Local Biomass Research Articles

Conceptual design and 4E analyses of a tetrageneration system in two different configurations based on poplar sawdust as a local woody biomass fuel

ABSTRACTIn this study, an innovative woody biomass‐fueled hybrid tetrageneration system composed of a single‐effect lithium bromide‐water absorption refrigeration system, a reverse osmosis desalination system, two organic Rankine cycle for the production of cooling, heating, power, and freshwater in two distinct configurations (configurations A and B), compared and discussed using energy, exergy, economic, and exergoeconomic analyses. The poplar sawdust used as a local woody biomass fuel was a by‐product of the Iran Wood and Paper Industries Company, located in northern Iran. The results revealed that the highest heating production and lowest exergy destruction were related to configuration B. The overall cost of configuration A was higher than that of configuration B. A detailed sensitivity analysis was also developed to study the effect of various factors on the thermodynamic and economic performance of the proposed configurations. By increasing the turbine inlet temperature of ORC1 from 625 to 692 K, the total sum unit costs of product of the system in configurations A and B decreased by 20 and 23 $ GJ−1, respectively (about 21%).

Using Lidar to Find the Southeast's Remnant Rivercane

abstract: The floodplains of the Southeast's stream network once hosted immense brakes of rivercane ( Arundinaria gigantea ), a disturbance-dependent native bamboo with both cultural and ecological significance. Ecologically, rivercane alters its local environments, boosts biodiversity and biomass, and protects streambanks from erosion and storm damage. Indigenous peoples of the Southeast have used rivercane for millennia, for material and cultural purposes, and formerly maintained its health and extent through harvesting and fire. Settler-colonial incursions largely destroyed rivercane, through the more intense disturbance of different land management practices, and brakes now exist mainly in relatively small areas. While numerous rivercane restoration projects are in process throughout its natural range, no comprehensive inventory of living rivercane exists. In this paper, we present both human context and the results of LiDAR analysis that identifies canebrakes based on the physical characteristics of the plant and brake. In our study area on the Little Tennessee River in western North Carolina, we found rivercane on about 9 percent of the floodplain area, based on QL1 LiDAR data available from the state of North Carolina. The technique can be applied in any part of rivercane's range, and the resulting inventory used in support of both cultural and ecological goals.

Sustainability analysis of primary wastewater treatment by willow plantations in Québec

Wastewater treatment is a necessary step to avoid environmental impacts of water consumption and usage. Traditional approaches are expensive and are limited to developed countries. Phytofiltration using fast-growing trees and shrubs like willows potentially offer an alternative. This paper aims to determine if wastewater treatment using phytofiltration can provide complementary environmental and economic benefits for rural communities in a Nordic climate such as the province of Québec, Canada. It looks at different perspectives of the wastewater treatment solution in a local and rural context. Based on life cycle analysis (LCA) and life cycle cost analysis (LCC), we found that, for an exemplar Québec municipality, the conventional wastewater treatment scenario impacted more on climate change, ecosystem quality and human health than the two phytofiltration of wastewater scenarios studied, where impact is highly dependant on the biomass valorization. The net present cost of the phytofiltration scenarios were lower than typical conventional treatment in Québec. For a biomass producer, conventional biomass production had the highest environmental impact on ecosystem quality, while biomass production from phytofiltration had the highest environmental impact on climate change, human health, and resources. We demonstrate that the phytofiltration is a viable and multifunctional technology that could provide good incentives for a local biomass value chain. it allows to both alleviate wastewater treatment burden and provide affordable biomass for bioenergy development for rural communities. Mobilizing local stakeholders will be key to make phytofiltration an alternative solution for both environmental burden alleviation and rural economic development.

Reduction in size-at-maturity in unprecedentedly strong cohorts of redfish (Sebastes mentella and S. fasciatus) in the Gulf of St. Lawrence and Laurentian Channel.

