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"The measurement of specific surface area of porous materials has long been important in physical sciences and is currently growing in importance in applied and environmental science. Numerous systems have been developed for surface area measurement by gas adsorption. Commercial systems are available which can measure a wide range of absolute surface area with relative ease. However, their cost is often prohibitive. In this study, an inexpensive apparatus for surface area measurement has been set up to be used for measuring supercritical adsorption of CO2. The Ono-KondoLattice model was used to represent the adsorption isotherm and to determine the surface area. The results of surface area determination using CO2 adsorption combined with OK model have been compared to the numbers obtained from nitrogen BET method. For surface area determination of zeolites and activated carbons, the new methodgive reasonable agreement results (within 10% deviation) compared to the results obtained from nitrogen BET method. In addition, thenew method also gives more reasonable results for surface area determination of coals. As known, the nitrogen BET method gives almost zero of coals? surface area. This might due to the characteristic of the coals? structure that might be change (the pores are closed) during the cooling process in nitrogen BET method. Moreover, the new method can also be used to determine the surface area of porous materials using CO2 adsorption data at various temperatures without sacrificing their accuracy."

"Hidrogen adalah salah satu energi terbarukan yang menjanjikan dan berpotensi menjadi pengganti bahan bakar fosil. Namun, aplikasi hidrogen sebagai bahan bakar memiliki kekurangan, yaitu dalam hal penyimpanannya. Dalam suhu kamar dan tekanan atmosfir, hidrogen memiliki rasio energi yang sangat rendah terhadap volumenya jika disimpan dalam bentuk gas sehingga perlu dilakukan berbagai penelitian yang berkaitan dengan metode dan material untuk menyimpan hidrogen terus dilakukan. Sejauh ini metode penyimpanan hidrogen memakai prinsip adsorpsi dengan karbon aktif berbentuk granular sebagai adsorben sangat menjanjikan karena bisa menurunkan tekanan dalam tangki dengan kapasitas penyimpanan yang relatif sama. Pada penelitian ini, karbon aktif yang digunakan pada penelitian ini adalah karbon aktif berbahan dasar zeolite alam. Proses pengambilan data dilakukan dengan metode volumetrik dan tipe adsorpsi yang digunakan adalah adsorpsi isotermal. Penyerapan dilakukan pada 3 temperatur berbeda, pertama pada temperatur 35°C dan tekanan mencapai 40 bar, yang kedua adalah pada temperatur 25°C dan tekanan mencapai 40 bar, dan yang ketiga pada temperatur 0°C dengan tekanan mencapai 40 bar. Pada temperatur 35°C, penyerapan hidrogen sebesar 0.01162kg/kg pada tekanan 39.3620 Bar. Pada temperatur 25°C, penyerapan hidrogen sebesar 0.01991kg/kg pada tekanan 40.2015 Bar. Pada temperatur 0°C, penyerapan hidrogen sebesar 0.03042kg/kg pada tekanan 39.6427 Bar. Data yang didapat selanjutnya dikorelasi dengan menggunakan persamaan model Langmuir, Toth, dan Langmuir-Freudlich.

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Hydrogen is one of promising and potential new energy sources as the substitute of fossil fuel.But, the application of hydrogen as fuel still has weakness in a storage system. Inroom temperature and atmosphere pressure, hydrogen has a very low energy/volume ratio if the hydrogen is stored in gas phase, so it's needed to do some research about the method and materials to adsorp hydrogen. Nowadays, hydrogen adsorption's method using granular activated carbon as the adsorbent is very promising since can reduce the pressure in cell with the adsorption capacity relatively same as other methods. In this research, the activated carbon which used is natural zeolite.

The method which used in this research is volumetric method and the type of adsorption in this research is isothermal adsorption. The adsorptions in this research are in 3 temperatures, first adsorption in 35oC and the pressure up to 40 bars. Then second adsorption in 25°C and the pressure up to 40 bars, and the third adsorption in 0oC. At temperature 35°C, the hydrogen adsorption is 0.01162kg/kg at 39.3620 Bars. At temperature 25°C, the hydrogen adsorption is 0.01991kg/kg at 40.2015 Bars. At temperature 0°C, the hydrogen adsorption is 0.03042kg/kg at 39.6427 Bars.The Data are corelated with some model equations Langmuir, Toth, and Langmuir-Freudlich."

