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This research, biodiesel production from waste cooking oil (WCO), was conducted using a montmorillonite-sulfonated carbon catalyst from molasses. The biodiesel product would be blended with diesel fuel with various volume variations to see its fuel properties. The catalyst was assessed by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), N2 adsorption-desorption isotherm, and acidity analysis using the titration method. The effect of the weight ratio of montmorillonite to sulfonated carbon was also evaluated. The process of esterification reaction was optimized using the response surface methodology with a central composite design (RSM-CCD). The study showed that the weight ratio of montmorillonite to sulfonated carbon of 1:3 generated the highest acidity of 9.79 mmol/g with a prominent enhanced surface area and was further employed to optimize the esterification reaction. The optimum condition was obtained at a reaction temperature of 78.12°C, catalyst weight of 2.98 g, and reaction time of 118.27 with an FFA conversion of 74.101%. The optimum condition for the mixture of FAME and diesel fuel was achieved at the composition of the B20 blend, which met the FAME standard. The reusability study revealed that the catalyst had adequate stability at three consecutive runs, with a reduced performance was 18.60%. The reduction of FFA conversion was due to the leaching of the catalyst’s active site. This study disclosed that the FAME generated from the esterification of FFA on WCO-catalyzed montmorillonite-sulfonated carbon had a promising option as biodiesel blends for increasing the quality of commercial diesel.

Remazol yellow is a synthetic dye that pollutes the environment and causes disease because it is carcinogenic and mutagenic. Photocatalyst is one of the technologies to remove the dye concentration, and tin oxide (SnO2) with cobalt (Co) dopant has the potential to be a good semiconductor in the process. Therefore, this study aims to synthesize SnO2/Co composites as a photocatalyst to degrade Remazol yellow dye. The photodegradation process was carried out with several variables, including the effect of time and the initial concentration of the dye and conditions under pHpzc. Furthermore, the composites were made with SnO to Co mass ratios of (2:1), (2:2), (2:3), and were characterized using X-Ray Diffraction (XRD), Scanning Electron Microscope-Energy Dispersive X-Ray (SEM-EDX), and Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-Vis DRS) instruments. Based on the results, the SnO2/Co (2:3) composite was selected as a photocatalyst to degrade the dye as the XRD characterization showed the formation of a typical peak of 2θ at 33o. The energy bandgap of SnO2 is 3.05 eV, while the (2:3) composite had a value of 2.8eV. Moreover, the SEM characterization showed a non-uniform surface with pores and elements composition of Sn, O, and Co with the values 61.24, 24.67, and 14.09 wt%, respectively. The optimum condition for photodegradation was obtained at a contact time and concentration of 180 minutes and 10 ppm, respectively, while the removal of the dye reached 65-80%.

Emissions from gasoline are one of the contributors to air pollution. Diisopropyl ether (DIPE) is an alternative oxygenate additive that can improve gasoline quality, minimizing CO and hydrocarbon gas emissions during combustion. However, there are very few studies on the use of pillared bentonite-based catalysts for DIPE production. This study aims to produce DIPE via dehydration of isopropyl alcohol using a molybdenum phosphide pillared bentonite (MoP-Bentonite) catalyst. The effect of Mo6+ metal concentration on the catalytic activity of isopropyl alcohol dehydration was also investigated. The catalyst that gives the highest DIPE yield will be analyzed by X-ray Diffraction (XRD), Scanning Electron Microscope-Energy Dispersive X-Ray (SEM-EDX), Gas Sorption Analyzer (GSA), and total acidity using the gravimetric method. In addition, the dehydration product will be analyzed by Gas Chromatography-Mass Spectroscopy (GC-MS). The results showed that MoP has been successfully pillared into bentonite and showed an increase in surface area, acidity, and catalytic activity. The highest yield of DIPE was obtained using a 4 mEq/g MoP-Bentonite catalyst with a DIPE yield of 64.5%.