Life-history traits, such as size-at-maturity, are key parameters to model population dynamics used to inform fisheries management. Fishery-induced evolution, density-dependent effects, and global warming have been shown to affect size- and age-at-maturity, and resulting spawning stock biomass (SSB) in a wide range of commercial fish stocks. Marked changes in redfish biomass and environmental conditions in the Gulf of St. Lawrence and Laurentian Channel over the past decade called for a review and update of size-at-maturity for commercially important deepwater redfish Sebastes mentella and Acadian redfish Sebastes fasciatus stocks. Following a 25-year moratorium, local redfish biomass has recently reached unprecedented levels, co-occurring with an overall warming of bottom water temperatures. Our objectives were (1) to perform a histological assessment of redfish reproduction stages, including the validation and fine-tuning of a robust visual chart to facilitate monitoring of size-at-maturity and SSB in a transforming environment, and (2) to evaluate changes in size-at-maturity in unprecedentedly strong cohorts of redfish, and consequences for stock status assessment and fisheries management. Each specimen was genetically identified to species, and gonad reproduction stages were determined by histology and macroscopic appearances. The present study enabled a robust visual chart for continued and cost-effective monitoring of redfish reproduction stages to be refined and validated, and has shown a large decrease in redfish length when 50% of the individuals are considered mature that led to an increase in estimates of SSB during the 2011-2021 period for S. mentella and S. fasciatus. These changes modified the perception of stock status, thus having significant implications for fisheries management. Given that fishery-induced evolution and community structure changes along with global warming are affecting numerous stocks worldwide, the present study outlines a major and global challenge for scientists and resources managers. As shown by our results, the monitoring and frequent updates of life-history traits in transforming environments are needed to provide reliable science advice for sustainable fisheries.

Various extracts of the brown seaweed Cystoseira barbata with different compositions exert biostimulant effects on seedling growth of wheat.

Worldwide, where the demand for novel and greener solutions for sustainable agricultural production is increasing, the use of eco-friendly products such as seaweed-derived biostimulants as pre-sowing treatment represent a promising and important approach for the future. Cystoseira barbata, a brown seaweed species abundant in the Mediterranean Region, was collected from the Marmara Sea and subjected to water, alkali, and acidic extractions, and the biostimulant activity of these extracts was tested on wheat (Triticum durum cv. Saricanak-98) using different rates through application to the seeds or germination medium (substrate) applications. The different extracts were characterized by mineral, total phenolic, free amino acid, mannitol, polysaccharide, antioxidant concentrations and hormone-like activity. The effects of the extracts on growth parameters, root morphology, esterase activity, and mineral nutrient concentrations of wheat seedlings were investigated. Our results suggest that the substrate application was more effective in enhancing the seedling performance compared to the seed treatment. High rates of seaweed extracts applied to substrates increased the shoot length and fresh weight of wheat seedlings by up to 20 and 25%, respectively. The substrate applications enhanced the root fresh weights of wheat seedlings by up to 25% when compared to control plants. Among the biostimulant extract applications, the water extract at the highest rate yielded the most promising results in terms of the measured parameters. Cystoseira barbata extracts with different compositions can be used as effective biostimulants to boost seedling growth. The local seaweed biomass affected by mucilage problems, has great potential as a bioeconomy resource and can contribute to sustainable practices for agriculture.

