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1.
Biotechnol Bioeng ; 121(2): 434-455, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37990982

RESUMEN

Despite their high persistence in the environment, organochlorines (OC) are widely used in the pharmaceutical industry, in plastics, and in the manufacture of pesticides, among other applications. These compounds and the byproducts of their decomposition deserve attention and efficient proposals for their treatment. Among sustainable alternatives, the use of ligninolytic enzymes (LEs) from fungi stands out, as these molecules can catalyze the transformation of a wide range of pollutants. Among LEs, laccases (Lac) are known for their efficiency as biocatalysts in the conversion of organic pollutants. Their application in biotechnological processes is possible, but the enzymes are often unstable and difficult to recover after use, driving up costs. Immobilization of enzymes on a matrix (support or solid carrier) allows recovery and stabilization of this catalytic capacity. Agricultural residual biomass is a passive environmental asset. Although underestimated and still treated as an undesirable component, residual biomass can be used as a low-cost adsorbent and as a support for the immobilization of enzymes. In this review, the adsorption capacity and immobilization of fungal Lac on supports made from residual biomass, including compounds such as biochar, for the removal of OC compounds are analyzed and compared with the use of synthetic supports. A qualitative and quantitative comparison of the reported results was made. In this context, the use of peanut shells is highlighted in view of the increasing peanut production worldwide. The linkage of methods with circular economy approaches that can be applied in practice is discussed.


Asunto(s)
Basidiomycota , Contaminantes Ambientales , Lacasa , Biotecnología , Biomasa , Hongos
2.
Compr Rev Food Sci Food Saf ; 23(6): e70027, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-39379297

RESUMEN

The global seaweed industry annually consumes approximately 600,000 tons of dried algal biomass to produce algal hydrocolloids, yet only 15-30% of this biomass is utilized, with the remaining 70-85% discarded or released as scum or wastewater during the hydrocolloid extraction process. This residual biomass is often treated as waste and not considered for further commercial use, which contradicts the principles of sustainable development. In reality, the residual algal biomass could be employed to extract additional biochemical components, such as pigments, proteins, and cellulose, and these ingredients have important application prospects in the food sector. According to the biorefinery concept, recycling various products alongside the principal product enhances overall biomass utilization. Transitioning from traditional single-product processes to multi-product biorefineries, however, raises operating costs, presenting a significant challenge. Alternatively, developing value-added utilization technologies that target seaweed waste without altering existing processes is gaining traction among industry practitioners. Current advancements include methods such as separation and extraction of residual biomass, anaerobic digestion, thermochemical conversion, enzymatic treatment, functionalized modification of algal scum, and efficient utilization through metabolic engineering. These technologies hold promise for converting seaweed waste into alternative proteins, dietary supplements, and bioplastics for food packaging. Combining multiple technologies may offer the most effective strategy for future seaweed waste treatment. Nonetheless, most research on value-added waste utilization remains at the laboratory scale, necessitating further investigation at pilot and commercial scales.


Asunto(s)
Algas Marinas , Algas Marinas/química , Biomasa , Reciclaje/métodos , Residuos Industriales/economía
3.
Prep Biochem Biotechnol ; 53(9): 1154-1163, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36794850

RESUMEN

Lignocellulosic residues, such as cocoa bean shell (FI), are generated in large quantities during agro-industrial activities. Proper management of residual biomass through solid state fermentation (SSF) can be effective in obtaining value-added products. The hypothesis of the present work is that the bioprocess promoted by P. roqueforti can lead to structural changes in the fibers of the fermented cocoa bean shell (FF) that confer characteristics of industrial interest. To unveil such changes, the techniques of FTIR, SEM, XRD, TGA/TG were used. After SSF, an increase of 36.6% in the crystallinity index was observed, reflecting the reduction of amorphous components such as lignin in the FI residue. Furthermore, an increase in porosity was observed through the reduction of the 2θ angle, which gives the FF a potential candidate for applications of porous products. The FTIR results confirm the reduction in hemicellulose content after SSF. The thermal and thermogravimetric tests showed an increase in the hydrophilicity and thermal stability of FF (15% decomposition) in relation to the by-product FI (40% decomposition). These data provided important information regarding changes in the crystallinity of the residue, existing functional groups and changes in degradation temperatures.


