Effect of Carbonization Time of Mesoporous Carbon in the Dyes Adsorption: Rhodamine B, Methylene Blue and Carmine

Study of dyes adsorption (rhodamine B, methylene blue and carmine) by using mesoporous carbon synthesized at various carbonization time has been done. Purpose of this research was to understand influence of carbonization time to performance of the mesoporous carbon in dyes adsorption. In addition, adsorption performance of the mesoporous carbon and commercial carbon were compared. The adsorption test were conducted at conditions: 0.1 g of adsorbent, 25 mL of dyes solutions 100 ppm and shaking rate 125 rpm for 4 hour. Filtrate was used to determine remain concentration of the dyes with UV-visible spectrophotometry. Result of the research showed that the carbonization time from 1 to 3 hours  improved the adsorption, whereas from 3 to 5 hours decreased it. The best character of the mesoporous carbon was obtained at carbonization time of 3 hours with adsorption values of 96.43 ± 0.37 % for rhodamine-B, 38.80 ± 1.44 % for methylene blue and 48.51 ± 1.55 % for carmine. The adsorption values of the mesoporous carbon were 0.97 times for rhodamine B, 0.48 times for carmine, and 0.39 times for methylene blue compared with the commercial activated carbon

CHARACTERIZATION OF IMMOBILIZEDLIPASE IN ALUMINOSILICATEFOR LACTOSYL PALMITATESYNTHESIS Karakterisasi Lipase yang Diimobilisasi dalam Aluminosilikat untuk Sintesis Laktosil Palmitat

ABSTRACT Whey lactose can be esterified enzymatically by using immobilized lipase. The lipase can be isolated from Rhizopus oryzae, purified and immobilized in mesoporous aluminosilica. The use of immobilized lipase has advantages, there are longer shelf life and repeatable use. It is necessary to characterize the immobilized lipase dan ester product. The aim of the research was to characterize immobilized lipase, including determination lipase adsorption type in mesoporous aluminosilicate, immobilized lipase stability during storage time, efficiency of repetitive use of immobilized lipase. The result showed that lipase adsorption in mesoporous aluminosilicate was physical adsorption type through hydrogen bound and electrostatic interaction. Immobilized lipase stability was relatively constant at storage temperature5 °c for 25 days resulting in 98.16%of initial activity. The repetitive use of immobilized lipase showed efficient until 5 uses within activity of 50.22%. The IR spectra of lactosyl palmitate from both whey and pure lactose result showed bands at wavelength number of 3462 cm-1(OHbond), 1739 cm-1and 1747 (C=O ester bond) 1295 cm-1dan 1242 cm-1(C-O ester bond). In addition, the HLB value for lactosyl palmitate (whey) 4.708 and lactosyl palmitate (pure lactose) 4.715, therefore both lactosyl palmitate is appropriate as emulgator in W/O. Keywords: immobilized lipase, aluminosilica, lactose, whey, lactosyl palmitat

Kajian Pengaruh Temperatur Aktivasi dengan Na OHTerhadap Karakter Karbon Aktif Mesopori Berbahan Dasar Limbah Kompleks Lumpur Industri Tekstil

ABSTRACT Textile sludge waste contains many organic matters so that it is potential to be used as mesoporous carbon precursor. Actived carbon with mesopore character is effective as adsorbentand catalyst carrier of large molecules. Synthesis of the activated mesoporous carbon was done with purpose to study influence of activation temperature toward chalC}ctersof the carbon. Process of the synthesis involved dry sludge (50 g) as precursor, concentrated sodium silicate solution Si02 24.5% and Na20 7.5% (50 mL) as template source, 1 M HCI solution (50 mL) as polimering agent, carbonization condition at 600 DC3 h under nitrogen.gas flow, activation conditions with NaOH 50% and various temperatures(400, 500, 600, 700, and 800 DC),and demineralizatin conditions with 0.1 M HCI solution for 4 hand 125rpm. All of the products were characterizedwith methylen blue method to detennine specific pore volumeand specific surface area. The carbon obtained at optimum temperature was characterizedagain with surface area analyzer. Result of the research showed that the optimum condition was achieved at activation temperatureof 500 DC.Characters of the synthesizedcarbon at the optimum condition were specific surface area of 638.32 m2/g,specific pore volume of 0.35 cm3/g,averagepore diameter of 21.78 A. and methylene blue number of 358.87 mg/g. Keywords: actived mesoporous carbon, textile sludge, temperatur

