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Potensi Polisakarida dari Limbah Buah-buahan sebagai Koagulan Alami dalam Pengolahan Air dan Limbah Cair: Review Hans Kristianto; Angelica Jennifer; Asaf Kleopas Sugih; Susiana Prasetyo
Jurnal Rekayasa Proses Vol 14, No 2 (2020)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.57798

Nowadays, various studies related to utilization of biobased materials as natural coagulants have been explored. Based on the source, natural coagulants can be classified as animal, vegetable, or microbial based. Furthermore, based on the active ingredients, it can be classified as protein, polyphenols, and polysaccharides. Polysaccharides are abundant natural ingredients and are often found in plants or animals. In this study, we focused on polysaccharides, especially those from fruit waste, such as seeds and fruit peels. It is known that around 25-30% of the total weight of fruit is generally wasted, even though it contains phytochemicals and various active ingredients that can be utilized, especially as a natural coagulant. This review will focus on the use of pectin and starch from fruit waste as natural coagulants for water- wastewater treatment. Generally, pectin is commonly found in the skin of fruits as part of the cell wall structure, while starch is found in fruit seeds as food reserves. To be used as a natural coagulant, pectin or starch need to be extracted first. In particular, starch needs to be modified either physically or chemically. The coagulation mechanism of pectin and starch usually follows the interparticle bridging mechanism. The use of pectin and starch from fruit waste needs to be explored and further investigated, to substitute the use of chemical coagulants.Keywords: coagulation; fruit waste; natural coagulant; polysaccharidesA B S T R A KDewasa ini berbagai studi terkait pemanfaatan bahan alam sebagai koagulan alami telah banyak dieksplorasi. Berdasarkan sumbernya, koagulan alami dapat digolongkan berbasis hewani, nabati, maupun mikrobial, sementara berdasarkan bahan aktifnya dapat digolongkan sebagai protein, polifenol, dan polisakarida. Polisakarida merupakan bahan alam yang berlimpah dan seringkali dijumpai pada tumbuh-tumbuhan dan hewan. Pada kajian ini difokuskan pada polisakarida terutama yang berasal dari limbah buah-buahan yang tidak termanfaatkan, seperti biji dan kulit buah. Diketahui sekitar 25-30% dari total berat buah pada umumnya terbuang, padahal memiliki kandungan fitokimia dan berbagai bahan aktif yang dapat dimanfaatkan, salah satunya sebagai koagulan alami. Pada tinjauan ini akan difokuskan pada pemanfaatan pektin dan pati dari limbah buah-buahan sebagai koagulan alami untuk pengolahan air dan limbah cair. Secara umum pektin umum dijumpai pada bagian kulit buah-buahan sebagai bagian dari struktur dinding sel, sementara pati umum dijumpai pada biji buah-buahan sebagai cadangan makanan. Untuk dapat dimanfaatkan sebagai koagulan alami, pektin ataupun pati perlu diekstrak terlebih dahulu, dan pati secara khusus perlu dimodifikasi baik secara fisika maupun kimia. Secara umum mekanisme koagulasi oleh pektin dan pati mengikuti mekanisme interparticle bridging. Pemanfaatan pektin dan pati dari limbah buah-buahan perlu dieksplorasi dan diteliti lebih lanjut, agar dapat mensubstitusi penggunaan koagulan kimia secara komersial.Kata kunci: koagulasi; koagulan alami; limbah buah-buahan; polisakarida

Adsorption of Ni(II) Ion onto Calcined Eggshells: A Study of Equilibrium Adsorption Isotherm Hans Kristianto; Novitri Daulay; Arenst Andreas Arie
Indonesian Journal of Chemistry Vol 19, No 1 (2019)
Publisher : Universitas Gadjah Mada

Adsorption is one of the most effective and economical method to treat heavy metals in water. In this study, we utilize waste chicken eggshells as biosorbent to adsorb Ni(II). Furthermore we study the effect of eggshell calcination on its adsorption performance. The effect of calcination on the characteristic of eggshell was observed using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope-Energy Dispersive X-ray Spectroscopy (SEM-EDS). It could be observed that CaCO3 in eggshell was converted into CaO, and from SEM images the calcined eggshell became more porous than the uncalcined one. The effect of various parameters such as initial Ni(II) solution pH and initial Ni(II) concentration was investigated using batch adsorption experiments. The data obtained then fitted to Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherms. The best pH for Ni(II) adsorption was found to be 6. From Langmuir and Dubinin-Radushkevich, it was found that calcined eggshells gave 60 times higher maximum adsorption capacity then uncalcined one. This increase was possible due to more porous structure of calcined eggshells. The adsorption process was found to be exothermic and physisorption. This result was confirmed by the decrease of % removal with increase of temperature. Furthermore, Langmuir isotherm was found to be the best model, indicating adsorption of Ni(II) was monolayer adsorption on homogenous surface.

