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Column Study and Desorption Performance of Coffee Biomass-Calcium-Alginate Beads to Remove Pb²⁺ Ions from Aqueous Solutions Hanifah, Sarina; Rusnadi, Rusnadi; Stiawan, Elva; Widianti, Riskia Chandra
Jurnal Riset Sains dan Kimia Terapan Vol. 11 No. 1 (2025): Jurnal Riset Sains dan Kimia Terapan, Volume 11 Nomor 1, Juni 2025
Publisher : Program Studi Kimia Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/JRSKT.111.01

Abstract

Heavy metal pollution, particularly by lead (Pb²⁺), poses a serious environmental threat and can significantly impact human health. This study aims to evaluate the performance of an adsorbent composed of a mixture of coffee waste and calcium alginate (Coffee-Calcium-Alginate/CCA beads) in removing Pb²⁺ ions through column experiments, as well as to assess the desorption efficiency and reusability of the adsorbent. Column studies were conducted at 1 ppm Pb2+ ions initial concentration, a flow rate of 2.2 mL/min, using a column with a length of 10 cm and a diameter of 7 mm to determine the breakthrough time of the adsorbate, while desorption was performed using HNO₃ to evaluate the efficiency of Pb²⁺ ions release and the potential for adsorbent reuse. The results demonstrated that the CCA adsorbent was able to retain high efficiency over two adsorption–desorption cycles, with desorption efficiencies of 96.35% and 86.64%. The desorption mechanism involves protonation of carboxylate groups and competition between H⁺ and Pb²⁺ ions at the active sites. Overall, CCA beads exhibit promising potential as an effective and reusable adsorbent for treating water contaminated with heavy metals. Future research could explore the effects of varying initial Pb²⁺ ions concentrations and column height to gain a more comprehensive understanding of desorption dynamics within the column system. Keywords: adsorption, coffee biomass, calcium alginate, Pb2+, leads
Isa Al-Masih 'inda Al-Qadiyaniyat: Dirasat Tahliliyat Naqdiyat Rusnadi, Rusnadi
Hanifiya: Jurnal Studi Agama-Agama Vol. 2 No. 2 (2019): Hanifiya: Jurnal Studi Agama-Agama
Publisher : Program Studi Studi Agama-Agama Pascasarjana UIN Sunan Gunung Djati Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15575/hanifiya.v2i2.6673

Abstract

This paper aims to conduct a study of Isa al Masih in the view of al-Qadiyaniah. Islam believes that the prophet Isa al-Masih was appointed by Allah to rise from the pursuit of the Jews who wanted to crucify and kill him and then be lowered at the end of time. This belief is opposed by followers of al-Qodiyaniyah, they consider that the belief of Muslims and Christians is a distorted belief. Al-Qodiyaniah believes that Isa al-Masih did not die and was not taken up to heaven. This study is using a library research method with a qualitative approach. Research results show that Jesus was crucified and did not die on the cross, but Isa al-Masih was lowered from the cross and then migrated to Kasymir until his death and was buried there. And as for the purpose of the appointment of Jesus according to Qodiyaniyah is the departure of Jesus to Kasymir after being crucified, and another purpose of the appointment of Jesus is to elevate the degree and praise for Jesus, not appointed his body. as well as the purpose of the fall of Jesus for the second time is the rise of Islam and Mirza Ghulam Ahmad is a person who is trying to revive that religion of Islam. And among al-Qodiyaniyah's beliefs is that Mirza Ghulam Ahmad is as Isa al-Masih and also as Imam al-Mahdi in one body.
The Ce3+ Metal Ion Adsorbent Based on Calcium Alginate Loaded Fe3O4 (Ca-Alg/Fe3O4) Haili, Hulqi Mila; Rusnadi; Yulianti, Silmi Nur'asni
International Journal of Applied Research and Sustainable Sciences Vol. 1 No. 4 (2023): December 2023
Publisher : MultiTech Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59890/ijarss.v1i4.1094

Abstract

Rare earth metal frequently utilized in technological advancements is cerium. The high utilization of cerium correlates with the depletion of primary REEs reserves and the accumulation of secondary materials that can enter aquatic environments. Recycling and recovery of REEs through methods such as solvent extraction, filtration, and adsorption are commonly employed. Adsorption is chosen due to the abundance of adsorbent materials in nature, simple fabrication, efficiency, and cost-effectiveness. Calcium alginate biosorbent loaded with magnetite (Ca-Alg/Fe3O4) has been used to adsorb (Ce3+)aq, with optimal conditions achieved at Ca-alginate:Fe3O4 ratio of 2:1 (w/w), 0.075 g, pH 4, a contact time of 210 minutes, and 250 ppm, [Ce3+]0. The adsorption process follows the Langmuir isotherm model with qmax at 50.505 mg/g. Hence, the Ca-Alg/Fe3O4 biosorbent shows potential in adsorbing (Ce3+)aq.
Wild Cats Diversity and Activity Patterns in Bukit Baka Bukit Raya National Park, Kalimantan, Indonesia Persada Agussetia Sitepu; Juliarta Bramansa Ottay; Gusti Wicaksono; Rusnadi; Firasadi Nursub’i; Risky Ananda Kurniawan; Utin Riesna Afrianti; Tomi Ariyanto
Journal of Tropical Biodiversity Vol 6 No 1 (2025): December 2025
Publisher : Universitas Nasional Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59689/bio.v6i1.328

