Search Results (1,442)

Microalgae are considered as sustainable starch producers, yet the carbon sources for this process in terms of starch productivity and functionality require further elucidation. The present study investigated the roles of CO₂ and acetate on the starch production in a marine microalga Tetraselmis subcordiformis, and the ordered structure and digestibility of the starches obtained were characterized. CO₂ and acetate could serve as efficient carbon sources for T. subcordiformis to accumulate starch, with the maximum starch content, yield, and productivity reaching 66.0%, 2.16 g/L, and 0.71 g/L/day on day 3 and the maximum biomass productivity reaching 0.94 g/L/day on day 2, respectively, when 2.5 g/L sodium acetate and 2% CO₂ were simultaneously applied. The addition of acetate under 2% CO₂ improved the photosynthetic efficiency and enhanced the activity of ADP-glucose pyrophosphorylase, facilitating the biomass and starch production. The supply of CO₂ and acetate changed the amylose/amylopectin ratio by affecting the activity of starch branching enzymes and isoamylases. FTIR and XRD analyzes showed that the supply of CO₂ reduced the long- and short-range ordered structure of starch, while acetate promoted the production of additional B- and V-type starch, resulting in a reduced digestibility. The combined supply of 2% CO₂ and 5 g/L sodium acetate enabled the most efficient production of functional resistant starch (RS) measured with Englyst’s method, with a maximum RS content and yield reaching 13.7%DW and 0.40 g/L, respectively, on day 3. This study provided novel insights into the efficient production of high value-added functional starch (RS) from microalgae. Full article

Biodegradable mulch films not only provide similar field benefits to conventional mulch films but also degrade naturally, rendering them an effective alternative to traditional polyethylene mulch films for mitigating “white pollution”. However, recent studies have focused on the material selection and soil ecological impacts of biodegradable mulch films, while their effects on soil water temperature regulation and root architecture in drip-irrigated rice cultivation remain unclear. To address this research gap, in this study, various treatments including no mulch (NM), conventional plastic mulch (PM), and four types of biodegradable mulch films (BM-W₁, BM-B₁, BM-B₂, and BM-B₃) were established, and their effects on the soil hydrothermal flux, root architecture, biomass accumulation, and resource use efficiency of drip-irrigated rice were analyzed at different growth stages. The results indicated the following: (1) Compared with the NM treatment, film mulching increased the soil hydrothermal fluxes and water retention capacity, thereby promoting root growth and biomass accumulation, ultimately increasing the effective panicle number and grain yield. (2) Among the biodegradable film treatments, BM-B₃ (with a degradation period of 105 days) maintained relatively higher soil temperature for a longer duration, which increased surface root distribution in the mid-to-late growth stages, further improving fine root growth and biomass accumulation, consequently enhancing both yield and water use efficiency. In contrast, BM-B₁ and BM-B₂ exhibited excessively rapid degradation rates, leading to significant fluctuations in soil moisture and temperature, thereby negatively affecting water supply and nutrient uptake and ultimately restricting root growth and development. (3) The entropy weight (EW) technique for order of preference by similarity to ideal solution (TOPSIS) model results revealed that although the PM treatment was more advantageous in terms of soil temperature, root dry weight, and soil moisture content, BM-B₃ provided a slightly higher yield than the PM treatment did and offered the advantage of biodegradability, making it a preferred alternative to conventional mulch film. In summary, this study revealed the mechanism by which biodegradable mulch films enhanced biomass accumulation and yield formation in drip-irrigated rice production by optimizing soil hydrothermal dynamics and root architecture, thereby exploring their potential as replacements for conventional mulch films. These findings provide a theoretical basis for the efficient and sustainable production of drip-irrigated rice in arid regions. Full article

