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Sugarcane Bagasse can be used as an adsorbent both under natural conditions and modified by chemical activation using sodium hydroxide (NaOH). Activation of sugarcane bagasse with NaOH was carried out at variations of 5:1, 10:1, and 20:1 (w/w). The absorption ability of bagasse adsorbent to methylene blue solution was carried out with the parameters of variation of contact time (60, 90, 120, 150, and 180 minutes), adsorbate concentration (20, 30, 40, 50, and 60 ppm) and temperature (30, 40, 50, and 60 oC). The adsorbent's characterization included determining the functional groups using FTIR, morphology, and mass of elements using SEM-EDX, and determining the surface area and volume of adsorbent pores using the BET methods. The highest adsorption percentage results were found in the NASB10:1 adsorbent at 99.50%. The optimum conditions for the NASB10:1 adsorbent are with a contact time of 120 minutes, an adsorbate concentration of 50 ppm, and a temperature of 30 oC or 303 K. The NASB10:1 adsorbent has the highest surface area compared to other adsorbents, namely 2.803 m2/g so that it can perform the maximum absorption of methylene blue.

Background: Biodegradation of petroleum hydrocarbon needs a specific technique called bioremediation to remove the environmental pollutants. Several indigenous microorganisms including fungi, bacteria, and actinomycetes are effective agents in degrading petroleum derivatives, aliphatic and polyaromatic hydrocarbons (PAHs). Objective: This research aimed to investigate indigenous fungi isolates from petroleum hydrocarbon contaminated soil in Siak which are capable to degrade hydrocarbon. Methods: The competence of indigenous fungi was isolated from a crude oil-contaminated soil which collected from one of oil-field in Siak, Riau. The effectiveness of isolates on the degradation crude oil was tested by culturing the isolates in Bushnell-Haas broth containing crude oil (5% v/v) for 16 days. A decrease in pH, change in optical density and amount of CO2 released were recorded to indirectly indicate the crude oil degradation by the fungi. To measure the percentage of crude oil biodegradation, gravimetric analysis was utilized. Results: The two colonies were selected and identified as Aspergillus sp LBKURCC151 and Penicillium sp LBKURCC153. The results showed that Aspergillus sp LBKURCC151 reached a higher level (61%) of biodegradation after 16 days under the optimum conditions in degrading total petroleum hydrocarbon than Penicillium sp LBKURCC153 (46%). Conclusion: These results indicated that Aspergillus sp LBKURCC151 and Penicillium sp LBKURCC153 are potential degraders for bioremediation in crude oil-contaminated area.

Preparation of manganese oxide by sol-gel method and its application as a catalyst for methyl orange (MO) degradation was carried out using hydrogen peroxide as an oxidant.The characterization of manganese oxide was conducted using X-Ray Diffraction and Scanning Electron Microscope. The effect of initial concentration of MO was examined. Degradation efficiency was decrease with increasing the concentration of MO. The degradation kinetics ofMO followed the second-order reaction kinetics.

In this study, the simultaneous action of surfactant modified clinoptilolite (SMC) as adsorbent for dyes and its antibacterial activity was investigated. Methylene blue (MB) and acid orange 7 (AO7) represent cationic and anionic dyes, respectively were used as adsorbate in this study and the antibacterial activity was studied against Gram-negative (Escherichia coli ATCC 11229) and Gram-positive bacteria (Staphylococcus aureus ATCC 6538 and Enterococcus faecalis ATCC 2921). Initially, natural zeolite clinoptilolite was modified with 3 different concentrations (0.1, 1.0 and 4.0 mM) of cationic surfactant hexadecyltrimethyl ammonium bromide (HDTMA-Br). The SMC samples were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), amount of HDTMA adsorbed and dispersion behaviour. Result from XRD shows that the HDTMA-Br molecules caused no effect on primary structure of the clinoptilolite since the clinoptilolite structure remained the same after modification with HDTMA-Br. Compared to the unmodified clinoptilolite, FTIR spectra of the SMC shows peak corresponds to C-H stretches which proved the attachment of HDTMA onto the clinoptilolite surfaces. In the dispersion behaviour study, SMC samples were located at the adjacent phase between the water and oil mixture. The amount of HDTMA-Br adsorbed onto the clinoptilolite increased with the increasing concentrations of the surfactant. The use of SMC as adsorbent and antibacterial agent were further studied against the ionic dyes and bacteria simultaneously. The results show that the adsorption capacity of SMC towards both ionic dyes increase with the increasing HDTMA-Br concentration. While for the antibacterial activity, the number of colony forming unit of bacteria seem to be highly reduced at the highest concentration of the HDTMA (4.0 mM) attached on the clinoptilolite. Hence, this study had shown that SMC has high adsorption capacity towards the ionic dyes at the same time reducing the growth of both Gram positive and negative bacteria in aquoes solution.