Abstract

Kalimantan is home to five species of wild cats, but scientific information about them is still limited. This study aims to examine the biodiversity, spatial distribution, relative abundance, activity patterns, and occupancy rate of wild cats in the Belaban Resort, Bukit Baka Bukit Raya National Park (BBBR NP). Data collection was conducted from March 2024 to August 2025 at 25 camera trap (CT) stations, which were operated for a total 6.756 trap-nights. The analysis includes calculation of the relative abundance index, occupancy, distribution, and activity patterns. A total 45 independent events of wild cats from three species were recorded, namely the sunda clouded leopard, leopard cat and marbled cat. The leopard cat has the highest relative abundance (5,01 events per 100 trap-nights). The sunda clouded leopard showed the highest occupancy probability (ψ = 0,794), while the marbled cat had the lowest abundance and occupancy. The spatial distribution showed that 60% of the camera stations recorded at least one species of wild cat, with two stations at elevation of 520-762 meters above the sea level recording to the highest detections, in line with the high presence of potential prey. There findings underscore the importance of maintaining forest cover, increasing area patrols, and involving the community in controlling hunting and encroachment as part of area management planning. Overall, the results of this study provide a scientific basis for the implementation of adaptive conservation and the strengthening of management strategies to ensure the sustainability of wild cat populations in the Belaban Resort, BBBR NP
Utilization of Freeze-Dried κ-Carrageenan for Methylene Blue Adsorption Iqbal, Muhammad; Prihadi, Az Zahra Utami; Theresia, Claresta Hara; Wahyuni, Sri; Triadhi, Untung; Aryana, Nurhani; Rusnadi, Rusnadi
Jurnal Kartika Kimia Vol 8 No 2 (2025): Jurnal Kartika Kimia (In Progress)
Publisher : Department of Chemistry, Faculty of Sciences and Informatics, University of Jenderal Achmad Yani

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26874/jkk.v8i2.992

Abstract

Methylene blue contamination in aquatic environments has become a global issue due to its widespread use in various industries. Methylene blue is a toxic, carcinogenic, and non-biodegradable dye. Adsorption can be employed as one method to mitigate this problem. The use of κ-carrageenan as an adsorbent offers an effective solution because κ-carrageenan is an abundant, easily obtainable, and economical biopolymer with promising adsorption performance. In this study, κ-carrageenan was cross-linked with K+ to form a hydrogel, which was then freeze-dried to produce a macroporous κ-carrageenan adsorbent. Characterization using FTIR confirmed the successful preparation of the adsorbent and the adsorption of methylene blue. SEM images showed changes in surface morphology, indicating successful adsorption. The adsorption process was optimum at pH 5, an adsorbent mass of 0.1 gram, and a contact time of 3 hours. Adsorption followed a pseudo-second-order kinetic model and the Langmuir isotherm model, with a maximum adsorption capacity, qmax of 128.7 mg/g at 328 K. Thermodynamic studies showed that the process was exothermic, became more disorder as a result of an increase in entropy, and occurred spontaneously. These results demonstrate that freeze-dried κ-carrageenan adsorbent has the potential for development in sustainable wastewater treatment technology.
KARAKTERISASI TERMOGRAVIMETRI DAN METRIK MUTU BAHAN BAKAR BRIKET BATOK KELAPA–KAYU TEMBESU Adi, Wily Priya; Intang, Ambo; Ilmi, Bahrul; Junita, Boni; Rusnadi, Rusnadi
TEKNIKA: Jurnal Teknik Vol 12 No 2 (2025)
Publisher : Universitas IBA Palembang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35449/teknika.v12i2.390