In the face of increasingly frequent natural disasters resulting from climate change and disruptions in the supply chains of energy resources, the demand for energy carriers based on locally sourced renewable resources is growing. Biomethane, derived from biomass and having multiple uses in the energy sector, fully meets these conditions. Analyses of the development and spatial distribution of biomethane production plants, the prevalence of methods of its production, and directions of applications, made on the basis of the data gained from official databases and research papers, are the main subjects of the paper. Additionally, the advantages and disadvantages of biomethane production, taking into account the results of the life cycle assessments, and the prospects for development of the biomethane market, facing regulatory and policy challenges, are considered. The results of the review indicate that biomethane production is currently concentrated in Europe and North America, which together generate over 80% of the globally produced biomethane. An exponential growth of the number of biomethane plants and their production capacities has been observed over the last decade. Assuming that the global strategies currently adopted and the resulting regional and national regulations on environmental and socio-economic policies are maintained, the further intensive development of the biomethane market will be expected in the near future. Full article

The reliance on fossil fuels poses significant challenges to the environment and sustainable development. To address the heating requirements of the pyrolysis process in a biomass gasification-based multi-generation system, this study explored the use of low-grade solar energy across the full solar spectrum to supply the necessary energy for biomass pyrolysis while leveraging high-grade solar energy in the short-wavelength spectrum for power generation. The proposed multi-generation system integrates the full solar spectrum, biomass gasification, gas turbine, and waste heat recovery unit to produce power, cooling, and heating. A detailed thermodynamic model of this integrated system was developed, and the energy and exergy efficiencies of each subsystem were evaluated. Furthermore, the system’s performance was assessed on both monthly and annual timescales by employing the hourly weather data for Hohhot in 2023. The results showed that the solar subsystem achieved its highest power output of around 2.5 MWh in July and the lowest of 0.7 MWh in December. The annual electrical output peaked at 10 MWh, occurring around noon in July and August, while the winter peak was typically 2–3 MWh. For the wind power subsystem, the power output was maximized in April at 5.17 MWh and minimized in August at 0.7 MWh. Additionally, considering the overall multi-generation system performance, the highest power output of 14.9 MWh was observed in April, with lower outputs of 10.9, 11.3, and 11.4 MWh from August to October, respectively. Overall, the system demonstrated impressive annual average energy and exergy efficiencies of 74.05% and 52.13%, respectively. Full article

The hydrogen (H₂) economy is seen as a crucial pathway for decarbonizing the energy system, with green H₂—i.e., obtained from water electrolysis supplied by renewable energy—playing a key role as an energy carrier in this transition. The growing interest in H₂ comes from its versatility, which means that H₂ can serve as a raw material or energy source, and various technologies allow it to be produced from a wide range of resources. Environmental impacts of H₂ production have primarily focused on greenhouse gas (GHG) emissions, despite other environmental aspects being equally relevant in the context of a sustainable energy transition. In this context, Life Cycle Assessment (LCA) studies of H₂ supply chains have become more common. This paper aims to compile and analyze discrepancies and convergences among recent reported values from 42 scientific studies related to different H₂ production pathways. Technologies related to H₂ transportation, storage and use were not investigated in this study. Three environmental indicators were considered: Global Warming Potential (GWP), Energy Performance (EP), and Water Consumption (WF), from an LCA perspective. The review showed that H₂ based on wind, photovoltaic and biomass energy sources are a promising option since it provides lower GWP, and higher EP compared to conventional fossil H₂ pathways. However, WF can be higher for H₂ derived from biomass. LCA boundaries and methodological choices have a great influence on the environmental indicators assessed in this paper which leads to great variability in WF results as well as GWP variation due credits given to avoid GHG emissions in upstream process. In the case of EI, the inclusion of energy embodied in renewable energy systems demonstrates great influence of upstream phase for electrolytic H₂ based on wind and photovoltaic electricity. Full article

