Maejo International Journal of Energy and Environmental Communication

Recent advances in microalgae-based biohydrogen production: A review of innovative strategies, pretreatment, genetic engineering, and bioelectrochemical technologies

2025-11-28T23:17:44+07:00

Microalgae are promising platforms for sustainable biohydrogen (H2) production, which couples both the production of H2 and CO2 sequestration and wastewater treatment. Limiting oxygen sensitivity of [FeFe]-hydrogenases and the limitations of reactors are the main implementation issues. This review discusses advances in the biohydrogen production from green microalgae and cyanobacteria. We discuss the photobiological H2 pathway, dark fermentative H2 from algal biomass and bioelectrochemical H2-hybrids. Process strategy involving nutrient-starvation methods, algae and bacteria consortia as well as photobiorector designs, is analyzed for better H2 yield. We review pretreatment approaches, i.e., mechanical, thermal, chemical, enzymatic, and bio-nanoparticle approaches that increase fermentative hydrogen production by solubilising solids. Genetic engineering advances are also featured, which include hydrogenase engineering, pathway modifications, and starch accumulation in species. We discuss some bio-electrochemical systems with a particular focus on the microalgae integration and microbial electrodelysis cells coupled with photosynthesis for hydrogen evolution. Pilot demonstrations are evaluated, where research priorities are genetic modifications, biorefinery concepts, reactor engineering and techno-economic analysis.

Energy commerce and business economics: A review of trends, challenges, and opportunities

2025-06-22T12:08:02+07:00

The energy industry globally is being reshaped by the influences of going green, reducing reliance on large utilities, and increased technology. These shifts prove that energy commerce and business economics greatly affect the changes in how, where, and what energy is used. Now that energy transactions are digital, they run smoothly, and the fairness of competition is boosted. Digitalization also helps businesses improve and achieve growth. The growth of this sector has come from steps like creating the market, dealing with issues in the market, supporting creative business ideas, fueling digital change, lessening regulations, and supporting consumer interests. Whenever the government is involved in projects, the team should pay special attention to the financial aspect, regulations, and sustainability during planning and implementation. Changes in energy markets are determined by rules set by regulators and the way they handle carbon trading. Thanks to AI, blockchains, and FinTech, there are now more opportunities for providing and trading energy. Still, the industry must deal with issues brought on by changes in regulations, swings in the market, and cybersecurity dangers. Soon, using Energy-as-a-Service, environmental, social, and corporate governance (ESG) finance, and merging AI, big data, and circular economy principles will make a big impact on sustainable development. Consequently, this research review demonstrates the value of combining technology, reorganizing systems, and developing economic approaches to drive the changes in energy commerce.

Sustainable treatment of dairy wastewater using a selective microalgal consortium of Chlorella vulgaris, Scenedesmus obliquus, and Chlorococcus minutus

2026-02-06T17:09:13+07:00

Dairy effluents are characterised by high concentrations of organic matter, nitrogen, phosphorus, suspended solids, and chemical additives, making them among the most challenging industrial wastewaters to treat. This study evaluates the potential of indigenous microalgae Chlorella vulgaris, Scenedesmus obliquus, and Chlorococcus minutus for the phycoremediation of dairy wastewater. The untreated wastewater, characterised by high biological oxygen demand (BOD: 768 mg/L) and chemical oxygen demand (COD: 945 mg/L), as well as nitrate (9.31 mg/L), phosphate (4.13 mg/L), and ammonium (0.68 mg/L), was subjected to microalgal treatment. All cultures significantly improved water quality, with the consortium consistently outperforming monocultures. By day 15, BOD and COD reductions exceeded 90%, nitrate removal reached 99.5%, phosphate removal reached 98.1%, and ammonium removal reached 92.6%. Biomass productivity increased steadily, with the consortium achieving the highest yield (1.70 g/L DW), indicating synergistic nutrient assimilation and enhanced growth stability. The findings demonstrate that native microalgal consortia provide an eco-friendly, cost-effective, and scalable approach for dairy wastewater treatment, while generating biomass suitable for biofuel and biofertilizer applications.

Contribution of cashew nut shells as base material in the multi-response optimised automobile brake pad composites in the composition mix

2025-05-04T08:38:17+07:00

The need to develop automobile brake pad materials from green and environmentally sustainable sources is an increasingly growing research direction. Many researchers have been working towards replacing carcinogenic asbestos with other agro-biomass reinforcements that are readily available, effective, and environmentally friendly. Therefore, Agro-waste such as Cashew Nut Shells has now emerged as a new and inexpensive material that could be used to form parts of brake pads composite matrix that are commercially viable and environmentally acceptable. This paper reports the contribution of Cashew Nut Shells (CNS) as a possible replacement of asbestos as base and reinforcement materials when utilized with other brake pads production ingredients. A total of twenty seven (27) trial composites of particle size 100 μm was generated via Taguchi Design of Experimental method and ANOVA from the optimized Grey Relational Analysis indicated that Cashew Nut Shells (CNS) has the highest significant contribution and effects on the multi-response performance of the developed brake pads composites with percentage contribution (p-value) of 27..558% while that of Granite and Plant Gum binder constituents were 25.892% and 15.479% respectfully.

