Biomass Values Research Articles

Upgrading lignocellulosic biomass to high-value products through the pretreatment driven by bio-based ethylene glycol solvent

Sustainable processing of lignocellulosic biomass is meaningful for comprehensive biomass conversion. Here, a ball milling (BM) assisted biomass-derived ethylene glycol (BEG) pretreatment is proposed to removes nearly 90 % of the lignin and increases cellulose accessibility by 3 times than raw biomass, facilitating subsequent enzymatic saccharification or catalytic conversion for 5-hydroxymethylfurfural (HMF), achieving yields of 92.9 % and 32.6 %. The synergistic effect of BM/BEG positively impacted delignification, followed by saccharification and HMF conversion. Introduction of biomass-derived solvent recovers the lignin with a well-preserved chemical structure, uniform molecular weight, short side chains, and high purity, making it highly suitable for downstream utilization. Density functional theory revealed hydrogen bonding and good miscibility between BEG and lignin units, suggesting reaction mechanisms and pathways. Molecular dynamics simulations showed that the solubilizing effect of BEG on lignin promoted cellulase-cellulose binding, thereby enhancing saccharification efficiency. The successful use of BEG solvents to maximize the biomass value is conducive to achieve closed-loop biorefinery approaches.

Compost as an Alternative to Inorganic Fertilizers in Cowpea [Vigna unguiculata (L.) Walp.] Production

ABSTRACTSoil fertility management is essential to sustain agricultural production in smallholder farming systems. An experiment was carried out to assess the viability of the combined use of compost and inorganic fertilizers as an alternative to conventional inorganic fertilization under greenhouse conditions. The 10 treatments, arranged in a randomized complete block design (RCBD) with six replications, consisted of a control, conventional mineral fertilization (150 kg NPK ha−1), composts added to the soil alone (2.5, 5, 7.5, and 10 t ha−1), and their combination with 50% of recommended rate of inorganic fertilizers (75 kg NPK ha−1). Application of 7.5 t ha−1 of compost and 50% of the recommended dose of inorganic fertilizer (75 kg NPK ha−1) gave the significantly highest seed yield, corresponding to a 30% increase over NPK‐fertilized plants. The combined application of 2.5 or 10 t ha−1 compost with 75 kg NPK ha−1 increased plant height by 38% compared with the NPK treatment. Additionally, stem diameter increased by 53% when 5 t ha−1 of compost and 75 kg NPK ha−1 were mixed. As expected, control plants produced the most nodules (108), 85% more than inorganic fertilization. Plants fertilized with 7.5 or 10 t ha−1 of compost and 75 kg NPK ha−1 produced 17% more pods, seeds per pod, and seeds per plant than NPK treatments. However, fertilization treatments had no significant effects on cowpea fresh and dry biomass or SPAD values. The results reveal that combining compost with inorganic fertilizer reduced synthetic fertilization by 50%, while producing growth and yields comparable to, or even higher than, recommended inorganic fertilization. This experiment demonstrated that integrated soil fertility management can be used as an alternative to the use of inorganic fertilizers in cowpea cultivation.

Improving Estimates for Barley Residue Biomass, Nutrients, and Economic Value

Improving Estimates for Barley Residue Biomass, Nutrients, and Economic Value

Comparative studies of machine learning models for predicting higher heating values of biomass

This study addresses the challenge of efficiently determining the higher heating value (HHV) of biomass, a crucial parameter in large-scale biomass-based energy systems. The conventional method of measuring HHV using an oxygen bomb calorimeter is time-consuming, expensive, and less accessible to researchers, particularly in developing nations. To overcome these limitations, we employed four machine learning (ML) models, namely Random Forest (RF), Decision Tree (DT), Support Vector Machine (SVM), and Extreme Gradient Boosting (XGBoost). These models were developed by using proximate and ultimate analysis parameters as input features. Up to 200 datasets were compiled from literature and used for the ML models. Our results demonstrate the effectiveness of all ML models in accurately predicting the HHV of biomass materials. Notably, the XGBoost model exhibited superior performance with the highest R-squared (R2) values for both training (0.9683) and test datasets (0.7309), along with the lowest root mean squared error (RSME) of 0.3558. Key influential input features identified for HHV prediction include carbon (C), volatile matter (Vm), ash, and hydrogen (H). Consequently, this research provides a reliable alternative for predicting HHV without the need for costly and time-intensive experimental measurements, facilitating broader accessibility in biomass energy research.