In this study, bentonite modified by zirconium nitride (ZrN) and zirconium phosphide (ZrP) catalysts was studied in the hydrocracking of crude palm oil to biofuels. The study demonstrated that bentonite was propitiously modified by ZrN and ZrP, as assessed by XRD, FTIR spectroscopy, and SEM-EDX analysis. The acidity of the bentonite catalyst was remarkably enhanced by ZrN and ZrP, and it showed an increased intensity in the Lewis acid and Brønsted acid sites, as presented by pyridine FTIR. In the hydrocracking application, the highest conversion was achieved by bentonite-ZrN at 8 mEq g

Eggshell is a solid waste that is available in abundance but is being left unused. Eggshell containing calcium in a high amount. Calcium can be used as a precursor for hydroxyapatite (HAp). Modification of HAp with SiO2 is expected to improve its low mechanical properties for biomedical applications. In this study, HAp is synthesized from the eggshell. Then, it was modified by adding SiO2 utilizing the coprecipitation method with concentrations of 10%, 20%, 30%, and 40%, respectively. The HAp and HAp/SiO2 were characterized using; X-ray diffraction and Fourier transform infrared spectroscopy. The analysis HAp and HAp/SiO2 were density, compressive strength, and hardness. The best mechanical properties of HAp/SiO2 were characterized using SEM-EDS. The HAp were prepared successfully with a ratio of Ca/P was 1.673, close to the theoretical 1.67. The addition of SiO2 caused a decrease in crystallite size and density but increased compressive strength and hardness. The best mechanical properties of HAp/SiO2 were obtained with SiO2 of 30% and 40% with similar values.

NiFe2O4 nanoparticles had been successfully synthesized by solution combustion method using urea fuel (organic precursor). The synthesized NiFe2O4 were characterized by X-ray diffraction (XRD), Scanning electron microscopy-Electron Dispersive X-ray Spectroscopy (SEM-EDs), Transmission Electron Microscopy (TEM), Fourier Transform Infra-Red (FTIR), Vibrating Sample Magnetometer (VSM), UV-Vis Diffuse Reflectance Spectroscopy (UV-Vis DRS), and Point of Zero Charge (pHpzc). NiFe2O4 nanoparticles irradiated with visible light were employed to degrade Congo red dye with the following variable: solution pH (3–8), H2O2 concentration (0.5–3 mM), and Congo red concentration (100–600 mg/L). XRD analysis results showed that the NiFe2O4 nanoparticles had a cubic spinel structure. The particle sizes are in the range of 10–40 nm. The magnetic properties of NiFe2O4 nanoparticles determined using VSM showed a magnetization saturation value of 47.32 emu/g. UV-Vis DRS analysis indicated that NiFe2O4 nanoparticles had an optical band gap of 1.97 eV. The success of synthesis was also proven by the EDS analysis results, which showed that the synthesized NiFe2O4 nanoparticles composed of Ni, Fe, and O elements. The removal efficiency of Congo red dye was 96.80% at the following optimum conditions: solution pH of 5.0, H2O2 concentration of 2 mM, Congo red dye concentration of 100 mg/L, and contact time of 60 min. The study of the photodegradation kinetics follows a pseudo-first order reaction with a rate constant value of 0.0853 min−1. Copyright © 2021 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).

Bagasse is the solid waste derived from the sugar-making process. A large amount of silica in bagasse is a potential source of silica. In this study, extraction of silica from bagasse was carried out in the following steps: pretreatment of bagasse using HCl solution, followed by calcination at varying temperatures (700 oC, 800 oC, and 900 ℃) using a furnace. Furthermore, extraction using NaOH solution and precipitation using HCl. Silica characteristics were obtained using X-Ray Diffraction (XRD), Scanning Electron Microscopy-Electron Dispersive Spectrometry (SEM-EDS), and BET surface area. The results showed that calcination temperature affected the characteristics of the silica produced. The silica extracted at 700℃ produced an amorphous phase with a broad peak at an angle of 2θ = 20-24°. It contained the most considerable silica content and surface area, 42.46% and 796.89 cm2/g, respectively. The extracted silica had an average diameter of 5.67 mm and a pore volume of 1.184 cm3/g.

