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Synthesis of nanocomposite SnO 2 -Fe 3 O 4 using the hydrothermal method was conducted in this study. The purpose of this study was to determine the best mass ratio in the synthesis of SnO 2 -Fe 3 O 4 . Nanocomposite SnO 2 -Fe 3 O 4 were made with mass ratio (1:1), (1:2) and (2:1) were characterized using XRD and FTIR. The result of SnO 2 characterization using XRD analysis was showed a sharp intensity peak at 2 = 26.5. The result of Fe 3 O 4 characterization using XRD analysis was showed a sharp intensity peak at 2 = 35.86. The XRD characterization result of SnO 2 -Fe 3 O 4 (1:2) 2 = 26.74 and 34.08. Based on the XRD characterization, it can be concluded the best mass ratio for SnO 2 -Fe 3 O 4 was (1:2). Characterization nanocomposite SnO 2 -Fe 3 O 4 using FTIR showed the absorption band at 590 cm -1 is a characteristic peak of Sn-O and the absorption band at 563 cm -1 corresponds to Fe-O.

The availability of clean water is a basic need for human life. Peat water is well-known as acidic water (low pH), high content of Fe 2+ and Mn 2+ and colored that make it hard to remove by conventional filtration method. Treatment in batch and continuous methods by using Calcium Oxide (CaO) and aluminum sulfate Al 2 (SO 4 ) 3 ×18H 2 O result in significance reduce of iron and manganese. The batch method in particular, able to reduce iron from 3.5 ppm to 0.1 ppm (97%), manganese from 0.59 ppm to null (100%) and color from 130 TCU to 1.7 TCU. Turbidity also reduced from 33.8 NTU to 1.9 NTU whereas pH increase from 3.19 to 6.8. The continuous method in different circumstances shows iron removal from 3.35 ppm to 0.05 ppm (98.6%), manganese from 0.5 ppm to null (100%) whilst pH raised from 3.19 to 7.16 and turbidity decrease from 31.8 NTU to 1.14 NTU. Both results fulfill the water quality standard required by Permenkes No. 416/Menkes/1990

The increase in energy consumption and an increase in the plastic waste generation are two major problems that arise along with economic growth and the increase in population. Styrofoam is one type of polystyrene plastic waste that can be processed into liquid fuels by cracking process. In this study, the cracking process of polystyrene plastic waste into liquid fuel carried by the catalytic cracking process using Al2O3 as a catalyst. This study aimed to determine the effect of the catalyst weight, length of cracking time and range of temperature in the catalytic cracking process of polystyrene plastic waste into liquid fuel toward the mass and characteristics of liquid fuels produced and to determine the composition of liquid fuels produced. The catalytic cracking process of polystyrene plastic waste with catalyst was done in the fixed bed type reactor by heating the reactor with a heater, where the process took place at temperature of 150°C, 200°C, 250°C and 300°C and the length of the process was varied into 20, 40, and 60 minutes and the catalyst weight was also varied, which were 4%, 6% and 8%, while the styrofoam weight was 250 grams. From the research, the highest mass of liquid fuel derived from polystyrene catalytic cracking process was in the amount of 48.8 grams and liquid yield percentage of 19.5% at temperature of 250°C, cracking time of 60 minutes and weight of 8% catalyst, while the characteristics of liquid fuel that were approaching the characteristics of gasoline was at temperatures of 250°C, cracking time of 60 minutes and weight of 6% catalyst, in which each value of density of 0.763 g/ml, specific gravity of 0.778 and oAPI gravity of 50.2. While other liquid fuels obtained from the cracking of polystyrene were still within the tolerance range characteristic properties of gasoline. Liquid fuels produced from the catalytic cracking process was analyzed using a GC-MS, in which the analysis results indicated that liquid fuels were included in the gasoline fraction.