This work presents an effective design of a strategy to manage biomass waste (empty fruit bunch—EFB, kernel shell, and fiber) available from the processing of oil palm (Elaeis guineensis) in Colombia as a renewable energy source. This type of study is conducted for the first time in the country, and the proposed strategy is structured in four phases. Firstly, an inventory of available biomass waste was prepared based on information from 45 African palm oil companies of the approximately 70 that exist in the country. It was determined that the country had about 2762 kt of available waste (63.64% EFB, 12.55% kernel shell, and 23.81% fiber) for the year 2023. The estimates were conducted using a model that correlates processing capacity, the biomass generated, and the biomass demanded. The validation was performed using national reports. Subsequently, the minimum number (six) of storage centers in Colombia, where the largest amount of biomass can be stored, was determined. The center of gravity method was used to find the geographical location of each bulk storage center (municipality of Aracataca, Agustín Codazzi, San Martín, Puerto Wilches, Castilla La Nueva, and Cabuyaru). The next step was to determine the transportation costs as a decision criterion to select the best bulk storage center. When the required storage capacity does not exceed 211 kt·year⁻¹, Agustín Codazzi is the best option because it has the lowest transportation cost (USD 1.01·t⁻¹). When the storage capacity requirements exceed 211 kt·year⁻¹ but are less than 423 kt·year⁻¹, then Puerto Wilches and/or Aracataca are the best options (transportation cost of USD 1.7·t⁻¹). In all cases, Cabuyaru has the highest costs (USD 6.56·t⁻¹). Finally, an energy potential of 50,196 × 10⁶ GJ·year⁻¹ for the collected biomass was estimated, which makes this kind of waste an environmental alternative that could replace coal in Colombia. Full article

Intensive research has been conducted for many years to develop environmentally friendly techniques for plant cultivation that optimize the fertilization process. One of the most promising areas within the fertilizer industry is using microbiologically enriched fertilizers, which incorporate beneficial bacteria or fungi. Biofertilizers are the focus of studies on both their production technologies and their effects on crop growth and yield, presenting a potential alternative to conventional mineral fertilizers. The prolonged and improper use of mineral fertilizers, along with inadequate plant protection, a lack of organic fertilization, and poor crop rotation practices, negatively impact soil health, disrupting microbial populations and ultimately diminishing yield quality and quantity. Microorganisms, particularly specific groups known as plant growth -promoting rhizobacteria (PGPR) and beneficial fungi, are estimated to make up 85% of the total soil biomass and play a crucial role in soil fertility by mineralizing organic matter, suppressing pests and pathogens, forming humus, and maintaining proper soil structure. They also provide optimal conditions for plant growth. Soil microorganisms can be categorized as either autochthonous, naturally present in the soil, or zymogenic, which develop when easily assimilable organic matter is added. Key microorganisms such as Micrococcus, Bacillus, Azotobacter, and nitrogen-fixing bacteria like Rhizobium and Bradyrhizobium significantly contribute to soil health and plant growth. Microbially enhanced fertilizers not only supply essential macro- and micronutrients but also improve soil quality, enhance nutrient use efficiency, protect plants against pathogens, and restore natural soil fertility, fostering a balanced biological environment for sustainable agriculture. Full article

The growing need for sustainable biomass use has led to the development of decision support tools that investigate the implementation of biomass valorization methods. Most existing tools focus on minimizing supply chain costs and emissions, often lacking a holistic approach that integrates economic, social, and circularity principle factors. This paper introduces the Biomass Valorization Recommender tool, a decision facilitation system developed to support biomass producers, policymakers, and technology providers in selecting optimal biomass valorization pathways. The tool applies a multi-criteria analysis that incorporates biomass quality characteristics, the biomass pyramid and waste hierarchy principles, and socio-economic indicators to evaluate potential valorization pathways of the selected biomass feedstock and technology. The scoring methodology generates a ranked inventory of biomass valorization pathways, such as food ingredients, chemicals, materials, biofuels, and energy production. Additionally, the tool evaluates co-digestion feasibility for anaerobic digestion applications, as well as biogas production potential, and provides biomass roadside cost data to enhance decision-making. A theoretical example in Italy using the industrial fermentation process demonstrates its applicability in biomass valorization solutions within a circular economy framework. This tool aims to identify and assess feedstock valorization opportunities for stakeholders seeking to increase feedstock flexibility and reduce waste by promoting sustainable biomass management, circular economy, and bioeconomy principles. Full article