Comparative analysis of hydrogen-rich syngas production from various feedstocks using bubbling fluidized bed

Any carbon-based materials, including any trash that contains carbon, may be converted into sustainable energy through the thermochemical process known as gasification. The bubbling fluidized bed (BFB) is used for sewage sludge (SS), plastic waste (PW), and refuse-derived fuel (RDF) gasification. The sensitivity analysis of gasification processes is examined. The maximum H2 selectivity in RDF gasification is 70 %, followed by SS (65 %) and PW (62 %) at S/B=2. PW gasification, although producing more H2, generates more CO and CO2 than RDF and SS because to its high carbon content. At 700°C–800°C, three feedstocks have good H2 selectivity. RDF gasification has the best selectivity of all component products over the temperature range. The H2/CO molar ratio range (1–2) for chemical synthesis suggests steam to biomass (S/B) values of 1.2–2.6 for RDF and SS. As S/B value increases, CO/CO2 molar ratio increases, which compresses CO2 for CO production, improving syngas quality, notably for power generation. In PW gasification, the H2/CO ratio (≤2) is expected at >750°C. Pressure only effects H2/CO and CO/CO2, in PW gasification. The evaluation of lower heating value (LHV) and cold gas efficiency (CGE) involves exploring a range of selected parameters. Elevated reaction temperatures positively influence both LHV and CGE; however, this is not the case for S/B ratio and reaction pressure. Among the gasification processes, PW gasification exhibits the highest LHV, while SS gasification demonstrates the highest CGE. Besides, the gasification efficiency (ƞG) is found about 35–41 % at the S/B=2, which is lower than the efficiency in terms of CGE (57.6 %) due to the energy consumption increase as the temperature increased. O2/S increases negatively affect product composition but allow parameter indicator value adjustment to parameter indicator of the desired syngas product quality.

Multi-scope decarbonization and environmental impacts evaluation for biomass fuels co-firing CHP units in China

Co-firing of waste biomass as low-carbon fuels in combined heat and power (CHP) units is an indispensable energy supply technology providing regional electricity and heat, especially in industrial parks, that can combat climate change and support the achievement of Sustainable Development Goals (SDGs) in China. In this study, we proposed a life cycle material-energy-carbon integrated GHG accounting framework for CHP units converting waste to energy with co-firing of sludge and biomass pellets, including supply and value chains. This framework enables the prediction of multi-scope GHG emissions and environmental impacts associated with co-firing based on the properties of biomass fuels. It facilitates the selection of suitable biomass fuels according to decarbonization or reduced environmental impact objectives. When considering CO2 emissions alone, co-firing with sludge appears to be a beneficial option due to the economic gains from waste disposal. However, this also leads to increased GHG emissions unless avoided emissions from original disposal are considered, thus highlighting the need to expand the regulatory framework pertaining to GHG emissions that recognizes non-CO2 GHG emissions. Additionally, the practice of co-firing biomass fuels presents a complex interplay between enhanced decarbonization effects but potentially more significant environmental impacts when the co-firing ratio increases, highlighting the trade-offs between enhanced decarbonization and environmental challenges. Leveraging this framework, our study evaluated the national decarbonization potential through the deployment of CHP units with sludge or biomass co-firing across various provinces, indicating that biomass pellets co-firing could lead to more substantial GHG emission reduction.