Layer double hydroxide Mg/Al was synthesized by inorganic synthetic method. Material was characterized using FTIR and XRD analyses and used as adsorbent of procion red dye in aqueous medium. Factors that affect the adsorption process are adsorption time as the kinetic parameter; and the temperature and concentration of procion red as the thermodynamic parameter. FTIR spectra of layer double hydroxides showed unique vibration at wavenumber 1300 cm-1 and 1600 cm-1. Characterization using XRD shows diffraction angles at 29o, 27o, and 28o, which are typical of Mg/Al double layer hydroxides. Adsorption of procion red using layer double hydroxide Mg/Al resulted adsorption rate 7.1 minutes-1, maximum adsorption capacity 111.1 mg/g at 60 oC with increasing energy by increasing adsorption temperature. Keywords: Layered double hydroxides, adsorption, procion red.

Pillarization of layered double hydroxides with polyoxometalate K4[α-SiW12O40]•nH2O at various times i.e. 3, 6, 9, 12, 24, 36 and 48 hours has been done. The pillared product was characterized by FT-IR spectrophotometer and XRD. The optimum pillared layered double hydroxides of polyoxometalate K4[α-SiW12O40]•nH2O was used as an adsorbent of procion red dye. The results of characterization using FT-IR spectrophotometer is not yet show the optimum pillarization process. The characterisation using XRD the successfully of pillared layered double hydroxides of polyoxometalate K4[α-SiW12O40]•nH2O showing the existence of diffraction angle 8.5o with intensity 355. Furthermore, the pillared layered double hydroxides of polyoxometalate K4[α-SiW12O40]•nH2O with time variation of 12 hours was applied as an adsorbent of procion red dye. The results show the adsorption rate was 0.523 min-1, the highest of absorption capacity at 70oC was 10.8 mol/g, the highest energy of absorption 70 oC was 125 kJ/mol. The enthalpy (∆H) and entropy (∆S), decrease as the increasing concentration of procion red dye. Keywords: layered double hydroxides, polyoxometalate, pillaration, procion red, adsorption

The optimization of COD removal from palm oil mill effluent (POME) using the Reverse Osmosis (RO) membrane was investigated. Experimental conditions for reduce the COD value of POME were achieved successfully using the Box Behken design. The values of affecting factors (POME concentration, pH and Transmembrane pressure were optimized according to the polynomial regression model. The predicted conditions to produce lower COD values were found to be POME concentration (vol. %) =28.30, pH =10.75 and Transmembrane pressure= 0.69 kPa. The predicted of COD value was 24.137 mg/l which in good agreed with experiment value as 25.763 mg/l was obtained.

Polyoxometalate H4[α-SiW12O40].nH2O intercalated layered double hydroxide (1:1) was used as adsorbent colored-dye. Polyoxometalate H4[αSiW12O40].nH2O intercalated layered double hydroxide ratio (1:1) was applied as the adsorbent of Congo red-dye, and produce 51.38 (min-1) of the adsorption rate, for the largest of the adsorption capacity (b) 9.091 mol/g at 70°C, the largest adsorption energy 10.752 kJ/mol at 30°C. The value of the enthalpy (ΔH) and entropy (ΔS) decreased with increasing concentration of Congo red-dye. Effect adsorption of pH was show the optimal pH at 8 with the amount Congo red absorbed were 47.529 ppm. Keywords: Hydrotalcite, layered double hydroxide, polyoxometalate, intercalated, Congo red, adsorption