Objective: The purpose of this study was to evaluate the anticholesterol activity of Paronema canescens leaves extract. Methods: These compounds were isolated via chromatography using silica gel as the stationary phase. Their structures were revealed using IR and 1D NMR data and by comparing their NMR data with the literature's data. The anticholesterol activity of compounds was tested using photometry via the Liebermann–Burchard reaction. Results: Betulinic acid (1) and stigmasterol (2) were isolated from the leaves extracts of sungkai (P. canescens). The betulinic acid (1) that was isolated showed anticholesterol activity with an IC50 value of 60.53 µg/ml, stigmasterol (2) 222.32 µg/ml, while the standard anticholesterol compound simvastatin had an IC50 of 24.68 µg/ml. Conclusion: The stigmasterol (2) has previously been reported from P. canescens while that of betulinic acid (1) is reported here for the first time and identifies its anticholesterol activity.

Coconut oil mill waste (CMW) contained high free fatty acid (FFA) content which potentially could be converted into a value-added product such as fatty acid methyl ester (FAME). In this study, a montmorillonite-sulfonated carbon catalyst was used to evaluate the kinetic parameter of FFA conversion from CMW into FAME. The characterization of FTIR and SEM-EDX confirmed that the -SO3H groups were successfully incorporated into montmorillonite- carbon catalyst. The highest catalyst acidity (9.4 mmol/g) was achieved by a ratio of montmorillonite to sulfonated carbon of 1:3 % w/w. The kinetic study using montmorillonite-sulfonated carbon 1:3 % w/w showed that the reaction temperature and molar ratio of methanol to FFA (% v/v) were positively correlated to the reaction rate. The highest rate constant of esterification towards the product (k1), reactant (k2), and equilibrium were 0.1187, 0.0595, and 1.995, achieved by a temperature of 80 ˚C, respectively. The Arrhenius constant and activation energy towards the product were 3.3085×106 and 50.3 J/mole, respectively. The reaction temperature was positively correlated to the equilibrium constant, which indicated that the reaction was endothermic. The kinetic model validation revealed that the predicted value from the model was adequately in accordance with the experimental value, as indicated by a high coefficient of determination.

In this study, MnFe 2 O 4 -activated carbon composite was synthesized by co-precipitation method and applied to adsorb methyl red dye. MnFe 2 O 4 -activated carbon composite was made with the mass ratio of activated carbon and MnFe 2 O 4 of 1:2. The composite characterization by using X-Ray Diffraction, Fourier Transform Infrared Spectroscopy, Scanning Electron Micrograph, and Energy-Dispersive X-Ray Spectroscopy, the surface area using the Brunauer, Emmett and Teller and magnetic properties by using Vibrating Sample Magnetometer. The adsorption parameters include contact time, and adsorbent weight. The spectra of FTIR MnFe 2 O 4 -activated carbon composite analysis show the presence of Fe-O and Mn-O which is not present in the spectra of activated carbon. SEM analysis shows that the composite has pores and MnFe 2 O 4 oxides are spread on its surface. The composition of the composite consists of C, O, Fe, and Mn. The composite has a surface area of 143.992 smaller than that of the activated carbon of 217.697 m 2 /g. However, the composite has magnetic properties with the saturatization magnetization of 17.91 emu/g. The optimum condition of the composite for adsorption of methyl red was obtained at a weight of 0.15 g, and contact time of 100 minutes. The adsorption of the composite was in accordance by pseudo-second-order kinetic and Langmuir isotherms with adsorption capacity of 81.97 mg/g.

