Biomass Harvesting Research Articles

Development of an individual-based tag recapture model to benchmark biomass and harvest rates in an iconic lobster fishery

The West Coast Rock Lobster Managed Fishery (WCRLMF) moved from input to output controls in 2010. This change affected the relativity of fishery-based data sources (e.g., catch rates and landed size composition), making the assessment of the fishery problematic. A novel examination of the stock dynamics was required to ensure the robustness of the stock assessment and associated management arrangements. This study derived estimates of current biomass levels and harvest rates from the release of over 60,000 tagged western rock lobsters (Panulirus cygnus). A Brownie tag-recapture (BTR) model was initially implemented to provide an assessment on a fishery-wide basis. Estimates from this were compared to those derived from a novel purpose-built tag-recapture individual-based model (IBM) that accounted for sex, size, month, and location-specific changes in catchability. The two models produced similar estimates on a fishery-wide scale—harvest rate (HR 0.26 vs 0.30, respectively) and legal-sized biomass (about 24,500 vs 20,735 t, respectively)—while the IBM also provided estimates on a far finer spatial and temporal scale. Both models indicate that the WCRLMF is currently in a very sustainable condition and is being fished at a rate below maximum economic yield (HRmey is about 0.39). These findings were in concert with estimates derived for this fishery based on two separate catch-rate based population models, an integrated population model and a biomass-dynamics model. Such strong agreement among all models provides great certainty in the current assessment and management of this important marine resource.

Evaluation of the performance of different membrane materials for microalgae cultivation on attached biofilm reactors

Attached microalgae production in wastewater is a promising method to further develop biofilm reactors by reducing economic costs associated with biomass separation and harvesting. However, the reliability of materials to support such adherence needs further investigation. Five common microfiltration membranes were evaluated in this study to assess their influence on the efficacy of harvesting Chlorella pyrenoidosa. The material-to-material, algae-to-algae, and algae-to-material interactions were studied based on the Extended Derjaguin, Landau, Verwey, Overbeek (XDLVO) theory. The results showed that Chlorella pyrenoidosa was hydrophobic and that the algae particles derived from this algae type tended to agglomerate. Furthermore, the algae–membrane adhesion free energy further validated the accumulation of biomass in the experiments — the cellulose acetate nitrate (CACN) membrane and the cellulose acetate (CA) membrane obtained an optical biomass production of 59.93 and 51.27 g m−2. The presence of these interactions promoted the adhesion of more microalgae particles to the membrane. Moreover, the relationship between the algae–membrane and the distance at which the microalgae approached the membrane surface was simulated. The study indicated that the XDLVO theory could be successfully applied to the mechanism for the adhesion of the attached culture of Chlorella pyrenoidosa to the membrane material.

Environmental Benefits of a Hybrid System for Algal Biomass Production, Harvesting and Nutrient Recovery Under a Life-Cycle Assessment

Environmental Benefits of a Hybrid System for Algal Biomass Production, Harvesting and Nutrient Recovery Under a Life-Cycle Assessment

Harvesting of Chlorella sorokiniana BR001 cultivated in a low-nitrogen medium using different techniques

ABSTRACT: The harvesting process is a current challenge for the commercial production of microalgae because the biomass is diluted in the culture medium. Several methods have been proposed to harvest microalgae cells, but there is not a consensus about the optimum method for such application. Herein, the methods based on sedimentation, flocculation, and centrifugation were evaluated on the recovery of Chlorella sorokiniana BR001 cultivated in a low-nitrogen medium. C. sorokiniana BR001 was cultivated using a low-nitrogen medium to trigger the accumulation of neutral lipids and neutral carbohydrates. The biomass of C. sorokiniana BR001 cultivated in a low-nitrogen medium showed a total lipid content of 1.9 times higher (23.8 ± 4.5%) when compared to the biomass produced in a high-nitrogen medium (12.3 ± 1.2%). In addition, the biomass of the BR001 strain cultivated in a low-nitrogen medium showed a high content of neutral carbohydrates (52.1 ± 1.5%). The natural sedimentation-based process was evaluated using a sedimentation column, and it was concluded that C. sorokiniana BR001 is a non-flocculent strain. Therefore, it was evaluated the effect of different concentrations of ferric sulfate (0.005 to 1 g L-1) or aluminum sulfate (0.025 to 0.83 g L-1) on the flocculation process of C. sorokiniana BR001, but high doses of flocculant agents were required for an efficient harvest of biomass. It was evaluated the centrifugation at low speed (300 to 3,000 g) as well, and it was possible to conclude that this process was the most adequate to harvest the non-flocculent strain C. sorokiniana BR001.

