Studi Awal Pembuatan Membran Chitosan-Silica Based dari Berbagai Limbah

Jember memiliki potensi perikanan terutama udang sebagai sumber kitin yang merupakan dasar pembuatan kitosan. Kitosan berasal dari limbah kulit udang yang dicampur dengan limbah lain yaitu padatan silika dari Pembangkit Listrik Panas Bumi dan fly ash dari Pembangkit Listrik Tenaga Uap untuk menghasilkan membran yang dapat digunakan dalam filtrasi logam berat dalam air. Membran tanpa silika dibuat sebagai negative control dan dengan silika murni sebagai positive control. Membran kitosan dibuat dengan cara mencampurkan 1,0 gram kitosan dalam 100 mL larutan asam asetat 2% v/v dan 0,8 gram senyawa silika serta 0,5 gram polyethylene glycol. Membran yang telah dibuat diuji untuk menyaring larutan yang mengandung logam berat Cu dan Pb. Konsentratsi optimum dari Cu dan Pb dalam badan cairan dapat dikurangi sebesar 87% dan 80% menggunakan membran kitosan-silika

A STUDY ON THE EFFECTIVENESS OF ANTIFUNGAL AGENTS ON COTTON FABRICS COLORED BY GAMBIR NATURAL DYES (UNCARIA GAMBIR)

The increasing interest in the use of natural dyes is not accompanied by sufficient information and method for the application due to broad natural dyes resources existence. Gambir (Uncaria gambir), one of promising favorable natural dyes, has been used as batik coloring for decades. However, the application of gambir extract as a textile colorant faces a severe problem to be encountered which is the microbial growth such as fungi, mold, and bacteria. This study proposed several antifungal agents to suppress the growth of the fungus such as chitosan, aloe vera, and formaldehyde. To conduct the fungus inhibition concentration of every antifungal agent, Aspergillus niger was introduced on the colored cloth medium with the addition of Potato Dextrose Broth (PDB) growth media. Three methods of antifungal addition during the coloring process were investigated namely pre-coloring, post-coloring, and mix coloring process. The growth of Aspergillus niger was observed and measured the diameter and thickness of the colony. One-way ANOVA was used to analyze the treatment significantly. The result showed that all concentration of chitosan and formaldehyde addition, significantly, could suppress the fungus growth. However, formaldehyde is a toxic ingredient and harmful to the environment which becomes a limitation in the application. Meanwhile, from the significance level, Aloe vera could not inhibit the Aspergillus niger growth with the addition of 2 and 5 g/L, but it could suppress the Aspergillus niger growth with the addition of 8 g/L. Furthermore, the optimum condition was observed on the addition of 5 g/L chitosan at post-coloring method because of the minimum growth area of the Aspergillus niger

Densification process of Merbau (Intsia bijuga) and Matoa (Pometia pinnata J.R. Forster & J.G Forster) Sawdust Waste for Biomass Based Solid Fuel Source in West Papua Indonesia: Optimization using Response Surface Methodology (RSM)

Merbau (Intsia bijuga) and matoa (Pometia pinnata J.R. Forster & J.G Forster) are two amongst many prominent biomass sources from West Papua, Indonesia. With their versatile characteristics, merbau and matoa wood are used in many industries such as furniture, music instrument, and many other specialty products. However, wood processing industries can emit up to 60% of the residue. In this study, the usage of both merbau and matoa sawdust wastes as solid fuel was studied using response surface methodology (RSM). merbau and matoa sawdust are sieved to get the desired particle size (-20+50 mesh). Two kinds of the sawdust are then mixed in various compositions (70, 50, and 30% merbau).  The mixed sawdust is then mixed with varied sticky starch solutions (1, 5, and 10%) to be formed in pellets with various moulding compression force (50, 100, and 150 kg/cm²). The pellets are then analyzed for its characteristics such as ash, moisture contents, and calorific value to be compared with its initial conditions. A full three-level factorial design under RSM was applied to explain the correlation between independent and dependent variables. The results show that statistically, merbau content, binder content, and compressive force showed relatively significant effects on the studied responses (ash content, moisture content, and calorific value). In addition, ANOVA analysis proved that each variable has significant effects on the responses that are confirmed by practically zero P-value. The coefficient of determinations (R²) are all above 0.96 and the normal probability plots confirm that the proposed models adequate the experimental results.Keywords: biomass waste; densification; merbau; matoa; RSM A B S T R A KMerbau (Intsia bijuga) dan matoa (Pometia pinnata Forster) adalah dua di antara sumber biomassa potensial yang berasal dari Papua Barat, Indonesia. Dengan karakteristiknya yang serbaguna, merbau dan matoa digunakan di banyak industri seperti furnitur, alat musik, dan banyak produk khusus lainnya. Namun, industri pengolahan kayu dapat menghasilkan hingga 60% residu. Di Pada penelitian ini, pemanfaatan limbah serbuk gergaji merbau dan matoa sebagai bahan bakar padat dipelajari dengan menggunakan response surface method (RSM). Serbuk gergaji merbau dan matoa diayak untuk mendapatkan ukuran partikel yang diinginkan (-20+50 mesh). Dua jenis serbuk gergaji kemudian dicampur dalam berbagai komposisi (70, 50, dan 30% merbau). Serbuk gergaji yang sudah tercampur kemudian dicampur dengan bahan perekat yang bervariasi larutan pati (1, 5, dan 10%) untuk dibentuk dalam pelet dengan berbagai gaya tekan cetakan (50, 100, dan 150 kg/cm²). Pelet kemudian dianalisis karakteristiknya seperti abu, kadar air, dan nilai kalor untuk dibandingkan dengan kondisi awalnya. Sebuah desain RSM tiga faktorial penuh diterapkan untuk menjelaskan korelasi antara variabel independen dan variabel terikat. Secara statistik, hasil penelitian menunjukkan bahwa kadar merbau, kadar pengikat, dan gaya tekan menunjukkan efek yang relatif signifikan pada respons yang dipelajari (abu kadar air, kadar air, dan nilai kalor). Selain itu, analisis ANOVA membuktikan bahwa masing-masing variabel memiliki efek signifikan pada tanggapan yang dikonfirmasi oleh nilai P yang mendekati nol. Koefisien determinasi (R²) seluruhnya berada di atas 0,96 dan grafik probabilitas normal mengonfirmasi bahwa model yang diusulkan cukup sesuai dengan hasil eksperimen.Kata kunci: limbah biomassa; densifikasi; merbau; matoa; RS