The Utilization of Pectin as Natural Coagulant-Aid in Congo Red Dye Removal Felicia M K Haryanto; Andranyssa V M Rumondor; Hans Kristianto; Susiana Prasetyo; Asaf K Sugih
Journal of Multidisciplinary Applied Natural Science Vol. 4 No. 1 (2024): Journal of Multidisciplinary Applied Natural Science
Publisher : Pandawa Institute

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.47352/jmans.2774-3047.179

Coagulation using inorganic compounds such as aluminum sulfate is commonly used in water-wastewater treatment. However, there are some drawbacks to its utilization, such as a significant decrease in the treated water’s pH, non-biodegradable sludge, and a potential negative impact on human mental health (dementia and Alzheimer's). The use of inorganic coagulants can be minimized with the addition of natural-based coagulant-aid such as pectin. In this study, Congo red solution, a model dye substance, was coagulated by varying the pH (3–7) using alum coagulant to determine the best pH for coagulation. At the best pH, pectin was introduced at various doses (0–30 mg/L), and subsequently various dye concentrations (50–100 mg/L). The effect of pectin as coagulant-aid was compared with aluminum sulfate and pectin only; with a response of %removal and sludge volume. It was found that the Congo red dye coagulation had the best %removal at pH 6 indicating a charge neutralization mechanism. The addition of 15 mg/L pectin at an aluminum sulfate dose of 30 mg/L resulted in 97.7% dye removal with a sludge volume of 14 mL/L at a Congo red concentration of 50 mg/L. This value is higher compared to those of aluminum sulfate and pectin only which gave 75.6 and 3.19% removals, respectively. Furthermore, the addition of pectin as a natural coagulant-aid could halve the sludge volume due to the formation of denser flocs. The results show a promising potential of pectin as a natural coagulant-aid in water-wastewater treatment.

Synthesis and Electrochemical Properties of SnO2 Composited Activated Carbon from Coffee Ground Waste for Supercapacitor Applications Agung Nugroho; Muhammad Reza Wirayudha Pratama; Hans Kristianto; Haryo Satriya Oktaviano; Arenst Andreas Arie; Ratna Frida Susanti
Jurnal Kimia Sains dan Aplikasi Vol 26, No 8 (2023): Volume 26 Issue 8 Year 2023
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jksa.26.8.293-299

Biomass has been considered an alternative source of electrode materials. Converting biomass into activated carbon is one of the possible approaches. Coffee ground waste is abundant as the world’s coffee-drinking culture grows. This paper describes a study that converted coffee grounds into activated carbon and tested its feasibility for electrode materials. We use a simple pyrolysis technique (800°C) to synthesize activated carbon from waste coffee grounds, with potassium hydroxide (KOH) as an activator. Tin oxide (SnO2), which has a high theoretical capacity, was impregnated into the carbon framework using a hydrothermal method operating at 180°C for 2 hours. The X-ray diffraction (XRD) pattern and Fourier transform infrared spectroscopy (FTIR) results show that SnO2 was successfully impregnated into the carbon structure. Raman analysis also shows that the carbon structure of the activated carbon still retains despite the presence of the metal oxide during the hydrothermal synthesis. Furthermore, electrochemical measurements utilizing the galvanostatic method using a three-electrode system demonstrated that the specific capacitance of the material increased by approximately 106% at 5 A/g following SnO2 impregnation. Long cycle testing further demonstrates that including SnO2 in the carbon, structure may sustain outstanding performance even at high current densities of 5 A/g for 100 cycles with 99% capacity retention. The results demonstrate the possibility of activated carbon from coffee ground waste composited with tin oxide as supercapacitor electrodes.