The synthesis of hydrotalcite and polyoxometalate H4[αSiW12O40].nH2O with the ratio (2:1), (1:1), (1:2) and (1:3) has been done. The product of intercalation was characterized using FT-IR spectrophotometer, XRD, and TG-DTA. Polyoxometalate H4[αSiW12O40].nH2O intercalated layered double hydroxide was optimised to use as adsorbent Congo red dye. Characterization using FT-IR was not showing the optimal insertion process. The result using XRD characterization was showed successful of polyoxometalate H4[αSiW12O40].nH2O inserted layered double hydroxide with a ratio (1:1) which the basal spacing was expanded from 7,8 Ȧ to 9,81 Ȧ. Furthermore, the thermal analysis was performed using TG-DTA. The result show that the decomposition of polyoxometalate H4[αSiW12O40].nH2O intercalated hydrotalcite with ratio (1:1) was occured at 80oC to 400oC with a loss of OH in the layer at 150oC to 220oC, and then the decomposition of the compound polyoxometalate H4[αSiW12O40].nH2O at 350oC to 420oC. Keywords: Hydrotalcite, Layered Double Hydroxide, Polyoxometalate, Intercalation

Photocatalyst Montmorillonite-TiO 2 was synthesized using template CTAB and natural clay for degradation of Permethrin. The porosity and crystalline phase of catalyst were evaluated using N 2 sorption analyzer and XRD diffraction. Permethrin photodegradation was optimized by varying reactant volume, irradiation time and initial concentration. Montmorillonite enhanced by CTAB showed typical porosity i.e. specific surface area, pore radii and pore volume for layer material. It properties decreased as this host material was impregnated with TiO 2 . XRD diagram indicated that space between layers of Montmorillonite expanded up to 4.7 A. The diffractogram also confirmed that TiO 2 formed an Anatase phase instead of Rutile. Photodegradation conducted at several condition showed relatively low photocatalytic activity. The highest photodegradation was achieved at 50 mL of Permethrin with initial concentration 10 ppm and 100 minutes’ irradiation. Keywords: Permethrin, Photodegradation, Montmorillonite-TiO 2

The optimization of the COD removal from palm oil mill effluent (POME) has done. The correlation of concentration and pH of POME, and Trans membrane pressure (TMP) of Reverse Osmosis (RO) membrane was optimized by response surface method using a second order polynomial model with Box Behken design consist of 17 runs. To determine whether the model was adequate for representing the experimental data; it was indicated by the ANNOVA table (p-value, lack of fit and R 2 values). The main factor influenced the COD removal was concentration and pH of POME. The optimum conditions were determined from 3D response surface and 2D contour graphs i.e. 28.30% of POME concentration at pH 10.75 and TMP 0.69 kPa to yield 24.1372 mg/L of COD value. The results demonstrate that the response surface method effective to minimize the number of experiment. Keywords: POME; RO membrane; RSM; ANN; COD

Leachate treatment containing methylmercury (CH3Hg+) can be done by using biodegradation method. Bacteria used in methylmercury biodegradation of the bacteria Empedobacter brevis. This study aims to examine the ability of bacteria in degrading methylmercury in leachate and determine the value of ?max and Ks. The degradation process is done with variation of inoculum concentration and incubation time aerobically. The parameters analyzed were the decrease of methylmercury content in the biodegradation process. The results showed that biodegradation of methylmercury by the bacterium Empedobacter brevis at 15% inoculum concentration was the highest decrease efficiency of 81%. The values of ?max and Ks in the bacterium Empedobacter brevis were 0.994 per hour with a substrate concentration of 1.588 mg /l.

Layered double hydroxides Mg/Al and Ca/Al has been synthesized by co-precipitation method with molar ratio M2+:M3+ (3:1) at pH 10. The synthesized materials were characterized by XRD and FTIR. The materials were used as adsorbent for the removal Cobalt (II) in aqueous solution. The adsorption experiments were studied through some variables adsorption such as variation of contact time, variation of temperature and variation of initial concentration. Kinetic parameters was obtained from variation of contact time. Data was analyzed by pseudo-first-order and pseudo-second-order kinetics models in linear analyses. The kinetic studies showed that the adsorption process more fitted by pseudo-second-order than pseudo-first-order based on coefficient correlation. Isotherm parameters was calculated using Langmuir and Freundlich isotherm models. The adsorption process was spontaneous and endothermic.