Dye contaminations have severe impacts to environment (air, soils, plants, water) due to their adverse effects. Most dyes are toxic, carcinogenic, mutagenic and resistant to bio-degradation. Photocatalysis-based advanced oxidation process (AOP) has been considered as the most effective and efficient way to treat this recalcitrant compounds. Manganese oxides are ubiquitous and environmentally friendly in natural environments and can act as semiconducting materials. Tunnel structure of manganese oxide such as α-MnO2 (cryptomelane) has been widely studied for broad applications as Fenton-based AOP. Catalytic efficiency of α-MnO2 could be further increased by doping α-MnO2 with a metal ion like the Cu ion. Although the synthesis and catalytic activity of Cu-α-MnO2 have been reported by previous studies, its photocatalytic performance using this one-pot-sol-gel approach for MB degradation has never been reported previously. Herein, Cu-doped α-MnO2 was synthesized by one-pot sol-gel method and characterized by X-ray diffraction (XRD), BET surface area and atomic absorption spectroscopy (AAS). The AAS results suggested the presence of Cu ions in α-MnO2 since the increase in doping Cu resulted in the corresponding increase in Cu content in the α-MnO2. The BET surface area indicated that the doping 10% Cu in α-MnO2 led to about two fold increase in suface area compared to undoped α-MnO2. The photo catalytic performance of Cu-α-MnO2 via UV light irradiation for the degradation of methylene blue (MB) was significantly higher that that of undoped α-MnO2 and was associated with the increased in surface area of Cu-α-MnO2 over undoped α-MnO2. The maximum degradation of MB was 97.9, 98.3, 98.7 and 99.5% achieved using α-MnO2, 1% Cu-α-MnO2, 5% Cu-α-MnO2, and 10% Cu-α MnO2 and 10% Cu-α-MnO2.

Textile industries consume considerable amounts of water in dyeing process, thus generating the enormous quantities of wastewater. The wastewater is a highly harmful to environment if discharged untreated or partially treated since it contains wide range of hazardous compounds and is also very difficult to treat. The structure of dye residues in wastewater is mostly complex polymeric structures, which is highly resistant to bio-degradation. The Fenton-based advanced oxidation process (AOP) was widely studied to treat recalcitrant organic contaminant and based on the production of OH following H2O2 activation by a catalyst. Manganese oxides are reported to be an active catalyst for degradation of a dye via Fenton process. Herein, bentonite supported MnO (MnO/bentonite) was synthesized via one-pot sol-gel synthesis and its catalytic activity was evaluated for the degradation of methylene blue (MB) using Fenton process. The X-ray diffraction results revealed the formation of the rock–salt MnO manganosite as crystalline phase of manganese oxide. The MnO/bentonite composite displayed higher performance for the degradation of MB than pure MnO. The maximum degradation of MB by MnO/bentonite composite was achieved by evaluating the process variables and compared to MnO (manganosite) as a control. In the optimum condition, the MnO/bentonite composite was able to degrade 92.97 % MB using 15 ml H2O2, 50 mg of catalyst and 25 ml MB (75 ppm) in 100 mL solution of initial MB concentration. Both catalyst concentration and H2O2 concentration seem to play a significant role for the degradation of MB using the composite MnO/bentonite.

Dye pollutions have become a major environmental problem due their mutagenic, carcinogenic nature, toxicity and stability. The effective removal of this recalcitrant material from wastewater requires immediate solution. The Fenton-based advanced oxidation processes have been considered as highly effective and efficient method for the degradation of highly stable organic contaminants. In this work, the composite MnO/oil palm fly ash (OPFA) was first synthesized, characterized and applied as a heterogeneous Fenton catalyst for the degradation of methylene blue (MB). The composite was characterized by X-ray powder diffraction (XRD), and Brunauer–Emmett–Teller (BET). The XRD result indicated that the manganese oxide phase in the composite is the rock-salt manganese oxide of manganosite MnO. The MnO/OPFA has a surface area of 278.541 m2/g, which is much higher than those of pure manganosite or OPFA. The catalytic test indicated that the concentration of hydrogen peroxide (H2O2) seems to play a significant role for the effective degradation of MB. The degradation of MB was 95.31 achieved only within 10 minutes of reaction time with the addition of 5 ml of H2O2, 125 mg catalyst using 100 ml 12.5 ppm MB.