Corrosion analysis of API X70 steel in seawater environment

2025-05-04T08:40:25+07:00

This study is designed to understand the corrosion and the mechanical properties of API X70 steel in a simulation of seawater. A special machine was built to simulate the corrosion of marine pipelines. The elemental structure and microscopic properties of the steel were identified with the help of spectroscopy and microscopy. Tests were conducted on welded samples for tensile strength, impact, compression, and hardness, first in air and again after being in seawater for twelve months. The equipment used for testing was a scanning electron microscope (SEM) to observe the fracture surfaces. It was found that the mechanical properties of API X70 steel became less resistant after being exposed to seawater. When tested in seawater, parent and weld materials had a yield strength of around 428 MPa and 416 MPa, which was a decrease from 560 MPa and 578 MPa in air. For the parent metal and the weld joint, tensile strengths were 634 MPa and 674 MPa, as compared to 512 MPa and 529 MPa afterward. Tests conducted on parent metal produced higher Charpy impact properties than HAZ and weld, and the lowest were found in seawater. Being in saltwater lowered the rigidity and toughness of the bones. Tests exposed brittle as well as ductile types of failure in SEM. The reductions in tensile strength due to the environment were 1.2-1.3, and those for impact were higher at 2.0. This information shows API X70 steel can be applied offshore and helps researchers understand how to handle corrosion better.

SHF, SSF, and co-fermentation of alkali and steam delignified agro-residues to bioethanol

2026-02-13T09:40:07+07:00

Five agro-residues, including sugarcane bagasse, sugarcane tops, sugarcane trash, corn husk and corn stover, were tested for bioethanol production by different fermentation methods using alkali-pretreated, enzymatically saccharified substrates. Co-fermentation of S. cerevisiae and C. shehatae was found to be more efficient in the bioethanol production than SHF and SSF. S. cerevisiae and C. shehatae complemented one another in the fermentation of hexose and pentose sugars. Together, these organisms had the highest ethanol yields from substrates: sugarcane bagasse (278.40 mg/g), sugarcane tops (262.75 mg/g), sugarcane trash (241.42 mg/g), corn husk (232.36 mg/g) and corn stover (239.82 mg/g). A scaled-up study was also carried out for sugarcane bagasse in optimised conditions. 1) 3.0% NaOH treatment (8 hours at room temperature) followed by autoclaving at 121oC for 1 hour. 2) Saccharification by cellulase enzymes (cellulase 15 FPU/g, b-glucosidase 10 IU/g and xylanase 5 U/g). 3) Fermentation by dual cultures (S. cerevisiae and C. shehatae). One kilogramme of pre-treated sugarcane bagasse with a 5% substrate concentration yielded 223 grammes of ethanol, 22.30 percent (w/w) of the pre-treated substrate.

Ectomycorrhizal inoculation with Astraeus odoratus accelerates establishment, functional growth traits, and survival of Dipterocarpus turbinatus in degraded tropical forests

2026-02-18T19:00:23+07:00

Successful restoration of degraded tropical forests requires high-quality seedlings that can establish fast and are environmentally resilient. Dipterocarpus alatus (Gurjan) is a timber species of construction and furniture and most of the seedlings do not survive after transplanting, making the reforestation less effective. This study examined the effect of Astraeus odoratus, an edible ectomycorrhizal fungus, on seedling growth and nutrient uptake in the field. Four-month-old nursery-grown seedlings were inoculated with a liquid suspension of basidiospores (50 mL seedling-1), and non-inoculated seedlings were used as controls. Growth parameters, accumulation of biomass, root colonization, and soil nutrient status were measured after four months, followed by the monitoring of the field transplant. Inoculated seedlings had much greater height (37.8 cm) and root collar diameter (5.89 mm) than controls (26.4 cm and 3.75 mm, respectively). Total dry biomass was also higher in treated seedlings (3.01 g) than in non-inoculated plants (2.34 g). According to the results, microscopic observations revealed ectomycorrhizal colonization with lateral roots and fungal sheaths. Enhanced phosphorus mobilization was through fungal enzymes. Inoculated seedlings had superior growth, a sign of successful establishment. Results confirm that A. odoratus bioaugmentation improved the growth of D. alatus. Integrating edible ectomycorrhizal fungi in nurseries offers a sustainable approach for restoring tropical forestry in the context of advantages for communities.