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Contact Name
Joko Waluyo
Contact Email
jokowaluyo@staff.uns.ac.id
Phone
+62271-632112
Journal Mail Official
equilibrium@ft.uns.ac.id
Editorial Address
Jl. Sutami 36A, Kentingan, Surakarta
Location
Kota surakarta,
Jawa tengah
INDONESIA
Equilibrium Journal of Chemical Engineering
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
Articles 5 Documents
Search results for , issue "Vol 1, No 2 (2017): Volume 1 No 2 July 2017" : 5 Documents clear
Kinetika Slow Release Pupuk Urea Berlapis Chitosan Termodifikasi YC Danarto; Anggita Nugrahey; Sela Murni Noviani
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.v1i2.40422

Abstract

During this time, the use of urea is not efficient, because about 40-70% of nitrogen in the fertilizer is not absorbed by plants. In order to increase the effectivity of nitrogen release in urea fertilizer, it needs to be coated with modified chitosan as slow releasing agent to form a hydrogel material by forming a cross linking with glutaraldehyde cross-linker.The aims of this research is to study the mechanism and the appropriate kinetic model of nitrogen release in slow releasing fertilizer of modified chitosan. This research was conducted by analyzing the ability of bio-hydrogel by calculating the percentage of swelling ratio and water retention of hydrogel and the nitrogen release in slow releasing fertilizer both in the soil and water. The experiments were conducted by varying the amount of urea used which  30 gram, 40 gram, 50 gram, 60 gram and 70 gram of urea fertilizer. The The release profile is then plotted on several models of diffusion kinetic such as zero order, first order, higuchi and korsmeyer peppas. The appropriate model of diffusion kinetic is chosen by the largest correction factor (R2).The results showed that nitrogen release of the slow releasing fertilizer in the soil with 50% urea content  and  the  water  followed  korsmeyer  peppas  model  with  fickian  mechanism. Nitrogen release in the soil with urea content of 30%, 40%, 60%, and 70% followed the korsmeyer peppas model with nonfickian mechanism.
Phase Control of TiO2 Prepared by TiCl4 Hydrolysis and Electrochemical Method Adrian Nur; Arif Jumari; Fauziatul Fajaroh; Nazriati Nazriati
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.v1i2.40423

Abstract

The phase structure of  TiO2   dependent on  applications. It  is  importat to develop an effective method to control the phase structure of TiO2. In this study, the TiO2 was synthesized by TiCl4 hydrolysis method. The control of hydrolysis was done by electrochemical method  in  a  cell  consisting  of  two  plate  carbon  as  electrodes.  The electrodes distance was set to 2.6 to 4 cm and immersed in solution at dimensions of (5 ×2) cm. The electrodes were connected to the positive and negative terminals of a DC power supply for 1 to 2.5 hours. The voltage was varied from 5 to 15 V at constant stirring and room temperature. The resulted suspension was aged for 48 hours. The solution wasfiltered. The powder dried directly in an oven at 150°C for 2 hours, washed 2 times, and dried again 60 °C for 6 hours. In this work, the voltage, electrode distance, and TiCl4 initial concentration can control the phase structure of TiO2.
Penentuan Pelarut untuk Adsorpsi Oryzanol dari Minyak Bekatul dengan Investigasi Kromatografi Lapis Tipis (Thin Layer Chromatography) Ari Diana Susanti; Wahyudi Budi Sediawan; Sang Kompiang Wirawan; Budhijanto Budhijanto
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.v1i2.40424

Abstract

Oryzanol yang terkandung dalam minyak bekatul mempunyai kekuatan antioksidan lebih  tinggi  daripada vitamin E  dan  terbukti  mempunyai efek hipokolesteromik sehingga berguna untuk kesehatan jantung dan pembuluh darah. Metode adsorpsi menggunakan adsorben silika merupakan salah satu metode isolasi oryzanol yang menjanjikan. Keberhasilan proses pemungutan oryzanol sangat ditentukan oleh pemilihan pelarut yang digunakan karena oryzanol merupakan senyawa ester sehingga sifatnya mirip dengan sifat trigliserida minyak bekatul yang ingin dipisahkan darinya. Oleh karena itu perlu ditentukan pemodifikasi pelarut sehingga diperoleh campuran pelarut yang cocok untuk proses tersebut. Modifikasi dilakukan terhadap pelarut utama n-heksana dan pemodifikasi potensial yang digunakan adalah etil asetat, diklorometana, kloroform, dan aseton. Performa campuran pelarut diuji menggunakan metode kromatografi lapis tipis (thin layer chromatography - TLC) menggunakan plat TLC silika gel grade 60. Hasil penelitian menunjukkan  kombinasi  n-heksana/aseton  =  85/15  memberikan  hasil  pemisahan oryzanol terbaik, sedangkan kombinasi    n-heksana/etil asetat = 90/10 patut dipertimbangkan apabila elusi secara gradien dipilih dalam proses pemisahan.
Synthesis of Carboxymethyl Cellulose (CMC) from Banana Tree Stem: Influence of Ratio of Cellulose with Sodium Chloroacetate To Properties of Carboxymethyl Cellulose Hendrik Aditya Mulyatno; Odisaputra Ihsan Pratama; Inayati Inayati
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.v1i2.40419

Abstract

Banana tree stem contain of 63-64% cellulose that can be processed into more valuable product. In this research, carboxymethylcellulose (CMC) from banana tree stem was  prepared  through  alkalization  and  carboxymethylation process.  The  aim  of  this research was to investigate the effect of cellulose to sodium chloroacetate 1:1 and 1:2 to the properties of CMC. Samples were analyzed their NaCl content, purity of CMC, and degree of substitution. The result showed that sample with ratio 1: 2 between cellulose with sodium chloroacetate resulted greater NaCl content, lower purity of CMC, and greater degree of substitution.
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.

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