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Study of dyes adsorption (rhodamine B, methylene blue and carmine) by using mesoporous carbon synthesized at various carbonization time has been done. Purpose of this research was to understand influence of carbonization time to performance of the mesoporous carbon in dyes adsorption. In addition, adsorption performance of the mesoporous carbon and commercial carbon were compared. The adsorption test were conducted at conditions: 0.1 g of adsorbent, 25 mL of dyes solutions 100 ppm and shaking rate 125 rpm for 4 hour. Filtrate was used to determine remain concentration of the dyes with UV-visible spectrophotometry. Result of the research showed that the carbonization time from 1 to 3 hours improved the adsorption, whereas from 3 to 5 hours decreased it. The best character of the mesoporous carbon was obtained at carbonization time of 3 hours with adsorption values of 96.43 ± 0.37 % for rhodamine-B, 38.80 ± 1.44 % for methylene blue and 48.51 ± 1.55 % for carmine. The adsorption values of the mesoporous carbon were 0.97 times for rhodamine B, 0.48 times for carmine, and 0.39 times for methylene blue compared with the commercial activated carbon.

Molecularly Imprinted Polymers (MIPs) have specific recognition capabilities and have been widely used for electrochemical sensors with high selectivity. In this study, an electrochemical sensor was developed for the determination of p-aminophenol (p-AP) by modifying the screen-printed carbon electrode (SPCE) with chitosan-based MIP. The MIP was made from p-AP as a template, chitosan (CH) as a base polymer, and glutaraldehyde and sodium tripolyphosphate as the crosslinkers. MIP characterization was conducted based on membrane surface morphology, FT-IR spectrum, and electrochemical properties of the modified SPCE. The results showed that the MIP was able to selectively accumulate analytes on the electrode surface, in which MIP with glutaraldehyde as a crosslinker was able to increase the signal. Under optimum conditions, the anodic peak current from the sensor increased linearly in the range of 0.5–35 µM p-AP concentration, with sensitivity of (3.6 ± 0.1) µA/µM, detection limit (S/N = 3) of (2.1 ± 0.1) µM, and quantification limit of (7.5 ± 0.1) µM. In addition, the developed sensor exhibited high selectivity with an accuracy of (94.11 ± 0.01)%.

Synthesis of alumina has been carried out by utilizing anodized waste as raw material. Anodized waste is a by-product of metal anodizing processes such as aluminium. This study aims to determine the effect of acidity (pH) and aging time on the mass of Al(OH) 3 and the property of Al(OH) 3 as well as Al 2 O 3 that produced. Anodized waste was deposited into Al(OH) 3 and then purified. Alumina synthesized by the sol-gel method with pH variations of 7, 8, 9, and 10 and aging times of 24, 48, and 72 hours. The Al(OH) 3, which has been produced, was characterized by PSA and powder XRD spectrophotometer. The results showed that the synthesis of Al(OH) 3 was influenced by pH and aging time. It affects the yield and particle size of Al(OH) 3 . The optimum condition of the synthesis was pH 7 and aging time of 24 hours with yield of 1.85 grams. Characterization by PSA at a current diameter of 90% indicate that higher pH value and longer aging time produces smaller particle size. Characterization by powder XRD shows that the Al(OH) 3 has gibbsite crystal phase with d values of 3.360, 3.217, 2.252, 2.029, and 1.649 A.

Batu kapur dapat ditingkatkan nilai dan kualitasnya melalui proses sintesis Precipitated Calcium Carbonate (PCC). PCC banyak digunakan dalam industri kertas karena memiliki keunggulan ukuran partikel yang lebih seragam serta derajat kecerahan dan kemurnian yang lebih tinggi. Review artikel ini bertujuan untuk mengetahui pengaruh temperatur sintesis PCC dengan modifier terhadap ukuran dan jenis kristal, mengetahui pengaruh penambahan modifier terhadap ukuran partikel PCC serta mengetahui kondisi sintesis yang menghasilkan PCC yang dapat diaplikasikan dalam industri kertas. Review artikel ini menggunakan metode kajian pustaka berdasarkan literatur jurnal ilmiah dengan menggunakan satu jurnal PCC tanpa modifier dan lima jurnal PCC dengan modifier yaitu Sodium Deoxycholate (SDC), asam oleat, dodecyltrimethylammonium bromide (DTAB), etilen glikol, dan ethylenediaminetetraacetic acid (EDTA). Metode sintesis yang digunakan dari jurnal yang diteliti adalah metode kaustik soda dan karbonasi. Penentuan jenis kristal PCC menggunakan data hasil X-Ray Diffraction (XRD) dan penentuan ukuran partikel menggunakan data hasil Scanning Electron Microscope (SEM) dan Particle Size Analyzer (PSA). Berdasarkan hasil review artikel terhadap jurnal penelitian yang digunakan, temperatur reaksi mempengaruhi ukuran dan jenis kristal PCC dengan modifier . Jenis kristal kalsit terbentuk pada temperatur rendah (≤30°C), vaterit umum terbentuk pada temperatur ≥40°C, dan aragonit terbentuk pada temperatur tinggi ≥60°C. Semakin tinggi temperatur, ukuran PCC yang dihasilkan cenderung meningkat. Penambahan modifier mempengaruhi ukuran kristal PCC dengan menghasilkan ukuran yang lebih kecil dibanding dengan PCC tanpa modifier. Ukuran partikel yang dihasilkan sebesar 0,6‒10 µm.