The alumina-activated carbon has the ability to adsorb and desorb the procion red MX-5B. The research evaluated the influence of desorption agent, contact time, and temperature on desorption process of procion red MX-5B dye with alumina-activated carbon composite and the adsorption capacity of the composite after desorption process. The desorption agents used in desorption process were solution with pH 2−10, H2O2 30 % (v/v), methanol 70% (v/v) and ethanol 70% (v/v). The variation of contact time was in the range from 30 to 270 min and the temperature was set between 30−75 °C. The result concluded that the highest desorption efficiency up to 98.56% was achieved using ethanol 70% (v/v) for 240 min at 45 °C. The desorption kinetic followed the pseudo-first-order with the release constant (kdes) of 6.56 × 10-2 min-1. The SEM micrograph showed there is a more porous surface on the composite after the desorption compared to before the desorption. The EDX analysis indicated that alumina content in the composite was reduced after desorption process. FTIR spectra of the composite before and after desorption process showed a peak of Al−O at 592 and 590 cm-1 which was proved that alumina still exists in the composite after the desorption process. The alumina-activated carbon composite was re-used to adsorb procion red MX-5B dye. After three times of desorption and re-adsorption process, the capacity adsorption was decreased from 12.38 to 7.38 mg/g.

The modification of bentonite by pillarization process of Al/Fe metal oxide has been carried with metal oxide with ratios 1:2 and 2:1. The product was characterized by FT-IR, XRD and pHpzc analysis. Thus, this optimal pillarization product was used as an adsorbent of Congo red and Direct green dyestuffs. The FTIR characterization does not show optimum pillarization processes for any metal oxide ratios, while the XRD analysis shows the optimum pillarization processes at ratio 2:1 i.e. 17.1 Å. In addition, the optimum pH for absorption of Congo red took place at 2 while for Direct green at 3. At 70oC, the highest adsorption capacity (Qe) reached 57.34 and 72.06 mol/g; and the highest adsorption energy (E) was found 3.23 kJ/mol and 4.14 kJ/mol for Direct green for Congo red and Direct green, respectively. Vice versa, the enthalpy (ΔH) and entropy (ΔS) values decreased as the increase of both Congo red and Direct green concentration.

The influence of montmorillonite and cane sugar mixture with composition of 1:3, 1:2, 1:1, 2:1, and 3:1 to the characteristics of the synthesized montmorillonite-carbon sulfonate composite catalyst had been investigated. The mixture of montmorillonite and cane sugar was carbonized at 400 oC for 15 hours and then sulfonated using sulfuric acid at 175 oC for 15 hours. The presence of sulfonate group was detected using FT-IR and the surface topology of the catalyst was characterized using SEM-EDX. FT-IR spectra showed the existence of sulfonate group at wave number of 1095 cm-1. SEM-EDX analysis showed that the catalyst with the montmorillonite and cane sugar ratio of 1:2 consisted of 1.06% sulfur. The catalyst activity was examined using an esterification reaction between acetic acid and ethanol, and the reaction products were characterized using GC-MS. The chromatogram peak at m/z = 88 confirmed that the product was ethyl acetate. Catalyst with the montmorillonite and cane sugar ratio of 1:2 was shown to have the highest acidity and gave the highest esterification product with 76.97% conversion.