Methylene blue (MB) is a blue cationic thiazine dye which is widely used in cotton fiber, wood and textile industries, but has an adverse effect to environment and living organism. It is urgent to find an alternative and effective solution for this recalcitrant compound. The Fenton process-based advanced oxidation process is considered as an effective method for the degradation of organic contaminants such as dyes. In this study, the composite α-MnO2/activated carbon (AC) was first synthesized by a facile, one-pot synthesis using sol-gel method and characterized by X-ray diffraction (XRD) and BET surface areas. The XRD results indicated that the tunnel cryptomelane-type manganese oxide (α-MnO2) was successfully synthesized as the minor phase in the activated carbon support. The composite α-MnO2/AC has higher specific surface area than the single α-MnO2. The catalytic studies indicated that the α-MnO2/AC has a much higher catalytic efficiency over single α-MnO2 for degradation of MB. The presence of the support and the increase in surface area of α-MnO2/AC could be responsible for its higher catalytic efficiency compared to single α-MnO2. In the optimum condition, the α-MnO2/AC was able to degrade 98.48 % and 99.2 % of MB within 10 and 120 minute of reaction time, respectively.

Modification of iron oxide nanoparticles by doping with transition metals has been intensively reported and many applications have been proven. Magnetic and structural properties, and the catalytic activity of undoped and manganese doped iron oxide nanoparticles for degradation of methylene blue have been studied. Preparation of undoped and manganese doped iron oxide nanoparticles was done by ball milling method using Logas natural sand as raw materials. The magnetic properties of the samples were determined using vibration sample magnetometer (VSM). A detailed analysis of the loop hysteresis reveals a reduction of saturation magnetization of the samples towards higher manganese-doping concentration (wt.%). The reduction in magnetization from 13.25 to 11.67 emu/g and enhanced the coercivity on manganese-doped samples from 224.35 to 352.18 Oe are observed to produce an improvement in the catalytic activity for manganese doped iron oxide nanoparticles compared to undoped samples. Catalytic activity of undoped and manganese doped iron oxide nanoparticles in the degradation of methylene blue was studied through ultraviolet visible spectroscopy (UV-Vis). Manganese doped iron oxide nanoparticles exhibit better catalytic activity for degrading methylene blue (88.880%) compared to that for undoped iron oxide nanopartices (81.805%) for 300 minutes reaction time.

Permana I, Awaluddin A, Saryono. 2019. Methylene blue decolorization fungi from crude oil-contaminated soils. Biodiversitas 20: 2693-2697. One of the world problems is the treatment to remove dyes in textile wastewater. Nowadays, the most effective and compatible method to the environment is decolorization by microorganisms. Therefore, the objective of this study is to find out the best fungi to decolorize synthetic dye methylene blue (MB). Total eight fungi that isolated from crude oil-contaminated soil were analyzed to study the effect of various parameters such as pH, the concentration of dyes, contact times and agitation on their rate of reaction. The initial screening showed that Penicillium sp. FTM7 had greater potential in biodegradation the MB. The optimum decolorization of MB by Penicillium sp. was found after 8 days incubation with agitation 150 rpm and concentration of MB is 40 ppm and unadjusted pH (95.45%). The decolorization of MB was found to follow first-order reactions.

Structural, morphological properties and the catalytic activity of magnetite (Fe3O4) nanoparticles for degradation of methylene blue have been studied. The magnetite nanoparticles were synthesised from Padang beach sand West Sumatera by 2 steps ball milling method. Structures and morphologies of the synthesized magnetite nanoparticles were investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was shown that the particle size of the magnetite nanoparticles can be controlled by milling ball size. The average grain size of magnetite particles milled for milling ball size of 0.7 cm and 1.5 cm was found to be 81.25 nm and 30.75 nm, respectively. Scanning electron microscopy (SEM) images show that the particle size of samples decreases as milling ball size increases and the grains exhibit irregular form. The effect of milling ball size on the degradation efficiency of catalytic reaction exhibited a good ability to degrade methylene blue from aqueous solutions with a maximum methylene blue removal rate of 86.79% for 10 hours reaction time.

