• Energy Research

In the recent past, Integrated Water Resource Management (IWRM) has emerged as the method of choice for resolving a wide range of water-related conflicts that arise between governments and stakeholders all over the globe. Despite a variety of regulations and initiatives being put into place, there is still skepticism over their actual execution. In 2006, the Philippine government began updating the water policy and regulatory framework to promote IWRM as a foundation for sustainable development. However, implementation of this national and subnational structure is still in process. This study intends to identify and rank the key elements likely to affect IWRM changes at the subnational level in Palawan Province. Specifically, this study aims to identify the elements that might improve the result of adopting IWRM, which is as important as designing policies, institutions, and instruments for putting the approach into action. This approach combined the Strengths, Weaknesses, Opportunities, and Threats (SWOT) and Analytic Hierarchy Process (AHP) techniques, a hybrid multi-criteria decision procedure, SWOT-AHP. Expert group discussion revealed the essential elements impacting IWRM implementation in this research, and these elements were categorized into SWOT categories. The AHP approach was used to determine the relative relevance of each component identified in the SWOT analysis. The results show that the following ranking groups have a higher priority for Puerto Princesa: threats (group weight 48.8%), strengths (35.4%), weaknesses (10.7%), and opportunities (5.1%). The ranking group for Roxas is the following: opportunities (36.8%), strengths (27.4%), weaknesses (21.5%), and threats (14.3%). Taytay has the following ranking group: opportunities (27.9%), weaknesses (27.1%), threats (24.7%), and strengths (20.3%). While El Nido has the following ranking group: strengths (33.5%), weaknesses (24.3%), opportunities (24%), and threats (18.2%). This research identified and prioritized the key components essential to the effectiveness of the IWRM concept in the research sites. This study recommends evaluating IWRM implementation using the upgraded element framework, enhancing the strategic framework to assess state, federal, and local IWRM governance performance.

One of the targets of the Sustainable Development Goals is clean and affordable energy. This is also the aim of the Biofuels Act of 2007 in the Philippines. However, this law is confronted with challenges such as the limitation of lignocellulosic feedstock, specifically available for bioethanol production. The present study sought to address the issue by exploring the potential of mango seed husk (MSH), a by-product of the mango industry, in bioethanol production. MSH is considered a waste material and its utilization also permit value-addition as this can serve as an alternative and affordable source of feedstock in energy production. Two pretreatment strategies are employed to exploit the cellulose and hemicellulose content of MSH, namely, dilute acid treatment and enzymatic hydrolysis. Results show that the %H2SO4 resulting in the highest glucose concentration and yield is 4% v/v at 95 °C hydrolysis temperature, 1:10 (w/v) solid-to-solvent ratio, and 60-min hydrolysis time. For enzymatic hydrolysis using a commercial enzyme preparation, the reaction time up to 72 h did not affect glucose concentration and yield at the following conditions: 50 °C hydrolysis temperature, 150 rpm, pH 5.0, 10% solids loading, and 4% enzyme loading. This could be attributed to the lignin and non-structural compounds present in MSHs. However, a combined process strategy of dilute acid pretreatment followed by enzymatic hydrolysis in the pretreatment of MSH contributes to an increased concentration and yield of sugars in the hydrolysates, which is advantageous for bioethanol production. Graphical Abstract.

Design strategies for achieving reliable, affordable, and clean electricity are crucial for energy sustainability. Attaining it requires managing the three core factors (TCF) of the energy trilemma (ET) to increase reliability (energy equity), minimize the levelized cost of electricity (LCOE) (energy equity), and avoid potential CO2 emission (environmental sustainability) simultaneously. This paper aims to present a design strategy for the hybrid energy system microgrid (HESM) model, consisting of a distributed rooftop solar PV (DRSP), battery, and diesel-generator to meet the increasing demand while balancing the TCF of the ET. The design strategy was applied in a cluster of 11 households in Gilutongan Island, Cebu, Philippines, where there is no open land space for a solar PV microgrid system. This study used PVSyst and HOMER Pro software to perform the techno-enviro-economic (TEE) analysis to select all feasible system configurations (FSCs). To identify the optimal FSC, a scoring mechanism that considers the LCOE based on the 5% household electricity expense limit, the 5% unmet load fraction, and the renewable penetration fraction was used. Results show that the optimal system requires an average of 32.2% excess energy from DRSP to balance the TCF of the ET based on the energy demand considered. Thus, planning when energy demand increases is vital to map the next appropriate steps toward sustainable energy transition. Overall, the obtained results can support project developers and policymakers to make informed decisions in balancing the ET from various trade-offs of energy systems.