Modifikasi Karbon Aktif dari Arang Tempurung Kelapa dengan Senyawa Logam-logam Transisi untuk Adsorpsi Polutan Organik

Karbon aktif adalah bahan berpori yang dapat digunakan sebagai adsorben dari polutan organik industri, seperti parasetamol. Penelitian ini dilakukan untuk mempelajari sifat-sifat kimia karbon aktif yang dimodifikasi dengan logam transisi Fe(III), Cu(II) dan Zn(II) [klorida, hidroksida dan oksida] dan kinerja adsorpsi dalam menghilangkan polutan obat parasetamol. Arang tempurung kelapa digunakan sebagai bahan baku. Karbon aktif (AC) dihasilkan dari aktivasi menggunakan aktivator KOH hingga 500oC selama 15 menit. Karbon aktif dioksidasi menggunakan H2SO4 (6M) pada 80oC selama 3 jam. Karbon aktif teroksidasi dimodifikasi dengan FeCl3, CuCl2 dan ZnCl2 untuk membentuk komposit FeCl3/AC, CuCl2/AC dan ZnCl2/AC. Komposit Fe(OH)3/AC, Cu(OH)2/AC dan Zn(OH)2/AC dibentuk dengan menambahkan larutan NaOH (5M) melalui kopresipitasi, kemudian dikalsinasi menjadi 950oC selama 5 menit untuk menghasilkan Fe2O3/AC, CuO/AC dan ZnO/AC. Semua komposit dikarakterisasi dengan spektrofotometri FTIR dan digunakan untuk uji adsorpsi parasetamol. Adsorben yang memberikan adsorpsi parasetamol tertinggi dikarakterisasi menggunakan difraksi sinar-X dan SEM-EDX. Karakterisasi menggunakan spektrofotometri FTIR menunjukkan bahwa modifikasi oleh senyawa logam transisi yang berbeda memiliki pola spektrum FTIR yang berbeda, terutama yang terhubung ke kelompok fungsional –OH dan C = C. Tes adsorpsi menunjukkan komposit CuO/AC memiliki daya adsorpsi yang terbaik yaitu yaitu sebesar 25,70 mg/g dan 95,56%. Pola difraktogram sinar-X CuO/AC menunjukkan adanya struktur kristal CuO dan karbon aktif amorf. Karakterisasi SEM-EDX menunjukkan komposisi dari : C (74,53±4,65%), O (12,24±3,34%), dan Cu (13,25±1,31%). Gambar SEM CuO/AC menunjukkan beberapa pori pada permukaan karbon aktif dan partikel putih menunjukkan kristal CuO

Synthesis of MFe2O4/CNS (M = Zn, Ni, Mn) Composites Derived from Rice Husk by the Hydrothermal-Microwave Method for Remediation of Paddy Fields

In this research work, MFe2O4/CNS was prepared using the hydrothermal–microwave method. The influence of cations (M) toward functional groups of composites and their performance in pesticide degradation were studied. Rice husk was pyrolyzed hydrothermally (200 °C, 6 h) and by microwave (800 W, 40 min). Each product was mixed with MCl2 (Zn, Ni, Mn), FeCl3, KOH, and water, and calcined (600 °C, 15 min) to obtain a composite. Characterization by XRD confirmed the MFe2O4/CNS structure. The FTIR spectra of the composites showed different band sharpness related to C-O and M-O. A mixture of dried paddy farm soil, composite, BPMC (buthylphenylmethyl carbamate) pesticide solution (0.25%), and H2O2 solution (0.15%) was kept under dark conditions for 48 h. The solution above the soil was filtered and measured with a UV-Vis spectrophotometer at 217 nm. Applications without the composite and composite–H2O2 were also conducted. The results reveal that dark BPMC degradation with the composite was 7.5 times larger than that without the composite, and 2.9 times larger than that without the composite–H2O2. There were no significantly different FTIR spectra of the soil, soil–BPMC, soil–BPMC-H2O2, and soil–BPMC-H2O2 composite and no significantly different X-ray diffractograms between the soil after drying and soil after application for pesticide degradation using the composite

