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This paper describes a method to synthesize a graphene oxide sand composites (GSC) as filter media (absorbent) for water purification. Graphene oxides is synthesized from graphite using modification of Hummer's method. The graphene oxide sand composites is prepared through solution method at 100 °C. The graphene oxide is analyzed using XRD, FTIR to confirm its formation. The FTIR spectrum and XRD diffraction pattern confirmed that the graphene oxide synthesized by this method is able to convert graphite into graphene oxide. Performance tests were conducted using a column to purify contaminated water which was mimicked using dyes such as rhodamine B, methylene blue and methyl orange.The initial concentration for all dyes were set for 5, 10, 25, 50 and 100 ppm. The color removal for methylene blue was 100% at all concentrations. However, for the rhodamine B and methyl orange, the color removal achieved 100% for the first three concentration 5, 10 and 25 ppm. The higher concentration of 50 and 100 ppm, the removal were slightly reduced. For the 50 ppm, the color removal of rhodamine B was 98% and for methyl orange 87% respectively. At 100 ppm, the color removal for rhodamine B drops to 92% and for the methyl orange was only 77% respectively. The GSC was very effective to remove methylene blue dyes at any concentration followed by rhodamine B and methyl orange. This GSC composite material is potential to be applied for water purification.

Kaolin is the clay mineral which containing silica (SiO2) and alumina (Al2O3) in a high percentage, that can be used as a nutrient in the synthesis of zeolites and amorphous silica alumina (ASA). The objective of this research is to convert the Belitung kaolin into silica and alumina as nutrients for the synthesis of zeolites and amorphous silica alumina, which are required in the preparation of the catalysts. Silica and alumina contained in the kaolin were separated by leaching the active kaolin called as metakaolin, using HCL solution, giving a solid phase rich silica and a liquid phase rich alumina. The solid phase rich silica was synthesized to zeolite Y by adding seed of the Y Lynde type, through the hydrothermal process with an alkaline condition. While, the liquid phase rich alumina was converted into an amorphous silica alumina through a co precipitation method. Characterization of zeolite and ASA were done using XRD, surface area and pore analyzer and SEM. The higher of alumina in liquid phase as a result of the rising molar of HCL in the leaching process was observed, but it didn’t work for its rising time. Products of ASA and zeolite Y were obtained by using liquid phase rich alumina and solid phase rich silica, respectively, which resulted through leaching metakaolin in 2.5 M HCl at temperature of 100° C for 2 hours.

Batteries and supercapacitors are one of the energy storage devices that had been used for a practical application most electronic devices such as mobile phone. The development of these energy storage devices is faced by the poor performance of (the) electrode. Electrode commonly used for batteries and supercapacitors is derived from nonrenewable carbon resources such as graphite. However, the availability of this material is becoming a long-term problem for the development of batteries and supercapacitors. Biomass from (the) waste plant as a green source for battery electrode is one of alternative carbon which has great potential, due to the low price, easy to process and has high stability. This paper reports the study of the biomass conversion into carbon electrode material having high electrical conductivity or low electrical resistivity using carbonization and pyrolysis process. The process involved FeCl3 as an activating agent to reduce the electrical resistivity of the material as low as possible. The research was studying the effect of biomass sources and the processing method on the electrical resistivity of the electrode produced. The biomasses used in the study were corncob, water hyacinth, rice straw, and coconut husk. The material is the waste plant which is available in abundant. The morphological analysis of the carbon surface was conducted using Scanning Electron Microscope-Energy Dispersive X-Ray (SEM-EDX). The lowest electrical resistivity was produced from corncob material through the carbonization process at 300°C for 2 h, activated by 4 M FeCl3 solution and followed by pyrolysis process at 800°C for 6 h. The FeCl3 is suspected responsible for the decreasing of the carbon resistivity or increasing the electrical conductivity produced, this correlates with the increase of the surface area of the material. The lowest electrical resistivity (highest electrical conductivity) produced from corncob has a value of 1 Ω with the surface area of 601 m2/g. This is considered better than graphite in term of electrical resistivity in which graphite has electrical resistivity between 10 - 30 Ω. The result of SEM images shows that the carbon surface activated by FeCl3 has more pores compared to the carbon without activation.

Korosi merupakan proses kerusakan material akibat berinteraksi dengan lingkungan yang korosif. Untuk mempelajari proses korosi di industri, maka dilakukan pengujian korosi di atmosfer, simulasi dalam skala lab untuk sistem air pendingin dan sistem air panas. Pengujian korosi dilakukan pada material baja lunak dengan metode Coupon dan laju korosi dihitung berdasarkan metode kehilangan berat. Penelitian ini bertujuan untuk menentukan laju korosi di lingkungan atmosfer, air pendingin, dan air panas berdasarkan pengaruh waktu. Hasil pengujian korosi di atmosfer menunjukkan bahwa lingkungan sekitar laboratorium kimia (gedung A) masih sangat baik dengan laju korosi 0,39mpy, sistem air pendingin mencapai 3,52 mpy dan di sistem air panas mencapai 137,12 mpy. Produk korosi dari ke tiga sistem berupa lapisan berwarna coklat dari Fe2O3.xH2O atau FeO(OH) menempel di permukaan logam. Dari ketiga lingkungan yang menunjukkan laju korosi terbesar adalah di sistem air panas.Pengendalian dengan coating dan proteksi katodik anoda korban dapat menurunkan potensial baja sampai dibawah kriteria proteksi (<-850mV/CSE), untuk coating mencapai – 896 mV/CSE, proteksi katodik anoda korban Mg dapat mencapai – 1696 mV/CSE, sedangkan potensial baja telanjang -762 mv/CSE