Assessment of alternative forest road routes and landslide susceptibility mapping using machine learning

Background: Forest roads are among the most basic infrastructure used for forestry activities and services. To facilitate the increased amount of biomass harvesting adequately, the existing road network may require modifications to allow forest transportation within harvesting units that are not yet accessed by the roads. The construction of a forest road can trigger landslides, so the necessary constraints should be considered when the road is being planned to preclude such problems. Landslide Susceptibility Mapping (LSM) has become an integral part of the growing process of machine learning (ML), providing a more effective platform for practitioners, planners, and decision-makers. This study aims to reveal the most suitable alternative routes for a forest road, especially in areas susceptible to landslides, and to provide an effective tool for decision-makers. Results: For this purpose, two models were developed through ML: Logistic Regression (LR) and Random Forest (RF). Elevation, slope, aspect, curvature, Topographic Wetness Index (TWI), Stream Power Index (SPI), distance from the fault, the road, and the stream, and lithology were considered as the main landslide susceptibility factors in these models. The best model was obtained by the RF approach with an Area Under ROC Curve (AUC) value of 81.9%, while the LR model was 78.2%. LSM data was used as a base, and alternative routes were obtained through CostPath analysis. Conclusion: It has been shown that the ML methods used in this study can positively contribute to decision-making by providing more effective LSM calculations in studies to determine alternative routes in a forest road network.

Microalgae Enrichment for Biomass Harvesting and Water Reuse by Ceramic Microfiltration Membranes

Microalgae Enrichment for Biomass Harvesting and Water Reuse by Ceramic Microfiltration Membranes

Calibration of disk pasture meter to estimate a fire fuel load (aboveground plant biomass) for fire management in the northeastern steppe of Mongolia

Grassland fires are the most common disturbance in Mongolia's east. Fire risk management in Mongolia's eastern grasslands should include fuel load estimates (aboveground plant biomass) to prevent fire damage. The disc pasture meter (DPM) is a common, rapid, and nondestructive method for estimating aboveground plant biomass in grasslands. Calibration is needed for the DPM application in a given area due to regional variations in climate and plant diversity, as well as site-specific environmental factors. We calibrated a DPM for Mongolia's north-eastern grasslands bordering Russia, classified as a very high-risk region for grassland fire. The calibration was carried out at twelve different sites, and double sampling (DPM reading and plant biomass harvesting) was done at 108 points. The mean of the total dry plant biomass of the sites was 11.27 centner ha-1 (±1.93 SE). The sites differed in total dry plant biomass and its composition. It indicates that the sites are needed different fire managements. Although we developed three linear regression models for DPM readings (100, 200, and 300) to estimate an optimal sampling effort, the model with 300 DPM models had the highest determination coefficient (0.82). Therefore, we suggest the model (y=3.18x+3.1) with the 300 DPM readings for further application.

Peculiarities of Photosynthetic Activity of Winter Pea Plants Depending on the Sowing Rates

