Conversion of feather and blood from chicken slaughterhouse waste for producing solid and liquid organic fertilizer excluding composting process with a variation of the mass ratio of feather and blood of a chicken has been conducted. The nitrogen, sulfur, and iron content in the solid and liquid product of the hydrothermal carbonization process were analyzed to identify and characterize the possibility of hydrolysate as a source of nitrogen, sulfur, and iron in soil fertilizer. Feather and blood of chicken waste were introduced to a hydrothermal carbonization reactor with the addition of limestone at a temperature range of 160–170 °C for the preparation of solid and liquid organic fertilizer. According to the FTIR interpretation, the solid product had functional groups such as NH, OH, CH sp3, SH, C=O, C=C, C–O–C, and C–H aromatic. The nitrogen, sulfur, and iron content of the optimal ratio in the solid phase were 4.67%, 1.63%, and 3694.56 ppm, while their contents in the liquid fertilizer were 3.76%, 1.80%, and 221.56 ppm, respectively. The vibration of 478 cm–1 is attributed to Fe–O paramagnetic (Fe2O3) confirmed by TEM images showed the diameter size less than 20 nm indicating the presence of superparamagnetic material.

Abstrak: Teknik recovery emas (Au) yang berkembang bersifat berbahaya dan berdampak buruk terhadap lingkungan. Penelitian ini bertujuan untuk mensintesis adsorben ramah lingkungan termodifikasi secara kimia dengan asam sulfat dari kulit mangga. Adsorben hasil sintesis selanjutnya diaplikasikan sebagai adsorben selektif emas (Au) dalam larutan. Nilai kapasitas, konstanta laju dan energi adsorpsi ditentukan dengan uji kinetika adsorpsi. Sintesis adsorben dilakukan dengan modifikasi menggunakan H2SO4 dengan bahan dasar kulit mangga sehingga membentuk struktur taut ulang (cross-link). Produk sintesis dikarakterisasi menggunakan FTIR dan SEM sebelum maupun sesudah menyerap emas. Data kandungan emas setelah proses adsorpsi diukur dengan alat AAS. Spektra FTIR menunjukan keberhasilan sintesis adsorben kulit mangga termodifikasi asam sulfat dan interaksinya dengan emas (Au), yaitu pada bilangan gelombang 1118,71 cm -1 yang menunjukkan ikatan C-O-C linkage yang terjadi antar selulosa dan pelebaran pada 3433,29 cm -1 akibat interaksi antara gugus OH dan Au(III). Hasil SEM menunjukan perbedaan morfologi permukaan adsorben sebelum dan sesudah menyerap emas yang terjadi karena penutupan rongga adsorben akibat peristiwa adsorpsi-reduksi Au(III). Proses adsorpsi emas oleh adsorben yang disintesis mengikuti model kinetika orde dua semu (pseudo-2) dengan nilai kapasitas, konstanta laju, dan energi adsorpsi adalah 130 mmol kg -1 , 0,1137 mM -1 s -1 dan 5442,72 J mol -1 .Abstract: Gold (Au) recovery techniques that are commoly used were dangerous and have a negative impact on the environment. This study aims to synthesize eco-friendly adsorbent prepared from chemically modified with sulfuric acid from mango peel. The synthesized adsorbent was then applied as a selective absorbent for gold (Au) in solution. Capacity, rate constant and adsorption energy were determined by adsorption kinetics test. The synthetic of adsorbent was carried out by H2SO4 modification to form a cross-link structure with mango peel as a basic material. Synthesized products before and after adsorption are characterized by FTIR and SEM. Data on gold content after the adsorption process was measured by AAS. FTIR spectra showed the synthesis of sulfuric modified mango peel adsorbent at 1118,71 cm -1 that associated C-O-C linkage between cellulose was successful and its interaction with gold (Au) was showed at 3433,29 cm -1 broad band that associated the interaction of OH groups and Au(III). SEM image showed differences in the morphology of the adsorbent surface before and after adsorbing gold because the hole closed on adsorbent, it was caused by Au(III) adsorption-reduction. The adsorption process of gold by the adsorbent synthesized followed pseudo-second order kinetics (pseudo-2) with capacity values, rate constants, and adsorption energies were 130 mmol kg -1 , 0.1137 mM -1 s -1 and 5442.72 J mol -1 .

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The development of nanotechnology applications is rapidly growing in many sectors. One of them is silver nanoparticles (AgNPs) which are metal nanoparticles that play an important role, especially in nanomedicine. The most effective method of purifying to obtain stable AgNPs is very important to study. Experiments on the separation of AgNPs have been carried out using the size exclusion chromatography and centrifugation methods to see the effectiveness of refining the two methods. This experiment begins with the synthesis of AgNPs using the chemical reduction method. Then, the synthesized AgNPs were purified by Size Exclusion Chromatography (SEC) and centrifugation method then analyzed using UV-Vis spectrophotometer to determine the maximum peaks before and after purification. The experimental results were obtained that centrifugation methods and SEC having the same effectiveness in refining AgNPs. The centrifugation method at various speed (0, 3000, 6000, 9000, 12000 and 15000 rpm) gave wavelength results 403, 404, 404, 405, 404, and 404 nm. The SEC method using Sephadex-25 column showed the 4th to 8th fractions gave the maximum wavelength 404, 404, 404, 405, and 404 nm, respectively. The maximum wavelength of both methods showed the surface plasmon resonance characteristic of AgNPs. However, centrifugation at 3000 rpm has better homogeneity than SEC method.

Bifunctional catalysts are often used in multiple reactions to synthesize certain products. The catalytic activity of bifunctional catalysts is influenced by parameters such as crystallinity, specific surface area, metal distribution, and morphology. Bifunctional catalysts are manufactured by adding metal to the support. The metal loading to the support often affects these parameters. Therefore, this research was conducted to determine the effect of CuO, MgO, and ZrO2 addition to HZSM5 on these parameters. The often-used loading method was deposition precipitation. The pH of the metal-support precursors' solution was increased to basic (pH of 8) to deposit the metal on the support. The loading effect was investigated by producing the following materials: CuO/HZSM5, CuO/ZrO2/HZSM5, CuO/MgO/HZSM5, and CuO/MgO/ZrO2/HZSM5. Each material was characterized using XRD, SAA, SEM, Mapping, EDS, and XRF. The results showed that all metal oxides could be embedded in the HZSM5. The loading of CuO, MgO, and ZrO2 to HZSM5 did not affect the crystallinity (structure) and morphology, increased the specific surface area, and was evenly distributed inside the pore of HZSM5. Further research is needed to determine the effect of crystallinity, specific surface area, and morphology on other metals and support types.