Martin Anda

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Karimunjawa National Park (KNP) is an emerging tourism destination in Indonesia, where increasing tourism has led to excessive groundwater use and land subsidence. These issues pose environmental and health risks from emissions and seawater intrusion. This study examines the potential effects of these factors on the environment and human health within KNP. The research utilizes OpenLCA software 2.0.1 and the Ecoinvent 3.8 database, applying the CML-IA Baseline method for environmental impact assessment and the EPS 2015d method for human health impacts. The results show that the largest environmental impact is eutrophication, with the highest values recorded at spot 11 (6.94E-06 kg PO4– eq). At spot 5, where copper (Cu) contamination reached the highest levels, the Authors observed the most significant ecotoxicity impacts, affecting freshwater (3.67E-06 kg 1,4-DB eq) ecosystems. Human health impacts, including intellectual disability (2.62E-10 Person-Years), and renal dysfunction (1.028E-13 case), were most significant at spot 5, linked to lead (Pb) contamination. The study suggests that reducing human activity in areas contributing to eutrophication and ecotoxicity, such as controlling nitrate and copper pollution, could mitigate environmental damage. Moreover, addressing human toxicity and health risks from lead requires improving waste management, ecosystem rehabilitation, pesticide reduction, and strengthening environmental monitoring. Public awareness of these risks is essential for effective mitigation.

The microalgae Botryococcus braunii holds significant promise for biofuel generation. This study delves into an innovative B. braunii biofilm cultivation approach to trim energy consumption as well as harvesting costs. The investigation encompassed two distinct processes, i.e., algae turf scrubber (ATS) biofilm and open raceway pond (ORP) systems. The simulation of integrated cultivation, harvesting, and lipid extraction processes was conducted using SuperPro Designer. Furthermore, capital and operational expenses were calculated to be further discussed in terms of techno-economics and profitability. The ATS biofilm reached a notably high biomass productivity of 38 g m− 2 d− 1 when compared to the ORP system (7.5 g m− 2 d− 1). Likewise, the ATS biofilm cultivation demonstrated lesser water consumption by up to 6-fold and facilitated a remarkable 77.3% reduction in total OPEX. Besides, the microalgae cultivation plant using the ATS biofilm system with a lifetime of 12 years leads to an IRR of up to 26.43% with a DPBP of 5.9 y if the biofuel product is sold at 3.7 USD L− 1. Given this potential, biofuel production from B. braunii in the ATS biofilm system can be an attractive option in terms of process reliance and feasibility for future large- and commercial-scale microalgae industries.

Hydrogen-based Power Systems (H2PSs) are gaining accelerating momentum globally to reduce energy costs and dependency on fossil fuels. A H2PS typically comprises three main parts: hydrogen production, storage, and power generation, called packages. A review of the literature and Original Equipment Manufacturers (OEM) datasheets reveals that no single manufacturer supplies all H2PS components, posing significant challenges in system design, parts integration, and safety assurance. Additionally, both the literature and H2PS projects’ database highlight a gap in a systematic hydrogen equipment and auxiliary sub-systems technology selection process, and how this selection affects the overall H2PS Balance of Plant (BoP). This study addresses that gap by providing a guideline for available technology options and their impact on the H2PS-BoP. The analysis compares packages and auxiliary sub-system technologies to support informed engineering decisions regarding technology and equipment selection. The study finds that each package’s technology influences the selection criteria of the other packages and the associated BoP requirements. Furthermore, the choice of technologies across packages significantly affects overall system integrity and BoP. These interdependencies are illustrated using a cause-and-effect matrix. The study’s significance lies in establishing a structured guideline for engineering design and operations, enhancing the accuracy of feasibility studies, and accelerating the global implementation of H2PS.

In recent years, research on Electric Vehicles (EVs) has gained considerable attention due to their potential to reduce reliance on fossil fuels and curb environmental pollution significantly. Various stakeholders play a pivotal role in the large-scale EV integration into the existing power grid by providing unique services, particularly in grid power management and charging of EV. This study provides a comprehensive analysis of the critical role played by key stakeholders in the large-scale integration of electric vehicles (EVs) into the power grid, with a particular focus on grid power management and charging infrastructure. It systematically examines the involvement of Distributed Network Operators (DNOs), EV Owners (EOs), and Charging Station Owners (CSOs), elucidating their respective objectives, responsibilities, and challenges. Furthermore, the paper delves into power management strategies, reactive power regulation, and advanced control methodologies aimed at enhancing grid stability. A case study on EV adoption in Western Australia is presented to contextualize current developments and future trajectories. The study concludes by identifying key challenges associated with EV-grid integration and providing strategic recommendations to facilitate a more resilient, efficient, and sustainable power system.
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Groundwater is a vital resource for clean water in urban areas. In some big cities in Indonesia, it has been discovered that there is a decline in the quality of groundwater in North Jakarta. The objective of this study was to assess the iron and manganese levels in the shallow groundwater of North Jakarta. The analysis and evaluation were performed by creating a spatial map using ArcGIS 10.8 software, illustrating the dispersion of groundwater quality from 2019 to 2023. The results revealed that iron (Fe) and manganese (Mn) varied within the concentration of pollutants. Geographic information systems have generated spatial maps that depict the distribution patterns of groundwater quality over five years. These maps were generated using interpolation methodologies. The levels of Mn and Fe in the groundwater of North Jakarta are marginally beyond the permissible thresholds established by national standards.