Increasing the Efficiency of Loading Devices for Biomass Boilers

The article examines a method of loading biomass waste into a boiler unit, which ensures the gas tightness of the boiler’s working chamber by forming a “plug” of biomass as it moves through the cylindrical channel of the screw feeder. Local biomass wastes (sunflower husks, coniferous wood sawdust, and walnut shells) were selected for the study, a distinctive feature of which is that they did not undergo any prior processing before use (drying, fractionation, grinding, etc.). The properties of biomass as a bulk material (angle of internal friction) were determined experimentally. According to the results, sawdust from coniferous wood has an average angle of internal friction that is 1.48 times bigger than that of sunflower husks and 1.29 times bigger than walnut shells, while the average loading mass of sawdust is 2.2 times less than that of sunflower husks and 2.6 times less than that of walnut shells. This low bulk density and high angle of internal friction for sawdust suggest the likelihood of spontaneous compaction and layer suspension. Experimental studies were also conducted on the compaction force of the biomass layer. It was found that neither coniferous wood sawdust nor walnut shells can be used in the proposed feeder because the sawdust forms a dense layer that does not disperse under any compaction, and the walnut shells do not form a “plug” in the studied pressure range. Therefore, only sunflower husks were used for further studies. The empirical dependence of the density of the sunflower husk layer on the compaction pressure was obtained from the results. It was determined that to ensure a suction level through a screw feeder with a diameter of 0.1 ÷ 0.25 m into the furnace of the boiler unit of no more than 0.1 m3/h with a pressure difference between the boiler furnace and the surrounding environment ΔP = 0.05 ÷ 0.3 kPa, the relative increase in the density of the “plug” from sunflower husks should not exceed the bulk density of the uncompacted layer by more than 11.5%. Experimentally, it was determined that the geometric dimensions of the “plug” from sunflower husk, which ensure the necessary level of gas tightness of the feeder, depend only on the diameter of the channel and are 1.136·d. Calculations were made to obtain the dependencies of the compaction force of the biomass waste layer on the level of suction (in the studied range Q = 0.01 ÷ 0.1 m3/h) into the furnace of the boiler unit under controlled pressure drops (in the studied range ΔP = 0.05 ÷ 0.3 kPa) between the boiler furnace and the surrounding environment for feeders with different screw diameters (d = 0.1 ÷ 0.25 m), which can be used for the practical determination of the geometric and operational parameters of the screw feeder when operating a boiler unit on sunflower husks.

Strategic planning and optimal tactical management of regional bioethanol supply‐chain system with high spatial resolution and uncertainties

AbstractAlthough bioethanol is viewed as a promising alternative to traditional fossil fuels, its commercialization is hindered by high production costs and uncertain policies. This study proposes a novel integrated framework to support decision making in the bioethanol supply‐chain system under complex uncertainties. By considering various geographical, economic, and environmental factors, potentially suitable sites are identified using a geographic information systems‐based (GIS‐based) multi‐criteria decision‐making approach. Then, a two‐stage stochastic, fuzzy, chance‐constrained programming model is developed to determine investment decisions (i.e. site and size of biorefineries) and operational strategies (i.e. production schedule, biomass supply network, etc.) in the face of uncertainties. The proposed research framework is tailored for a case study in Henan Province, China, which suggests the installation of six biorefineries with a total capacity of 679.11 million liters to reduce local carbon emissions by 1.54 million tons. Decision makers with different risk preferences can use this method to find optimal tradeoff strategies between system cost and risk under uncertainties. Sensitivity analysis also reveals that increasing the proportion of bioethanol blending targets is the key exogenous variable to promote the use of local biomass resources.

Concept Design of the WRB-6 Water-Tube Boiler with a Stepped Grate and a Furnace for Burning Straw Bales in a Cigar System

The article presents the conceptual design of the solid fuel from the forest and sawmill production waste and agricultural waste biomass-fired water boiler. The project was supported by thermal and flow calculations. The designed WRB-6 boiler is a 3-pass unit with a fully screened furnace chamber and is equipment of a local biomass heating plant. It is fired with biomass, transported over no more than 30 km. The furnace has a double function – dual fuel. Both fuels can be burned simultaneously or alternately, depending on seasonal availability. In the front part there is a channel for feeding and burning large bales of cereal straw. The lower closure of the chamber is a mechanically inclined grate for the combustion of wood biomass in the granulation of chips. As part of the work, calculations of the amount of biomass fuels possible to be obtained on the local market with economy of delivery were also performed. As a result of the calculations, the temperatures of water and flue gas at the outlet, boiler efficiency, slagging and impurity indices for biomass were also presented.