The preparation of metal oxide CaO from chicken eggshell has been carried out by decomposition at various temperatures 600, 700, 800, 900, and 1000 o C. The metal oxide CaO was characterized using XRD. Furthermore, The optimum temperature for preparation of CaO was determined based on the XRD pattern, then the characterization of CaO was extended using FT-IR spectrophotometer and BET analysis. The results show that the optimum temperature for preparation of CaO from chicken eggshell is 900 o C with peak of 2Ө at 32.3 o , 37.4 o , 53.9 o , 64.2 o and 67.5 o , respectively. The FT-IR spectrums show the unique vibration for Ca-O at 393 cm -1 . The BET analysis show that CaO has surface area 68 m 2 /g with pore volume 1.65 cm 3 /g and pore size 6.6 nm which can be classified as mesoporous. Keywords: eggshell, base catalyst, CaO, BET, mesoporous Abstrak (Indonesian): Pembuatan oksida logam CaO dari cangkang telur ayam telah dilakukan melalui dekomposisi pada berbagai suhu 600, 700, 800, 900, dan 1000°C. Oksida logam CaO dikarakterisasi dengan XRD. Selanjutnya, Suhu optimum untuk persiapan CaO ditentukan berdasarkan pola XRD, setelah itu karakterisasi CaO dilanjutkan menggunakan FT-IR spektrofotometer dan analisis BET. Hasil penelitian menunjukkan bahwa suhu optimum untuk pembentukan CaO dari cangkang telur ayam adalah 900°C dengan puncak 2Ө muncul di 32.3°, 37.4°, 53.9°, 64.2° dan 67.5°. Spektrum FT-IR menunjukkan vibrasi unik untuk Ca-O di 393 cm -1 . Analisis dengan BET menunjukkan bahwa CaO memiliki luas permukaan 68 m 2 /g dengan volume pori 1,65 cm 3 /g dan ukuran pori 6,6 nm yang dapat diklasifikasikan sebagai mesopori. Kata kunci: kulit telur, katalis basa, CaO, BET, mesopori

The aim of the present work was to The Preparation of Methyl Ester Sul f onate From Ketapang Seed Oil As Surfactant. The research is to determine the optimum condition synthesis of methyl ester sul f onate surfactant with reaction time variations (3.5; 4.0; 4.5; 5.0; 5.5 hours) . The methyl ester from ketapang seed oil were analysis by GC-MS and identif ied methyl ester sul f onate by using FTIR spectroscopy. The methyl ester from ketapang seed oil showed containing of methyl palmitoleic, methyl linoleic, methyl palmitate, methyl stearate, methyl oleic, methyl palmitolenat and methyl eicosenoate. The optimum condition of methyl ester sulfonate at reaction time 4.5 hours with the mass of methyl ester sulfonate 34,85 g. For the FTIR spectra of sulfonate group is indicated by shifting of wave number at 1118.71 cm - 1 until 1029.1 cm -1 . The c haracteristics of methyl ester sulfonate at the optimum reaction time have emulsion stability 71.684%, density 0 . 8714 g/mL, surface tension 36.232 dyne/cm, and maximum absorbance 1.428 at the maximum wavelength 660 nm. Keywords: Surfactant, methyl ester sulfonate, time reaction, ketapang seed oil

Synthesis of chitosan-SiO2 composite has been done using the precipitation method. The chitosan-SiO2 composite was applied to removal methyl red dyes from the solution. The chitosan-SiO2 composite was characterized using Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), and Scanning Electron Microscopy/Energy Dispersive X-Ray Spectroscopy (SEM-EDS). Adsorption by batch method with variables including contact time, weight of adsorbent and initial concentration. The FT-IR spectrum of composite showed the - OH, C-H, C-N, N-H, C-O (ether), C-H asymmetric, C-H symmetric, Si-O-Si, Si-OH and Si-O group. XRD spectra of chitosan-SiO2 composites showed a widening peak at 2θ = 19.95 and amorphous. From SEM-EDS spectra show the morphology of chitosan-SiO2 composite was rough, porous and inhomogeneous with constituent elements C, N, O, Na and Si. The chitosan-SiO2 composite has a pHpzc value at pH 7.9. Adsorption data of chitosan-SiO2 composite for adsorption methyl red dyes followed Langmuir isotherm with maximum adsorption capacity 20.876 mg/g. Adsorption methyl red dye onto chitosan-SiO2 composites according to pseudo-second order.