"Pencemaran air merupakan dampak negatif dari berkembangnya aktivitas perindustrian. Limbah dari proses industri dapat mengandung zat warna hingga mencapai 10 %. Oleh karena itu, penting untuk mengetahui metode penanganan limbah tersebut. Adsorpsi merupakan metode yang efektif dan efisien untuk menangani kontaminasi zat warna dalam lingkungan perairan. Kertas koran bekas berpotensi menjadi adsorben zat warna karena banyak mengandung selulosa. Pada penelitian ini, serat koran bekas (WNF) dimodifikasi dengan nanokitosan (NCH) untuk meningkatkan kemampuannya dalam mengadsorpsi zat warna congo red. WNF diperoleh setelah proses deinking menggunakan NaOH 4 %. NCH dengan ukuran partikel 123,8 nm dibuat dengan melarutkan kitosan dalam larutan asam asetat 1,67 x 10-2 M. Modifikasi WNF dengan NCH mencapai kondisi optimum pada rasio 0,01 g WNF/mL NCH. Proses adsorpsi congo red menggunakan WNF/NCH berlangsung baik pada pH 5,0. Kondisi kesetimbangan proses adsorpsi tercapai dalam waktu 10 menit. Kapasitas adsorpsi maksimum dari WNF/NCH sebesar 33,502 mg g-1 dengan menggunakan massa WNF/NCH 0,075 g dan konsentrasi awal congo red 400 mg L-1. Proses adsorpsi mengikuti model isoterm adsorpsi Langmuir dan kinetika adsorpsi orde dua semu. Hasil menunjukkan WNF/NCH dapat menjadi alternatif adsorben rendah biaya dalam penanganan limbah zat warna.

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Water pollution is a negative effect emerged by industrial activities. These industries produce wastewater containing about 10 % dye stuffs. Adsorption has been considered to be the most effective and efficient process for treating dye contaminants in wastewater. Waste newspaper which is mainly consists of cellulose was found to be a potential adsorbent for dye removal. In this research, waste newspaper fiber (WNF) was modified by nanochitosan (NCH) to improve its ability for removal of congo red from aqueous medium. WNF was obtained after deinking treatment using 4 % NaOH. NCH with particle size of 123.8 nm was formed by dissolving chitosan particle in 1.67 x 10-2 M acetic acid solution. Modification of WNF using NCH reached optimum condition at ratio 0.01 g WNF/mL NCH. Adsorption study indicated that pH 5.0 favored the adsorption of congo red using WNF/NCH. The equilibrium condition was reached within 10 minutes. The maximum capacity of WNF/NCH for adsorption of congo red was 33.502 mg g-1 under dose of 0.075 g and initial concentration of 400 mg L-1. The adsorption process and equilibrium of congo red were well fitted by a pseudo-second order kinetic model and Langmuir isotherm, respectively. The results showed that nanochitosan-modified waste newspaper fiber may be utilized as a low cost adsorbent for dye-contaminated wastewater treatment."

