The objectives of this study are to investigate the influence of concentration variation of potassium hydroxide (KOH) and to remove a heavy metal in liquid waste of the activated carbon. The raw material of activated carbon was obtained from pineapple crown waste. Pineapple crowns pre-carbonized at 180 oC for 1 hour. Chemical activation was carried out using KOH with concentration 2M, 3M, and 4M for 20 hours at 30 oC and temperature 60 oC for 2 hours. Microwave irradiation was conducted at 630 Watt of output power for 15 minutes. The physical properties of activated carbon were characterized using scanning electron microscopy to determine surface morphology of activated carbon, X-ray diffraction to calculated microstructure (i.e. interlayer spacing and microcrystalline dimension) using Bragg’s and Scherer’s equations, specific surface area was calculated from N2 adsorption-desorption isotherm using BET equation, Fourier-transform infrared (FTIR) identify the functional groups of activated carbon, and heavy metals absorption was tested using atomic adsorption spectrophotometric. The highest surface area of activated carbon is 300,901 m2/g for activated carbon with concentration 2M corresponding to the highest stack height (Lc) of activated carbon of 10,470 nm. The carbon chain structure shows the functional groups C-H, C≡C, O-H, C-OH, and CH2 at wavenumbers of 2889,49 cm-1, 2360,97 cm-1, 2339,97 cm-1, and 998,21 cm-1, respectively.
This study aims to determine the influence of concentration of potassium hydroxide (KOH) on the adsorption of Pb2+ and Cu2+ metal ions in industrial used water. The activated carbon was prepared from pineapple crown waste. Pineapple crown was pre-carbonized at 180oC for 1 hours. Chemical activation was done using KOH with variations in concentrations of 2, 3, and 4 M. The samples were irradiated by using a microwave at 630 Watt of output power for 15 minutes. KOH activation and microwave irradiation power were influenced to the physical properties of the samples. Activated carbon obtained were characterized using SEM, EDX, FTIR and AAS. The results showed that highest adsorption were obtained from activated carbon that was activated by KOH 2 M. Adsorption efficiency for Pb2+ and Cu2+ metals were 81.15% and 49.71%, respectively. The carbon chain structure shows the functional groups C-H, C≡C, O-H, C=C at wavenumber 2889.49 cm-1, 2360.97 cm-1, 2339.97 cm-1.
Science and technology show a trend that continues to develop. This has an impact on tools such as defense equipment produced or owned by a country to be more sophisticated. A country must have a defense system that can protectthe entire terriroty of the country,one of which is its airspace. Violations in the airspace often occur because the defense system is still weak. One of the tools that play a role in conducting surveillance for airspace is Radar. Currently, Indonesia still has several blank spot areas that are not detected by Radar. This needs to be solverd by placing Radar in some areas that cannot be detected or blank spot areas using a geographic information system (GIS). GIS is one of the platforms used in mapping without having to survey the location directly.
Portabilitas instrumen merupakan bagian penting yang digunakan untuk menilai apakah suatu model atau sistem pengukuran mudah diimplementasikan dan pada akhirnya berkaitan juga dengan efektifitas dan efisiensi penggunaan sumber daya dalam penggunaannya. Penelitian ini mempunyai tujuan yaitu untuk menganalisis portabilitas dari instrumen pengukuran digital SPBE. Penelitian ini menggunakan metode penelitian kuantitatif dengan bantuan software XLSTAT. Penelitian ini menggunakan 2 analisis, yaitu analisis kemudahan baca dan analisis outlier. Hasil penelitian menunjukkan bahwa instrumen SPBE tidak portabel yang didukung dengan hasil outlier 50,2% dan skor kemudahan baca 19,59.
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