Optimising carbon fixation through agroforestry: Estimation of aboveground biomass using multi-sensor data synergy and machine learning

As agricultural land expansion is the primary driver of deforestation, agroforestry could be an optimal land use strategy for climate change mitigation and reducing pressure on forests. Agroforestry is a promising method for carbon sequestration. With recent advancements in geospatial and data science technology, the ability to predict aboveground biomass (AGB) and assess ecosystem services in agroforestry is rapidly expanding. This study was conducted in the Belpada Block of Balangir, Odisha, a forest-dominated region of eastern India. We recorded species occurrence and measured plant parameters, including Circumference at Breast Height (CBH), height, and geolocation, in 196 plots (0.09 ha) in agroforestry intervention sites and noted the tree species. This study used Sentinel-1 and Sentinel-2 multi sensor data to achieve data synergy in AGB estimation. Three machine learning models were used: Random Forest (RF), Support Vector Machine (SVM), and Artificial Neural Network (ANN). The RF model exhibited the highest level of prediction accuracy (R2 = 0.69 and RMSE = 17.07 Mg/ha), followed by the ANN model (R2 = 0.63 and RMSE = 19.35 Mg/ha), SVM model (R2 = 0.54, RMSE = 21.97 Mg/ha. The spectral vegetation indices that are (Normalized Difference Vegetation Index (NDVI), Soil-Adjusted Vegetation Index (SAVI), Enhanced Vegetation Index (EVI), Modified Simple Ratio (MSR), Modified Soil-Adjusted Vegetation Index (MSAVI), Difference Vegetation Index (DVI), and SAR backscatter values, were found important variables for AGB prediction. The findings revealed that agroforestry interventions and plantations resulted in an average carbon stock increase of 15 Mg/ha over five years in the study area. The Plant Value Index (PVI), which indicates the importance of species in the local economy and biomass carbon storage, showed that Tectona grandis was the dominant species with the highest PVI value (88.35), followed by Eucalyptus globulus (56.87), Mangifera indica (53.75), and Azadirachta indica (15.45). This approach enables the expansion of monitoring efforts to assess carbon stock in agroforestry systems, thereby promoting effective management strategies.

Techno-economic assessment of a biomass gasification-based polygeneration system for greenhouses

Decentralized biorefineries are an attractive solution to reduce the carbon footprint of agricultural greenhouses, by converting the abundant local residual biomass into value-added products such as biofuels. While the thermodynamic performance of many biomass system configurations has been investigated in the literature, techno-economic assessments are needed to validate the potential of such facilities. This approach is applied to a small-scale polygeneration system for the use-case of a southern Quebec greenhouse. The polygeneration system can produce heat, electricity, methanol, hydrogen, and a CO2-rich stream. A TRNSYS model is used to simulate the heat demand of a 20 000 m2 greenhouse. The work presented here compares the polygeneration system with a conventional solution based on biomass combustion. Nine configurations between 1120 and 5600 kW of thermal output power are investigated for both system types. Twenty-seven market scenarios are generated from the combination of three pricing scenarios for electricity, methanol, and hydrogen: pessimistic, baseline, and optimistic. Fixed capital investment (FCI), operation expenses (OPEX), and NPV are presented. In the most pessimistic market scenario, the best polygeneration system would have an NPV of −8.2 M CAD. In the baseline and optimistic scenarios, the same polygeneration system would have an NPV of 17.6 M CAD and 40.2 M CAD, respectively. By comparison, the best combustion-based solution would have the highest NPV at −5.0 M CAD. Those results highlight that small decentralized polygeneration systems are promising. However, their profitability is heavily dependent on future energy market developments.

