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Generally, biomass consists of various amounts of minerals. These minerals influence the biomass characteristics and behavior during their use in a thermochemical process such as pyrolysis. The conversion during pyrolysis and its final product will be affected. This research was carried out to study the impact of washing treatment in water and acid solutions on the rice husk as the raw material for pyrolysis. Also, the effect of acid strength (citric acid as the weak acid while nitric acid as the strong acid) and its concentration (1, 5, and 10 wt.%) was investigated. The results confirmed from the thermogravimetry (TGA/DTG) analysis, surface analysis (SEM), and spectra (FTIR) analysis describe the treatment using water caused less change on the rice husk surface structure and its thermal degradation. However, it seems hard to reduce the minerals (proved from XRF analysis). Meanwhile, the treatment using acids solution resulted in lower mineral composition than the rice husk without treatment. This result is more visible for demineralization using a 5 wt.% nitric acid solution. However, for a higher concentration (washing treatment using 10 wt.% solutions of nitric acid), the degradation on rice husk structure was more occurred.

Rice husk (RH) is an agricultural waste that contains cellulose. Rice husk fiber (RHF) can be used as a source of fiber in the manufacture of magnetic nanoparticle biocomposite. The purpose of this study is to synthesize and characterize magnetic nanoparticle biocomposite used as an adsorbent and evaluate its performance on the adsorption of Mn2+ ions and Total Suspended Solid (TSS) in peat water. Rice husk fiber was delignified to eliminate lignin levels. Furthermore, the biocomposite was made through the solvothermal method with and without the addition of hexanediamine. The products produced are two types of adsorbents, namely magnetic nanoparticle biocomposite with an amino group (RHB-MH) and rice husk fiber biocomposite without an amino group (RHB-M). These biocomposites were used to adsorb Mn2+ ions in peat water. Evaluations were carried out at pH 5, 6, 7, and 8 with an optimum adsorption time of 60 minutes. The solutions at the time of adsorption were evaluated to determine the optimum conditions of the adsorption process carried out. The observation of magnetic nanoparticle biocomposite based on the analysis of Scanning Electron Microscopy (SEM) shows magnetic nanoparticles formed on the surface of rice husk fiber with a diameter of 30-50 nm. X-Ray Diffraction (XRD) analysis showed that the delignification of rice husk increased Crystallinity Index (CrI) by 64.98% and reduced silica content by 78%. Fourier Transform Infra-Red (FT-IR) spectrometer show absorption peak at 570 cm-1 for Fe-O bonds and Fe3O4 peak around 1627 cm−1, indicating the presence of N-H bending. The optimum condition for Mn2+ adsorption was achieved at pH 5 and 60-minutes duration with an adsorption capacity of 54.7 mg/g and 190.78 mg/g for RHB-M and RHB-MH. The TSS reduction achieved the effectiveness of 60.2% and 90.3% for BSP-M and BSP-MH, respectively.

The high number of natural organic matter contain in wetland water may cause its water has brown color and not consumable. In other hand, intrusion of sea water through wetland aquifer create water become saline, notably on hot season. Coagulation is effective method to applied for removing of natural organic matter. However, it could not be used for salinity removal. Hence combination of coagulation and pervaporation process is attractive method to removing both of natural organic matter and conductivity of wetland saline water. The objective of this works is to investigate optimum coagulant doses for removing organic matter by coagulation process as pretreatment and to analysis performance of coagulation-pervaporation silica-pectin membrane for removing of organic matter and conductivity of wetland saline water. Coagulation process in this work carried out under varied aluminum sulfate dose 10-60 mg.L-1. Silica-pectin membrane was used for pervaporation process at feed temperature ~25 °C (room temperature). Optimum condition of pretreatment coagulation set as alum dose at 30 mg.L-1 with maximum removal efficiency 81,8 % (UV254) and 40 % (conductivity). In other hand, combining of coagulation-pervaporation silica-pectin membrane shows both of UV254 and salt rejection extremely good instead without pretreatment coagulation of 86,8 % and 99,9 % for UV254 and salt rejection respectively. Moreover, water flux of silica-pectin membrane pervaporation with coagulation pretreatment shown higher 17,7 % over water flux of wetland saline water without pretreatment coagulation. Combining of coagulation and pervaporation silica-pectin membrane is effective to removing both of organic matter and salinity of wetland saline water at room temperature.