Abstract

Briket bioenergi dari batok kelapa dan kayu tembesu dikarakterisasi untuk memandu pemilihan komposisi pada aplikasi konversi termokimia. Analisis proksimat (kadar air, zat terbang, abu, fixed carbon) dan ultimat (C–H–N) dilakukan mengikuti ASTM D7582 dan ASTM D5373. Termogravimetri (TGA) melengkapi dengan memetakan tahapan kehilangan massa dan residu abu. Pada lima komposisi (90:10 hingga 10:90, batok:tembesu, interval antar komposisi adalah perubahan 20% untuk setiap komponen), kenaikan tembesu secara sistematis menurunkan kadar karbon (68 - 57 wt%) dan fixed carbon (60 - 49 wt%) serta sedikit menaikkan hidrogen (4,2 - 5,5 wt%). Kurva TGA menunjukkan pengeringan awal di bawah ~400 K, devolatilisasi dan reaksi arang dominan pada ~600–1000 K, serta residu stabil yang setara 3 – 3,5 wt% abu. Campuran 90:10 memberikan metrik mutu paling unggul, mengindikasikan densitas energi dan hasil arang yang lebih baik dibanding campuran dengan tembesu lebih tinggi. Hasil ini memberi dasar empiris untuk pemilihan bahan bakar dan penetapan set-point reaktor (jendela pengeringan/devolatilisasi) pada gasifier skala kecil dan combustor unggun tetap. Kata kunci : briket, batok kelapa, kayu tembesu, karakterisasi, mutu bahan bakar.
BINDER‑DRIVEN TRADE‑OFFS PADA BRIKET ARANG TEMPURUNG KELAPA: KERANGKA ISOKONVERSI TERMOGRAVIMETRI DENGAN PATI TAPIOKA (15–20 WT%) Hasyemi, A. Ghalib; Intang, Ambo; Ilmi, Bahrul; Junita, Boni; Rusnadi, Rusnadi
TEKNIKA: Jurnal Teknik Vol 12 No 2 (2025)
Publisher : Universitas IBA Palembang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35449/teknika.v12i2.392

Abstract

Pemilihan perekat pada briket arang mengendalikan integritas mekanik sekaligus perilaku termokimia. Tujuan penelitian ini adalah untuk mengkaji pengaruh variasi perekat pati tapioka (15 dan 20 wt%) terhadap perilaku dekomposisi termokimia briket arang tempurung kelapa. Briket dievaluasi menggunakan pencatatan kehilangan massa terhadap waktu serta analisis turunan sesuai praktik termogravimetri (TG/DTG). Profil pemanasan non‑linier menuntut perbandingan berbasis waktu dan derajat konversi: metrik yang dihitung mencakup α(t), laju incremental dα/dt, metrik waktu menuju konversi tα​ (α=0,10–0,90), serta residu akhir. Hasil menunjukkan konversi lebih dini dan lebih cepat pada beberapa tahap untuk perekat 20% (mis., t0.1​: 62,05 menit vs 101,35 menit; t0.9​: 220,10 vs 245,57 menit), dengan puncak DTG sekitar t≈200 menit. Namun, residu meningkat tajam dari ~5,85% (15%) menjadi ~17,80% (20%), yang mengindikasikan pembentukan arang dan/atau re‑polimerisasi tar yang lebih kuat. Studi ini turut mengartikulasikan kerangka pelaporan agar dataset multi‑β (≥3 laju pemanasan linier) berikutnya dapat menghasilkan energi aktivasi isokonversi Ea​(α) melalui FWO/KAS. Secara praktis, kisaran perekat menengah (≈10–15%) tampil sebagai titik awal rasional untuk menyeimbangkan kekuatan, kinetika konversi, dan residu. Studi ini memperkaya sains formulasi briket dengan metrik reprodusibel berdimensi‑nol dan translasi rekayasa yang jelas ke desain reaktor dan kendali mutu. Kata kunci : arang tempurung kelapa, pati tapioca, briket, termogravimetri, energi aktivasi
PENGARUH KADAR PEREKAT TAPIOKA TERHADAP SIFAT FISIKO‑KIMIA DAN KINETIKA PEMBAKARAN SEMU BRIKET ARANG SEKAM PADI Riwansyah, M. Fadly; Intang, Ambo; Ilmi, Bahrul; Junita, Boni; Rusnadi, Rusnadi
TEKNIKA: Jurnal Teknik Vol 12 No 2 (2025)
Publisher : Universitas IBA Palembang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35449/teknika.v12i2.389

Abstract

Studi ini memetakan pengaruh kadar perekat tapioka (15, 20, 25, 30, dan 35 % massa terhadap arang sekam padi) terhadap sifat fisiko‑kimia briket serta parameter reaktivitas berupa konstanta laju semu kapp dari analisis termogravimetri (TGA). Analisis proksimat (ASTM D7582) dan analisis ultimate CHN (ASTM D5373) dilakukan pada sampel yang digiling. Hasil menunjukkan kadar air dan zat terbang meningkat dengan penambahan perekat, sedangkan karbon tetap menurun hampir linear. Nilai kapp per komposisi diturunkan dari rerata plateau kuasi‑mantap pada jejak laju isothermal. Regresi linear memperlihatkan korelasi negatif yang signifikan secara statistik antara kadar perekat dan kapp. Untuk menilai kestabilan proses, disusun pula Individuals (I) dan Moving Range (MR) chart untuk k_app pada seluruh kadar perekat yang diuji. Integrasi temuan ini mengarah pada rekomendasi awal kadar perekat 15–20 %, yang menjaga reaktivitas pada tingkat yang dapat diterima sekaligus membatasi pengenceran karbon tetap. Optimalisasi lanjutan perlu memasukkan integritas mekanik dan nilai kalor. Korelasi dan chart yang disajikan dapat berfungsi sebagai alat siap‑pakai untuk pengendalian proses dan spesifikasi produk briket biomassa. Kata kunci : briket arang sekam padi, perekat tapioka, konstanta laju semu kappk, TGA isothermal