. Peas are a crop that is quite picky about weather conditions, therefore, against the backdrop of worsening climatic conditions, it is necessary to pay attention to the wintering form. The main advantage of overwintering peas is that it uses the moisture of the winter period and thanks to this forms above-ground and underground biomass of plants even before the onset of summer drought. At the beginning of the recovery of spring vegetation, plants have a well-developed root system that penetrates deep into the soil up to 10 cm, while spring peas at this time are just beginning to sow. As a result, the potential yield of winter peas is 2-3 times higher than that of spring peas. The purpose of the research was to determine the influence of varietal features of plants, seed sowing rates on the photosynthetic activity of crops and grain yield of winter peas in the conditions of southern Ukraine. Research methods: field, laboratory, computational, statistical. As a result of the research, the peculiarities of the growth of the above-ground mass of plants, the photosynthetic activity of crops and the formation of grain yield of winter pea varieties were studied. The optimal rate of winter pea seed sowing, at which the genetic potential of varieties is fully realized, has been revealed. The norm of seed sowing was established, at which winter pea plants formed the maximum area of the leaf surface. Research has established that in most cases the maximum level of biomass harvest is formed at the minimum density of plants in the budding phase. As the density increases, the biomass gradually decreases, which is a reliable sign of the significant advantage of crops with lower sowing rates in terms of photosynthesis productivity.It was determined that the highest winter pea grain yield, on average over the years of research and according to the studied sowing rates, was formed by the Enduro variety. Research has established that wintering peas form a small area of the leaf surface, which is characterized by a high level of difference in productivity at a reduced seeding rate. The practical aspects and conclusions reflected in the article are aimed at improving the processes of wintering pea productivity in the conditions of southern Ukraine, in particular, at significantly more efficient use of moisture during the growing season of plants for the formation of a unit of harvest

A report on characterization of submerged fermentation of Phellinus linteus in Vietnam

Phellinus linteus strain GC was cultured for harvesting biomass by submerged fermentation method in 100 L fermenter which produced in Vietnam. The process of cultivation of this fungus was performed in aerobic conditions with aeration at 1 vvm, stirred at 150 rpm, temperature from 27oC to 29oC. The observation of cultivation was performed to evaluate the optimum time of growth which produce highest biomass of the mycelium for application purpose of using as functional food. The pH of medium was slightly changed with decrease then increase again, and reached about 6.0 when cultivation process ends. The biomass of mycelium was gradually increased until about 11 days of cultivation with about 30 g/L of dried biomass and the content of of sugar reduced in medium decreased from 40 g/L to 6 g/L.

Growth and nutrients removal characteristics of attached Chlorella sp. using synthetic municipal secondary effluent with varied hydraulic retention times and biomass harvest intervals

Advanced nutrients removal from low strength municipal secondary effluent is of urgent need, while microalgae-based approaches can achieve satisfactory effluent polishing without extra chemicals and energy consumption, and the obtained biomass could be processed into value-added products. Conventional suspended systems are either faced with algae-water separation issue, or with the requirement of membrane modules and low scale-up probability. The widely applied attached systems for water remediation such as Algal Turf Scrubbers can resolve the algae-water separation issue, but the biofilm is often dominated by filamentous microalgae, which are of high ash content and low commercial value. Attached systems dominated by selected microalgal strains, however, are mostly fed with high strength wastewater, and the growth and nutrients removal characteristics of these microalgae using low strength effluent is so far unclear. This study explored the potential of using attached Chlorella sp. for synthetic municipal secondary effluent polishing and biomass production, and investigated the effects of hydraulic retention time (HRT) and biomass harvest interval on microalgal growth, extracellular polymeric substances (EPS) content, harvested biomass composition, and nutrients removal. When only HRT was concerned, highest microalgal growth rate (0.77 g/m2/d) and EPS content (80.8 mg/g dry cell weight, DCW) were found at HRT = 2 d, meanwhile total nitrogen and total phosphorus were respectively reduced to 1.2 mg/L and 0.1 mg/L. Attached microalgal growth increased to more than 1.2 g/m2/d at 4 d harvest interval, generating biomass with 27.9–35.2% protein, 20.6–23.4% polysaccharides, and 21.6–26.4% lipid. The biomass EPS content was significantly positively correlated to biomass productivity, reaching highest level (156.8 mg/g DCW) at 4 d harvest interval. Nutrients removal performances, however, were inferior to those without biomass harvest. The mismatch between attached microalgal growth and nutrients removal highlighted the need to balance biomass production and effluent polishing performances when using low strength effluent as culturing medium.

Transcriptome analysis of potential flocculation-related genes in Streptomyces sp. hsn06 with flocculation activity on Chlorella vulgaris biomass.