Ecological Dynamics of Water Hyacinth in Coimbatore Lakes: Implications for Biomass, Carbon Stock, and Nutrient Management

In aquatic ecosystems, water hyacinth (Eichhornia crassipes) often proliferates, impacting water quality and ecological balance. This study investigates the density, biomass, carbon stock, and nutrient concentrations of E. crassipes across five significant lakes in Coimbatore: Krishnampathy, Kurichi, Ukkadam, Singanallur, and Sulur. Field surveys, laboratory analyses and statistical methods were adopted in this study. The highest density of E. crassipes was observed in Krishnampathy Lake (59±2.5, no./m2). The biomass values (kg/m2) ranged from 1.00 to 7.33 for leaf, 3.23 to 8.03 for stalk, and from 1.47 to 10.80 for root samples. The carbon stock values (kg/m2) ranged from 0.51 to 3.74 for leaf, 1.49 to 3.73 for stalk, and from 0.68 to 4.19 for root samples, revealing the species potential role in reducing atmospheric carbon in mitigation of climate change. We have studied the macro and micro-nutrient concentrations present in E. crassipes, and also we checked the relationship between chlorophyll content and nutrient concentration with the carbon stock of different plant parts of E. crassipes. This study contributes to a better understanding of the ecological dynamics of water hyacinth in inland water bodies and its potential implications for carbon cycling and nutrient dynamics.

The Effects of Frass and Vermicompost Fertilization on the Biometrical Parameters of Plant and Soil Quality, and the Rhizobiome, in Red Beet (Beta vulgaris L.) Cultivation

Insect frass and vermicompost hold potential applications as fertilizers, with their abilities to improve plant resilience against unfavorable environmental conditions and increase their resistance to pests and diseases. In this study, we explored the effects of vermicompost fertilization, mealworm frass, and superworm frass as potential plant fertilizers for red beet cultivation. We analyzed the connections among chemical parameters, rhizobiome structure and function, and the biometrics of fertilizer-treated plants. In general, soils enriched with vermicompost and superworm frass exhibited the highest macroelement contents. Dry superworm frass fertilization was characterized by the increased availabilities of total nitrogen, NH4-N, and NO3-N. The use of vermicompost and mealworm frass resulted in significantly higher red beet biomass values. The presence of the highest N-fixation potential and key hormonal substances involved in plant development, such as auxins and gibberellins, was demonstrated using wet superworm frass. The results indicated that wet superworm frass, similar to vermicompost and dry superworm frass, exhibits high chemoheterotrophic potential. This suggests an r-type strategy and high adaptive flexibility of rhizobial bacteria. As a consequence, both life in the root zone and the microbiome itself may be better adapted to sudden, unfavorable environmental changes or attacks by plant pathogens.

STATUS OF THE TURBOT (Scopthalmus Maeoticus, Pallas, 1814) AGGLOMERATIONS ALONG THE ROMANIAN BLACK SEA COAST

The main commercially valuable species in the Black Sea is turbot (Scophthalmus maeoticus, Pallas, 1814). Thus, turbot stock assessment is vital to ensure its sustainable use, to support economic and ecological stability, to inform science-based management decisions, and to promote the conservation of marine biodiversity. To determine turbot aggregations, the BioIndex routine, developed in R language, was used to estimate different biological indicators related to this target species. In particular, the routine allows the estimation of time series of mean abundance and biomass indices, the inverse CV of abundance indices, mean individual weight and sex ratio at the GSA level. Taking into account the biomass values resulted for the study period (2019-2020) a significant increase was observed in the values from the period 2012-2018 and the maximum yield (RMM) obtained of 329,048 tons for the Romanian area of the Black Sea.

Long term succession of engineering species Gongolaria barbata (Stackhouse) Kuntze (Fucales: Ochrophyta) along the Romanian Black Sea coast

Background and purpose: Cystoseira sensu lato are of great interest due to their primary role in maintaining high biodiversity and the functioning of rocky habitats, and as provider of crucial ecosystem services. Conspicuous historical declines have been reported in many regions, Romanian Black Sea coast included. Gongolaria barbata (Stackhouse) Kuntze (Fucales: Ochrophyta) is the only remaining representative of Cystoseira s. l. along the Romanian coast and currently the most important habitat-forming species, with extended to patchy canopies in the southern rocky coasts. To better understand the status of such ecological important species, we analyse and compare the succession of Gongolaria infralittoral populations during reference (60s), decline (70s) and more recent period (2009 – 2022), based on an extensive literature review (historical quantitative data) and recent information from annual monitoring program. Material and methods: Quadrats (20 × 20 cm) were used for sampling both in the past and present, with a total number of 144 samples collected between 2009 – 2022. Both historical and recent data were statistically analysed using non – parametric tests due to the absence in normality and homogeneity of data sets. Results: Following sea ice from 1972 and violent storms as the main drivers of local Gongolaria decline, out of the thirteen known development areas from the reference period, nowadays only five are left. However, recent wet biomass and density values are appropriate to those of the reference period (1962 – 1971) and much higher compared to the maximum decline period (1972 – 1979). Conclusions: G. barbata has been in a fragile balance along the Romanian coast in the last decade, highly sensitive in front of increasingly anthropogenic activities.