The CaMnO3 perovskite type-oxide has been synthesized using a citrate sol-gel method using two different MnO2 precursors and calcium carbonate. The cryptomelane-type manganese oxide precursor produced well-crystalline CaMnO3 perovskite, whereas pyrolusite-type manganese oxide (commercial) generated mixtures of CaMnO3 perovskite and un-reacted MnO2 using the same CaCO3 as other precursor. The CaCO3/MnO2 mole ratio seems to play a crucial role to obtain high purity of the CaMnO3 perovskite. The CaMnO3 perovskite proves to have high catalytic activity for the degradation of methylene blue (MB) using hydrogen peroxide as an oxidant. This Fenton catalyst is able to degrade 98.5% of MB within 20 minutes of degradation times at pH 2.

Structural properties, morphology, and the catalytic activity of hematite (α-Fe2O3) nanoparticles for degradation of methylene blue have been studied. For this purpose, the hematite particles were synthesised from Logas natural sand by 2 steps ball milling method. X-ray diffraction (XRD) confirmed the presence of a hematite (α-Fe2O3) phase. However, other phases such as SiO2 and FeTiO3 are also confirmed by XRD. Scanning electron microscopy (SEM) showed a wide distribution of particle sizes. Moreover, the shape of the grains is irregular form. The effect of reaction time and hematite nanoparticles dosage which affect the efficiency of catalytic reaction was investigated. Catalytic activity of hematite nanoparticles in the degradation of methylene blue (MB) was studied through ultraviolet visible spectroscopy (UV-Vis).

The pristine cryptomelane (OMS-2) and Fe-OMS-2 (1%, 5%, and 10%) have been successfully synthesized by a one-step sol-gel method and characterized by XRD, SEM, BET surface area and AAS. The incorporation of Fe (III) within the structure of OMS-2 leads to an increase in surface area, pore-volume, and catalytic activity for the degradation of methylene blue (MB) and a decrease in the content of K+ and average of pore diameter. The catalytic test indicated that the catalytic activity of Fe-OMS-2 1% is considerably higher that of pure OMS-2. The highest degradation of MB is 93.5% achieved using Fe-OMS-2 1% after 120 minutes of degradation time, the initial concentration of MB of 20 ppm, the catalyst concentration of 0.125 mg and the H2O2 volume of 15 mL. The enhanced catalytic activities of Fe-OMS-2 compared to pristine OMS-2 for catalytic degradation of MB are associated with an increase in surface area, pore-volume, and smaller particle size. The results from catalytic studies imply that the metal doping is an effective strategy to enhance the catalytic activities of OMS-2 for degradation of MB.

The sol-gel method was used to prepare pure cryptomelane and Cu-doped cryptomelane octahedral molecular sieve manganese oxide materials using CuSO4·5H2O as the dopant source. The one-step synthetic approach is applied for a facile preparation of the Cu-doped cryptomelane by reacting the whole reactants including the dopant in a one pot (known as one-pot synthesis). The CuSO4·5H2O was added to the solution mixtures of KMnO4 and glucose with the molar ratios of 0, 1%, 5% and 10% to KMnO4 (the molar ratio of Cu/Mn is 0; 0.01; 0.05; and 0.10). The as-synthesized pure and Cu-doped cryptomelane-type manganese oxides have been characterized using a wide range of experimental techniques. The XRD was used to identify the phase cystal of manganese oxides, crystallinity and phase purity, whereas AAS was used for the determination of the elemental composition of the samples. The SEM micrographs of the un-doped and doped cryptomelane materials all revealed their same aggregation morphology. The comprehensive N2 sorption analyses confirmed that this synthesized materials are porous materials with the mesopores type and have total BET surface areas in the range of 82-145 m2/g. The effects of the dopant concentration were tested in catalytic degradation of methylene blue using hydrogen peroxide as an oxidant. The results indicated that high Cu-doped concentration resulted in the enhanced degradation of methylene blue. The higher degradation of methylene blue for Cu-doped cryptomelane was correlated with the increase in surface area and total pore volume, but decreased average pore radius.

