Maejo International Journal of Energy and Environmental Communication <p><span id="ContentBody_cBody_LabelAbout">Maejo International Journal of Energy and Environmental Communication (Maejo Int. J. Energ. Environ. Comm. or MIJEEC), the international journal for the publication of all preliminary communications in Environmental Science, Applied Science and Energy Engineering is one of the peer-refereed journals of Maejo University. ISSN: 2673-0537; ISSN: 2774-0064 (Online) Frequency: 3 issues/year.&nbsp;</span></p> School of Renewable Energy, Maejo University, Thailand en-US Maejo International Journal of Energy and Environmental Communication 2673-0537 <p>Copyright © 2019 MIJEEC - Maejo International Journal of Energy and Environmental Communication, All rights reserved. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial- Attribution 4.0 International (CC BY 4.0) License</p> Predation properties of Rotifera Lecane isolated from an eutrophicated reservoir to toxic cyanobacteria Microcystis <p>A rotifer was isolated from a biofilm sample collected from a eutrophic reservoir in Kashima city, Saga, Japan. After morphological and molecular phylogenetic determination using 18S rRNA gene sequencing, the isolated rotifer was identified as a <em>Lecane inermis</em>. In a mixed culture of <em>Lecane inermis</em> and microcystin-producing toxic<em> Microcystis</em> <em>aeruginosa</em> (NIES102), the number of <em>Microcystis</em> cells decreased as the <em>Lecane </em>population increased. This suggests that <em>Lecane</em> preys on toxic <em>Microcystis</em>, resulting in a predator-prey interaction. By the 14th day of the mixed culture, 99.5% of the <em>Microcystis</em> cells were degraded. Data on the population dynamics of <em>Lecane</em> and <em>Microcystis</em> in this mixed culture were fitted to a predator-prey model, which was expressed by nonlinear differential equations. &nbsp;As a result, the model analysis suggested that <em>Lecane</em> could reveal the predation properties of <em>Microcystis</em> cells and may also consume bacteria as a food source.&nbsp; <em>Lecane inermis</em> is effective in promoting the degradation of microcystins (MCs) in the mixed culture. After 14 days of mixed culture, the degradation percentages of total MCs were 98.6% (MC-RR), 96.6% (MC-YR), and 93.9% (MC-LR).</p> Somsri Saenchan Kazuya Shimizu Norio Iwami Hideaki Maseda Huynh Van Vu Odwa Makrwede Tomoaki Itayama Copyright (c) 2023 Somsri Saenchan, Kazuya Shimizu, Norio Iwami, Hideaki Maseda, Huynh Van Vu, Odwa Makrwede, Tomoaki Itayama 2023-10-24 2023-10-24 5 3 16 23 10.54279/mijeec.v5i3.251146 Prediction of MBR operating parameter using LSTM neural network <p class="p1">This study investigated the forecasting ability of the long short-term memory neural network model (LSTM model), which is a type of recurrent neural network (RNN), for the dynamic character of membrane bioreactor (MBR). MBR is an advanced wastewater treatment system that combines activated sludge process with a membrane separation system. In this study, dissolved oxygen (DO), pH, trans membrane pressure (TMP), mixed liquor suspended solids (MLSS), and air flow rate of a bench-scale MBR were measured to obtain the time series data, and the time interval for each time series was unified to 1 hour. The training period of 640 hours was adopted for the LSTM model, and the remaining 160 hours were used as the testing period. The trained LSTM model predicted DO, pH, TMP, and MLSS one step ahead (one hour ahead), and multiple steps forecasts up to 6 hours ahead were also tested. The LSTM model succeeded in predicting MLSS one hour ahead with high accuracy. On the other hand, for DO and pH, the values predicted one hour ahead by the LSTM model reproduced their temporal fluctuation patterns to some extent. However, all of them tended to show predicted values that were lower than the actual values. The predicted values from the LSTM model did not reproduce the pattern of TMP changes well. In addition, the LSTM model was investigated the effect of forecasting horizons and look back period.