STUDY OF NaOH - ACTIVATION TEMPERATURE INFLUENCE TOWARD CHARACTER OF MESOPOROUS CARBON BASED ON TEXTILE SLUDGE WASTE

Textile sludge waste contains many organic matters so that it is potential to be used as mesoporous carbon precursor. Actived carbon with mesopore character is effective as adsorbent and catalyst carrier of large molecules. Synthesis of the activated mesoporous carbon was done with purpose to study influence of activation temperature toward characters of the carbon. Process of the synthesis involved dry sludge (50 g) as precursor, concentrated sodium silicate solution SiO2 24.5% and Na2O 7.5% (50 mL) as template source, 1 M HCl solution (50 mL) as polimering agent, carbonization condition at 600 °C 3 h under nitrogen gas flow, activation conditions with NaOH 50% and various temperatures (400, 500, 600, 700, and 800 °C), and demineralizatin conditions with 0.1 M HCl solution for 4 h and 125 rpm. All of the products were characterized with methylen blue method to determine specific pore volume and specific surface area. The carbon obtained at optimum temperature was characterized again with surface area analyzer. Result of the research showed that the optimum condition was achieved at activation temperature of 500 °C. Characters of the synthesized carbon at the optimum condition were specific surface area of 638.32 m2/g, specific pore volume of 0.35 cm3/g, average pore diameter of 21.78 Å, and methylene blue number of 358.87 mg/g.   Keywords: actived mesoporous carbon, textile sludge, temperatur

The Effect of Caramelization and Carbonization Temperatures toward Structural Properties of Mesoporous Carbon from Fructose with Zinc Borosilicate Activator

Mesoporous carbon was prepared from fructose using zinc borosilicate (ZBS) activator. The synthesis involves caramelization and carbonization processes. The effect of both process temperature toward porosity and functional group of carbon surface are investigated in this research. The caramelization was conducted hydrothermally at 85 and 100 °C, followed by thermally 130 °C. The carbonization was conducted at various temperatures (450–750 °C). The carbon-ZBS composite were washed by using HF 48% solution, 1M HCl solution, and aquadest respectively to remove ZBS from the carbon. The carbon products were characterized with nitrogen gas adsorption-desorption method, FTIR spectrophotometry, X-ray diffraction, and Transmission Electron Microscopy. The highest mesopore characteristics is achieved at 100 °C (caramelization) and 450 °C (carbonization), including Vmeso about 2.21 cm3/g (pore cage) and 2.32 cm3/g (pore window) with pore uniformity centered at 300 Å (pore cage) and 200 Å (pore window), containing the surface functional groups of C=O and OH, degree of graphitization about 57% and aromaticity fraction about 0.68

Study of Structural Properties of Mesoporous Carbon From Fructose with Zinc Borosilicate Activator

Structural properties, including pore structure, functional group of carbon surface, and crystal structure of carbon built by zinc borosilicate (ZBS) and ZnCl2 (Z) have been investigated in this work. Physically, ZBS and ZnCl2 may act as template of carbon, whereas the Zn(II) cation act as chemical activator of carbonization. All precursors of ZBS (silicagel, boric acid, and ZnCl2) may act as catalysts of caramelization. The caramelization was conducted hydrothermally at 85oC and thermally 130oC. The carbonization was conducted at 450oC. The resulted carbons were washed by using HF 48% solution, 1M HCl solution, and aquadest respectively. The solid products were characterized by using nitrogen gas adsorption, infrared spectrophotometry, X-ray diffraction, and Transmition Electron Microscopy. Result of research showed that ZBS built larger mesopore volume, larger pore domination of pore size, more hydrophobic carbon, and more amorf than ZnCl2.</p