Litter and pruning biomass are integral to nutrient cycling in the plant–soil ecosystem, contributing significantly to organic matter formation and humus development through decomposition and nutrient mineralization, which ultimately influence soil fertility and health. However, the litterfall dynamics in mango orchards are not well understood, and its contribution to nutrient cycling has seldom been measured. This study aimed to estimate litterfall and pruning biomass in mango orchards and assess the nutrient contents of various biomass components. Litter and pruning biomass samples were collected from four commercial mango orchards planted with Kensington Pride (‘KP’) and ‘B74’ (‘Calypso^®’) cultivars in the Darwin and Katherine regions, using litter traps placed on the orchard floors. Samples were sorted (leaves, flowers, panicles, fruits, and branches) and analyzed for nutrient contents. Results showed that most biomass abscissions occurred between late June and August, spanning approximately 100 days involving floral induction phase, fruit set, and maturity. Leaves made up most of the abscised litter biomass, while branches were the primary component of pruning biomass. The overall ranking of biomass across both regions and orchards is as follows: leaves > branches > panicles > flowers > fruits. The carbon–nitrogen (C:N) ratio of litter pruning material ranged from 30 (flowers) to 139 (branches). On a hectare basis, litter and biomass inputs contained 1.2 t carbon (C), 21.2 kg nitrogen (N), 0.80 kg phosphorus (P), 4.9 kg potassium (K), 8.7 kg calcium (Ca), 2.0 kg magnesium (Mg), 1.1 kg sulfur (S), 15 g boron (B), 13.6 g copper (Cu), 99.3 g iron (Fe), 78.6 g manganese (Mn), and 28.6 g zinc (Zn). The results indicate that annual litterfall may contribute substantially to plant nutrient supply and soil health when incorporated into the soil to undergo decomposition. This study contributes to a better understanding of litter biomass, nutrient sources, and nutrient cycling in tropical mango production systems, offering insights that support accurate nutrient budgeting and help prevent over-fertilization. However, further research is needed to examine biomass accumulation under different pruning regimes, decomposition dynamics, microbial interactions, and broader ecological effects to understand litterfall’s role in promoting plant growth, enhancing soil health, and supporting sustainable mango production. Full article

Tropical acidic soils exhibit inherently low fertility and reduced microbial activity, driven by low pH and accelerated organic matter mineralization, phosphorus (P) fixation, and aluminum (Al³⁺) and iron (Fe³⁺) toxicity. These constraints limit agricultural productivity, necessitating sustainable and low-cost soil amendments essential for improving the soil fertility in such regions. This study investigated the effects of biochar, kitchen stove ash (KSA), and their combined application on the soil chemical properties, nutrient dynamics, and microbial functions in a tropical acidic soil. The treatment included the unamended control and two doses of 0.25% w/w (B₁₀) and 0.5% w/w (B₂₀) corncob biochar, 0.03% w/w kitchen stove ash (A_sh), and 0.027% w/w commercial-grade calcium carbonate (L_ime). Each biochar dose was added alone or in combination with either ash (A_sh + B₁₀ and A_sh + B₂₀) or calcium carbonate (L_ime + B₁₀ and L_ime + B₂₀). After eight weeks of laboratory incubation at 20 °C, the soil pH, N and P bioavailability, microbial biomass, and extracellular enzyme activities were measured. The combined application of 0.5% w/w biochar with 0.03% w/w KSA (A_sh + B₂₀) resulted in the most significant improvements in all of the examined soil fertility indicators than the individual amendments. Specifically, the soil pH was increased by 40% (+1.9 pH units) compared with the unamended control. Available phosphorus, mineral nitrogen, and total potassium were increased by 49%, 22%, and 36%, respectively, compared with the unamended control. Regarding the microbial parameters, the A_sh + B₂₀-treated soil showed the highest microbial respiration (+56%), microbial biomass (+45%), and extracellular C- and N-cycling enzyme activities compared with the unamended soil. The ash supplied minerals (P, K, and Mg) provided a more beneficial effect on the soil’s nutrient content and microbial functions than the calcium carbonate. The study demonstrated that underutilized kitchen ash may supplement biochar’s liming and nutrient supply potentials, even at a lower application rate, to improve the fertility of weathered acidic soil. Full article

