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Kinetics and Thermodynamics Study of Ultrasound-Assisted Depolymerization of k-Carrageenan in Acidic Solution Ratnawati Ratnawati; Nita Indriyani
Bulletin of Chemical Reaction Engineering & Catalysis 2020: BCREC Volume 15 Issue 1 Year 2020 (April 2020)
Publisher : Department of Chemical Engineering - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.15.1.6738.280-289

K-carrageenan is a natural polymer with high molecular weight ranging from 100 to 1000 kDa. The oligocarrageenan with low molecular weight is widely used in biomedical application. The aim of this work was to depolymerize k-carrageenan in an acidic solution with the assistance of ultrasound irradiation. The ultrasonication was conducted at various pH (3 and 6), temperatures (30-60 °C), and depolymerization time (0-24 minutes). The results show that the depolymerization reaction follows pseudo-first-order kinetic model with reaction rate constant of 1.856×10-7 to 2.138×10-6 s-1. The reaction rate constant increases at higher temperature and lower pH. The Q10-temperature coefficients of the depolymerization are 1.25 and 1.51 for pH 6 and 3, respectively. The enthalpy of activation (ΔH‡) and the Gibbs energy of activation (ΔG‡) are positive, while the entropy of activation (ΔS‡) is negative, indicating that the activation step of the ultrasound-assisted depolymerization of k-carrageenan is endothermic, non-spontaneous, and the molecules at the transition state is more ordered than at the ground state. The ΔH‡ and the ΔS‡ are not affected by temperature, while the ΔG‡ is a weak function of temperature. The ΔH‡ and ΔS‡ become smaller at higher pH, while the ΔG‡ increases with the increase of pH. The kinetics and thermodynamics analysis show that the ultrasound-assisted depolymerization of k-carrageenan in acidic solution is possibly through three mechanisms, i.e. bond cleavage due to cavitational effect of microbubbles, hydroxyl radical and hydrogen peroxide, as well as proton. Copyright © 2020 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).

Pemanfaatan Kotoran Ternak Sebagai Biogas Dan Pupuk Organik Di Desa Klasmelek Nita Indriyani; Suhria Heremba; Ivan Agustian; Muhammad Salim; Sohibul Ma’arif; Ira Resky; Tiurma Panjaitan
Jurnal Abdimasa Pengabdian Masyarakat Vol 5 No 1 (2022): Jurnal ABDIMASA Pengabdian Masyarakat
Publisher : Universitas Pendidikan Muhammadiyah Sorong

Show Abstract | Download Original | Original Source | Check in Google Scholar

Masyarakat Kampung Klasmelek termasuk golongan ekonomi menengah ke bawah. Kebanyakan dari mereka hanya menjadi ibu rumah tangga. Dengan memberikan pelatihan melalui program yang dilaksanakan, diharapkan dapat memberikan kegiatan positif dan bermanfaat kepada ibu-ibu Rumah Tangga di Kampung Klasmelek. Sumber lain yang dapat diberdayakan atau dikembangkan lagi adalah pengolahan jerami yang dapat dijadikan silase sebagai pakan ternak dan pemanfaatan kotoran hewan yang dapat dijadikan biogas. Salah satu sumber energi alternatif yang diterapkan di Kampung Klasmelek adalah biogas. Biogas ini berasal dari berbagai macam limbah organik seperti sampah biomassa, kotoran manusia dan kotoran hewan yang dapat dimanfaatkan menjadi energi. Limbah biogas ini sudah langsung bisa digunakan sebagai pupuk oleh karena kandungan gasnya sudah dikeluarkan, sehingga pada saat diaplikasikan pada tanaman dia sudah layak menjadi pupuk organik (tidak panas lagi). Manfaat penerapan teknologi sumber daya bagi masyarakat adalah kotoran hewan ternak tidak lagi berceceran di sepanjang jalan karena dapat dimanfaatkan menjadi biogas bahkan limbah dari pembuatan biogas (Bio Slurry) sendiri dapat dimanfaatkan kembali menjadi pupuk organik, serta dapat membantu menyuburkan lahan pertanian Klasmelek

Pemberdayaan Kelompok Peternak Kabupaten Sorong Dalam Pembuatan Silase dan Pemanfaatan Kotoran Sapi nita indriyani
Jurnal Abdimasa Pengabdian Masyarakat Vol 5 No 2 (2022): Jurnal ABDIMASA Pengabdian Masyarakat
Publisher : Universitas Pendidikan Muhammadiyah Sorong