A sulfonated carbon acid catalyst (C–SO3H) was successfully generated from palm empty fruit bunch (PEFB) carbon via hydrothermal sulfonation via the addition of hydroxyethylsulfonic acid and citric acid. The C–SO3H catalyst was identified as containing 1.75 mmol g−1 of acid and 40.2% sulphur. The surface morphology of C–SO3H shows pores on its surface and the crystalline index (CrI) of PEFB was decreased to 63.8% due to the change structure as it became carbon. The surface area of the carbon was increased significantly from 11.5 to 239.65 m2 g−1 after sulfonation via hydrothermal treatment. The identification of –SO3H, COOH and –OH functional groups was achieved using Fourier-transform infrared spectroscopy. The optimal catalytic activity of C–SO3H was achieved via hydrolysis reaction with a yield of 60.4% of total reducing sugar (TRS) using concentrations of 5% (w/v) of both C–SO3H and cassava peel starch at 100 °C for 1 h. The stability of C–SO3H shows good performance over five repeated uses, making it a good potential candidate as a green and sulfonated solid acid catalyst for use in a wide range of applications.

Utilization of heterogeneous catalyst in the biodiesel production process can minimize the cost of separation process and subsequently reduce the biodiesel price. This study aims at developing a low-priced heterogeneous catalyst CaO/SiO2 prepared from cheap and abundant wastes of eggshell and peat clay for the production of biodiesel from wasted cooking oil. CaO catalyst was capable to produce biodiesel with the yield of 78%. The presence of silica as a support generated from waste of peat clay improved the biodiesel yield to 91%. The optimum reaction time was 60 min and the biodiesel yield increased with temperature. A reaction mechanism during transesterification process was proposed based upon the characterization analysis. The mechanism suggested that the silica contributed in the esterification reaction and the CaO played a positive role in biodiesel production via transesterification. The kinetic study confirmed the proposed mechanism. The pre-exponential factor (A) and activation energy (Ea) were 5.44 × 108 min−1 and 66.27 kJ/mol. The proposed reaction mechanism and kinetic study lead to an essential step of biodiesel production for further research development or application at a larger scale.

Amine group on rice husk magnetic nanoparticle bicomposites (RHB-MH) was synthesized by one-step solvothermal method. The new finding of biocomposites is utilization of rice husk cellulose as a support which produced high amine content on surface of magnetic nanoparticle (MNPs). The rice husk cellulose (RH-D), iron(III) chloride hexahydrate, Na-acetate anhydrate were mixed in ethylene glycol, then kept at ±200 °C for 6 h. Amine modified MNPs was constructed by addition of 1,6-hexanediamine in mixture before the reaction. The MNPs was growth on surface of RH-D then formed biocomposites. The Fe content about 93.11 % and the magnetic nanoparticle structure was proved by specific peaks at 36°, 43°, 63° for magnetite. The magnetic saturation value of biocomposites about 16.4 emu/g. The thermal stability of biocomposites showed up to 200 oC with less than 10 % of mass degradation. Higher amine content of 12.3 mmol/g on biocomposites was achieved after addition of 7 mL of 1,6-hexanediamine (RBH-MH2). Amine functional group on biocomposites exhibited the resonance bands at 1645 cm−1 and 1050 cm−1. The adsorption of Pb(II) ion on RBH-MH2 follows pseudo 1 st order kinetic and well-fitted by Langmuir adsorption isotherm model which have maximum capacity of 680.19 mg/g at room temperature and pHe∼5. The RBH-MH2 have significant effect to capture Pb(II) ion due to electrostatic interaction and showed 3.6-fold higher adsorption capacity than rice husk biocomposites without modification. The amine-rich on biocomposites does not only provide an easy retrievable from aqueous solution but also potential candidate for effective green adsorbent.

The main purpose of this study is to produce and generate a solid acid catalyst from biomass with high reactivity that can be used in catalytical reactions such as hydrolysis, and is environmentally friendly and reusable. A biocarbon-based sulfonated catalyst was prepared by the carbonization of palm empty fruit bunches (PEFB), followed by sulfonation. In order to enhance the acidity of the biocarbon, different concentrations of hydroxyethylsulfonic acid were added to the solution during sulfonation at 180 C for 4 h in a Teflon stainless steel autoclave. The H ion capacity of the biocarbon-sulfonated acid catalyst (BSC) was increased twofold (3.57 mmol/g) in the presence of 10% of hydroxyethylsulfonic acid and 10% of acrylic acid. X-Ray Fluorescence (XRF) analysis showed that the BC-SO H contained 38% of S. The original structure of the PEFB after carbonization disintegrated from the fibrous materials onto porous carbon. The crystalline index (CrI) of the PEFB significantly decreased to about 32% and a wide broad peak of a X-Ray Diffraction (XRD) pattern of around 20-30 were observed, which shows that an amorphous biocarbon structure had been identified. Fourier Transform Infra-Red (FT-IR) analysis confirmed that the -SO H, COOH and -OH functional groups were deposited on the carbon due to specific peaks at around 1180 cm , 1724 cm and 3431 cm , respectively. Decomposition of the sulfonic groups on the biocarbon-sulfonated solid catalyst was observed from 227.9 C, as it shown by thermal gravimetric analysis (TGA). Keywords Acid catalyst; Biocarbon; Palm empty fruit bunch; Sulfonated; Sulfonation