Carbon composite of NiO hydrothermal impregnation from sugarcane bagasse and its electrochemical properties Nasti, Al Nadine De; Siburian, Kyfti Yolanda; Sembiring, Abraham Danofan; Kristianto, Hans; Susanti, Ratna Frida; Oktaviano, Haryo Satriya; Nugroho, Agung
Jurnal Rekayasa Proses Vol 17, No 2 (2023)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.88210

Sugarcane bagasse (SB) can synthesize activated carbon (AC) through a two-step calcination process at calcination at 400oC and activation at 800oC. NaOH 0.1 M is used to activate the pre-carbonized sample in the activation step. The AC samples undergo hydrothermal impregnation with nickel oxide (NiO) at 110°C. The X-ray diffraction (XRD) pattern and Energy dispersive X-ray spectroscopy (EDX) confirmed the presence of NiO after this process. Scanning Electron Microscope (SEM) indicates the presence of pore structures in the sample morphology. A three-electrode system with 1 M Na2SO4 as an electrolyte was employed to assess the electrochemical properties. The specific capacitance for activated carbon derived from SB stands at 89.53 F/g at 0.05 A/g current density, while after impregnation with NiO, it increases to 250.53 F/g at the same current density. The results demonstrate the possibility of activated carbon from sugarcane bagasse waste composited with NiO as supercapacitor electrodes.

An offline Practicum Workshop as An Aid for Students’ Chemistry Laboratory Practical Skills: A Case Study Kristianto, Hans; Gandajaya, Linda; Simanjorang, Lisbet Warty; Saptasari, Heny
JURNAL PENDIDIKAN SAINS (JPS) Vol 11, No 2 (2023): JURNAL PENDIDIKAN SAINS UNIVERSITAS MUHAMMADIYAH SEMARANG
Publisher : Pendidikan Kimia Unimus

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26714/jps.11.2.2023.9-14

The COVID-19 pandemic has caused disruption in various sectors including education. Since it was announced for the first time in mid-March 2020 in Indonesia, teaching and learning activities have been carried out online, either synchronously or asynchronously. If ordinary lecture activities still allow the delivery of material by changing forms and media, practicum activities in the chemistry laboratory are completely impossible to carry out and replaced with various forms of virtual learning. This study focuses on evaluating the perceptions of students' practical skills in various basic skills after returning to offline activities, and implementing practicum workshop activities as a corrective effort to improve student skills. Based on the results obtained, students have a low perception of skills, namely in the range 2.56 ± 1.02 to 3.42 ± 1.16 on a scale of 6.00. It can be seen that the effectiveness of virtual practicum is low in terms of skills and there is a need for corrective action so that students can catch up on the basic skills of practice in the chemistry laboratory. After the workshop activities, there was a significant increase (p < 0.05) in students' perceptions of skills with a range of 4.87 ± 0.66 to 5.26 ± 0.73 on a scale of 6.00. Based on the results in this study, it is suggested that other study programs to map and evaluate students' practical skills after the COVID-19 pandemic and take corrective measure to ensure the attainment of practical skills learning outcome.

Carbon composite of NiO hydrothermal impregnation from sugarcane bagasse and its electrochemical properties Nasti, Al Nadine De; Siburian, Kyfti Yolanda; Sembiring, Abraham Danofan; Kristianto, Hans; Susanti, Ratna Frida; Oktaviano, Haryo Satriya; Nugroho, Agung
Jurnal Rekayasa Proses Vol 17, No 2 (2023)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.88210

Sugarcane bagasse (SB) can synthesize activated carbon (AC) through a two-step calcination process at calcination at 400oC and activation at 800oC. NaOH 0.1 M is used to activate the pre-carbonized sample in the activation step. The AC samples undergo hydrothermal impregnation with nickel oxide (NiO) at 110°C. The X-ray diffraction (XRD) pattern and Energy dispersive X-ray spectroscopy (EDX) confirmed the presence of NiO after this process. Scanning Electron Microscope (SEM) indicates the presence of pore structures in the sample morphology. A three-electrode system with 1 M Na2SO4 as an electrolyte was employed to assess the electrochemical properties. The specific capacitance for activated carbon derived from SB stands at 89.53 F/g at 0.05 A/g current density, while after impregnation with NiO, it increases to 250.53 F/g at the same current density. The results demonstrate the possibility of activated carbon from sugarcane bagasse waste composited with NiO as supercapacitor electrodes.