Sources and composition of elemental carbon during haze events in North China by a high time-resolved study

Despite the implementation of stringent emission reduction measures in the past year, severe winter haze events still occurred frequently in North China, with only marginal decreases observed in elemental carbon (EC) concentrations. EC not only constitutes a fraction of particle mass but also interacts with boundary layer and influences haze formation. Given the complex composition of EC, characterizing its sources and composition during haze processes is challenging yet crucial for understanding haze formation and evolution. Here, hourly-resolution PM2.5 samples were collected during three different haze event (P1-P3) in the North China Plain to investigate dynamic changes in EC source across different haze processes. The average EC concentrations and char/soot ratios were 9.94 ± 4.80 μgC·m−3, 14.5 ± 6.93 μgC·m−3, 15.9 ± 5.54 μgC·m−3, and 2.42 ± 0.98, 2.70 ± 0.88, 2.61 ± 0.95 for P1, P2 and P3, respectively. Backward trajectory analysis showed distinct variations in EC concentration and composition under the influence of different air masses during the three haze events, with local air masses influenced days exhibiting higher EC concentrations and char/soot ratios. The char/soot ratio based diagnostic method suggested that EC was predominantly influenced by coal combustion and vehicle emissions. Further positive matrix factorization analysis suggested that biomass burning and residential coal combustion were the main contributors of EC (58 %) and played a dominant role in driving variations in EC concentrations during haze episodes. Potential source contribution function analysis results highlight that local biomass burning and residential coal combustion could be major reason for the EC elevation in different haze events. Our results provide valuable insights into the sources and composition of EC during haze events, facilitating the implementation of effective measures for mitigating both EC and PM pollution.

Multiple energy resources integration in the food industry: A technoeconomic analysis

This study focuses on exploring sustainable energy solutions for the industrial sector, with a particular emphasis on meeting the electrical and thermal needs of the local bakery industry. Several alternative energy sources were proposed in this study, including solar irradiation, and the utilization of agricultural residues (such as olive tree pruning and residues of tomato crop). An anaerobic digestion (AD) reactor, a photovoltaic (PV) system, wind turbines (WT), a gasification system, and a combined heat and power (CHP) unit were used as parts of the developed hybrid renewable energy system (HRES). The objective was to optimize the system's performance by considering renewable energy sources (RES) penetration, energy cost, and ecological footprint.Furthermore, this investigation identified research gaps in the supply of thermal energy demand using renewable energy sources in an industrial setting and evaluated the integration of waste-to-energy technologies in HOMER Pro. Through modelling, optimization, and evaluation, different HRES configurations were assessed to determine the most cost-effective and optimal system for the bakery industry. The optimal suggested HRES showed a 65% reduction (from 0.4362 €/kWh to 0.1533 €/kWh) in the levelized cost of electricity (LCOE). Gasification achieved better results than AD, with the addition of a gasifier leading to a 40% decrease in the LCOE. The renewable fraction for the optimal HRES was 87.9%. There was a reduction in carbon dioxide emissions by 63%, while the HRES had a payback time of 3.17 years. Overall, the findings of this study show that utilizing local biomass and waste can play a significant role in the energy transition, leading to cost reduction and improved economic performance.

Soil management in the Atlantic Forest’s rural properties:

The environmental benefits arising from the interaction between matter and energy flows of permacultural systems acceleratethe recovery processes of degraded areas, which can be potentiated by the increase of plant biomass associated with thegreen manure technique, proposed in this work for the study territory: the surroundings of two Conservation Units (UC),of the Private Reserve of Natural Heritage (RPPN) type, the RPPN Águas Claras I and II. The RPPN Águas Claras I andII are located in the Macabu River basin, a microbasin of the Carukango River. The objective of this study was to analyzeareas submitted to reforestation and agroforestry system (SAF) projects, through estimates of local biomass obtained withthe aid of secondary data from the UCs’ forest inventory. As a result, it was possible to list Ficus sp and Sparattospermaleucanthum as priority native species for forest restoration. It was concluded that it is necessary to consort the two specieswith the planting of species considered green manures, in order to increase forest biomass and stimulate the improvementof soil conditions in the degraded portion of the reserve. This strategy can accelerate the regeneration process, as indicatedby secondary soil analysis data using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS),performed in the area of implementation of the SAF.