Clay mineral (montmorillonite) based nanocomposites was modified their surface functional groups for removal of Pb(II) and As(V) of aqueous solution. Magnetic nanoparticles with an amine functionalized surface (MH) were successfully synthesized onto the surface layer of montmorillonite (Mt) as an organomodified mineral solid via one-pot solvothermal reaction. The synthesis of amino magnetic nanoparticles coated montmorillonite (Mt@MH) was carried out by one-pot solvothermal reaction of 1,6-hexanediamine, iron(III) chloride hexahydrate and Mt in ethylene glycol at ±198 °C for 6 h. The MH nanoparticles with diameter size around 30–50 nm were obtained. Characterizations were performed using powder X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), superconducting quantum interference device (SQUID), and Fourier transform infrared spectroscopy (FT-IR) analysis. The insertion of MH onto the surface layer of Mt does not only serve as an easily retrievable adsorbent but also provide a high adsorption capacity towards Pb(II) and As(V) ion. The adsorption isotherms of Pb(II) and As(V) at room temperature were well-fitted with Langmuir model providing maximum adsorption capacity for Pb(II) and As(V) of 38.15 mg/g at pHe˜6.5 and 19.10 mg/g at pHe˜3.5, respectively. The Mt@MH showed 2-fold higher adsorption capacity than MH and Mt. It is due to surface functionalization with the amine group (6 mmol/g) on the adsorbent. The electrostatic interaction was proposed as the primary driving forces for Pb(II) and As(V) adsorption onto the Mt@MH.

Gelatin is a biopolymer that can be obtained from the partial hydrolysis of collagen skin tissue of chicken leg. This study aims to utilize gelatin of chicken leg skin in combination with soy protein isolate (SPI) as raw material for edible film production. The experiment was initiated by extracting gelatin and edible film was prepared by mixtures of SPI in ethanol solution and gelatin solution (containing 1% chitosan, w/v) with different weight ratio for SPI : gelatin (1:1, 1:2, 1:3, 1:4, and 1:5) then heated at 70 °C for 45 min and added 10% glycerol. Furthermore printed and dried in oven for 24 h at 60 °C. The yield of preparation of gelatin from chicken leg skin was obtained about 40.3%. Higher concentration of gelatin in solution gives a transparent color and smooth surface of edible film. Base on mechanical properties analysis, the composition of 1:3 has the best result of tensile strength and elongation at break about 4.80 MPa and 113.37%, respectively. The antibacterial activity test showed low antibacterial activity with a 0.3 cm inhibit zone.

The sulphonated biocarbon (C-SO 3 H) has been prepared from carbonization of corn cob and followed by one-step hydrothermal treatment. This research focus on characterization of C-SO 3 H and evaluate the capability of C-SO 3 H for hydrolyzed banana peel starch, and also investigate the optimum concentrations of substrate and the reaction time for hydrolysis. The C-SO 3 H was produced from corn cob (±60 mm mesh); it was carbonized at 400 °C for 1 hour. The resulting carbon was sulphonated by hydroxy ethyl sulphonic acid at 180 °C for 4 hours, and then washed with 50% methanol and water, and then resulting biocarbon was dried at 80 °C for 6 hour in oven. Based on Scanning Electron Microscopy (SEM) observation, structure morphology of corn cob was changed due to carbonization process. The C-SO 3 H after sulphonation has random pores with diameter around 3 µm–10 µm. The X-Ray Diffraction (XRD) showed increased of crystalline index of corn cob about 133% after carbonization. Analysis of EDX result for S component on C-SO 3 H is 3.79% w/w and capacity of H + is 1.447 mmol/g. The apparent peaks of -SO 3 H functional groups (1207 cm -1 and 1720 cm -1 ) on C-SO 3 H were indicated the by Fourier Transform Infra Red (FTIR). Optimum hydrolysis concentration of banana peel starch is 7% w/v for 60 min at 100 o C which Total Reducing Sugar (TRS) concentration about 0.688 mg/mL. Reusability of C-SO 3 H for 4 repeated used which showed a good performance that only 6% of decreasing activity of C-SO 3 H. The utilization of corn cob can be enhanced of corn cob and also it can be utilized as heterogeneous catalyst.