Metabolite Compounds of Euglena sp. on Mass Cultivation System under MgCl2 and CaCl2 Salt Stress

Euglena sp. is rich in primary and secondary metabolite compounds. This cosmopolitan organism can survive extreme conditions such as salt stress because it can increase cell growth rate and metabolism. This mass cultivation research uses an open pond system that is very vulnerable to contamination, so variations in salinity of MgCl2 and CaCl2 are used as treatments because they minimize contamination. The research examines the correlation of salt types to cell growth rate, biomass, monosaccharide profile, paramylon, pigment, and lipid of Euglena sp. Research methods include preparation, medium making, mass cultivation, and measurement of test parameters. Data were analyzed through One-Way ANOVA followed by DMRT, with a 5% confidence level. Based on the research result, the highest value of biomass and paramylon content and productivity at CaCl2 treatment with consecutive values 0.013 ± 0.001, 0.002 ± 0.000, 9.556 ± 0.070, and 0.149 ± 0.019. Monosaccharides analysis produced in the form of sucrose, glucose, fructose, and arabinose amounted to < 10 ppm. CaCl2 treatment produced the highest sucrose of 6251 ppm. The highest chlorophyll-a and carotenoid pigments are located at CaCl2 treatment, respectively (1.698 ± 0.051)b and (0.500 ± 0.032)b. At the same time, the salt treatment has a significant effect on lipid content. To summarize, almost all metabolite compounds were highest in CaCl2 treatment. This research is expected to contribute to developing the Euglena sp. mass cultivation system as a source of bioenergy and biomaterials.

Assessing the Effectiveness of Vermi-Liquids as a Sustainable Alternative to Inorganic Nutrient Solutions in Hydroponic Agriculture: A Study on Diplotaxis muralis

Organic products are gaining popularity due to their positive impact on human health and the environment. While hydroponics is commonly used in vegetable production, it relies on mineral fertilizers derived from limited and non-renewable resources. As a result, farmers are actively seeking sustainable farming solutions. This study comprehensively evaluated the effectiveness of vermi-liquids (organic nutrient solutions) as a replacement for conventional inorganic nutrient solutions in promoting growth and nutrient acquisition in Diplotaxis muralis plants in a controlled environment. The results showed that plant biomass and SPAD values of D. muralis grown in Hoagland solution and enhanced vermitea (vermitea having relatively low pH and high EC) were higher compared to standard vermitea (high pH and low EC). The findings also revealed improved nutrient assimilation of phosphorus, potassium, calcium, iron, manganese, copper, and zinc in the enhanced vermitea plants. The heavy metal contents in D. muralis leaves were evaluated, too, and they were found to fall significantly below the safe threshold, rendering them safe for human consumption. However, the standard vermitea, with its high pH and low EC, performed poorly as a hydroponic solution. This research suggests that enhanced vermitea can completely replace chemical nutrient solutions in hydroponic agriculture. This substitution could lead to reduced production costs and improved product quality.