CuFe2O4-bentonite composite successfully synthesized using chemical co-precipitation method and using to adsorp Ni(II) from electroplating wastewater. The composite was characterized by Fourier Transform Infra Red and Scanning Electron Microscope-Energy Dispersive X Ray Spectroscopy. The FTIR spectra of CuFe2O4-bentonite composite presented the characteristic of CuFe2O4and bentonite. Typical of bentonite obtained by the bands at 1033.8 cm-1correspondent to the intensity of Si-O. The observed two peaks at 432.0 cm-1and 536.2 cm-1attributed to the tetrahedral and octahedral of CuFe2O4. The result indicated that CuFe2O4particles deposited on the surface of bentonite. The main component of CuFe2O4-bentonite composite contained of CuFe2O4and bentonite from EDX spectra. Batch experiments were carried out to investigate optimum condition of adsorption Ni(II) onto CuFe2O4-bentonite composite. The optimum condition for initial concentration of Ni(II) 50 mg L-1and volume 50 mL obtained at weight of CuFe2O4-bentonite composite of 100 mg, contact times at 60 minutes and pH of the solution 5. The adsorption efficiency of Ni(II) from electroplating wastewater using CuFe2O4-bentonite composite at optimum condition was 99.136 %, respectively.

Teknologi biogas telah berkembang sejak lama namun aplikasi penggunaannya di masyarakat sebagai sumber energi alternatif belum berkembang secara luas. Beberapa kendala antara lain yaitu kekurangan informasi dan pengetahuan dari masyarakat. Teknologi biogas merupakan teknologi yang memanfaatkan proses fermentasi atau dekomposisi dari bahan organik oleh mikroorganisme secara anaerobik (tanpa udara) sehingga dihasilkan gas metana. Gas metana adalah gas yang memiliki sifat mudah terbakar sehingga dihasilkan energi panas. Energi panas ini diaplikasikan dalam bentuk api kompor sehingga dapat dimanfaatkan sebagai bahan bakar alternatif rumah tangga. Salah satu bahan organik yang bisa digunakan sebagai bahan baku adalah enceng gondok. Enceng gondok merupakan tumbuhan air dan sering menjadi tanaman pengganggu bagi tumbuhan lain dan hewan. Namun kandungan selulosanya yang besar sehingga tanaman ini dapat dimanfaatkan sebagai sumber biogas. Proses pembuatan Biogas dari enceng gondok menggunakan  reaktor digester dari drum plastik dan penampung gas dari plastik polietilen dengan sistem balon. Sedangkan sumber mikroorganisme yang dapat mendekomposisi enceng gondok digunakan kotoran sapi. Jumlah kotoran sapi yang digunakan± 1-5% dari jumlah enceng gondok yang digunakan. Sedangkan perbandingan  banyaknya  air yang digunakan dengan  enceng gondok adalah 1 : 1. Waktu yang dibutuhkan untuk proses dekomposisi enceng gondok sehingga penampung  gas bervolume ± 1000L dapat penuh sekitar 3 minggu. Jumlah enceng gondok sekitar 70 kg dapat menghasilkan gas untuk keperluan memasak selama 50 hari. Keberhasilan pembuatan bahan bakar biogas dari enceng gondok ini diharapkan dapat membantu kesulitan masyarakat memperoleh bahan bakar untuk keperluan rumah tangga.

CuFe2O4 nanoparticles were synthesized by co-precipitation method from the solution of CuCl2 and FeCl3 in alkaline condition. The prepared magnetic CuFe2O4 can be used to adsorb Cr (VI) ions from aqueous solution and separated from medium by magnetic technique. The characterization of CuFe2O4 with X-Ray diffraction (XRD) showed cubic units shells with diameter in the range 15-20 nm which obtained by Transmission Electron Microscope (TEM). The saturation of magnetization is around 13 emu g-1 measured with Vibrating Sample Magnetometer (VSM). Batch adsorption studies were carried out to optimize adsorption condition. Effective conditions for adsorption of Cr (VI) were found at the weight of CuFe2O4 was 1.0 g with contact time of 60 minutes and pH 3 with adsorption capacity 9.20 mg g-1.