This work presents a new approach for solid state fermentation based on the study of structural changes caused by Penicillium roquefort, which is important to understand the changes in the lignocellulosic matrix after the fungus growth. The results provided important information regarding changes in the crystallinity of the residue, existing functional groups and changes in degradation temperatures. Consequently, they can help in proposals for the total use of the residual solid after fermentation, as well as contribute to reducing the lack of this information in the literature.


Asunto(s)
Penicillium , Penicillium/metabolismo , Lignina/metabolismo , Fermentación
4.
Molecules ; 28(17)2023 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-37687008

RESUMEN

Spirulina consists of a cluster of green-colored cyanobacteria; it is commonly consumed as a food or food supplement rich in bioactive compounds with antioxidant activity, predominantly C-phycocyanin (C-PC), which is related to anti-inflammatory action and anticancer potential when consumed frequently. After C-PC extraction, the Spirulina residual biomass (RB) is rich in proteins and fatty acids with the potential for developing food products, which is interesting from the circular economy perspective. The present work aimed to develop a vegan oil-in-water emulsion containing different contents of Spirulina RB, obtaining a product aligned with current food trends. Emulsions with 3.0% (w/w) of proteins were prepared with different chickpea and Spirulina RB ratios. Emulsifying properties were evaluated regarding texture and rheological properties, color, antioxidant activity, and droplet size distribution. The results showed that it was possible to formulate stable protein-rich emulsions using recovering matter rich in protein from Spirulina as an innovative food ingredient. All the concentrations used of the RB promoted the formulation of emulsions presenting interesting rheological parameters compared with a more traditional protein source such as chickpea. The emulsions were also a source of antioxidant compounds and maintained the color for at least 30 days after production.


Asunto(s)
Antioxidantes , Spirulina , Animales , Antioxidantes/farmacología , Biomasa , Decapodiformes , Suplementos Dietéticos , Emulsiones
5.
J Environ Manage ; 301: 113832, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34624578

RESUMEN

Biomass-fuelled Combined Heat and Power Generation (CHP) systems can efficiently convert chemical energy contained in biomass into electricity and heat. Currently there is a large number of abandoned forests and biomass of agroforestry origin that is not being used. The use of residual biomass as a source of energy in CHP systems is presented as a particularly attractive alternative for energy obtention. This paper presents the results of a biomass boiler coupled to an Organic Rankine Cycle (ORC). Three residual biomasses, named pruning vine, pruning kiwi and gorse have been selected due to their potentiality and availability in the Galicia-North Portugal Euroregion. For this purpose, micro-cogeneration tests at bench scale were performed, based fundamentally on varying dissipation conditions in the low-grade temperature range (below 100 °C). Micro-cogeneration performance was assessed based on the electrical power and efficiency obtained, along with the global efficiency achieved (electrical plus thermal). Combustion measurements comprised gaseous emissions analyses and determination of the efficiency of the process. Micro-cogeneration results obtained show that differences in temperature between the hot and the cold source have a significant influence. The higher the temperature difference, the higher the electrical power and efficiency, as well as the higher global performance obtained, with values close to the maximum of the ORC employed (i.e 4 kWe, 9% and 96% respectively). Thus, the technical feasibility of the system to simultaneously obtain heat and electricity from low grade heat sources in small-scale applications was demonstrated. Regarding to combustion, parameters regulated by European emission standards are under the limits using the biofuels (residual biomasses) studied. Thereby, the suitability of those biomasses in thermochemical valorization processes was demostrated.


Asunto(s)
Biocombustibles , Calor , Biomasa , Electricidad , Temperatura
6.
Appl Microbiol Biotechnol ; 105(3): 975-989, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33447867