Bioethanol used as topical antiseptics: pretreatment optimization of bioethanol production from tobacco industrial waste

Bioethanol can be used for biosolvents and antiseptics material in the pharmaceutical industry. With the abundance of tobacco production in Jember, East Java, Indonesia, tobacco stalks become a promising biomass raw material for bioethanol. The purpose of this study was to determine the effect of temperature on the pretreatment process of bioethanol production. Settings and Design of this study using Conventional pretreatment with batch system. The materials used in this study include industrial tobacco waste, HCl, H2SO4, aquadest, filter paper, and aluminum foil. The pretreatment method used is chemical methods. The effect of pretreatment temperature was analyzed on the pretreatment process for the optimization of bioethanol production. Statistical analysis used a percentage frequency distribution. The test results of cellulose with H2SO4 solvents are 6.99 % at temperature 100 °C, 6.60 % at temperature 120 °C, and 4.47 % at temperature 140 °C. The test results of cellulose with HCl solvents are 6.00 % at temperature 100 °C, 6.23 % at temperature 120 °C, and 5.66 % at temperature 140 °C. Conclusions of this study, the optimum temperature in the pretreatment process with H2SO4 for the temperature range 100 °C to 140 °C is 100 °C, with the cellulose content produced as much as 6.99 %. The optimum temperature in the pretreatment process with HCl for the temperature range 100 °C to 140 °C is 120 °C, with the cellulose content produced as much as 6.23 %

Optimization Model on the Effect of Clove Oil, Formaldehyde, and Chitosan Added to Batik Fabric Colored with Gambier (<i>Uncaria gambir</i> Roxb): Antifungal Properties and Stability

Triggered by the concept of sustainability, the use of natural dyes in batik fabric processing has increased recently. To inhibit fungus growth on batik fabric colored with natural dyes, either clove oil or formaldehyde was added as an antifungal agent. To increase the stability of the interaction between the antifungal agent and the batik fabric, chitosan was used as a crosslinker. A modified version of the standard tests American Association of Textile Chemists and Colorists (AATCC) 30 and Response Surface Methodology (RSM) was applied as the characterization method. The results showed that the growth percentage of fungi in Batik treated with either clove oil or formaldehyde was much lower than that in the control sample. Growth of Aspergillus niger could be prevented by about 32% using clove oil and 94% using formaldehyde. The optimal condition was obtained with 1% chitosan as a crosslinking reagent, 15.91 ppm of formaldehyde, and 60-min immersion time, with absorbance intensity of formaldehyde crosslinking solution and fungus growth areas being 0.159 and 2.47%, respectively

Optimization of Microwave-Assisted Alkali Pretreatment for Enhancement of Delignification Process of Cocoa Pod Husk

In this study, the optimization of microwave-assisted alkaline (MAA) pretreatment is performed to attain the optimal operating parameters for the delignification of cocoa pod husk (CPH). The MAA performance was examined by heating the CPH solid with different particle sizes (60–120 mesh) and NaOH solution with a different sample to a solvent (SS) ratio (0.02–0.05 g/L), for short irradiation time (1–4 min). Box-Behnken Design (BBD) was utilized to optimize the percentage of lignocellulose composition changes. The results show that by enlarging particle size, the content of lignin and cellulose decreased while hemicellulose increased. By prolong irradiation time, the content of lignin and hemicellulose decreased while cellulose elevated. On the other hand, increasing the SS ratio was not significant for hemicellulose content changes. From FTIR and SEM characterization, the MAA drove the removal of lignin and hemicellulose of CPH and increased cellulose slightly. Supported by kinetic study which conducted in this work, it was exhibited that MAA pretreatment technology is an effective delignification method of CPH which can tackle the bottleneck of its commercial biofuel production. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).