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Effects of Copper on Euglena sp. Local Strains and Remediation Capabilities Ardipeni, Witia; Suyono, Eko Agus; Dewayanto, Nugroho; Mufida, Na’imatul; Erfianti, Tia; Amelia, Ria; Kurnianto, Dedy
HAYATI Journal of Biosciences Vol. 32 No. 2 (2025): March 2025
Publisher : Bogor Agricultural University, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.4308/hjb.32.2.387-394

Abstract

One of the well-known industries in Yogyakarta is the Kotagede silver craft, which produces heavy metal waste, one of which is copper. The copper content in the liquid waste of electroplating Kotagede silver crafts is 4.628 mg/L. At the same time, Indonesian Government Regulation No. 22 (2021) stipulates a critical limit of Copper (Cu) content in river and lake water, which is 0.2 mg/L. The purpose of the study was to analyze the effects of copper on local strains of Euglena sp. (growth, photosynthetic pigment production, and superoxide dismutase enzyme) as well as the effectiveness of Euglena sp. in copper remediation. The study was conducted by adding a copper solution obtained from CuSO4•5H2O to the culture medium of Euglena sp. The parameters observed in the study were growth (number of cells and biomass), photosynthetic pigment content (chlorophyll a, chlorophyll b, carotenoid total), Superoxide dismutase enzyme of Euglena sp. as well as the effectiveness of Euglena sp. in copper remediation. The results showed that copper inhibited the growth of Euglena sp. The highest growth was the control treatment (without adding copper to the culture medium). Likewise, the content of photosynthetic pigments and the culture of Euglena sp. exposed to copper were lower when compared to the control culture. The activity of the SOD enzyme is increased in cultures exposed to copper. The result of the research is Cu metal absorption efficiency by Euglena sp. by 21.93%, 10.93%, and 9.47% for a Cu concentration of 10 ppm, 15 ppm, and 20 ppm.
The Role of Renewable Energy in ReducingCarbon Emissions in Cirebon District Nurfalah, Agni; Setiawan, Bakti; Dewayanto, Nugroho
ASEAN Journal of Systems Engineering Vol 9, No 1 (2025): ASEAN Journal of Systems Engineering
Publisher : Master in Systems Engineering

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ajse.v9i1.79545

Abstract

The adverse effects of the use of fossil energy such as global warming make people slowly decrease the use of fossil energy including in the electric power generation sector. Emissions from burning fossil fuels such as carbon dioxide are one of the components that make up and dominate the composition of greenhouse gases. It is this greenhouse gas that prevents the sun's heat from being reflected back into the atmosphere, so that it accumulates over many years which causes the temperature of the earth's surface to increase.               Slowly the use of fossil energy is stopped and replaced with new renewable energy which produces less greenhouse gases. In meeting the demand for electricity supply, Cirebon Regency is still relying on Steam Coal Power Plants to supply electricity demand. According to projection, Cirebon's total electricity demand will be 109.860,28 GWh by 2050. If Cirebon still continues to use Steam Coal Power Plants until 2050 it's estimated that it will emit 100.489.721,74 tons of carbon dioxide emissions.               Cirebon Regency has alternative energy potential from municipal solid waste (MSW) that can be utilized. Every day, every person in Cirebon Regency can produce 0,541 kg of waste. From the observations, the electrical energy that can be generated and utilized from waste until 2050 is 8.360,45 GWh, of which 2.462,34 GWh is generated from organic waste and 5.898,12 GWh is generated from combustible waste.                   The electrical energy that can be generated from city waste is sufficient for 7,61% of the electricity needs of Cirebon Regency. With an energy mix scheme between PLTU and waste-based power plants, total carbon dioxide emissions can be reduced by 3,05%.
TECHNO-ECONOMIC ANALYSIS OF THE POTENTIAL FOR HYBRID POWER PLANT IN GUNUNG SEWU GEOPARK, PACITAN REGENCY Prima, Putri; Setiawan, Ahmad Agus; Dewayanto, Nugroho
ASEAN Journal of Systems Engineering Vol 9, No 1 (2025): ASEAN Journal of Systems Engineering
Publisher : Master in Systems Engineering