RESUMEN

Consolidated bioprocessing (CBP) featuring concomitant hydrolysis of renewable substrates and microbial conversion into value-added biomolecules is considered to bring substantial benefits to the overall process efficiency. The biggest challenge in developing an economically feasible CBP process is identification of bifunctional biocatalyst merging the ability to utilize the substrate and convert it to value-added product with high efficiency. Yarrowia lipolytica is known for its exceptional performance in hydrophobic substrates assimilation and storage. On the other hand, its capacity to grow on plant-derived biomass is strongly limited. Still, its high potential to simultaneously overproduce several secretory proteins makes Y. lipolytica a platform of choice for expanding its substrate range to complex polysaccharides by engineering its hydrolytic secretome. This review provides an overview of different genetic engineering strategies advancing development of Y. lipolytica strains able to grow on the following four complex polysaccharides: starch, cellulose, xylan, and inulin. Much attention has been paid to genome mining studies uncovering native potential of this species to assimilate untypical sugars, as in many cases it turns out that dormant pathways are present in Y. lipolytica's genome. In addition, the magnitude of the economic gain by CBP processing is here discussed and supported with adequate calculations based on simulated process models. KEY POINTS: • The mini-review updates the knowledge on polysaccharide-utilizing Yarrowia lipolytica. • Insight into molecular bases founding new biochemical qualities is provided. • Model industrial processes were simulated and the associated costs were calculated.


Asunto(s)
Yarrowia , Celulosa , Hidrólisis , Inulina , Ingeniería Metabólica , Almidón , Xilanos , Yarrowia/genética
7.
Molecules ; 24(18)2019 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-31514386

RESUMEN

In this work, two types of biomass preparations (VMSM and M3) from the filamentous fungus Botryosphaeria rhodina MAMB-05, which were previously used in a process of production of ß-glucan, were assessed as biosorbents of lead. The operating conditions, optimized through response surface methodology and experimental design, were shown to be pH 5.29 and a biosorbent dose of 0.23 g/L for the VMSM biomass type; and pH 5.06 and a dose of biosorbent of 0.60 g/L for the M3 biomass type, at a constant temperature of 27 °C. Fourier transform-infrared spectroscopy analyzed the presence of functional groups on the biomass surface. In addition to give an extra value to the by-product biomass, the VMSM-type from B. rhodina MAMB-05 showed an excellent lead biosorption capacity (qm) with a value of 403.4 mg/g for the Langmuir model, comparing favorably with literature results, while the M3 subtype biomass showed a value of 96.05 mg/g.


Asunto(s)
Ascomicetos/química , Plomo/aislamiento & purificación , Adsorción , Biodegradación Ambiental , Biomasa , Cinética , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Factores de Tiempo
8.
Artículo en Inglés | MEDLINE | ID: mdl-38372920

RESUMEN

In Portugal, the number of fires and the size of burnt areas are rising dramatically every year, increasing with improper management of agroforestry wastes (AFRs). This work aims to study the composting of these wastes with minimal operational costs and understand the environmental impact and the compost application on burnt soil. Thus, a study of life cycle assessment (LCA) was carried out based on windrow composting processes, considering the avoided environmental impacts associated with the end-product quality and its application as an organic amendment. Three composting piles were made with AFRs from the Residual Biomass Collection Centre (RBCC) in Bodiosa (Portugal). Sewage sludges (SS) from an urban wastewater treatment plant were used as conditioning agent. One pile with AFRs (MC) and another with AFRs and SS (MCS) were managed according to good composting practices. Another pile with the AFRs was developed without management (NMC), thus with a minimal operational cost. Periodically, it was measured several physical and chemical parameters according to standard methodologies. Eleven environmental impacts of compost production, MC and MCS, were analyzed by a LCA tool, and their effect on the growth of Pinus pinea was evaluated, using peat as reference. Composting evolution was expected for both piles. Final composts, MC and MCS, were similar, complying with organic amendment quality parameters. Compost NMC, with no operational management, showed the highest germination index. Piles MC and MCS showed similar environmental impacts, contributing to a negative impact on global warming, acidification, and eutrophication. Greater growth was obtained with application of MCS, followed by MC, and finally, peat. Composting is a sustainable way to valorize AFRs wastes, producing compost that could restore burnt soils and promote plant growth and circular economy.