Las complejas redes de raíces y troncos sobre el suelo hacen que los bosques de manglares atrapen la basura plástica. Probamos cómo los macroplásticos se relacionan con la biomasa de los árboles, la abundancia de raíces, la geomorfología de los manglares y la proximidad a la desembocadura de los ríos, estudiando los márgenes terrestres y marítimos de siete bosques en Filipinas, un punto de acceso global para la contaminación plástica marina. Los macroplásticos fueron abundantes (media ± s.e.: 1.1 ± 0.22 ítems m-2; rango: 0.05 ± 0.05 a 3.79 ± 1.91), más grandes en la zona terrestre (media ± s.e.: 1.60 ± 0.41 m-2) y dominados por ítems derivados de la tierra (sobres, bolsas). La abundancia y el peso del plástico aumentaron con la proximidad a las desembocaduras de los ríos, y la abundancia de las raíces predijo el área de superficie de la basura plástica (es decir, la suma acumulada de todas las áreas de superficie de cada elemento plástico por parcela). El estudio confirma que los ríos son una vía importante para la contaminación plástica marina, y que las raíces de los manglares son el atributo biológico que regula la retención de basura. Los resultados sugieren que la gestión de residuos terrestres que evita que los plásticos entren en los ríos reducirá la contaminación plástica marina en el sudeste asiático. Des réseaux complexes de racines et de troncs hors sol font que les forêts de mangroves piègent les déchets plastiques. Nous avons testé la relation entre les macroplastiques et la biomasse des arbres, l'abondance des racines, la géomorphologie des mangroves et la proximité de l'embouchure des rivières, en étudiant les marges terrestres et maritimes de sept forêts des Philippines, un point chaud mondial pour la pollution plastique marine. Les macroplastiques étaient abondants (moyenne ± s.e. : 1,1 ± 0,22 éléments m-2 ; plage : 0,05 ± 0,05 à 3,79 ± 1,91), les plus importants dans la zone terrestre (moyenne ± s.e. : 1,60 ± 0,41 m-2) et dominés par les éléments d'origine terrestre (sachets, sacs). L'abondance et le poids du plastique augmentent avec la proximité des embouchures des rivières, l'abondance des racines prédisant la surface de la litière en plastique (c'est-à-dire la somme cumulative de toutes les surfaces de chaque élément en plastique par parcelle). L'étude confirme que les rivières sont une voie majeure de pollution plastique marine, les racines de mangrove étant l'attribut biologique qui régule la rétention des litières. Les résultats suggèrent que la gestion des déchets terrestres qui empêche les plastiques de pénétrer dans les rivières réduira la pollution plastique marine en Asie du Sud-Est. Complex networks of above-ground roots and trunks make mangrove forests trap plastic litter. We tested how macroplastics relate to tree biomass, root abundance, mangrove geomorphology and river mouth proximity, surveying landward and seaward margins of seven forests in the Philippines, a global hotspot for marine plastic pollution. Macroplastics were abundant (mean ± s.e.: 1.1 ± 0.22 items m-2; range: 0.05 ± 0.05 to 3.79 ± 1.91), greatest at the landward zone (mean ± s.e.: 1.60 ± 0.41 m-2) and dominated by land-derived items (sachets, bags). Plastic abundance and weight increased with proximity to river mouths, with root abundance predicting plastic litter surface area (i.e., the cumulative sum of all the surface areas of each plastic element per plot). The study confirms rivers are a major pathway for marine plastic pollution, with mangrove roots are the biological attribute that regulate litter retention. The results suggest land-based waste management that prevent plastics entering rivers will reduce marine plastic pollution in Southeast Asia. تجعل الشبكات المعقدة من الجذور والجذوع فوق الأرض غابات المانغروف تحبس القمامة البلاستيكية. اختبرنا كيفية ارتباط اللدائن الكلية بالكتلة الحيوية للأشجار، ووفرة الجذور، والجيومورفولوجيا في غابات المانغروف، وقرب مصب النهر، وقمنا بمسح الهوامش البرية والبحرية لسبع غابات في الفلبين، وهي نقطة ساخنة عالمية للتلوث البلاستيكي البحري. كانت المواد البلاستيكية الكبيرة وفيرة (متوسط ± s.e: 1.1 ± 0.22 عنصر m -2 ؛ النطاق: 0.05 ± 0.05 إلى 3.79 ± 1.91)، وأكبرها في المنطقة البرية (متوسط ± s.e: 1.60 ± 0.41 m -2) وتهيمن عليها العناصر المشتقة من الأرض (الأكياس، الأكياس). زادت الوفرة البلاستيكية والوزن مع القرب من مصبات الأنهار، مع توقع وفرة الجذور لمساحة سطح القمامة البلاستيكية (أي المجموع التراكمي لجميع المساحات السطحية لكل عنصر بلاستيكي لكل قطعة أرض). تؤكد الدراسة أن الأنهار هي مسار رئيسي للتلوث البلاستيكي البحري، مع جذور المنغروف هي السمة البيولوجية التي تنظم الاحتفاظ بالقمامة. تشير النتائج إلى أن إدارة النفايات البرية التي تمنع دخول البلاستيك إلى الأنهار ستقلل من التلوث البلاستيكي البحري في جنوب شرق آسيا.