Pemanfaatan ekstrak protein dari kacang-kacangan sebagai koagulan alami: review Hans Kristianto; Susiana Prasetyo; Asaf Kleopas Sugih
Jurnal Rekayasa Proses Vol 13 No 2 (2019): Volume 13, Number 2, 2019
Publisher : Jurnal Rekayasa Proses

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.46292

Coagulation and flocculation are commonly used in water and wastewater treatment. Inorganic coagulant such as alum (Al2(SO4)3), ferrous sulphate (FeSO4), and polyaluminium chloride (PAC) are commonly used. These coagulants are known for its effectiveness and simple operation procedure. However, there are some drawbacks such as reduction in pH, potential negative health effect when the treated water is consumed, and large sludge volume. To overcome these problems, utilization of natural coagulants has been proposed. Based on its active coagulating agent, natural coagulant could be divided as polyphenolic, polysaccharides, and protein. Protein from beans and seeds is commonly used as the source of active coagulating agent, due to its effectiveness, availability, and relatively simple pretreatment is needed. Usually the protein is extracted by using 0.5-1 M NaCl solution as globulin is the major protein fraction in beans.The extracted protein could act as cationic polymer to neutralize negatively charged colloids through adsorption-charge neutralization mechanism. Extracted protein could work effectively to treat turbid and waste water with lower cost compared to alum. However, most of existing studies are still focused on small – pilot scale utilization thus further explorations are still needed.

Potensi polisakarida dari limbah buah-buahan sebagai koagulan alami dalam pengolahan air dan limbah cair: Review Hans Kristianto; Angelica Jennifer; Asaf Kleopas Sugih; Susiana Prasetyo
Jurnal Rekayasa Proses Vol 14 No 2 (2020): Volume 14, Number 2, 2020
Publisher : Jurnal Rekayasa Proses

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.57798

Nowadays, various studies related to utilization of biobased materials as natural coagulants have been explored. Based on the source, natural coagulants can be classified as animal, vegetable, or microbial based. Furthermore, based on the active ingredients, it can be classified as protein, polyphenols, and polysaccharides. Polysaccharides are abundant natural ingredients and are often found in plants or animals. In this study, we focused on polysaccharides, especially those from fruit waste, such as seeds and fruit peels. It is known that around 25-30% of the total weight of fruit is generally wasted, even though it contains phytochemicals and various active ingredients that can be utilized, especially as a natural coagulant. This review will focus on the use of pectin and starch from fruit waste as natural coagulants for water- wastewater treatment. Generally, pectin is commonly found in the skin of fruits as part of the cell wall structure, while starch is found in fruit seeds as food reserves. To be used as a natural coagulant, pectin or starch need to be extracted first. In particular, starch needs to be modified either physically or chemically. The coagulation mechanism of pectin and starch usually follows the interparticle bridging mechanism. The use of pectin and starch from fruit waste needs to be explored and further investigated, to substitute the use of chemical coagulants.

Design of Student and Course Learning Outcomes Measurement Kristianto, Hans; Prasetyo, Susiana; Susanti, Ratna Frida; Adithia, Mariskha Tri
Jurnal Pendidikan Indonesia Vol 10 No 1 (2021)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat

Measurement of the outcomes becomes a vital part in OBE system to ensure the attainment of each outcome. In Indonesia, OBE was adopted in 2015 for higher education level. However, the changes were not accompanied with clear method to measure the outcomes, which became the urgency of this research. In this study, a preliminary method to measure student learning outcomes (SLO) and course learning outcomes (CLO) was presented. The measurement of SLO and CLO attainment was started by SLO mapping to courses, which usually had been done at curriculum design. Based on the mapping, formulation of CLO with a set of direct assessment was planned at the start of each course. After the teaching learning activities, a series of calculation was designed to obtain the attainment of SLO and CLO for each student, course, and whole study program. In the same time the final mark for GPA calculation of each student could also be obtained. The designed method could play an essential part in teaching-learning quality assurance and curriculum continuous improvement, which is aligned with both international and national accreditation criteria and standards. Furthermore, this study could provide insight for other study program in SLO and CLO attainment measurement.

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