Vegetation, fire and climate history in central-western Tasmania (41°S), Australia, over the last ∼21,000 years

We present high resolution pollen and macroscopic charcoal records from Basin Lake, a relatively small mid-latitude (42°S) lake located in central-western Tasmania, Australia, to examine vegetation, fire and climate change since and during the Last Glacial Maximum (LGM). We find dominance of cold-resistant alpine vegetation with buttongrass moorland and scant trees between ∼21.0-17.7 cal kyr BP, with local biomass burning and low lake levels between ∼21.0-20.0 cal kyr BP and a reduction in local biomass burning and a rise in lake levels between ∼20.0-17.7 cal kyr BP. These data suggest glacial-cold conditions during the last millennia of the LGM, with relatively humid conditions between ∼21.0-20.0 cal kyr BP and a further increase in humidity between ∼20.0-17.7 cal kyr BP. These shifts suggest an intensification of the South Westerly Winds (SWW) over the site between ∼20.0-17.7 cal kyr BP. An increase in cold-temperate rainforest taxa followed between ∼17.7-16.0 cal kyr BP along with lake-level lowering, suggesting a warm pulse and southward shift of the SWW at the beginning of the Last Glacial Termination (T1). Subsequent cold-temperate conditions and increased precipitation ensued between ∼16.0-14.9 cal kyr BP promoted by increased SWW influence. A rise in cold-resistant and hygrophilous rainforest taxa and lower biomass burning activity occurred between ∼14.9-12.8 cal kyr BP under colder conditions, enhanced precipitation and major SWW influence. A multi-millennial warm/dry interval began at ∼12.8 cal kyr BP with a decline in rainforest taxa, high fire activity and low lake levels and a further opening of the vegetation in response to elevated biomass burning between ∼11.1-8.9 cal kyr BP. We suggest a decline in the SWW influence that started at ∼12.8 cal kyr BP and accentuated between ∼11.1-8.9 cal kyr BP at the beginning of the Holocene. We detect increases in precipitation between ∼8.9-5.8, ∼3.4-1.9 cal kyr BP and the last ∼900 years, with declines in the intervening intervals. Our data indicate a pronounced and sustained fire-driven shift to a more open and shrub dominant landscape after ∼5.0 cal kyr BP, in synchronous with other pollen data from Tasmania's west, reflecting an increased efficacy of Aboriginal burning under more variable and overall reduced precipitation. Our climate inferences from Basin Lake are coherent with variations of the SWW identified in other terrestrial mid-latitudes records, suggesting synchronic changes in the SWW during and since the LGM.

Characteristics of atmospheric black carbon and its wet scavenging in Nanning, South China

Based on in-situ measurement of black carbon (BC) and carbon monoxide (CO), the characteristics of BC emissions and wet scavenging were comprehensively investigated in Nanning, South China. The average annual BC concentration was 1.02 ± 0.53 μg m−3 with higher pollution levels during winter. In winter, a higher net BC/CO (ΔBC/ΔCO) ratio of 3.3 ± 0.3 ng m−3 ppb−1 along with an increased absorption Ångström exponent (AAE) and BC mass from biomass burning (BCbb), indicated a significant contribution of biomass burning to BC emissions. However, emissions from the traffic sector consistently exerted a dominant influence throughout the year. Cluster analysis of backward trajectories identified three types of air masses with distinct origins. Cluster #1 originated from Guangxi province and its vicinity, intermittently influencing the sampling site throughout the year with varying effects between winter and summer. This air mass brought in clean sea breeze in summer whereas transported a higher proportion of BCbb to the site during wintertime due to local open biomass burning. Cluster #3 primarily arrived in autumn and winter (October–December) from polluted central China, resulting in substantially high BC mass at the site. Cluster #2 coincided with the period (January–March) when extensive surface open biomass burning events occurred in Southeast Asia (SEA) regions. These BC aerosols in cluster#2 initially rose to higher altitudes above SEA before being regionally transported, but were significantly scavenged by clouds and precipitation during vertical uplift. The remaining BC exhibited a notably lower BC loss rate on relative humidity (RH) of −0.01 ng m−3 ppb−1 %−1 compared to cluster #1 (−0.03) and cluster #3 (−0.06), corresponding to an average BC transport efficiency of 0.85, 0.73, and 0.53, respectively. Nonetheless, air masses in cluster #2 could still transport considerably high BC mass to Nanning due to dry conditions and less wet scavenging along trajectory pathways. These findings provide valuable insights for policymakers and government officials in regulating and mitigating BC pollution in South China.