Chlorella vulgaris is a biomass energy provider with promising potential to help alleviate the energy crisis. Streptomyces sp. hsn06, as an actinomycete, can harvest C. vulgaris biomass safely and efficiently through flocculation activity, and proteins contribute greatly to the flocculation effect. However, potential flocculation protein-related genes are unclear. The mycelia of strain hsn06 after culture with glucose as the sole carbon source exhibited significantly higher flocculation activity as well as higher protein contents than those cultured with starch as the carbon source. To further explore the flocculation mechanism, the mycelia of strain hsn06 with distinct flocculation activities after culture with different carbon sources were examined by transcriptome analysis. We found that 403 genes were differentially up-regulated in mycelia cultured with glucose, compared to those cultured with starch as the carbon source. Five significantly differentially expressed protein-related genes were determined and confirmed by qRT-PCR, which indicated that three of the selected genes were potential flocculation-related genes. These results advance our understanding of potential flocculation-related genes during the harvesting of microalgal biomass.

Carbon and Nitrogen Dynamics in Mexican Management Forest: Simulation of Biomass Harvesting and C and N Amendments

AbstractSustainable silvicultural management requires the maintenance of long-term ecosystem processes. We used the CENTURY model to simulate the impact of wood extraction and organic amendments on aboveground biomass, carbon (C) storage, and the availability of nitrogen (N) in the two dominant silvicultural methods in Mexico: the silvicultural development method (SDM) and irregular forest management (IFM). The values of the mean absolute percentage error for the SDM and IFM were 2.1% and 3.3% for C in aboveground biomass, 5.7% and 5.0% for soil organic carbon (SOC), and 14.9% and 21.6% for N, respectively. Simulation for the SDM (1967–2068) suggested a reduction of ~7% in C in soil, microbial biomass, and litter, 9% in aboveground biomass C, and ~20% in the mineral N available. For IFM, the simulation (2009–2019) suggested a reduction of 14% in the accumulation of aboveground biomass and 13% in the mineral N available. Simulation of the adoption of management practices suggested that N mineral availability would increase by 2%–3% without drastically reducing the SOC, improving aboveground biomass production by ~7%, in each management system.Study ImplicationsIn Mexico, current silvicultural management is causing alterations in the biological and chemical processes of the soil, but the future impacts on the production of forest wood and loss of fertility cannot be estimated by direct measurements. We simulated two silvicultural management alternatives with two rotation cycles and measured the response in terms of SOC, nitrogen availability, and aboveground biomass. The model shows that improving forest residue management by adding organic amendments to the soil would counteract changes in soil microbial activity, nitrogen availability, SOC, and aboveground biomass in the future. Managers should consider this information to reorient current crop residue management to achieve the objectives and the sustainability of forest management in Mexican temperate forests.

Promotion effect of bacteria in phycosphere on flocculation activity of Aspergillus niger on Synechocystis biomass

The cyanobacterium Synechocystis with high scientific research value and application potential to aquaculture is hard to harvest its biomass. Bioflocculation is an economical and efficient method for harvesting microalgal biomass. In this study, Aspergillus niger 7806F3, a fungus that showed high flocculation activity on Synechocystis cells, was selected to assess its potential for the harvest of microalgal biomass. The analyses of flocculation activity and flocculation mechanism indicated that mycelial pellets of Aspergillus niger 7806F3 exhibited high flocculation activity on Synechocystis biomass through charge neutralization mechanism, and proteins of mycelial pellets participated in the flocculation activity. The flocculation activity of strain 7806F3 on aseptic algal culture indicated that bacteria in the phycosphere can promote the flocculation effect of strain 7806F3 on algal cells. Bacterial community analysis indicated that the addition of mycelial pellets changed the bacterial community diversity in the Synechocystis phycosphere, increasing the abundance of genus Pseudomonas in the phycosphere. Finally, Pseudomonas sp. Algal4 was isolated from the Synechocystis phycosphere and confirmed with the ability to promote the flocculation activity of strain 7806F3 on Synechocystis cells. This study not only provides a method to harvest Synechocystis biomass, but also confirms the promotion effect of bacteria in phycosphere on flocculation activity, which provided a new understanding for the interaction between the algae and bacteria in the phycosphere.