9.
Polymers (Basel) ; 16(4)2024 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-38399869

RESUMEN

The use of residual microbial biomass from various industries in emerging pollutant removal strategies represents a new area of research in the field. In this case, we examined how to remove reactive dyes from an aqueous solution utilizing a biosorbent made of residual biomass from immobilized Saccharomyces pastorianus (S. pastorianus) in a polymer matrix using a dynamic system. Fluidized bed column biosorption investigations were carried out on a laboratory scale. Brilliant Red HE-3B was chosen as the target molecule. The main parameters considered for this purpose were the flow rate (4.0 mL/min; 6.1 mL/min), initial pollutant concentration (51.2 mg/L; 77.84 mg/L), and biosorbent mass (16 g; 20 g). The experimental data of the fluidized bed study were evaluated by mathematical modeling. The Yoon-Nelson, Bohart-Adams, Clark, and Yan models were investigated for an appropriate correlation with the experimental data. An acceptable fit was obtained for a flow rate of 4 mL/min, an initial pollutant concentration of 51.2 mg/L, and a biosorbent amount of 20 g. The obtained results indicate that the biosorbent can be used efficiently in a dynamic system both for the removal of the studied dye and in extended operations with a continuous flow of wastewater. As a conclusion, the investigated biocomposite material can be considered a viable biosorbent for testing in the removal of reactive dyes from aqueous environments and creates the necessary conditions for the extension of studies toward the application of these types of biosorbents in the treatment of industrial effluents loaded with organic dyes.

10.
Sci Total Environ ; 868: 161661, 2023 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-36669660

RESUMEN

In the present work, the residual biomass of the green seaweed Ulva lactuca was chosen as feedstock to undergo separate hydrolysis and fermentation process to produce bioethanol. The hydrolysis process was optimized for cellulase, biomass, temperature, and time conditions. The maximum yield of fermentable sugars was 13.48 mg/mL. The recovered hydrolysate was subjected to fermentation using Saccharomyces cerevisiae. The bioethanol produced was subjected to gas chromatography coupled mass spectrometry analysis to determine the presence of ethanol. The technical performance and economic feasibility of the bioethanol production from U. lactuca were evaluated using the lab-scale data obtained for optimized conditions. The plant capacity was 10 MT/day of bioethanol production. The plant's capital investment and annual operating cost were 3.18 M$ and 0.86 M$ respectively. The total annual revenue of the plant was 1.41 M$. The minimum selling price of bioethanol was 0.47 $/kg. The ROI, payback period, IRR and NPV of the plant were 16.99 %, 5.89 years, 11.57 % and 291,000 $ respectively. The utilization of residual biomass for biofuels helps to develop an economic and environmentally sustainable plant.


Asunto(s)
Algas Marinas , Ulva , Algas Marinas/química , Ulva/química , Biomasa , Cromatografía de Gases y Espectrometría de Masas , Azúcares , Fermentación , Biocombustibles , Hidrólisis , Saccharomyces cerevisiae
11.
Waste Manag ; 167: 46-54, 2023 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-37245395

RESUMEN

Herein, biochar from biomass residues is demonstrated as active materials for the catalytic cracking of waste motor oil into diesel-like fuels. Above all, alkali-treated rice husk biochar showed great activity with a 250% increase in the kinetic constant compared to the thermal cracking. It also showed better activity than synthetic materials, as previously reported. Moreover, much lower activation energy (185.77to293.48kJmol) for the cracking process was also obtained. According to materials characterization, the catalytic activity was more related to the nature of the biochar's surface than its specific surface area. Finally, liquid products complied with all the physical properties defined by international standards for diesel-like fuels, with the presence of hydrocarbons chains between C10-C27 similar to the ones obtained in commercial diesel.


Asunto(s)
Hidrocarburos , Petróleo , Biomasa , Carbón Orgánico
12.
Bioresour Technol ; 345: 126548, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34906704

RESUMEN

Xylose, the most abundant pentose sugar of the hemicellulosic fraction of lignocellulosic biomass, has to be utilized rationally for the commercial viability of biorefineries. An effective pre-treatment strategy for the release of xylose from the biomass and an appropriate microbe of the status of an Industrial strain for the utilization of this pentose sugar are key challenges which need special attention for the economic success of the biomass value addition to chemicals. Xylitol and xylonic acid, the alcohol and acid derivatives of xylose are highly demanded commodity chemicals globally with plenty of applications in the food and pharma industries. This review emphasis on the natural and metabolically engineered strains utilizing xylose and the progressive and innovative fermentation strategies for the production and subsequent recovery of the above said chemicals from pre-treated biomass medium.