Preparation of low-cost activated carbon from Doum fiber (Chamaerops humilis) for the removal of methylene blue: Optimization process by DOE/FFD design, characterization, and mechanism

Within the context of a circular economy, this work aims to valorize local lignocellulosic biomass of Doum fiber (Chamaerops humilis), as a highly promising adsorbent material for the removal efficiency of methylene blue (MB) dye via the adsorption process. Thus, this study investigates the potential of both raw (RDF) and activated carbon from Doum fiber (ACDF) as adsorbents. The first task was to enhance the adsorption efficiency of MB onto activated carbon by systematically optimizing its synthesis conditions. To achieve this, a full factorial design (FFD) approach of four factors (activation time, activation temperature, contact time, and concentration of H3PO4) at two levels was employed, using H3PO4 as the activating agent. A series of batch experiments were performed to characterize the adsorption properties of MB onto RDF and ACDF by describing the adsorption conditions, determining the kinetic and isotherm models, and evaluating the thermodynamic parameters. The results obtained revealed that ACDF had significantly higher surface affinity for MB than RDF, with an adsorption capacity of 83.82 mg. g−1. The adsorption process was found to be spontaneous and endothermic for ACDF, while for RDF, it was exothermic. The adsorption data for both ACDF and RDF exhibited a good fit to the Langmuir isotherm model, indicating monolayer adsorption. Furthermore, the kinetic data demonstrated excellent agreement with the pseudo-second-order model, suggesting a three-step rate-controlling mechanism. According to the results of density functional theory (DFT) calculations, the adsorption mechanism of MB mainly involves electrostatic interactions, hydrogen bonds, and n-π, π-π interactions with the two adsorbents.

Effect of multi sourced compost on a rainfed olive tree grove in an arid land: Management practices to adapt to global climate change

In southern Tunisia, in an arid environment subjected to climate change, the olive-production sector is important for the local Economy. With low local biomass production a multi sourced compost composed of olive waste byproducts and seaweed was tested on an Arenic Calcisol. The application at the subsurface of 180 kg (0.5 m3) of compost per tree in a rainfed olive tree (Olea europaea L.) grove with declining productivity showed a significant increase in total C, N, K, P, and respiration rate in amended horizons. Surprisingly the soil volumic water content (Vw%) at the subsurface (0–20 cm) below amended (7.5% ± 2.3) was not significantly different below non amended trees (6.9% ± 3.3). It increased slightly under non-amended trees, from 6.6% (±4.3) at a depth of 5 cm–8.1% (±1.5) at 65 cm depth, while below the amended olive trees the Vw% increased from 6.7% (±3.4) in the composted horizon at 5 cm depth to 13.5% (±1.1) at 70 cm depth. The main positive effect of composting on soils was decreasing the water loss due to capillary rise, since the compost developed clear hydrophobic properties. Two years after applying the compost, olive tree branches were 15% longer and olives were 40% heavier on amended trees.