A Review about Microalgae Wastewater Treatment for Bioremediation and Biomass Production—A New Challenge for Europe

Microalgae have received much attention in the last few years. Their use is being extended to different fields of application and technologies, such as food, animal feed, and production of valuable polymers. Additionally, there is interest in using microalgae for removal of nutrients from wastewater. Wastewater treatment with microalgae allows for a reduction in the main chemicals responsible for eutrophication (nitrogen and phosphate), the reduction of organic substrates (by decreasing parameters such as BOD and COD) and the removal of other substances such as heavy metals and pharmaceuticals. By selecting and reviewing 202 articles published in Scopus between 1992 and 2020, some aspects such as the feasibility of microalgae cultivation on wastewater and potential bioremediation have been investigated and evaluated. In this review, particular emphasis was placed on the different types of wastewaters on which the growth of microalgae is possible, the achievable bioremediation and the factors that make large-scale microalgae treatment feasible. The results indicated that the microalgae are able to grow on wastewater and carry out effective bioremediation. Furthermore, single-step treatment with mixotrophic microalgae could represent a valid alternative to conventional processes. The main bottlenecks are the large-scale feasibility and costs associated with biomass harvesting.

Algal biomass harvesting using low-grade waste heat: the effect of waste heat temperature and air speed on dewatering algal suspension

This study investigated the feasibility of evaporating water from heated algal biomass in an evaporation tank. Computational fluid dynamic (CFD) analysis was performed with Ansys Fluent, and the results were verified with experiments. The results of CFD analysis showed a positive effect on the evaporation rate. As the speed of the air stream increased from 0 to 3 m/s, the evaporation rate increased from 9 to 200 mL/h. It was also observed that the temperature of the mixture of air and water vapor decreases more rapidly, but the temperature of the liquid decreases more slowly, as the speed of the air stream increases. The liquid flow is more disturbed as the speed of the air stream increases while the air streamlines are more parallel at higher speeds. Finally, as the speed of the air stream increased from 0 to 3 m/s, the liquid pressure at the bottom of the tank decreased from 270 to 140 pa. The experimental results were compared with the calculation based on the stagnant film theory and showed excellent agreement. The CFD results underestimated the evaporation rate by 10% compared with the experimental results.

The use of remote sensing tools for accurate charcoal kilns’ inventory and distribution analysis: Comparative assessment and prospective

Historical charcoal production is one of the significant factors affecting today’s forest dynamics. A key challenge is to develop tools to investigate historical charcoal production over large areas, allowing a more comprehensive understanding of past impacts and history of charcoal production over a given landscape. In this study, high-resolution remote-sensing airborne LiDAR images over a large woodland area were used to compare manual on-screen versus algorithm-based automatic methods to inventory charcoal kilns with inputs of field-validated data. The results revealed that (1) the on-screen detection method provided less false-positives, (2) the automatic method detects a higher number of kilns and (3) kiln distribution seemed to be connected mostly to land ownership rather than to environmental variables. This study validates a new method of charcoal kilns’ inventory and spatial analysis that can be applied to other areas to better understand the effect of past biomass harvesting for charcoal production on forest dynamics.

Improving Crop Lodging Resistance by Adjusting Plant Height and Stem Strength

Crop height not only determines plant resistance to lodging and crowding, but also affects crop architecture, apical dominance, biomass, and mechanical harvesting. Plant height is determined by the internode elongation, regulated by genes involved in gibberellin (GA) and brassinosteroid (BR) biosynthesis or related signaling networks. Plants’ genetic inability to synthesize or respond to GAs and BRs induce dwarfness. However, the signaling mechanisms of GAs and BRs for controlling plant height individually or collectively are still unclear. Since stem mechanically supports plant during the whole life span, components that affect stem physical strength are also important to crop lodging resistance. One of the major components is lignin, which forms stem structure, thus contributing to crop lodging resistance. In this review, we looked into the reported genes involved in lignin, GAs, and BRs biosynthesis and summarized the signaling networks centered by these genes. Then, we filled the knowledge gap by modifying plant height through interrupting normal GA and BR metabolism utilizing core gene inhibitors. Therefore, we highly endorsed the current approaches of using plant growth regulators (PRGs) to maintain an ideal plant height under lodging stress, and proposed possibilities of modifying crop culm strength against lodging as well.