"[Formaldehida merupakan senyawa berbahaya yang terkandung dalam udara indoor dalam bentuk gas. Efek negatif dari menghirup senyawa formaldehida, bagi manusia, bermacam-macam mulai dari bersin-bersin, sakit tenggorokan, keracunan akut, penyakit kulit, hingga kanker. Pada beberapa penelitian sebelumnya senyawa formaldehida dipisahkan dari udara dengan proses adsorpsi. Untuk mengetahui kinerja adsorpsi formaldehida dari udara dengan karbon aktif, dilakukan uji kinerja dengan mengalirkan udara terkontaminasi formaldehida ke dalam kolom berisikan unggun diam karbon aktif. Dalam penelitian ini, kinerja proses diketahui dengan membuat model matematika guna memperoleh kurva breakthrough dengan bantuan software COMSOL Multiphysics 4.4. pada variasi nilai laju alir umpan (40 ml/min – 85 ml/min), konsentrasi awal formaldehida (50 ppm – 200 ppm), serta tinggi unggun karbon aktif (3 cm – 4.5 cm). Selanjutnya, dilakukan simulasi adsorpsi karbon dioksida dari udara untuk mengetahui pengaruh polutan lain terhadap kinerja adsorpsi formaldehida dari udara dengan karbon aktif. Hasil yang didapatkan dari penelitian ini adalah profil konsentrasi formaldehida luaran akan semakin lambat meningkat ketika laju alir umpan semakin rendah, konsentrasi awal formaldehida semakin rendah, dan tinggi unggun karbon aktif semakin tebal. Didapatkan pula bahwa keberadaan polutan lain (karbon dioksida) tidak memiliki pengaruh yang signifikan terhadap kinerja adsorpsi formaldehida dari udara dengan karbon aktif., Formaldehyde is a hazardous chemical substance that is contained in indoor air in gaseous phase. Negative effects of inhaling formaldehyde for human may vary from cough, sore throat, poisoned, skin disease, even cancer. In many other researches, formaldehyde is separated from air by adsorption process. In order to find out the performance of the adsroption column, performance tests are done by flowing formaldehyde-contaminated air to column containing fixed activated carbon bed. In this research, the process performance is studied by developing a mathematical model to produce breakthrough curves of the adsorption process using COMSOL Multiphysics 4.4. at various gas flow rate (40 ml/min – 85 ml/min), initial conentration of formaldehyde (50 ppm – 200 ppm), and activated carbon bed depth (3 cm – 4,5 cm). Then, a simulation of carbon dioxide adsorption is also done to find out how much other pollutant influences the formaldehyde adsorption process. The result from this research is the concentration of formaldehyde in the outflow needs longer time to increase at lower gas flow rate, lower initial concentration of formaldehyde, and higher activated carbon bed depth. Also, the presence of other pollutant (carbon dioxide) in the air does not have significant effect to formaldehyde adsorption from air using activated carbon.]"

"Pencemaran lingkungan merupakan salah satu masalah yang di Indonesia, salah satunya ialah pencemaran lingkungan air oleh zat warna dari industri tekstil dan pakaian. Zat warna merupakan salah satu polutan organik yang keberadaannya sangat berbahaya bagi lingkungan dan ekosistem air karena dapat menyebabkan keracunan, perubahan mutagenik pada makhluk hidup bahkan kematian. Metode adsorpsi dinilai paling efektif untuk mengurangi pencemaran air dan memiliki berbagai macam adsorben dengan penggunaan dan bahan yang mudah serta memiliki nilai efesiensi tinggi. Pada penelitian ini disintesis karbon aktif berasal dari bahan alam, yaitu limbah tandan kosong kelapa sawit yang dimodifikasi ukuran porinya menggunakan silika gel bekas sebagai template dan menggunakan gugus sulfonat di permukaannya. Pada penelitian ini sintesis karbon aktif dengan metode hard template dan untuk pori diisi oleh ekstrak silika dari kaolin. Hasil sintesis diaplikasikan sebagai adsorben dengan methylene blue dan rhodamine B dalam air. Hasil sintesis dikarakterisasi menggunakan FTIR, XRD, BET, dan SEM-EDX untuk mengetahui ikatan kimia, morfologi, dan luas permukaan. Aplikasi adsorpsi zat warna methylene blue dan rhodamine B mencapai kapasitas adsorpsi maksimum pada pH 9 dan waktu kontak 60 menit pada adsorpsi karbon aktif dan karbon aktif tersulfonasi pada methylene blue dan pada pH 5 dan waktu kontak 60 menit pada adsorpsi karbon aktif dan karbon aktif tersulfonasi.

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Environmental pollution is one of the problems in Indonesia, one of which is the pollution of the water environment by dyes from the textile and clothing industry. Dyes are one of the organic pollutants whose existence is very dangerous for the environment and aquatic ecosystems because they can cause poisoning, mutagenic changes in living things and even death. The adsorption method is considered the most effective for reducing water pollution and has various kinds of adsorbents with easy use and materials and has a high efficiency value. In this study, activated carbon was synthesized from natural materials, namely empty palm fruit bunches waste which modified its pore size using used silica gel as a template and using sulfonate groups on its surface. In this study, the synthesis of activated carbon was carried out using the hard template method and the pores were filled with silica extract from kaolin. The result of the synthesis was applied as an adsorbent with methylene blue and rhodamine B in water. Synthesis results were characterized using FTIR, XRD, BET, and SEM-EDX to determine chemical bonding, morphology, and surface area. The adsorption application of methylene blue and rhodamine B dyes achieved maximum adsorption capacity at pH 9 and a contact time of 60 minutes for the adsorption of activated carbon and sulfonated activated carbon on methylene blue and at pH 5 and a contact time of 60 minutes for the adsorption of activated carbon and sulfonated activated carbon."