Research about the synthesis of chitosan/alumina composite using the sol-gel method and its application to removal procion blue MX-R dye had been conducted. The synthesized chitosan/alumina composite was characterized using FTIR to determine functional group, SEM-EDS to find out the surface morphology and elements composition of chitosan/alumina composite. The pHPZC is used to determine the appropriate pH condition on the adsorption process of chitosan and chitosan/alumina composite on procion blue dye solution. The FTIR spectra of chitosan represent the functional groups O-H, N-H, C-H and C-O while the chitosan/alumina composite is the addition of functional group of Al-O. The morphology of chitosan/alumina composite analysis by SEM showed that is heterogenous and porous. The EDX analysis showed that the present Al element of 5.49 % in the composite which indicates that synthesis of composite has been successful. Chitosan and composite have different pH pzc where chitosan at pH 6.02 and composite at pH 7.26. The optimum condition adsorption of procion blue MX-R using chitosan obtained at an initial concentration of 180 mg/L and contact time of 60 minutes, while the chitosan/alumina composite obtained at an initial concentration of 160 mg/L and 50 minutes contact time. The isotherm model that is suitable for describing the adsorption process is Freundlich isotherm for both adsorbents. The composite has the effectiveness of adsorption on procion blue MX-R from wastewater songket industry greater than chitosan ie 85.696 and 60.829 %, respectively.

The study on cellulose modification with acetic acid to cellulose-acetate has been carried out. Cellulose is extracted from the kepok banana peel (Musa paradisiaca L.). Modified cellulose acetate was characterized by FTIR spectroscopy and SEM-EDS. Cellulose acetate to removal of methylene blue with adsorption parameter include initial concentration (10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 mg/L), pH solution (3, 4, 5, 6, 7, and 8) and contact time (15, 30, 45, 60, 75, and 90 minutes). The peak of FTIR cellulose acetate obtained by functional groups -OH, C-H, C=O, and C-O esters. The morphology of cellulose-acetate has a more homogeneous than cellulose. Adsorption of cellulose-acetate on methylene blue optimum at an initial concentration of 90 mg/L, pH of solution 6, and contact time of 30 minutes. The adsorption kinetics corresponds to pseudo-second order and adsorption equilibrium corresponds to Langmuir isotherms with adsorption capacity of 42.107 mg/g.

Acid mine drainage (AMD) has characteristic very low pH solution and containing metal ions in high concentration. This paper presents the use of CaCO 3 , Ca(OH) 2 and the combination of both to increase the pH and decreased the concentration of Fe and Mn ions for acid mine drainage. The research variables are the effect of reactant dosage, contact time and temperature by batch studies. The AMD before treatment has pH solution of 3.38, Fe and Mn ions concentration of 44.6 and 7.19 mg/L, respectively. The dosage of CaCO 3 to increased pH solution about 7.0 was found 2400 mg/L at contact time 60 minutes and temperature 40 °C. The amount of Ca(OH) 2 for the neutralization of AMD solution smaller than CaCO 3 is 210 mg/L at contact time 45 minutes and temperature 40 °C. The combination dosage of CaCO 3 1000 mg/L and Ca(OH) 2 90 mg/L can increased the pH of AMD solution to 7.10 and reduction concentration of Fe to 3.53 and Mn to 4.51 mg/L. Therefore, the integrated of CaCO 3 and Ca(OH) 2 has the potential to be applied to treatment acid mine drainage.