Valorization of forest waste biomass by catalyzed pyrolysis

Harvesting of forest residual biomass contributes to regulating wildfires during hot and dry seasons. The collected biomass can be converted into liquid biofuel by pyrolysis. Simple pyrolysis procedures such as slow pyrolysis will allow to dimension and design of mobile pyrolysis units to avoid biomass transportation fees and guarantee efficient management of forest residues. Portuguese forest wastes, particularly biomass from maritime pinus and eucalyptus globulus, were characterized by thermogravimetry and pyrolyzed in a fixed bed reactor, at 698 K, using commercial alkali carbonates and zeolites, bauxite ores, and marble dust as catalysts. Pyrolysis data for mixed biomasses showed the existence of synergy effects. The catalytic pyrolysis experiments led to improved bio-oil quality for all the tested catalysts. The bio-oil produced from pyrolysis with sodium carbonate was the most volatile, since the maximum peak of the volatilization rate is at 390 K, while the bio-oils produced by the remaining catalysts have maximum volatilization at 410 K. Marble dust, a waste from ornamental stones industry, revealed excellent catalytic properties during biomass pyrolysis, allowing an improved bio-oil yield with a decrease in the oxygen-containing functional groups.

Economic feasibility of forest biomass feedstock supply chains: clean and dirty chips for bioenergy applications

AbstractThere is a lack of economic feasibility analyses on the harvesting of forest biomass to supply low‐carbon bioenergy feedstocks using actual data on the mixed product harvest in the hardwood region of the northeast USA. This study is a techno‐economic analysis of three different scenarios (clean chips, dirty chips, or pulpwood) based on data collected from whole‐tree harvesting systems over 6 years. Each scenario had two different cases: one with costs and revenues allocated by mass (allocated system), and the other without allocation (whole system). The six cases of three scenarios tested resulted in a wide range of positive net present values (NPVs) from $1 713 000 to $819 in US dollars. Clean chip production generated substantial NPVs and dirty chips generated marginal NPVs. The minimum selling prices (MSPs) of clean chips from two cases were similar, $45.92 and $45.55 per green metric ton (Mg), with maximum hauling distances (MHDs) of 247 and 250 km (km). The MSPs for dirty chips from four cases ranged from $34.38 to $37.47 per Mg with the range of MHDs from 184 to 351 km. MSP and sensitivity analyses suggest that the selling prices and harvesting production levels of clean chips and dirty chips, and purchase prices of forestry logging equipment are the key factors that most influence the profitability of the regional forest biomass feedstock supply chain. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd

Effective harvesting of Scenedesmus using quaternary ammonium chitosan and xanthan gum: Formation of mega flocs with oppositely charged polyelectrolytes

Microalgae are a promising sustainable source of biomass while large-scale harvesting of microalgal biomass is a major technological and economic challenge. In this study, a flocculation method and mechanism for the formation of compact mega flocs was developed using two oppositely charged polyelectrolytes, quaternary ammonium chitosan (N-[(2-hydroxy-3-trimethyl ammonium) propyl] chitosan, HTCC) and xanthan gum (XG). With 8 mg/L HTCC and 16 mg/L XG, Scenedesmus cells could be flocculated into mega flocs with diameters larger than 5 mm and were harvested by 500-μm-pore-sized sieves with an efficiency over 95%. The flocs were generated within 12 s and resisted strong hydraulic shear (stirring at 960 rpm), reducing energy consumption and handling time for the subsequent separation. With HTCC or XG alone, the harvest efficiency was consistently lower than 30%. The flocculation mechanism was investigated by changing the order in which the HTCC, XG, and Scenedesmus cells were added, and by fluorescence staining, scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The results showed that the mega flocs were formed by the crosslinking of HTCC and XG, based on their long-chain molecular structure and electrostatic interaction. Scenedesmus cells were enmeshed in the polymer matrix of HTCC and XG and then aggregated into large flocs. Thus, an effective, eco-friendly, and sustainable flocculation strategy for microalgae biomass was developed using the biodegradable components HTCC and XG.