SOYBEAN AND WASTE COOKING OIL BASED FEEDSTOCKS AS A SUSTAINABLE BIOFUEL

Fuel in transportation is necessary and gas release from transportation activity raises concern of pollution. Sustainable fuels sources are from biomass can convert to the alternative to the bioenergy fuel. It is actively investigated with concern in the environmental effects if using conventional fuels from reservoir of fossil fuels. Hence, to counter these consequences, Sustainable Fuels (SF) is investigated as it is considered a renewable source of fuel. Thus, this study aims to establish an experiment to determine the suitability of biomass fuel by using soybean and waste cooking oil feedstocks. An experiment is set up to produce biomass fuel by using feedstock from different biomass particularly from soybean oil, a first-generation edible feedstock and waste cooking oil, a second-generation nonedible feedstock. The method chosen to produce biomass fuel is transesterification. The experiment will test the effects of a catalyst, namely solid Potassium Hydroxide, KOH, with three levels of concentration 0.75%, 1%, and 1.5% w/w KOH. Once the biomass fuel is produced it will undergo a series of tests to study the effect of parameters such as density, kinematic viscosity, caloric value, acid value and Fatty Acid Methyl Ester (FAME). The results show that using the feedstock 0.75 w/w% of KOH, the yield of biomass fuel is the most for both feedstocks. It is noted that soybean oil yields slightly greater feedstock than waste cooking oil. The density for both feedstock is very similar at 0.87-0.88 g/cm3. The acid value of biomass fuel produced from waste cooking oil is much higher than soybean oil at 0.28 but still under the acceptance range of 0.5. The concentration of catalyst used is a major factor in the yield of biomass fuel. It is also noted that the first-generation edible feedstock of soybean oil produces greater quality of biomass fuel. Nevertheless, first-generation feedstock still poses the food competition threat in comparison to second-generation feedstock. Therefore, establishment of the second-generation feedstock from waste cooking oil produces biomass fuel that is close to the quality of soybean oil, it is a more preferred feedstock compared to soybean oil.

Advanced membrane photobioreactors in algal CO2 biofixation and valuable biomass production: Integrative life cycle assessment and sustainability analysis

This paper presents and discusses the life cycle assessment (LCA) of CO2 capture and of microalgae biomass production in an advanced membrane photobioreactor (mPBR) system for climate change mitigation and the generation of renewable energy carriers. The study aims to evaluate environment-relevant aspects and propose alternative solutions for optimization of the environmental sustainability of the biologically based technology. The mPBR biotechnology, composed by an adsorption column, coupled with a reactor with a self-forming dynamic membrane (SFDM) module inside, was used for the experimental activities. Four principal operational steps (cultivation, harvesting, cleaning and drying) at three different scenarios were investigated and evaluated in terms of energy demand and environmental impacts amongst the boundary conditions based on the “cradle-to-gate” model. The ReCiPe 2016 and the Cumulative Energy Demand (CED) methodologies were applied for the assessment. In addition, a sensitivity analysis has been conducted.The results showed that across the operational phases, algae cultivation and drying are the most phases that lead to greater environment-relevant aspects. Analysing different scenarios, the use of wastewater as a source of nutrients for algae (Chlorella vulgaris species), with respect to the use of synthetic nutrients with the same biomass productivity, resulted to be the most feasible and attractive alternative in terms of environmental impact. Finally, the sensitivity analysis highlighted how the environmental performance can be significantly improved by enhancing the productivity and the harvesting rate.The study provides important information to the different actors involved in the biotechnologies sectors, to be able to build and/or evaluate different production options with a holistic and proactive approach, in order to optimize the technologies with a view to maximize its environmental sustainability.

Predicting calorific value and ash content of sand shrub using Vis-NIR spectra and various chemometrics

Calorific value (CV) reflects the ability of material flow and energy conversion of plants, which is the key indices of combustion properties for utilization and development of energy plants. However, the commonly used method for CV determination of solid fuels is bomb calorimetry in the laboratory using powder samples, which hinders the capability of rapid and non-destructive prediction for a large-scale samples in a natural environment. Visible and near infrared spectroscopy (Vis-NIR) has been widely proposed as a replace for laboratory determination in properties prediction. However, chemometrics are essential for spectral analysis. Various chemometrics including competitive adaptive reweighted sample (CARS), lifting wavelet transform (LWT), successive projections algorithm (SPA), and convolutional neural networks (CNNs) optimized by whale optimization algorithm (WOA) were employed to optimize models. Additionally, canopy spectra were measured in the field instead of powder samples’ spectra collecting from laboratory. The results demonstrated that CARS-WOA-CNN was the best to predict CV and ash content (AC) with R2 of 0.858 and 0.751, respectively. Compared to raw full spectra, spectral dimension was reduced from 2048 to 93 and 22 for CV and AC, respectively. Overall, this study provided a meaningful strategy for harvest planning and assessing value of biomass in the field.