Asunto(s)
Xilitol , Xilosa , Biomasa , Fermentación , Glucosa , Xilosa/análogos & derivados
13.
Environ Sci Pollut Res Int ; 29(47): 71882-71893, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35606590

RESUMEN

The production of pellets from residual biomass generated monocropping by Brazilian agribusiness is an environmentally and economically interesting alternative in view of the growing demand for clean, low-cost, and efficient energy. In this way, pellets were produced with sugarcane bagasse and coffee processing residues, in different proportions with charcoal fines, aiming to improve the energy properties and add value to the residual biomass. The pellets had their properties compared to the commercial quality standard. Artificial neural networks and multivariate statistical models were used to validate the best treatments for biofuel production. The obtained pellets presented the minimum characteristics required by DIN EN 14961-6. However, the sugarcane bagasse biomass distinguished itself for use in energy pellets, more specifically, the treatment with 20% of fine charcoal because of its higher net calorific value (17.85 MJ·kg-1) and energy density (13.30 GJ·m-3), achieving the characteristics required for type A pellets in commercial standards. The statistical techniques were efficient and grouped the treatments with similar properties, as well as validated the sugarcane biomass mixed with charcoal fines for pellet production. Thus, these results demonstrate that waste charcoal fines mixed with agro-industrial biomass have great potential to integrate the production chain for energy generation.


Asunto(s)
Celulosa , Saccharum , Biocombustibles , Biomasa , Carbón Orgánico/química , Café , Redes Neurales de la Computación
14.
Materials (Basel) ; 16(1)2022 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-36614729

RESUMEN

Volatile organic compounds (VOCs) released in air represent a major potential for environmental pollution. Capture methods based on activated biochar have attracted attention because of their low cost and for the high removal capacity of the material due to its physical and chemical properties. In this paper, activated biochars were developed and their adsorption performance for VOC capture was evaluated. In the first step, biochars derived from rapeseed cake (RSC) and walnut shells (WSC) were obtained through a carbonization process and then were activated using basic/acid agents (KOH/H2SO4) to increase their performance as adsorbents. Acetone and toluene were used as the VOC templates. The adsorption capacities of toluene and acetone for non-activated biochars were reduced (26.65 mg/g), while that of activated biochars increased quite significantly, up to 166.72 mg/g, and the biochars activated with H2SO4 presented a higher adsorption capacity of VOCs than the biochars activated with KOH. The higher adsorption capacity of biochars activated with H2SO4 can be attributed to their large surface area, and also to their larger pore volume. This activated biochar adsorbent could be used with good results to equip air purification filters to capture and remove VOCs.

15.
Nanomaterials (Basel) ; 12(21)2022 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-36364617

RESUMEN

Nanocomposites based on 13X zeolite (13XZ), calcium oxide (CaO) and metal zinc particles (Zn) were prepared. The resulting nanocomposites were characterized by different techniques. Then, a comparative study on catalytic and noncatalytic pyrolysis of biomass waste was performed to establish the influence of nanocomposites used as catalysts on the yields and characteristics of liquid and solid products. Residual rapeseed biomass (RRB) was employed for pyrolysis experiments and a fixed bed reactor was used. By introducing CaO and metal zinc particles into 13X zeolite mass, the surface area (SBET) of nanocomposites was reduced, and this decrease is due to the introduction of nano-calcium carbonate and nano-zinc particles, which occupied an important space into zeolite structure. By adding CaO to 13XZ, the pore structure was changed and there was a decrease in the micropores volume. The analysis of the pore area distribution showed a hierarchical pore structure for nanocomposites. The elements composition showed that the main elements contained in nanocomposites are Si, Al, Ca and Zn, confirming the preservation of the zeolite structure. Using these nanocomposites as catalysts in pyrolysis process, the residual biomass could be valorized, producing bio-oil and biochar for the management and sustainability of this low-value waste.