Chitosan as adsorbent has been used widely, however it was not effective yet for metal ions adsorption in industrial scale. In acidic condition, chitosan’s active site tends to decrease. This drawback can was solved by coating of chitosan active site on alumina. This paper discloses to overcome that limitation. The charateristic of the active side was analysed by FTIR spectrometry toward vibration N-H group at 1679.15 cm-1, C=O group of oxalate at 1703.30 cm-1, and Al-O group of alumina at 924.07 cm-1. The adsorption capacity of the developed adsorbent was tester to adsorb Cr(VI) ions under various of pH value such as 1, 2, 3, 4, 5, 6, and 7. The contact time affect toward the adsorption was also reported in 20, 30, 40 50, 60, 70, and 80 minute. In addition, the concentration effects (100, 200, 300, 400, 500, and 600 ppm) was also studied. Chromium (VI) was measured using spectronic-20. Adsorption capacity was obtained at 66.90 mg/g under optimum conditions pH 2, and contact time 60 minute, respectively.

A study concerning the adsorption of Mg (II) ions using phosporilation chitin adsorbent. The process is a surface modification of adsorbent chitin by enriching the phosphate group that acts as a hard base so it would be more suitable binding Mg (II) ions, which acts as a hard acid. This research aims to study the effect of contact time and concentration variations of Mg (II) ions on the adsorption process using phosporilation chitin adsorbent. Variables to be examined in this study in order are contact times (40, 60, 80, 100, and 120 minutes) and the concentration of Mg (II) ions variation are (10, 25, 50, 75, 100, 125, 150, 175, and 200 ppm). The results for the characterization of phosporilation chitin adsorbent can be detect from the IR absorption band at wavenumber 1099.35 cm -1 are suspected of phosphate ions and IR absorption band at wave number 1272.93 cm -1 and 1201.57 cm -1 are estimated as phosphate covalent. The contacts times significantly affect the adsorption Mg (II) ions by the phosporilation chitin adsorbent, then the optimum of contact time is 120 minutes. Adsorption capacity of phosporilation chitin adsorbent for the Mg(II) ions is 499 mg/g.

One techniques to reduce the concentration of heavy metal Cd(II) in aqueous solution is adsorption by chitosan. To modify the surface textures and expose the active binding sites, composite biosorbent has been prepared by coating chitosan onto alumina. The aims of this research were to identify the functional group of chitosan-alumina, to characterize adsorption of Cd(II) by using chitosan-alumina adsorbent including optimum pH, optimum agitation time, and to determine the adsorption capacity of the adsorbent. The functional group of chitosan-alumina was identified by infrared spectrophotometer. Determination of the optimum condition was carried out at 40 ppm Cd(II), 125 rpm and 0,1 g adsorbent. Calculation of adsorpted Cd(II) based on its concentration in aqueous phase before and after adsorption process. The concentrations of Cd(II) in aqueous phase after adsorption process were determined by using Atomic Absorption Spectroscopy (AAS). Identified functional groups of chitosan-alumina were -OH (3466.39 cm-1), -NH amine (1625.15 cm-1), C=O (1703.30 cm-1), and Al-O (1302.07 cm-1). The optimum pH was reached at pH 7, optimum agitation time at 15 minutes, and adsorption capacity of chitosan-alumina was 15.35 ± 0.05 mg/g. Keywords: adsorption, chitosan-alumina, characterization of adsorption

Textile sludge waste contains many organic matters so that it is potential to be used as mesoporous carbon precursor. Actived carbon with mesopore character is effective as adsorbent and catalyst carrier of large molecules. Synthesis of the activated mesoporous carbon was done with purpose to study influence of activation temperature toward characters of the carbon. Process of the synthesis involved dry sludge (50 g) as precursor, concentrated sodium silicate solution SiO2 24.5% and Na2O 7.5% (50 mL) as template source, 1 M HCl solution (50 mL) as polimering agent, carbonization condition at 600 °C 3 h under nitrogen gas flow, activation conditions with NaOH 50% and various temperatures (400, 500, 600, 700, and 800 °C), and demineralizatin conditions with 0.1 M HCl solution for 4 h and 125 rpm. All of the products were characterized with methylen blue method to determine specific pore volume and specific surface area. The carbon obtained at optimum temperature was characterized again with surface area analyzer. Result of the research showed that the optimum condition was achieved at activation temperature of 500 °C. Characters of the synthesized carbon at the optimum condition were specific surface area of 638.32 m2/g, specific pore volume of 0.35 cm3/g, average pore diameter of 21.78 Å, and methylene blue number of 358.87 mg/g. Keywords: actived mesoporous carbon, textile sludge, temperature