</p> Vu Van Huynh Minh Binh Nguyen Tetsuro Ueyama Satoshi Shirayanagi Tetsuo Imai Saenchan Somsri Tomoaki Itayama Copyright (c) 2023 Vu Van Huynh, Minh Binh Nguyen, Tetsuro Ueyama, Satoshi Shirayanagi, Tetsuo Imai, Saenchan Somsri, Tomoaki Itayama 2023-10-30 2023-10-30 5 3 24 34 10.54279/mijeec.v5i3.251165 Techno-economic feasibility analysis on sustainability polyhydroxy- alcanoates production process transitions from high-strength organic wastewater <p class="p1">Polyhydroxyalcanoates (PHAs) are promising biodegradable plastics that can replace conventional petroleum-based plastics and mitigate oceanic pollution. High organic wastewater has been examined as a potential substrate for lowering the manufacturing cost of PHAs. In this study, the three main indicators, including net present value (NPV), internal rate of return (IRR), and payback period (PBP), were used to calculate the economic feasibility of PHA production. For a project lifetime of 20 years, the cost of the PHA manufacturing process reached $994,143. The annual process operation cost was $159,711. The payback period was 6.79 years, and the internal return rate was 16%. However, if costs increased by 20%, the benefits would decrease by 25%. Since the price of PHAs is higher than that of conventional plastic, various government supports are expected to stimulate the market of PHAs potentially. This study successfully determines the techno-economic analysis of PHA production to form high-strength wastewater with MMC as the microbial source.</p> Mingyan Shen Vannasinh Souvannasouk Sasithorn Saipa Chen-Yeon Chu Nuttiya Tantranont Chayanon Sawatdeenarunat Chen-Hua Hsueh Hsuan-Chen Wu Copyright (c) 2023 Mingyan Shen, Vannasinh Souvannasouk, Sasithorn Saipa, Chen-Yeon Chu, Nuttiya Tantranont, Chayanon Sawatdeenarunat, Chen-Hua Hsueh, Hsuan-Chen Wu 2023-12-02 2023-12-02 5 3 52 58 10.54279/mijeec.v5i3.253406 Energy-efficient extraction and environmental impact of the kinetic release of total phenolic compounds from longan extract beads <p class="p1">The purpose of this work was to investigate the kinetics of the total phenolic compound release from hydrogel in the form of gel beads with alginate and alginate with other wall materials consisting of alginate beads (100A), gelatin (30G/70A), gum arabic (30GA/70A), and pectin (30P/70A) in two media solutions: simulated gastrointestinal fluid (SGF) and simulated intestinal conditions (SIF) for 6 hours. 30GA/70A was found to have an optimal encapsulation effectiveness of 74.86 percent based on the test findings. The release characteristics of 30GA/70A beads tended to the total phenolic compound release was higher than other formulas. The kinetic model of Higuchi and Korsmeyer- Peppas' release It is applied to all kinds of beads to release the total phenolic compound. The best-fitting model in terms of mean R<span class="s1">2</span> (0.989) was found to be the Korsmeyer-Peppas model. This indicates the principle of diffusion controlled.<span class="s2"> Moreover, the a</span>nalytical procedures require sample pretreatment since direct sample processing is usually impossible. MAE is an eco-friendly option that reduces solvent use and energy consumption while enhancing recovery rates. MAE is a potential, cost-effective way to extract valuable plant components with low environmental impact.</p> Varunya Fuangchoom Nukrob Narkprasom Somkiat Jaturonglumlert Jaturapatr Varith Kanjana Narkprasom Copyright (c) 2023 Varunya Fuangchoom, Nukrob Narkprasom, Somkiat Jaturonglumlert, Jaturapatr Varith, Kanjana Narkprasom 2023-11-09 2023-11-09 5 3 35 42 10.54279/mijeec.v5i3.253786 Sustainable management of rice straw addressing burning issues and harnessing bioethanol potential <p class="p1">Asian rice feeds half the world and produces hundreds of millions of tons of rice straw. Farms burning rice straw in open fields release harmful chemicals and greenhouse gases, impair soil quality, and affect health. No viable alternatives make open-field burning bans difficult to enforce. Rice straw bioethanol could replace fossil fuels and greenhouse gases. Optimizing bioethanol production requires pretreatment, hydrolysis, fermentation, and distillation. Chemically, rice straw offers bioenergy and industrial potential. Bioconversion and animal feed are conceivable due to their high dry matter (93.23%) and crude protein (27.13%). Its 35.10% crude fiber and 69.10% neutral detergent fiber indicate high cellulose and hemicellulose content, making it ideal for biofuel production. Enzymatic hydrolysis is aided by low acid detergent lignin (4.27%) but hampered by high silica (11.20%). Multiple pretreatment methods were investigated to improve enzymatic digestibility. Grinding and steam explosion enhanced lignocellulosic surface area. NaOH and H<sub><span class="s1">2</span></sub>SO<sub><span class="s1">4</span></sub> stripped lignin and hemicellulose to reveal cellulose. The highest fermentable sugar concentrations after enzymatic hydrolysis were from alkali-steam explosion pretreatment. <em>Saccharomyces cerevisiae</em> fermentation produced the maximum ethanol from combination pretreatment. Steam-exploded straw yielded 25.8 g/L, alkali- and acid- treated 30 g/L, and alkali-steam explosion 35 g/L. This study found that rice straw's sustainable bioethanol potential benefits the environment and economy. More research should optimize pretreatment and fermentation to scale up and profit from bioethanol.