This study examines the embodied carbon of paving blocks by substituting Portland Composite Cement (PCC) with landfill waste incineration ash at 0%, 25%, 50%, 75%, and 100% replacement levels. Using Life Cycle Assessment (LCA) and mechanical testing, the embodied carbon value was calculated per ISO 14040 standards. Results show that a 50% replacement achieves a 33% reduction in embodied carbon (120 kgCO₂e/m³ vs. 180 kgCO₂e/m³ for conventional paving blocks) while maintaining compressive strength within SNI criteria. These findings highlight the potential for eco-cement paving blocks to support sustainable construction and inform policies promoting low-carbon building materials.

Sedimentation in Lake Tempe, South Sulawesi, Indonesia, has led to significant reductions in the water storage capacity, necessitating dredging efforts and the reuse of Dredged Material (DM) for artificial island construction. This study focuses on designing stable embankments for these islands, which face heightened risks of failure due to the use of low-quality backfill materials and the extreme hydrological conditions. The objective is to determine the required embankment height and assess the effectiveness of geosynthetics and bamboo piles in enhancing slope stability. A comprehensive approach was employed, combining hydrological and geotechnical analyses. The hydrological analysis, based on the 20-year (Q20) and 50-year (Q50) return periods, determined embankment heights of 8.36 meters and 9.2 meters, respectively. The geotechnical analysis using slope stability models revealed that geosynthetic reinforcement significantly outperformed bamboo piles, achieving safety factors well above the critical threshold (1.25) compared to the sub-threshold values for the bamboo piles. These findings underscore the critical role of geosynthetics in mitigating failure risks and enhancing the resilience of embankments constructed with DM.

Anaerobic digestate animal effluent (ADAE) contains high N and P nutrients which need to be treated. In this study, an integrated process was proposed using a microalgae consortium of Chlorella and Scenedesmus. The system was designed for 71 m3/d (medium-sized) and 355 m3/d (large-sized) animals of ADAE. Process simulation estimated to produce 83–417 kg d-1 of microalgae biomass which can be used as further products. As much as 2 kg of animal feed and 36–180 L/d of bio-oil can be produced during the treatment of 1 m3/d of ADAE. The produced biogas can generate 247–1,217 MWh y-1 of electricity. Likewise, the process can reduce greenhouse gas emissions by 2 kg-CO2eq kg−1 of hot standard carcass weight (HSCW). This integrated system offers merits in treating ADAE as well as producing chemicals and energy with low environmental burdens.

In environmental conservation, mangrove forests play a crucial role. Retransplanting mangrove propagules, however, faces challenges, and success rates are notably low. Achieving an optimal protector for propagules, balancing strength without impeding growth, is challenging. Mangrove propagules require a temporary protector with an optimal balance, neither too weak nor too strong, to shield them from current waves which is difficult. We propose using pervious concrete pots with high-volume fly ash activated with low NaOH concentrations. The investigation focuses on the influence of the mixing procedure on workability, compressive strength, and mineral composition. The novel discovery in this study is the specific sequence of stirring the ingredients using an alkali activator, which adds an interesting dimension to the research. It is recommended to adopt Sequence 2 in pervious concrete production, where NaOH dissolved FA in the mixture forming albite as N-A-S-H gel product. It surely enhanced both workability and the strength confirming uniform application processes. The two recommended variants, PFS-60 and PFBS-50, effectively utilize coal ash, meeting the target compressive strength range of 3–5 MPa and providing support for mangrove pots over a 3–4 year period. Notably, both compositions maintained consistent mechanical properties during exposure to tidal conditions for 240 days.They exhibit high permeability (694 liter/m²/minute), facilitating efficient water passage without sediment entrainment.
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Co-firing biomass in coal-fired power plants presents a viable method to reduce reliance on fossil fuels and promote the use of thermal renewable energy sources, aligning with carbon neutrality and net-zero emission goals. This study conducts a comprehensive combustion analysis of various biomass-coal mixtures to evaluate their effectiveness. Mixtures containing 1%, 3%, and 5% biomass from rice husks, ironwood sawdust, and teak sawdust were analyzed. The results indicate that incorporating biomass with coal decreases the theoretical air requirements for combustion, thereby enhancing combustion efficiency and reducing emissions. Specifically, each 1% increase in biomass content results in a reduction in theoretical air requirements by 2.4% for rice husks, 0.3% for ironwood sawdust, and 0.9% for teak sawdust. Moreover, biomass addition lowers the fuel's calorific value and ignition point, leading to faster ignition and more efficient burning in the combustion chamber. These findings underscore the need for further research to optimize biomass-coal co-firing, including long-term operational studies at power stations and life cycle impact assessments to understand the full environmental, social, and economic implications. The insights from this study are instrumental in developing more efficient combustion systems and optimizing biomass-coal mixtures for better performance. This research provides valuable references for advancing biomass co-firing in coal-fired power plants, particularly in Indonesia, contributing to a more sustainable and environmentally friendly power generation strategy.