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Journal : Journal of Green Science and Technology

Characterization of Coffee Business Waste in the form of Robusta Coffee Dregs as Adsorbent: A Preliminary Study Sihombing, Rony; Soeswanto, Bambang; Adhitasari, Alfiana; Yusuf, Yusmardhany; Putri, Alifhah Ananda; Fatah, Khalaida Fania; Clarisa, Shintiya; Gunawan, Sinna Chaerunnabila; Leoanggraini, Unung; Muhari, Emma Hermawati; Kurnia, Dianty Rosirda Dewi
Journal of Green Science and Technology Vol 9 No 1 (2025): Journal of Green Science and Technology Vol. 9 No. 1 March 2025
Publisher : Faculty of Engineering, Universitas Swadaya Gunung Jati

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33603/jgst.v9i1.9104

Abstract

Robusta coffee grounds are widely produced in several types of businesses, one of which is the coffee industry (coffee shop). This pulp can be reused by business people by being used as an adsorbent and paired with the industrial waste. The purpose of this research is to identify the carbon of Robusta coffee grounds between before and after chemical activation. The methods used were sieving, drying at 25°C to 110°C, carbonization at 600°C, immersion in 0.1M HCl solution. Carbonization of Robusta coffee grounds was carried out using BET, FTIR and SEM. The results showed an increase in carbon surface area from 0.588 m2/g to 14.609 m2/g. The results of the FTIR method showed a change in functional groups on several peaks between pre- and post-activation conditions. The results of the SEM method showed an increase in pore size from 5.5 µm (before activation) to 11 µm (after activation). Keywords: Robusta coffee, Coffee grounds, FTIR, Adsorbent
Enhancing Hard Anodization ff Aluminum 1100 using Variated Concentration and Aeration in 20% Sulfuric and Phosphoric Acid Electrolytes Leoanggraini, Unung; Yusuf, Yusmardhany; Nugraha, Ganjar; Samuel, Samuel; Sarip, Fahmi Haddad; Trirahayu, Dhyna Analyes; Sihombing, Rony
Journal of Green Science and Technology Vol 8 No 2 (2024): Journal of Green Science and Technology Vol.8 No.2 September 2024
Publisher : Faculty of Engineering, Universitas Swadaya Gunung Jati

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33603/jgst.v8i2.9424

Abstract

Aluminum is widely used in manufacturing, especially in automotive and aerospace, due to its light weight and easy form, although it is worn. The purpose of this research is to get the highest layer formation efficiency. During the application, hard anodizing creates a new layer in the form of a anatural protective layer on the metal surface. In hard anodized aluminum, the specimen sanded, degreasing with base, and acid neutralization. Then, hard anodizing is performed by connecting the workpiece to the positive pole and the cathode to the negative pole with a current density of 3A/dm² for 30 minutes in an electrolyte solution at a temperature of 5°C. The variations used are the mixture composition between sulfuric acid (concentration 15% - 20%) and low concentration phosphoric acid (0%, 1%, 2%, 3%, 4%, 5%) which are differentiated into aerated and non-aerated systems. Then weigh the anodized work piece to determine the weight gain of the metal due to the formed layer. The weight of the obtained layer is used to determine the efficiency of the formation of oxide layer.  The best layer formation efficiency is found in the sulfuric acid - phosphoric acid concentration variation (15% - 1%) in the aerated system at 73.47%. While the non aerated system at 73.28%. The aerated condition shows superior results compared to the non-aerated system, yielding better efficiency values than the non-aerated system.  Keywords: Aluminum 1100, Hard Anodizing, Mechanical Properties, Aeration, Electrolyte
The Effect of Variations in Sulfuric Acid - Oxalic Acid Electrolyte Concentration and Additional Aeration on 1100 Series Aluminum Anodization Results Leoanggraini, Unung; Irianto, Indra; Aji, Restu; Paramitha, Tifa; Sihombing, Rony
Journal of Green Science and Technology Vol 8 No 2 (2024): Journal of Green Science and Technology Vol.8 No.2 September 2024
Publisher : Faculty of Engineering, Universitas Swadaya Gunung Jati

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33603/jgst.v8i2.9425

Abstract

Aluminum is one of the materials used in making various types of goods because it has good properties such as being light, ductile and has good corrosion resistance. One of the disadvantages of aluminum is its low level of hardness. This can be overcome by treating aluminum, one of which is the anodization process. In this research, variations in the type of electrolyte used were sulfuric acid-oxalic acid, the electrolyte concentration was 16% with an interval of 0.5, the temperature used was room temperature with a current density of 3/dm2 and a coating time of 30 minutes. The aim of this research is to determine the acid concentration and the effect of the aeration system on mechanical properties. From the data obtained, it was found that the difference in weight of the best metal with the addition of aeration at a concentration of 13.5+2.5 was 0.0411 gr. This shows that as the concentration of oxalic acid increases it can accelerate the process of aluminum oxide formation, then for electrolyte concentrations of 16+0, 15.5+0.5, 15+1, 14.5+1.5 and 14+2 the difference in mass weight metals increased respectively by 0.0337 gr, 0.0335 gr, 0.0366 gr, 0.0390 and 0.0411 gr. In the anodization process without   additional aeration, the best metal weight difference is found at an electrolyte concentration of 13.5+2.5 of 0.0401 gr. This shows that increasing the concentration of oxalic acid can accelerate the process of aluminum oxide formation. Then at electrolyte concentrations of 16+0, 15.5+0.5, 15+1, 14.5+1.5 and 14+2 the difference in metal mass weight gradually increases by 0.0182 gr, 0.0293 gr, 0.0318 gr, 0.0322 and 0.0362 gr. Keywords: Aluminum, Anodization, Oxide Coating, Electrolyte Solution, Sulfuric Acid, Oxalic acid