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36232/jurnalabdimasa.v5i2.2463

Sebagian besar masyarakat Kabupaten Sorong yang beternak sapi memiliki kebiasan menggembalakan ternak secara liar. Masyarakat belum menyadari secara penuh akan tertib ternak. Kebiasaan masyarakat setempat menganggap bahwa ternak hanya dilepas liar, sehingga dapat mengakibatkan berbagai masalah diantaranya mengganggu kelancaran lalu lintas yang dapat menimbulkan kecelakaan, mengganggu atau merusak barang milik orang lain, menimbulkan pencemaran, dan merusak keindahan dan kebersihan Kabupaten Sorong. Kegiatan pengabdian yang dilakukan tim FST UNIMUDA Sorong di Kabupaten Sorong ini mengenalkan dan mensosialisasikan penerapan teknologi sederhana kepada masyarakat. Kotoran sapi yang selama ini diabaikan oleh masyarakat dapat dimanfaatkan secara optimal sebagai biogas dan pupuk cair. Selain itu, ketidaktahuan masyarakat akan pembuatan pakan ternak berupa silase dapat tersampaikan dengan baik. Silase adalah hijauan ternak yang diawetkan yang disimpan dalam kantong plastik yang kedap udara atau silo, drum, dan sudah terjadi proses fermentasi dalam keadaan tanpa udara atau anaerob. Sisa pembuatan biogas (sludge) dapat dibuat menjadi pupuk organik. Pembuatan biogas akan menghasilkan gas (produk utama) dan lumpur bahan organik (produk samping).

Ultrasonic-Assisted Flavonoid Extraction from Ant Nest Nita Indriyani; Yusnita La Goa; Muthmainnah Ely; Elton Mendy
CHEESA: Chemical Engineering Research Articles Vol 5, No 2 (2022)
Publisher : Universitas PGRI Madiun

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25273/cheesa.v5i2.12231.59-64

The extraction of active substances from ant nests can be affected by various extraction methods, whether conventional or sonication. Sample extraction was carried out by maceration and ultrasonic methods with the use of solvents to yield flavonoid compounds. The solvents used were aquadest, 70% ethanol and n-hexane, with a material-to-solvent ratio of 1:50 (w/v). The highest flavonoid content of 14% was obtained by ultrasonic-assisted extraction method, with aquadest as the solvent and at operating conditions of 24 minutes at a temperature of 40oC. Due to their high aquadest solubility and the presence of one or more sulphate ions that are bound to the hydroxyl phenol or sugar, the flavonoids produced are classified as flavonoid sulphate.

Kinetics and Thermodynamics Study of Ultrasound-Assisted Depolymerization of k-Carrageenan in Acidic Solution Ratnawati Ratnawati; Nita Indriyani
Bulletin of Chemical Reaction Engineering & Catalysis 2020: BCREC Volume 15 Issue 1 Year 2020 (April 2020)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.15.1.6738.280-289

K-carrageenan is a natural polymer with high molecular weight ranging from 100 to 1000 kDa. The oligocarrageenan with low molecular weight is widely used in biomedical application. The aim of this work was to depolymerize k-carrageenan in an acidic solution with the assistance of ultrasound irradiation. The ultrasonication was conducted at various pH (3 and 6), temperatures (30-60 °C), and depolymerization time (0-24 minutes). The results show that the depolymerization reaction follows pseudo-first-order kinetic model with reaction rate constant of 1.856×10-7 to 2.138×10-6 s-1. The reaction rate constant increases at higher temperature and lower pH. The Q10-temperature coefficients of the depolymerization are 1.25 and 1.51 for pH 6 and 3, respectively. The enthalpy of activation (ΔH‡) and the Gibbs energy of activation (ΔG‡) are positive, while the entropy of activation (ΔS‡) is negative, indicating that the activation step of the ultrasound-assisted depolymerization of k-carrageenan is endothermic, non-spontaneous, and the molecules at the transition state is more ordered than at the ground state. The ΔH‡ and the ΔS‡ are not affected by temperature, while the ΔG‡ is a weak function of temperature. The ΔH‡ and ΔS‡ become smaller at higher pH, while the ΔG‡ increases with the increase of pH. The kinetics and thermodynamics analysis show that the ultrasound-assisted depolymerization of k-carrageenan in acidic solution is possibly through three mechanisms, i.e. bond cleavage due to cavitational effect of microbubbles, hydroxyl radical and hydrogen peroxide, as well as proton. Copyright © 2020 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).

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