Integrating survey and observer data improves the predictions of New Zealand spatio-temporal models

AbstractIn many situations, species distribution models need to make use of multiple data sources to address their objectives. We developed a spatio-temporal modelling framework that integrates research survey data and data collected by observers onboard fishing vessels while accounting for physical barriers (islands, convoluted coastlines). We demonstrated our framework for two bycatch species in New Zealand deepwater fisheries: spiny dogfish (Squalus acanthias) and javelinfish (Lepidorhynchus denticulatus). Results indicated that employing observer-only data or integrated data is necessary to map fish biomass at the scale of the New Zealand exclusive economic zone, and to interpolate local biomass indices (e.g., for the east coast of the South Island) in years with no survey but available observer data. Results also showed that, if enough survey data are available, fisheries analysts should: (1) develop both an integrated model and a model relying on survey-only data; and (2) for a given geographic area, ultimately choose the index produced with integrated data or the index produced with survey-only data based on the reliability of the interannual variability of the index. We also conducted a simulation experiment, which indicated that the predictions of our spatio-temporal models are virtually insensitive to the consideration of physical barriers.

Spatial predictions and uncertainties of forest carbon fluxes for carbon accounting

Countries have pledged to different national and international environmental agreements, most prominently the climate change mitigation targets of the Paris Agreement. Accounting for carbon stocks and flows (fluxes) is essential for countries that have recently adopted the United Nations System of Environmental-Economic Accounting - ecosystem accounting framework (UNSEEA) as a global statistical standard. In this paper, we analyze how spatial carbon fluxes can be used in support of the UNSEEA carbon accounts in five case countries with available in-situ data. Using global multi-date biomass map products and other remotely sensed data, we mapped the 2010–2018 carbon fluxes in Brazil, the Netherlands, the Philippines, Sweden and the USA using National Forest Inventory (NFI) and local biomass maps from airborne LiDAR as reference data. We identified areas that are unsupported by the reference data within environmental feature space (6–47% of vegetated country area); cross-validated an ensemble machine learning (RMSE=9–39 Mg C textrm{ha}^{-1} and textrm{R}^{2}=0.16–0.71) used to map carbon fluxes with prediction intervals; and assessed spatially correlated residuals (<5 km) before aggregating carbon fluxes from 1-ha pixels to UNSEEA forest classes. The resulting carbon accounting tables revealed the net carbon sequestration in natural broadleaved forests. Both in plantations and in other woody vegetation ecosystems, emissions exceeded sequestration. Overall, our estimates align with FAO-Forest Resource Assessment and national studies with the largest deviations in Brazil and USA. These two countries used highly clustered reference data, where clustering caused uncertainty given the need to extrapolate to under-sampled areas. We finally provide recommendations to mitigate the effect of under-sampling and to better account for the uncertainties once carbon stocks and flows need to be aggregated in relatively smaller countries. These actions are timely given the global initiatives that aim to upscale UNSEEA carbon accounting.

Estimation of biomass utilization potential in China and the impact on carbon peaking.

China has abundant agricultural and forestry waste resources that are crucial sources of energy for substituting fossil fuels and achieving the carbon peaking and carbon neutrality goals. These resources play an essential role in reducing carbon dioxide emissions and promoting sustainable development. This paper presents an estimation of the number of biomass resources that can be used for energy in 2020 by using parameters such as the grass-to-grain ratio coefficient and excretion coefficient. Moreover, the potential for conversion of biomass resources into biomass energy is evaluated by using parameters such as lower heating value and gas production coefficient. Finally, based on the whole life cycle theory, the potential of biomass energy utilization to reduce carbon dioxide emissions and its impact on carbon peaking is calculated. It was found that the total amount of fossil fuels that can be replaced by biomass energy is 256 million tons of standard coal. Utilizing biomass energy can reduce carbon dioxide emissions by approximately 520 million tons, with a peak impact of 4-6% on carbon peaking. The research results presented in this article can provide valuable data to support the promotion of green transformation in various regions. The findings can serve as a useful reference for formulating localized biomass utilization plans and designing effective emission reduction policies.