Birnesitte-type octahedral layer manganese oxides were successfully synthesized via precipitation method with the different mole ratios of potassium permanganate and oxalic acid (KMnO4/H2C2O4). The precipitation reaction occurs only at certain mole ratios (i.e. 3:5 and 2:3) of KMnO4/H2C2O4 were applied. However, at lower mole ratio of KMnO4/H2C2O4 (1:4) or higher mole ratio KMnO4/H2C2O4 (3:1) the reactants remain solution even at longer the reaction times. The precipitated solid product was calcined up to 600 °C and referred to as the CC catalysts, whereas the products without calcination were denoted to as the CNC catalysts. The solid CC and CNC catalysts were then characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Atomic Absorption Spectroscopy (AAS) and the oxidation states of manganese in the manganese oxide catalysts were determined together with the zero point charge (pHzpc) as well as particle sizes. The data from XRD indicated the CNC catalysts showed wide peaks with low intensities, indicating poor crystallinity of birnessite whereas the CC catalysts generated much higher crystalline birnessite. The morphology of the CC and CNC catalysts displayed similar aggregates of particles with irregular shapes and sizes but CNC catalyst exhibit smaller particle size. Data from AOS of manganese indicated that CNC catalyst (3.12) have lower values than that of CC (4.00), indicating the presence of more defects which was consistent with XRD result, low values pHzpc (3.17-3.92) and K/Mn (0.44-0.50). The catalytic activities of birnessite catalysts were tested for the degradation of methylene blue (MB) dye with H2O2 as an oxidant. The CNC catalysts showed substantially higher catalytic activities for MB degradation compared to the CC catalysts. The maximum degradation of methylene blue was 97.73% for the CNC catalyst using mole ratio (KMnO4/H2C2O4) of 2:3, whereas the CC catalysts can degrade only 83.27% of MB using mole ratio (KMnO4/H2C2O4) of 3:5.

The cryptomelane-type manganese oxide catalysts have been prepared by sol-gel method based on the redox reaction between potassium permanganate and glucose or oxalic acid. These catalysts belong to a class of porous manganese oxides known as octahedral molecular sieves (OMS). The SEM results indicated that the marked difference between the morphology of the cyptomelanes produced from glucose and oxalic acid. The glucose precursor produces cotton-shaped morphology, whereas the oxalic acid precursor leads to the formation of the disk-like appearances. The XRD results indicated that the glucose precursor produces more crystalline cryptomelane than that of oxalic acid. The effect of catalyst dosage on methyelene blue degradation was evaluated. Dye-decomposing activity was proportional to the amount of catalyst used, increasing of the catalyst amount leads to higher degradation of methyelene blue at short period of reaction. With different crystalline structures and morphology appearances of the cyptomelanes, ...

Titanium dioxide is one of the most investigated materials for photoelectrochemical (PEC) water splitting. However, TiO2 has a wide band gap of approximately 3.2 eV, which limits its absorption energy to UV only, and the photoexcitation products (i.e., electron and hole) easily recombine. Developing a composite with other semiconductor materials is one of the efforts for improving the performance of TiO2 photoelectrode. In this study, a composite of TiO2/Co3O4 thin films was developed, and its performance in PEC water splitting was investigated. Co3O4 was synthesized using a hydrothermal method, and TiO2 P25 was used. TiO2 and Co3O4 were mixed by ball milling before coating on a clean FTO and annealing at 550 °C. Two weight variations of TiO2:Co3O4 were used (95:5 and 90%:10%). XRD and FESEM analysis were used to investigate crystallinity phase and surface morphology. The optical band gap of the thin films was determined by UV-Vis spectroscopy, where the film with 90:10 weight ratio of TiO2:Co3O4 obtained the smallest band gap of 2.9 eV. Co3O4 improved the current density and TiO2 performance by approximately three times.

The octahedral molecular sieve cryptomelane-type manganese oxide (OMS-2) and Fe-doped OMS-2 (1%, 5%, 10%) were successfully synthesized by the redox reaction between KMnO4 and citric acid using the sol-gel method. The sol products were heated at 120°C and followed by calcination at 600°C. The as-synthesized pristine manganese oxide and Fe-OMS-2 were then characterized by XRD to determine their crystallinity and phase structure. The XRD results indicated that both the pristine and Fe-doped manganese oxides produced tunnel cryptomelane-type manganese oxides. No other peaks due to other phases are detected, indicating that Fe ions are well distributed in the framework of cryptomelane. The oxidative activities, either the pristine and Fe-OMS-2, were evaluated for degradation of methylene blue (MB) at pH ranges 2-6 by the addition of HCl solution. The oxidative tests showed that the oxidative degradation of methylene blue greatly increase with a decrease in solution pH and decrease with an increase in concentration Fe species in Fe-OMS-2 compared to pristine cryptomelane.

