Heavy metals concentrations exceeding the recommended threshold are hazardous for the environment, so there is a need for handling it safely. The purpose of this research was to determine the adsorption capacity and kinetics of adsorption. This research uses an adsorption method in the process of removing Pb(II) heavy metal ions using persimmon tannin gel. Besides the influence of contact time, pH, and the concentration of Pb(II) metal ions on adsorption, a kinetics study was also carried out. The adsorption rate is obtained through the adsorption rate constant (K) and the reaction order generated from the kinetics model. Based on the results of the research, showed the optimum adsorption process, which is 20 minutes and at a pH of 5. The maximum adsorption capacity of 17.62 mg/g with the value of the standard energy changes of Gibbs adsorption (-ΔG° = -14.274 kJ/moll) indicates that the adsorption takes place through physical interaction. The kinetic adsorption gives the adsorption rates a constant of, k = 0.008231 g/mg.min.
Synthesis and characterization of of Graphene-Mnnanocomposites as Pesticide sensor electrodes have been carried out. This study aims to determine the method for synthesizing and characterizing the products of Graphene-Mnnanocomposite synthesis. Modification of Graphene using Mn nanoparticles for profenophos analysis with cyclic voltammetry. This research using with the Modified Hummers method and the liquid phase adsorption method followed by hydrothermal. Characterization of Graphene-Mn oxide nanocomposites are displayed using XRD, SEM-EDX and FTIR. The XRD results showed that there are peaks of Mn3O4 (30.57, 44.39), MnO2 (34.14), and MnO (39.85, 57.85, 68.94). SEM-EDX analysis reveals the surface of graphene sheets containing aggregates in shape small particles attached to graphene sheets. The results of the EDX analysis consisted of Mn 6.26%, C 53.60% and O. 15.45%. The FTIR test indicates the presence of Mn-O bonds in wave number 615.29 cm-1 and other functional groups, such as O-H, C-O, C = C, and C-H. Electrodes with the best composition at pH 6 will be used to detect pesticides profenofos with the Cyclic Voltammetry (CV) method at a scate rate of 0.05 V / s. The detection limit obtained from graphane-Mn measurements on profenofos is 0,000667 M. and the repeatability of graphane-Mn performance is 0.0131. The age of Graphene-Mn electrodes in analyzing profenofos pesticides is 17 days. The selectivity test using Pb (NO3)2 0.1M and Phenol 0.1M disrupting compounds occurred in a negative direction.
Sintesis ester sinamat dengan mereaksikan asam sinamat dan senyawa-senyawa alkohol telah dilakukan.Tujuan penelitian ini adalah untuk mengetahui kinerja katalis heterogen, nafion, sebagai katalis asam pada sintesis ester-ester sinamat dibandingkan dengan katalis homogen yang lazim digunakan yakni H2SO4 dan p-TsOH. Metode yang digunakan adalah reaksi esterifikasi Fischer yang berlangsung pada suhu 100 oC selama 18 sampai dengan 48 jam. Progres reaksi diikuti menggunakan TLC dan hasil-hasil reaksi dianalisis dengan 1H NMR.Hasil penelitian menunjukkan bahwa penggunaaan sikloheksanol sebagai pereaksi memberikan hasil yang sangat signifikan ketika menggunakan katalis homogen, baik itu H2SO4 maupun p-TsOH dimana lebih dari 85% produk diperoleh. Dengan menggunakan Nafion, sebagai katalis hanya 31% produk berhasil diperoleh apabila menggunakan kondisi yang sama dengan yang diterapkan saat menggunakan katalis homogen. Pada saat reaksi berlangsung lebih lama yaitu 48 jam hasil reaksi meningkat menjadi 78%. Hal yang menarik adalah ketika fenetil ester digunakan sebagai pereaksi menggantikan sikloheksanol, maka hasil yang diperoleh dari ketiga jenis katalis di atas 90%.Hal ini menunjukkan bahwa Nafion adalah katalis heterogen yang cukup menjanjikan untuk digunakan pada reaksi esterifikasi asam sinamat dan turunannya.
This research aimed to obtain ethanol from fermented palm sugar with high purity. There are two main techniques used in this study to increase the purity of alcohol, namely modified multilevel distillation and the use of molecular sieve as the principal dehydrator agent. The process carried out to produce ethanol uses a distillation and dehydration process, with raw materials fermented using Saccharomyces cerevisiae and traditional technology. At first, prepare two column reflux distillation apparatus had been designed and constructed successfully to prepare bio ethanol. The sugar content of palm sugar used was 12.4%. Bioethanol is produced from 10% inoculum concentration and variations in fermentation time of 12 hours, 24 hours 36 hours, and 48 hours at pH 5. The results of measurement using alcoholmeter, the highest alcohol concentration was obtained at the condition of 36 hours fermentation time by 9%. The distillation and dehydration process is carried out continuously at a distillation temperature of 79 °C with a mass of 20 gram molecular sieves. The results of measurement of alcoholmeter obtained bioethanol levels of 54%.
Pada penelitian analisis spektrum vibrasi dilakukan menggunakan spektroskopi infra merah pada rentang 500-4000 cm-1 untuk molekul karbamida. Struktur molekul, frekuensi vibrasi dasar dan intensitas dan intensitas pita vibrasi diinterpretasikan dengan bantuan optimasi struktur dan perhitungan medan gaya koordinat normal berdasarkan metode density functional theory (DFT). Penugasan getaran yang lengkap dari bilangan gelombang dibuat pada dasar distribusi energi potensial. Hasil B3LYP/6-31G skala memperlihatkan kesesuaian dengan nilai ekperimen.
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