Spatiotemporal variation in phenology of the invasive brown macroalga Sargassum muticum (Yendo) Fensholt and the environmental parameters relationships along four different sites on the Atlantic coast of Morocco

The alien brown seaweed Sargassum muticum (Yendo) Fensholt is currently observed along the coasts of Morocco. The present study aimed to evaluate the impact of physicochemical parameters on the distribution of S. muticum at four sites on the Atlantic coast of Morocco harvested between 2019 and 2020. This study showed that the highest biomass, thalli length, and fertility values were recorded in sampling sites characterized by optimal physicochemical (temperature, pH, and salinity) and nutrient H₃PO₄ during summer. The highest biomass values were recorded in August for Sidi Bouzid and Moulay Abdellah sites, conversely, in Saada and Jorf Lasfar sites the highest values were observed in February and March respectively. The thallus length was slightly larger in Moulay Abdellah site with 77.30 ± 14.09 cm compared with the three other sites during the summer/spring periods. Minimum thalli length was recorded in September for all studied sites. The thalli of S. muticum were fertile earlier in Sidi Bouzid and Saada during spring and peaked during the summer season for all studied sites showing a positive correlation with increasing temperature.Finally, the collected data shows that indeed physicochemical parameters influence bioecological parameters. Thus, contributed to a better understanding of the temporal variation of S. muticum phenology on the Moroccan Atlantic coast, these data provide the necessary information for coastal marine management and biomonitoring program as well as sustainable utilization of this renewable marine resource.

Reef health assessment of Pulau Payar Marine Park during the COVID-19 pandemic in Malaysia

Pulau Payar Marine Park (PPMP) consists of four islands, namely Pulau Payar, Pulau Kaca, Pulau Lembu and Pulau Segantang. This study was carried out in PPMP from June 2020 to February 2021, during the implementation of Malaysia’s Movement Control Order in response to the Covid-19 pandemic in the country. The purpose of this study was to determine the species, coverage and biomass of corals and fish present within the area and to assess its coral health status. Data were derived at 11 sites at depths of 5 to 10 m. The Point Intersect Line method was applied to record benthic communities for every meter across two 50-meter transect lines. The outcomes showed that benthic communities were dominated by scleractinian corals, with an average of 25% coverage at all islands. Pulau Payar, Pulau Kaca, Pulau Lembu and Pulau Segantang were characterized by 37%, 33%, 25% and 37% live coral cover respectively. A total of 14 families, 30 genera and 49 species of scleractinian coral species were identified, giving the latest comprehensive species list for this marine park. The most common species recorded was Porites lutea, followed by Physogyra lichtensteini. The fish survey revealed a total of 39 fish species from 23 genera, encompassing 16 families, with Lutjanidae being the dominant group. Fish biomass values varied between 20 g/m2 and 183 g/m2 at each site. Shannon-Wiener diversity (H), Evenness (E) and coral health index (CHI) were calculated for each island. The H values ranged between 2.03 and 3.01. Pulau Payar had the highest value of H, at 3.01, and the highest number of species. The E values ranged from 0.75 to 0.85, showing that the scleractinian corals of PPMP were relatively evenly distributed. CHI at each site ranged from 0.17 to 0.24. Overall, the health condition of the coral reefs in PPMP was considered degraded. This study provides valuable insights into the benthic and fish communities of PPMP through its health assessment.

Transcriptomic Insights into Molecular Response of Butter Lettuce to Different Light Wavelengths.