The cryptomelane-type manganese oxides octahedral molecular sieve with different crystalline phases have been successfully synthesized and characterized. The oxides were synthesized using precipitation method through the redox reaction between KMnO4 and C6H8O7 with a mole ratio of 5:1 by the variation of flow rates (1, 2, and 3 mL/min). The prepared catalysts were characterized by XRD to determine their phase structures, purity, and crystallinity. The XRD results indicated that the samples without heat treatment (calcination) displayed the poor tunnel structures of cryptomelane-type manganese oxides with low intensities and broad peaks. Upon the thermal treatment at 600°C for 4 hours, the much more crystalline phases of similar cryptomelane structures were obtained. The high flow rate results in the more crystalline cryptomelane for calcined samples, whereas the flow rate has no substantial influence on the crystallinity of uncalcined samples. The catalytic activities of both oxides were evaluated for the degradation of methylene blue (MB) with H2O2 as an oxidant. The catalytic degradation of MB greatly enhanced using the uncalcined cryptomelane compared to calcined cryptomelane. The high flow rate has a positive impact on the degradation of MB for calcined samples, but the effect of flow rate results in the higher degradation of MB until a certain flow rate. The 98.4% degradation of MB was achieved by uncalcined samples under the optimum condition.

The cryptomelane manganese oxide octahedral molecular sieve (OMS-2) and Cu-modified cryptomelane octahedral molecular sieve (Cu-OMS-2) with different Cu concentrations (1, 5, 10%) were successfully prepared by one-step sol-gel synthesis. The XRD patterns of OMS-2 and Cu-OMS-2 remain unchanged, indicating the Cu ions are well incorporated within OMS-2, except the peak due to (101) plane appears and grows significantly until 5% Cu incorporation. The SEM images revealed that the additions of Cu ions in the OMS-2 have a remarkable impact on the Cu-OMS-2 morphologies, especially for 10% Cu incorporation. The bulk analysis by AAS showed the steady decreases in K+ and Mn concentrations, and increase in Cu concentrations, suggesting that some Cu2+ ions are replacing K+ in the tunnel and Mn in the framework of OMS-2. The catalytic tests for the degradation methylene blue (MB) by heterogeneous Fenton processes revealed that the catalytic performance of Cu-OMS-2 increases remarkably with the increased concentrations of Cu doping. The increased catalytic activities for Cu-OMS-2 are associated with the smaller particles sizes are revealed by SEM results.

The catalytic activities of the octahedral layer birnessite-type manganese oxides for the degradation of methylene blue (MB) dye have been studied. The oxide catalysts were prepared via a facile precipitation method using the reaction between KMnO4 (oxidant) and citric acid or oxalic acid (reductant), where the acid is added dropwise into KMnO4 until certain volume achieved to generate a brownish black precipitate. The solid product was treated with either calcination or without calcination process, respectively. The samples without calcination display poor crystallinity with low intensity and broad peak and are identified as birnessite-type manganese oxides. The calcination, however, led to the formation of the highly crystalline birnessite materials. The birnessite catalysts synthesized by the different reductants displayed different crystallinity, morphology, average oxidation state (AOS) of manganese, zero-point charge pH (pHzpc) and particle size that affect their catalytic activities. The results indicated that the activities of birnessite-type manganese oxide catalysts for MB degradation correlated with the nature of catalysts. The citric acid-prepared manganese oxide catalyst (CAC) showed slight higher crystalline phase compared with the oxalic acid-prepared manganese oxide catalyst (OAC). The data from AOS of manganese suggested that the CAC catalysts have a lower value of AOS of manganese than OAC catalysts, indicating more defects due to the presence of more oxygen vacancy or more Mn3+ content. The smaller particle size and AOS of manganese for CAC catalysts are also considered to be responsible for their higher catalytic activities for MB degradation. The birnessite-type manganese oxide catalysts prepared without calcinations also showed much enhanced catalytic activities for MB degradation.

The Fe-doped octahedral molecular sieve manganese oxides have been successfully synthesized by one-pot synthesis of the reaction between KMnO4 and glucose using sol-gel methods. The oxide products are then characterized by various techniques such as X-ray diffraction, scanning electron microscopy, atomic absorption spectroscopy and average oxidation state (AOS) of manganese in manganese oxides. The as-synthesized manganese oxide and Fe-doped manganese oxides are used as catalysts for the degradation of methylene blue dye using hydrogen peroxide as oxidants. The results indicated that the Fe-doped manganese oxide catalyst displayed much enhanced catalytic activities compared to undoped manganese oxide for methylene blue degradation. The differences in catalytic activities have been correlated with the difference in surface properties and crystallinity.