</p> Warangkhana Khaodee Panupat Chaiworn Copyright (c) 2023 Warangkhana Khaodee, Panupat Chaiworn 2023-11-24 2023-11-24 5 3 43 51 10.54279/mijeec.v5i3.254154 Influence of setting time and compressive strength for coal bottom ash as partial cement replacement in mortar <p class="p1">Environmental degradation from forestry practices to extract limestone from mountains, as well as subsequent calcination in cement factories and dumping of coal bottom ash (CBA) waste from thermal power plants, are among the wastes from industry. However, it is essential for the construction industry to look for sustainable solutions to mitigate the negative impact on the environment. In order to promote an environmentally friendly and sustainable ecosystem, the use of recycled CBA waste as a partial substitute for cement in the manufacturing process has significant potential to mitigate the environmental damage caused by the two distinct sectors of cement and waste management. A series of six mortar preparations were prepared, each containing varying percentages of CBA as a partial substitute for cement. The percentages used ranged from 0% to 50% by weight of cement. The time tests were performed on freshly prepared pastes. All samples were cured with water until the respective test time was reached. The experiment included the evaluation of the compressive strength of hardened mortar cubes at three different time intervals: 7, 14 and 28 days. The findings of the study demonstrate that the incorporation of CBA as a partial substitute for cement affects both the setting time and the compressive strength of the mortar. It has been shown that the use of up to 20% CBA as a cement replacement effectively increases the compressive strength of the mortar. Conclusively, the successful use of CBA as a partial substitute for cement in the manufacture of mortar has the potential to reduce the amount of cement consumed, eliminate the need for landfill space for waste disposal, and contribute to the production of a more sustainable environment, thereby promoting a better lifestyle for the surrounding population.</p> Mohammad I. Al Biajawi Rahimah Embong Copyright (c) 2023 Mohammad I. Al Biajawi, Rahimah Embong 2023-09-23 2023-09-23 5 3 1 5 10.54279/mijeec.v5i3.250979 Organic farming management: A approach towards sustainable agriculture development towards green environment <p class="p1">This paper delves into the dynamic intersection of organic farming and technological innovation within the realm of sustainable agriculture. We explore the profound impact of modern technology on organic farming practices, shedding light on how precision agriculture, big data, and biotechnology are reshaping the organic landscape. Organic farming's integration of high-tech solutions not only enhances its eco-friendly credentials but also increases productivity and profitability. Furthermore, we embark on a journey into the future of sustainable agriculture, emphasizing the pivotal role of regenerative practices, agroforestry, and advanced technologies. The convergence of traditional wisdom and cutting-edge innovation holds the promise of nourishing a burgeoning global population while preserving the delicate balance of our planet's ecosystems. As we navigate the intricate tapestry of sustainable agriculture, one thing becomes clear: the future is bright, dynamic, and firmly rooted in our commitment to a healthier, more sustainable world.</p> Navytchmathra Gammatantrawet Chanthana Susawaengsup Krittiya Tongkoom Tawan Chatsungnoen Winitra Leelapattana Suthira Sitthikun Rapeephun Dangtungee Prakash Bhuyar Copyright (c) 2023 Navytchmathra Gammatantrawet, Chanthana Susawaengsup, Krittiya Tongkoom, Tawan Chatsungnoen, Winitra Leelapattana, Suthira Sitthikun, Rapeephun Dangtungee, Prakash Bhuyar 2023-10-05 2023-10-05 5 3 6 15 10.54279/mijeec.v5i3.251199