Phenolic compounds areorganic pollutants that are toxic and carcinogenic.The presence of phenol in the environmentcan be adverse to humanand the environmentalsystem. One methodthat iseffective toreduce thephenolisadsorption. In this study, the adsorption of phenol in aqueous solution using Ca-bentonite/chitosan composite was investigated. Chitosan is the deacetylation product of chitin from shrimp waste. Characterization of Ca-bentonite/chitosan composite was done by using Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy-Energy Dispersive X Ray Spectroscopy (SEM-EDX). Batch adsorption studies were performed to evaluate the effects of some parameters such as initial concentration of phenol, composite weight, pH and contact time. The results showed that FTIR spectra of Ca-bentonite/chitosan composite presented the characteristic of peak of Ca-bentonite and chitosan that confirmed the successful synthesis of composite. The SEM-EDX characterizationresultsshowedCa-bentonite surfacecoverage by chitosanand the presence ofcarbonandnitrogenelementsinCa-bentonite/chitosancompositeindicated that chitosan had bonded with bentonite. The optimum condition of adsorption of Ca-bentonite/chitosan to phenol was obtained at 125 mg.L-1 of concentration in which the weight of composite was 1.0 g, the pH of solution was 7, the contact time was 30 minutes, and the capacity of adsorption was 12.496 mg.g-1., Phenolic compounds are organic pollutants that are toxic and carcinogenic.The presence of phenol in the environment can be adverse to human and the environmental system. One method that is effective to reduce the phenol is adsorption. In this study, the adsorption of phenol in aqueous solution using Ca-bentonite/chitosan composite was investigated. Chitosan is the deacetylation product of chitin from shrimp waste. Characterization of Ca-bentonite/chitosan composite was done by using Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy-Energy Dispersive X Ray Spectroscopy (SEM-EDX). Batch adsorption studies were performed to evaluate the effects of some parameters such as initial concentration of phenol, composite weight, pH and contact time. The results showed that FTIR spectra of Ca-bentonite/chitosan composite presented the characteristic of peak of Ca-bentonite and chitosan that confirmed the successful synthesis of composite. The SEM-EDX characterization results showed Ca-bentonite surface coverage by chitosan and the presence of carbon and nitrogen elements in Ca-bentonite/chitosan composite indicated that chitosan had bonded with bentonite. The optimum condition of adsorption of Ca-bentonite/chitosan to phenol was obtained at 125 mg.L-1 of concentration in which the weight of composite was 1.0 g, the pH of solution was 7, the contact time was 30 minutes, and the capacity of adsorption was 12.496 mg.g-1. ABSTRAKFenol merupakan polutan organik yang bersifat toksik dan karsinogenik. Keberadaan fenol di lingkungan berbahaya bagi manusia dan sistem lingkungan. Salah satu metoda yang efektif digunakan untuk mengurangi fenol adalah adsorpsi. Pada penelitian ini dipelajari kemampuan komposit Ca-bentonit/kitosan untuk mengadsorpsi fenol. Kitosan diperoleh dari hasil deasetilasi kitin yang diekstraksi dari limbah udang. Karakterisasi komposit Ca-bentonit/kitosan dilakukan menggunakan Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy-Energy Dispersive X Ray Spectroscopy (SEM-EDX). Metoda Batch digunakan untuk mempelajari proses adsorpsi dengan parameter meliputi konsentrasi awal fenol, berat komposit, pH larutan dan waktu kontak. Hasil penelitian menunjukkan bahwa spektra FTIR komposit Ca-bentonit/kitosan merupakan gabungan dari serapan Ca-bentonit dan kitosan. Hasil karakterisasi menggunakan SEM-EDX menunjukkan permukaan Ca-bentonit tertutup oleh kitosan, keberadaan unsur karbon dan nitrogen pada komposit Ca-bentonit/kitosan mengindikasikan telah terbentuknya ikatan Ca-bentonit dengan kitosan. Kondisi optimum adsorpsi fenol menggunakan komposit Ca-bentonit/kitosan diperoleh pada konsentrasi awal fenol 125 mg.L-1, berat komposit 1,0 g, pH larutan 6 dan waktu kontak 30 menit dengan kapasitas adsorpsi sebesar 12,496 mg.g-1.