Redox reaction between KMnO4 and glucose usingsolvent-free method produces the octahedral layer birnessite-type manganese oxide. The effects of mole ratios, temperatures, and calcinations time on the structures and crystallinity of the oxides were studied throughthe X-ray powder diffraction analysis. The mole ratio of KMnO4/glucose (1:3) produces the purebirnessite with low crystallinity, whereas the mole ratio of KMnO4/glucose (3:1) yields high crystalline birnessite with minor components of hausmannite-type manganese oxide.The increasing of the temperature and calcinations times (300-700 °C and 3-7 h, respectively) willimprove the crystallinity and the purity of the as-synthesized oxide. Further experiments also showed that the as-syntesized octahedral layer birnessite-type manganese oxides have catalytic activity on the degradation of methylene blue (MB) dye with H2O2 as oxidant. The results revealed that the effective degradation could be achieved only in the presence of both the birnessite and H2O2, whereas without the addition of catalyst (H2O2only) or addition of H2O2 (catalyst only), the 3.5% and 15.5% of MB removal were obtained, respectively.

Dahlia is a floriculture plant with tuber that rich of inulin. Inulin is soluble in hot water and it will settle on cool temperature in alcohol. Extraction of result from 100 g dahlia tuber taken from Bukittinggi, West Sumatra is 4% inulin (w/w dahlia tuber). Inulin flour produced is white gray. Qualitative tests with Seliwanoff and Nelson-Somogyi methods shows that inulin positive contained of fructose and reducing sugar. Extracted result of inulin can be converted into levulinic acid using acid catalyst at high temperature. In this experiment, production of levulinic acid will bundle with variate temperature, reaction time and catalyst concentration of hydrochloride acid. The reaction of inulin convertion was done in ampul that burned in oven. Conversion result of 5% inulin to be levulinic acid on heating 150 o C hydrochloride acid concentration 0,1 M about 25 minutes was 12,33% (w/w inulin). On heating 170 o C hydrochloride acid concentration 0,1 M about 15 minutes is 26,25% (w/w inulin), while on heating 150 o C hydrochloride acid concentration 1 M about 15 minutes is 32,28% (w/w inulin). Experiment result showed that concentration of glucose, levulinic acid and formiat acid increase with increasing in reaction reaction temperature while fructose concentration decrease from 55,14 mg/mL to be 0,12 mg/mL. The longer time reaction and the higher concentration of catalyst hydrochloride acid, the lower concentration of glucose and fructose and the larger concentration of levulinic acid and formic acid.

The new titanium alkoxy–diolate precursors [Ti(OCH2CH2O)(OCH2CH2NMe2)2]2 (1) and [Ti(OCMe2CMe2O)(OCH2CH2NMe2)2]2 (2) have been prepared and structurally characterised by single crystal X-ray diffraction. Both compounds exhibit binuclear centrosymmetric structures with bridging alkoxide groups, containing two six-coordinate Ti atoms in distorted octahedral environments. In (1) the oxygen from the ethylene glycolate ligand is involved in bridging, whereas in (2) the bridging oxygen is provided by the dimethylamino ethoxide ligand. Complexes (1) and (2) are potential precursors for Ti-containing oxides and both complexes have been investigated as precursors for the deposition of TiO2 thin films by liquid injection metalorganic chemical vapour deposition (MOCVD). Significantly, only complex (2) led to reproducible TiO2 deposition in the temperature range 325–450 °C, whilst complex (1) exhibited a marked pre-reaction leading to highly irreproducible film growth. The difference in MOCVD behaviour between the complexes is rationalised in terms of their molecular structure.

The effect of quenching of tris(2,2'-bipyridine)ruthenium(II) [Ru(bpy)_3^(2+)] luminescence by Co(phen)_3^(3+) in various locations in and on bentolite-H clay has been investigated. Ru(bpy)_3^(2+) incorporated into the interlayer region of bentolite-H by ion exchange exhibited spectral properties that were distinct from the Ru(bpy)_3^(2+) incorporated by incipient wetness methods. For example, the samples showed different diffraction, luminescence emission, and lifetime decays. The method of preparation, the nature of counterion (chloride or cyanide), and the presence of a quencher [Co(phen)_3^(3+) influence the emission properties. For example, incipient wetness methods allow deposition on outer surfaces (OUT) of the clay whereas ion-exchange leads to deposition primarily in the interlayer spacing (IN) based on spectroscopic and diffraction data. The luminescence intensities and lifetimes decrease in the order Ru(0UT) > Ru(IN) > Ru(OUT)/Co(IN) > Ru(IN)/Co(0UT) > Ru(OUT)/Co(OUT) ≃ Ru(IN)/Co(IN). Different methods of preparation and treatment result in location of Ru(bpy)_3^(2+) at different internal or external sites in the clay which give different luminescence and lifetime properties. By controlling the locations of Ru(II) and Co(III) (inside or outside), the quenching rates could be modulated. The location of the Ru(II) complex seems to control both the photophysical properties and the efficiency and rate of quenching by Co(III). The Ru(IN) and Co(IN) sample is very similar to the Ru(OUT) and Co(OUT) sample. These two samples are considerably different from the Ru(IN)/Co(OUT) sample and the Ru(OUT)/Co(IN) sample.