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ajse.v9i1.79689

Abstract

Gunung Sewu has been designated as a Global Geopark Area by The United Nations Educational, Scientific and Cultural Organization (UNESCO) in 2015. In the preparation of the Gunung Sewu Masterplan as a UNESCO Global Geopark (UGGp), the provision of environmentally friendly and sustainable electricity is one of the strategies to utilize the renewable energy. The application of Hybrid Power Plants (HPP) that utilize wind and solar energy in the industrial and tourism sectors can have a positive impact on regional income where economic growth is one of the strategic issues of Pacitan Regency.The average wind speed in Pacitan is 3.41 m/s and the average solar radiation reaches 5.69 kWh/m2/day so that it can be said that the potential for solar and wind energy in the Gunung Sewu Pacitan  Geopark is reliable and feasible to be used as an environmentally friendly energy source. The simulation of HPP that will be implemented at Buyutan Beach illustrates that the system could produce an output of 7,519 kWh/yr. This result is able to meet the annual demand of 4,107 kWh/yr and even exceed the annual requirement.The economic analysis of the simulated HPP system produces a negative Net Present Value (NPV). This could be due to the large value of Operational Expenditure (OpEx) and Capital Expenditure (CapEx) and the low purchase price (National Electricity Company’s feed in tariff).  However, this research also proposes a scenario so that the HPP system can still be applied by dividing the cost components contained in the budget plan into two parts. In the proposal obtained cash inflows of Rp. 8,640,834.80/year and a positive or feasible NPV.
Evaluasi Peramalan Permintaan Pupuk NPK Phonska di Jawa Tengah Menggunakan Metode Mean Absolute Scaled Error (MASE) Amdarso, Fajar Primazona; Sari, Wangi Pandan; Dewayanto, Nugroho
Syntax Literate Jurnal Ilmiah Indonesia
Publisher : Syntax Corporation

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36418/syntax-literate.v10i6.60374

Abstract

Penyediaan pupuk subsidi sangat penting bagi produktivitas pertanian di Indonesia. Namun dalam penyediaanya terdapat risiko ketidaksesuaian antara suplai dan kebutuhan karena kebutuhan pupuk yang bersifat musiman. Studi ini membahas peramalan kebutuhan pupuk bersubsidi, khususnya pupuk NPK Phonska di Jawa Tengah melalui metode SARIMA. Peramalan kebutuhan ini dapat digunakan untuk mendukung perencanaan suplai. Sebanyak 29 area penjualan dimodelkan secara independen memakai data penjualan periode 2016–2023 dan menggunakan KNIME, sebuah platform analitik open-source yang dapat menyederhanakan proses pemodelan yang kompleks. Kinerja model dievaluasi menggunakan Mean Absolute Percentage Error (MAPE) dan Mean Absolute Scaled Error (MASE), dengan rata-rata MAPE sebesar 46,75%, yang menunjukkan akurasi yang cukup baik. SARIMA namun hanya berhasil di 13,8% area penjualan saat ditinjau dengan MASE. Hal ini mungkin terjadi karena faktor eksternal seperti variabilitas iklim dan perubahan kebijakan. Penelitian ini menyoroti keunggulan pragmatis penggunaan MASE dalam mengevaluasi peramalan kebutuhan musiman dan menunjukkan bahwa SARIMA yang dijalankan pada KNIME dapat memodelkan banyak deret waktu secara simultan dan terukur. Penelitian mendatang dapat mengeksplorasi penyertaan variabel eksogen atau model machine learning untuk meningkatkan akurasi.
Analisis Kinetika Pertumbuhan Mikroalga Spirulina Sp. Menggunakan Pemodelan Richard dan Gompertz pada Fotobioreaktor Algaetree Setiantoro, Arief Eko; Dewayanto, Nugroho; Budiman, Arief
Jurnal Ilmiah Universitas Batanghari Jambi Vol 24, No 2 (2024): Juli
Publisher : Universitas Batanghari Jambi

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33087/jiubj.v24i2.5369

Abstract

Algaetree is a closed cultivation system with a photobioreactor type created by Gadjah Mada University in collaboration with the Indonesian Institute of Arts Yogyakarta. The aim of this research was to see the effectiveness of the growth kinetics of the microalgae type Spirulina sp. The research was carried out by carrying out variations in data sampling at 3 (three) points where microalgae grow in Algaetree. The dose was 10 ml using the sampling method, then 2 ml was taken to be examined using a microscope and the number of microalgae cells found on the haemocytometer was counted. The microalgae cells were studied and counted on 4 haemocytometer columns, then the number of cells was accumulated and the standard deviation and growth kinetics were calculated using Microsoft Excel and Python software. As a result, it was found that the highest cell number of microalgae on the Algaetree was 69166.67 cells/ml, with a standard deviation of 4249.18, while the maximum growth kinetics of microalgae on the Algaetree with the Richard model and the Gompertz model, the most significant value was the Richard model, namely (miumax ) 1.9958, curve fitting parameter (A) 6.8700, stationary phase (V) 397.43, and r-square (R^2) close to 1, namely 0.9674. This value shows that there is a match between the data processed and the cultivation system used. The results of the cultivation process can be seen that the kinetics of microalgae growth is quite significant, meaning that spirulina type microalgae can grow well in a tool called Algaetree. In the next process, Algaetree can be used as a reference object for comparing microalgae growth from a closed cultivation system with an open cultivation system.