This study investigates the socioeconomic determinants governing biomass energy transitions in rural areas of Eastern China through a multiregional spatial analysis. Drawing on time-series data from national and local statistical yearbooks, screened and processed to ensure consistency, the research analyzes evolving rural energy consumption patterns across nine cities in Heilongjiang, Jiangsu, and Guangdong provinces. Biomass energy potential was estimated by integrating crop production and domestic waste data with region-specific residue-to-product ratios, calorific values, and conversion efficiencies. These estimates were further spatialized through GIS-based surplus–deficit modeling to reveal regional disparities in supply–demand balance. The analysis identifies a critical income threshold, whereby lower-income regions exhibit rapid growth in energy consumption until reaching a saturation point around RMB 13,000, while higher-income areas experience continued increases in energy demand beyond the capacity of biomass resources to supply. The findings emphasize that an integrated approach, incorporating agricultural residue and domestic waste utilization, is essential for facilitating sustainable energy transitions, particularly in economically advanced regions. Furthermore, the study develops a scalable framework that integrates socioeconomic and spatial variables into biomass energy planning, underscoring the need for regional transition strategies to address not only resource endowments but also demographic mobility, urbanization dynamics, and income-driven consumption behaviors. Full article

Potassium chloride (KCl) is the main source of potassium (K) in Brazilian agriculture, but its high import dependency and the need for split applications increase costs and expose the system to supply and efficiency risks. Understanding the availability and release kinetics of potassium (K) from biochar-based fertilizers (K-BBFs) is crucial for optimizing their use as full or partial substitutes for KCl in Brazilian agriculture. This study evaluated biochars derived from banana peel (BP), coffee husk (CH), and chicken manure (CM), both in their pure form and co-pyrolyzed with KCl (composites) at 300 °C and 650 °C, as K sources for corn grown in two contrasting Oxisols. For pure biochars, feedstock type and pyrolysis temperature significantly influenced K content and release kinetics. Higher pyrolysis temperatures increased K content in BP and CH biochars but not in CM, while also slowing K release in CH and CM. Co-pyrolysis with KCl increased biochar yield, ash content, and K availability. Composites released more K than pure biochar but less than KCl, and at a slower rate. Notably, banana peel biochar co-pyrolyzed with KCl at 650 °C (CBP650) exhibited 36% slower K release and reduced KCl use by 82% while maintaining similar K use efficiency and corn growth. All K-BBFs matched KCl in promoting robust corn growth in clay soil, increasing biomass by 5.3 times and K uptake by 9 times compared to unfertilized (no K addition) plants. In sandy Oxisol, K-BBFs boosted biomass by up to 3.5 times compared to unfertilized plants, though some pure biochars were less effective than KCl in supporting full corn growth. Soil texture strongly influenced K availability, with sandier soils exhibiting higher K levels in solution. These findings suggest that kinetic release studies in abiotic systems, such as lysimeters with sand, are not suitable for evaluating K-BBFs as slow-release fertilizers. Due to lower K retention in sandy soil and solution K levels exceeding 1100 mg L⁻¹, split applications of some K-BBFs are recommended to prevent corn cation uptake imbalances and soil K leaching. Additionally, granulating biochar–KCl composites may enhance K retention and regulate its release in sandy Oxisols. Full article