The demand for petroleum has increased recently due to the increase of world population, industries andtransportation. Biodiesel (fatty acids methyl esters) has become attractive because of high price of petroleum,limited recourses of crude oil, and environmental concerns. Most biodiesel is produced by transesterification oftriglycerides of refined/edible type oils using methanol and homogeneous catalyst such NaOH and KOH. The useof heterogeneous calcined CaCO3 catalyst, has advantages such as the ease of phase separation betweencatalyst and biodiesel. This paper presents factors affecting the synthesis of biodiesel from crude palm using thecalcined CaCO3 catalyst . The synthesis is carried out by two steps, the acid-catalyzed pre-esterification of free-fatty acid and followed by base-catalyzed transesterification of triglycerides. A study of optimizing the reactioncondition of the esterification followed by transesterification of crude palm oil (CPO) is performed to obtainmaximum production of biodiesel. Under conditions of catalyst calcination temperature of 9000C, reactor time of1.5 hours, catalyst dosage of 1,5%, reaction temperature of 700C and methanol/oil molar ratio of 9 : 1, the oilconversion is 74,6%. The as-synthesized biodiesel meets the requirements of Indonesian National Standard (SNI)for biodiesel.

Biodiesel is one of alternative fuels. Biodiesel can be made from coconut oil and is referred to as cocodiesel. Thisresearch studies the optimum condition of cocodiesel production by methanolysis reaction between coconut oiland methanol using heterogen catalyst of calcium carbonate (CaCO 3) is calcined for 1.5 hours at 900oC. In order toget optimum condition, several experimental parameters are applied such as catalyst concentration 1-3 %-wt andmolar ratio of methanol/coconut oil 4:1-12:1. The optimum condition obtained from this experimental as follow:catalyst concentration was 2%, molar ratio of methanol/coconut oil was 8:1 at 600C, produced the higgest conversionof cocodiesel 75.02%. The cocodiesel meet the requirement of Standar Nasional Indonesia (SNI) specifications.Based on data analysis, the product has a qualification as diesel fuel. SNI Biodisel is density (40 0C) 850-890Kg/m3,kinematic viscosity (40 0C) 2,3-6,0 mm2/s, cetane number min 51, iod number max 115 gr iod/100 gram,moisture content max 0,05 % volum, acid number max 0,8 mg KOH/g, flash point min 100 0C.

Biodiesel is one of alternative energies. Biodiesel can be made from coconut oil and is referred to as cocodiesel. This research studies the optimum condition of cocodiesel production by methanolysis reaction between coconut oil and methanol using heterogen catalyst of calcium carbonate (CaCO 3 ) is calcined for 1.5 hours at 900°C. In order to get optimum condition, several experimental parameters are applied such as catalyst concentration 1–3 %-wt and molar ratio of methanol/coconut oil 4∶1–12∶1. The optimum condition obtained from this experimental as follow: catalyst concentration was 2%, molar ratio of methanol/coconut oil was 8∶1 at 60°C, produced the higgest conversion of cocodiesel 75.02%. The cocodiesel meet the requirement of Standar National Indonesia (SNI) specifications, where the density was 860 kg/m3, kinematic viscosity was 2.44 mm2/s, flash point was 110°C, water content was 0,039%-v, setana number was 65.94, acid number was 0.049 mg KOH/g and iod number was 6.35 gr Iod/100 gr. Based on data analysis, the product has a qualification as diesel fuel.

High consumption of chicken in Indonesia leads to a considerable amount of chicken skin as a waste. The utilization of this chicken skins as possible biodiesel feedstock was therefore investigated. The transestrification between this chicken fats and methanol was conducted using calcium oxide as solid catalyst. The variables affecting the yield of biodiesel during transesterification, such molar ratio of methanol to oil, reaction time, reaction temperature, catalyst concentration ware investigated. With 1 % catalyst, when the transesterification was carried out at molar ratio of methanol to oil of 6∶1, reaction time of 1.5 hours, reaction temperature of 50 °C, yield of 75.4% was achieved. The fuels properties, namely, kinematic viscosity, specific gravity, flash point, cetane number, water content and iodine number are found within the limit of Indonesian National standard for Biodiesel.