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Pengaruh pH dan Konsentrasi pada Penyerapan Ion Logam Cu(II) Menggunakan Kulit Buah Matoa ( Pometia pinnata ) Berliana Salsabila; Edi Nasra; Hardeli Hardeli; Indang Dewata; Desy Kurniawati
Periodic Vol 12, No 2 (2023): PERIODIC
Publisher : Departemen Kimia FMIPA UNP

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/periodic.v12i2.117510

Abstract

 One of the effective methods in handling the impact of pollution by copper metal is the biosorption method using matoa peel powder (Pometia pinnata). The purpose of this research is to determine the optimum absorption conditions and the optimum capacity for absorption of copper metal ions (Cu2+) using the batch method with variations in pH, concentration, particle size, contact time, and stirring speed.. The results of the research showed that the optimum conditions for the absorption of Cu2+ metal ions were at pH 5, concentration of 220 ppm, particle size of 180 m, contact time of 90 minutes and stirring speed of 300 rpm was 12,059 mg/g. The adsorption isotherm of Cu2+ metal with matoa skin biosorbent (Pometia pinnata) tends to follow the Freundlich isotherm equation with a determinant coefficient (R) of 0,9992.Keywords — Biosorption, Metal ion Cu2+, pomettia pinnata, Batch method
Pengaruh Waktu Kontak dan Kecepatan Pengadukan Terhadap Penyerapan Zat Warna Methylene Blue Menggunakan Biosorben Kulit Matoa (Pometia pinnata) Mufi Nasda; Desy Kurniawati; Edi Nasra
Periodic Vol 12, No 2 (2023): PERIODIC
Publisher : Departemen Kimia FMIPA UNP

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/periodic.v12i2.118347

Abstract

Methylene blue is an aromatic hydrocarbon compound or thiazine dye with the chemical formula C16H18N3SCl which is most often used in industry, this cationic dye is very dangerous with a threshold value ranging from 5-10 mg/L in water and is difficult to degrade in the environment because it contains benzene compounds. The purpose of this study was to reduce the impact of methylene blue pollution on the waters. The adsorption method was selected in batches by utilizing plantation waste from matoa fruit peel as an adsorbent in the absorption of MB waste, because it is more effective, inexpensive, and environmentally friendly. Matoa skin contains cellulose and lignin, so it is considered potential to be used as an adsorbent. The results showed that the matoa skin adsorbent was able to adsorb methylene blue dye at an optimum contact time of 120 minutes and a stirring speed of 200 rpm, which was measured using a UV-Vis spectrophotometer at a wavelength of 664 nm.
Methylene blue adsorption by langsat peel (Lansium domesticum) waste Desy Kurniawati; Yona Prestica; Salmariza Sy.; Niza Lian Pernadi
Jurnal Litbang Industri Vol 13, No 2 (2023)
Publisher : Institution for Industrial Research and Standardization of Industry - Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24960/jli.v13i2.8176.93-98

Abstract

The potential of langsat peel (LP) as an absorbent to remove methylene blue (MB) dye from the textile industry was investigated in this study. A batch method was employed to determine the optimum conditions and adsorption capacity of langsat peel with variations in pH, initial dye concentration, and particle size of the adsorbent. The analysis principle relied on measuring the absorbance of the MB dye before and after adsorption using a Spectronic 20D+ spectrophotometer at a maximum wavelength of 665 nm. The results indicated that the optimum conditions were pH 6, a concentration of 300 ppm, and a particle size of 150 µm. The adsorption process followed the Freundlich isotherm with an R2 value of 0.918 and Kf values of 4.655 mg/g. According to the Langmuir isotherm, the maximum adsorption capacity obtained was 44.843 mg/g.
Enhancing Students’ Achievement in Chemical Equilibrium Through a Scientific Literacy-Integrated 7E Learning Cycle E-Module Ahmad Maulana Ardi; Desy Kurniawati; Hardeli; Rahadian Zainul; Umar Kalmar Nizar
Jurnal Penelitian Pendidikan IPA Vol 11 No 5 (2025): May
Publisher : Postgraduate, University of Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jppipa.v11i5.11211