Lettuce is a widely consumed leafy vegetable; it became popular due to its enhanced nutritional content. Recently, lettuce is also regarded as one of the model plants for vegetable production in plant factories. Light and nutrients are essential environmental factors that affect lettuce growth and morphology. To evaluate the impact of light spectra on lettuce, butter lettuce was grown under the light wavelengths of 460, 525, and 660 nm, along with white light as the control. Plant morphology, physiology, nutritional content, and transcriptomic analyses were performed to study the light response mechanisms. The results showed that the leaf fresh weight and length/width were higher when grown at 460 nm and lower when grown at 525 nm compared to the control treatment. When exposed to 460 nm light, the sugar, crude fiber, mineral, and vitamin concentrations were favorably altered; however, these levels decreased when exposed to light with a wavelength of 525 nm. The transcriptomic analysis showed that co-factor and vitamin metabolism- and secondary metabolism-related genes were specifically induced by 460 nm light exposure. Furthermore, the pathway enrichment analysis found that flavonoid biosynthesis- and vitamin B6 metabolism-related genes were significantly upregulated in response to 460 nm light exposure. Additional experiments demonstrated that the vitamin B6 and B2 content was significantly higher in leaves exposed to 460 nm light than those grown under the other conditions. Our findings suggested that the addition of 460 nm light could improve lettuce's biomass and nutritional value and help us to further understand how the light spectrum can be tuned as needed for lettuce production.

Valorization of wastewater from industrial hydroponic cultivations using the microalgal species Chlorella vulgaris

The continuous increase in the world population is associated with a greater demand for food. This need has driven the development of new cultivation systems capable of producing large quantities of vegetable biomass in a small space, with precise and regulated control of the use of resources. Among these, vertical farms are systems developed in height, and they produce continuously throughout the year.The hydroponic system is commonly used in vertical farming and entails the growth of plants in a solution rich in nutrients, easily assimilated by plants. However, hydroponic solutions still contain nutrient salts at the end of the productive cycle. Consequently, spent hydroponic solutions cannot be directly released into the environment because they would cause water pollution. Thus, they need to be appropriately treated, increasing production costs.Microalgae represent a cost-effective solution for treating and valorizing hydroponic wastewater. They can easily consume the residual nutrients, generating valuable biomass that can be exploited as a biofertilizer, a biostimulant, or even as a valuable food supplement.The present work showed the ability of the model eukaryotic microalga Chlorella vulgaris to use valuable resources derived from industrial cultivations of basil and tobacco in a hydroponic deep-water culture system. Although the use of spent hydroponic solutions slightly affected the microalgal biomass accumulation of more than ~40 % compared to the fresh solution, possibly due to the presence of root exudates that have an antagonistic effect toward microalgae, the phytoremediation activity of microalgae was achieved. The reported results described the consumption of more than 80 % and 70 % of P and N residual nutrients in hydroponic formulations, respectively. Moreover, more than 2 g/L of microalgal biomass was generated after 7 days of growth in air-lifted photobioreactors. The outcomes of this research provide new insights toward greater sustainability of vertical farming, following circular economy principles.

In situ pretreatment of wood samples with deep eutectic solvents for enhanced lignin removal and enzymatic Saccharification efficiency optimization

Deep eutectic solvents (DESs) are commonly utilized as an effective pretreatment method for biomass materials, particularly for enhancing the value of lignocellulosic biomass. However, to the best of our knowledge, the utilization of DESs for in situ pretreatment of wood samples has been seldom reported. In this study, the ability of five DESs systems to in-situ pretreatment of balsa wood samples was investigated. Among of them, the Choline Chloride-Ethylene Glycol-P-Toluenesulfonic Acid (ChCl-EG-PTSA) system showing an excellent lignin removal rate (the lignin removal of 87.34 % and cellulose retention of 86.32 %), which is significantly better than the delignification effect of the traditional acid chlorite method (lignin removal of 72,13 % and cellulose retention of 64.57 %). In addition, in the subsequent enzymatic saccharification experiments, after the wood samples were pretreated in situ by the ChCl-EG-PTSA system, the enzymatic saccharification yield of cellulose reached 75.46 %, and the enzymatic saccharification yield of xylose reached 92 %. At the same time, this study also used SEM, FTIR, XPS, TGA and other testing technologies to conduct detailed analysis and characterization of the pretreated samples. This comprehensive analysis unequivocally demonstrated the viability of the ChCl-EG-PTSA system as an environmentally sustainable and efficient approach for pretreating forest biomass. Significantly, this in-situ wood pretreatment strategy significantly lays a robust research groundwork for the development of multifunctional wood fiber composites in subsequent stages.