbon from coconut fiber by various phosphoric acid (H3PO4) activator concentration (0,1M; 0,5M; 1M; 1,5M; 2M) and variation of contact time (30; 60; 90; 120; 150; 180 minutes) to obtain optimum adsorption capacity of chromium. Analysis of the activated coconut fiber carbon by SAA obtained a surface area of 53,39 m2/g. The potassium chromate (K2CrO4) solution was adsorbed by the adsorbent and then analyzed by a UV-VIS Spectrophotometer to measure the chromium content. This study proved that chromium adsorption by activated coconut fiber carbon was increased by the time until reaching optimum condition. Enhancement of adsorption capacity was directly proportional as the more concentrated phosphoric acid activator. Maximum adsorption capacity obtained was 3,464 mg/g and the optimum condition was at contact time of 150 minutes with the phosphoric acid activator concentration of 2M.
Kinetics Study on Hydrothermal Decomposition of Glucose in NaOH Solution with CuO Catalyst Bregas Siswahjono Tatag Sembodo; Tatra Prima Baladina; Muhammad Yusuf Haidar
Equilibrium Journal of Chemical Engineering Vol 5, No 2 (2021): : Volume 5 No 2 December 2021
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v5i2.54553

Abstract

Biomass is an abundant resource of renewable energy and can be processed into various chemicals. In its development, hydrothermal decomposition became a method that was considered quite efficient. This study aimed to determine reaction kinetics and product composition of hydrothermal decomposition process with CuO catalyst. Experiment was conducted by heating 10 grams glucose in 80 mL NaOH solution at temperatures of 33, 50, 110, 210, 260, 280, and 288oC using CuO catalyst. Reaction was conducted in autoclave equipped with a magnetic stirrer. After being heated, autoclave was cooled to ambient temperature. Treated material is filtered to separate insoluble solid and liquid phases. After being separated, solid residue was dried in oven at 105oC for 24 hours. Filtrate composition was analyzed by GC-MS method and glucose concentration was analyzed by Lane Eynon method. Filtrate was atmospherically distilled at 100oC before GC-MS analysis to ensure that sample was free of water and glucose residue. According to kinetics calculation, reaction was 2nd order, activation energy was 28.894 kJ/mol, and pre-exponential factor was 4.17×104 min-1. GC-MS analysis showed that there were 20 compounds contained in product sample with 3 dominant compounds in form of 4,5-Dibromo-hex-2-enoic acid methyl ester, 2-Bromooctadecanal, and 9-Octadecenoic acid, propyl ester.

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