Abstract

Scientific literacy is crucial in chemistry education, yet PISA results indicate that Indonesian students still struggle with abstract concepts like chemical equilibrium. To address this issue, this study developed a scientific literacy-integrated e-module based on the Learning Cycle 7E model to improve student learning outcomes. Using an educational design research approach with the Plomp model, the e-module’s validity, practicality, and effectiveness were evaluated. Validation by subject matter and media experts yielded high validity scores of 0.89 and 0.91, respectively. Practicality testing involving teachers and students resulted in high scores of 91.27% and 89.70%. Effectiveness analysis, measured using the N-Gain formula, showed a significant improvement in students' learning outcomes. These results indicate that the developed e-module is valid, practical, and effective in supporting the understanding of chemical equilibrium among senior high school students.
Development of Acid Base E-Module Based on Guided Discovery Learning to Improve Digital Literacy Skills of Senior High School Phase F Students Haifa Hafifah; Yerimadesi Yerimadesi; Alizar Alizar; Desy Kurniawati
Jurnal Penelitian Pendidikan IPA Vol 11 No 7 (2025): July
Publisher : Postgraduate, University of Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jppipa.v11i7.11382

Abstract

This study aims to analyze the validity, practicality, and effectiveness of the acid-base e-module based on guided discovery learning on students' digital literacy skills. The development model used is the Plomp development model. The developed e- module was validated by three lecturers and two chemistry teachers. The module's practicality test was carried out by three chemistry teachers and 33 high school students. The module's effectiveness test was carried out using the pre-experimental method with a non-equivalent control group design. The validity test is explained using Aiken's V formula. The overall validity test results were obtained of 0.91 with a valid category. The results of the e-module practicality test carried out by teachers and students were 89.4 and 87.09% with a very practical category. The average N-Gain value in the experimental class was 0.75, which is in the high category. Based on the results of data analysis, it can be concluded that the acid-base e-module, based on guided discovery learning that was developed, is valid, practical, and effective in improving the digital literacy skills of Phase F (Grade XI) high school students
PENGEMBANGAN E-LKPD BERBASIS DISCOVERY LEARNING TERINTEGRASI ETNOSAINS PADA MATERI ASAM BASA Astuti; Desy Kurniawati
Jurnal Penelitian Pendidikan IPA Vol 11 No 10 (2025): October
Publisher : Postgraduate, University of Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jppipa.v11i10.12475

Abstract

This study aims to develop an e-LKPD based on discovery learning integrated with ethnoscience on acid-base material. The background of this study is based on the problem of low student understanding of the acid-base concept, the lack of visual and interactive media, and the limited use of technology in chemistry learning. This research is a design research study using the development model by Plomp, which consists of three stages: preliminary research, development/prototyping, and assessment phase. The results of the study show that the developed learning media is valid with an Aiken’s V value of 0.94, after being validated by seven experts (four content validators and three media validators). The practicality test indicates that the media is highly practical, with a practicality level of 98.5%. Meanwhile, the effectiveness test shows that the media is effective, proven by the learning outcomes of students using the e-LKPD being significantly higher than those in the class that did not use the developed e-LKPD. Therefore, the e-LKPD based on discovery learning integrated with ethnoscience on acid-base material that was developed is feasible to be used as an innovative alternative in chemistry learning to improve student learning outcomes.
Development of an Acid–Base Module Based on Problem-Based Learning Integrated with TPACK to Improve Senior High School Students’ Learning Outcomes Rela Faradina; Desy Kurniawati; Budhi Oktavia; Alizar
Jurnal Penelitian Pendidikan IPA Vol 11 No 9 (2025): September
Publisher : Postgraduate, University of Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jppipa.v11i9.12535

Abstract

The Merdeka Curriculum emphasizes students’ ability to understand and apply their conceptual knowledge to solve contextual problems. This study aims to determine the validity, practicality, and effectiveness of an acid–base module based on problem-based learning integrated with TPACK in improving the learning outcomes of Phase F senior high school (SMA/MA) students. The development model used in this research was the 4-D model. The acid–base module was validated by three chemistry lecturers and two chemistry teachers. The practicality test of the module was conducted by three chemistry teachers and 31 students. The effectiveness of the module in improving learning outcomes was analyzed using the N-gain test. The validity test was analyzed using Aiken’s V, which consisted of content and construct validity, yielding results of 0.89 and 0.91, respectively, both categorized as valid. The practicality results from teachers and students were 98.61% and 86.87%, respectively, both in the high category. The N-gain analysis resulted in a value of g = 0.79, categorized as high. Based on the hypothesis test, the calculated t-value was greater than the critical t-value. These findings confirm that the developed acid–base module based on problem-based learning integrated with TPACK is valid, practical, and effective for significantly enhancing students’ learning outcomes.