Cold stress critically restricts maize seedling growth in Northeast China, yet the mechanism by which cold priming (CP) enhances cold tolerance through proline–nitrogen metabolic networks remains unclear. This study systematically investigated CP’s synergistic regulation in cold-tolerant (Heyu27) and cold-sensitive (Dunyu213) maize using a two-phase temperature regime (priming induction/stress response) with physiological and multivariate analyses. CP alleviated cold-induced photosynthetic inhibition while maintaining a higher chlorophyll and photosynthetic rate, though biomass responses showed varietal specificity, with Heyu27 minimizing growth loss through optimized carbon–nitrogen allocation. Antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were pre-activated during early stress, effectively scavenging reactive oxygen species (ROS) and reducing malondialdehyde (MDA) accumulation, with Heyu27 showing superior redox homeostasis. CP enhanced proline accumulation via bidirectional enzyme regulation (upregulating ∆¹-pyrroline-5-carboxylate synthase/reductase [P5CS/P5CR], inhibiting proline dehydrogenase [ProDH]) and reprogrammed nitrogen metabolism through glutamate dehydrogenase/isocitrate dehydrogenase (GDH/ICDH)-mediated ammonium conversion to glutamate, alleviating nitrogen dysregulation while supplying proline precursors. Principal component analysis revealed divergent strategies: Heyu27 prioritized proline–antioxidant synergy, whereas Dunyu213 emphasized photosynthetic adjustments. These findings demonstrate that CP establishes “metabolic memory” through optimized proline–nitrogen coordination, synergistically enhancing osmoregulation, reactive oxygen species (ROS) scavenging, and nitrogen utilization. This study elucidates C₄-specific cold adaptation mechanisms, advancing cold-resistant breeding and stress-resilient agronomy. Full article

Concerns about sustainable energy sources arise due to the non-renewable nature of petroleum. Escalating demand for fossil fuels and price inflation negatively impact the energy security and economy of a country. The generation and usage of biofuel could be suggested as a sustainable alternative to fossil fuels. Several studies have investigated the potential of using edible crops for biofuel production. However, the usage of algae as suitable feedstock is currently being promoted due to its ability to withstand adverse environmental conditions, capacity to generate more oil per area, and potential to mitigate energy crises and climate change with no detrimental impact on the environment and food supply. Furthermore, the biorefinery approach in algae-based biofuel production controls the economy of algal cultivation. Hence, this article critically reviews different cultivation systems of algae with critical parameters including harvesting methods, intended algae-based biofuels with relevant processing techniques, other applications of valorized algal biomass, merits and demerits, and limitations and challenges in algae-based biofuel production. Full article

As global energy demand continues to rise, microalgae have gained attention as a promising feedstock for biofuel production due to their environmental adaptability and renewable nature. This study investigated the growth performance and stress tolerance of Desmodesmus sp. KNUA231 under varying pH and salinity conditions to evaluate its potential as a biofuel candidate. The strain was cultivated under controlled laboratory conditions and exhibited stable growth across a broad pH range (4–10) and moderate salinity levels (up to 5 g L⁻¹ NaCl), indicating its resilience to diverse environmental conditions. Fatty acid methyl ester (FAME) analysis revealed that the biodiesel properties of Desmodesmus sp. KNUA231 comply with ASTM and EN standards in specific parameters, reinforcing its feasibility as a renewable biofuel feedstock. Additionally, its high calorific value (CV) suggests its potential as an energy-dense biomass source. The results of inductively coupled plasma mass spectrometry (ICP) analysis show that the soil is supplied with essential nutrients while minimizing heavy metal contamination, suggesting the possibility of biofertilizers. Although Desmodesmus sp. KNUA231 demonstrated promising characteristics for biofuel applications, further research is required to optimize large-scale cultivation and improve productivity for industrial applications. These findings highlight the potential of Desmodesmus sp. KNUA231 as a biofuel resource, particularly in non-optimal environmental conditions where pH and salinity fluctuations are common, contributing to the ongoing search for sustainable bioenergy solutions. Full article