16.
Polymers (Basel) ; 14(14)2022 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-35890630

RESUMEN

Two types of biosorbents, based on Saccharomyces pastorianus immobilized in calcium alginate, were studied for the removal of pharmaceuticals from aqueous solutions. Synthetized biocomposite materials were characterized chemically and morphologically, both before and after simulated biosorption. Ethacridine lactate (EL) was chosen as a target molecule. The process performance was interpreted as a function of initial solution pH, biosorbent dose, and initial pharmaceutical concentration. The results exhibited that the removal efficiencies were superior to 90% for both biosorbents, at the initial pH value of 4.0 and biosorbent dose of 2 g/L for all EL initial concentrations tested. Freundlich, Temkin, Hill, Redlich-Peterson, Sips, and Toth isotherms were used to describe the experimental results. The kinetic data were analyzed using kinetic models, such as pseudo-first order, pseudo-second order, Elovich, and Avrami, to determine the kinetic parameters and describe the transport mechanisms of EL from aqueous solution onto biosorbents. Among the tested equations, the best fit is ensured by the pseudo-second-order kinetics model for both biosorbents, with the correlation coefficient having values higher than 0.996. The many potential advantages and good biosorptive capacity of Saccharomyces pastorianus biomass immobilized in calcium alginate recommend these types of biocomposite materials for the removal of pharmaceuticals from aqueous solutions.

17.
Materials (Basel) ; 15(13)2022 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-35806780

RESUMEN

In this study, ethacridine lactate removal from aqueous solution using a biosorbent material based on residual microbial biomass and natural polymers in fixed-bed continuous column was investigated. Composite beads of Saccharomyces pastorianus residual biomass and calcium alginate were obtained by immobilization technique. The prepared biosorbent was characterized by Fourier transformed infrared spectroscopy, scanning electron microscopy, and analysis of point of zero charge value. Then, laboratory-scale experiments by fixed-bed column biosorption were conducted in continuous system. To this purpose, the column bed high (5 cm; 7.5 cm), initial pollutant concentration (20 mg/L; 40 mg/L), and solution flow through the column (0.6 mL/min; 1.5 mL/min) were considered the main parameters. Recorded breakthrough curves suggest that lower flow rates, greater bed heights, and a lower concentration of ethacridine lactate led to an increased biosorption of the target compound. The biosorption dynamic was investigated by nonlinear regression analysis using the Adams-Bohart, Yoon-Nelson, Clark, and Yan mathematical models. Conclusively, our research highlights, firstly, that the obtained biosorbent material has the required properties for retaining the ethacridine lactate from aqueous solution in continuous system. Secondly, it emphasizes that the modeling approach reveals an acceptable fitting with the experimental data for the Yoon-Nelson, Clark, and Yan models.

18.
Waste Manag ; 152: 102-111, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36007470

RESUMEN

This study was focused on the anaerobic digestion of residual biomass from the production of penicillin and l-cystine. The biogas potential tests of individual substrates and their mixture showed good anaerobic biodegradability. The highest measured specific biogas production was 712 l/kg volatile solids (VS) for penicillin biomass and 676 l/ kg VS for cystine biomass. The biogas potential tests were performed at different inoculum-to-substrate ratios (ISR) and showed that high concentrations of nitrogen and sulphur present in residual biomass have a major impact on the anaerobic processes. The long-term operation of the laboratory anaerobic reactor showed that the mono-digestion of the penicillin biomass was stable at an OLR of 1 kg/(m3.d). When co-digestion of penicillin and cystine biomass at a ratio of 0.9:0.1 (on a VS basis) and at the same OLR was enhanced, the operation of the laboratory model turned unstable. During this phase of the operation, the course of anaerobic processes was affected by ammonia and especially sulphide inhibition. Sulphide inhibition was effectively reduced by direct dosing of FeCl2 (in-situ sulphide control), at a molar iron-to-sulphur ratio of ß = 1 (mol Fe/mol S). When suppressing sulphide inhibition, the operation of the laboratory model became stable even at a co-digestion ratio of 0.5:0.5 (VS basis). The results of this work open a new scope for future applications in the anaerobic digestion of waste biomass with high sulfur content, coming from industrial fermentation processes.


Asunto(s)
Biocombustibles , Cistina , Anaerobiosis , Biocombustibles/análisis , Biomasa , Reactores Biológicos , Metano , Penicilinas , Azufre
19.
J Hazard Mater ; 420: 126598, 2021 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-34274805

RESUMEN

Two biomass types of Botryosphaeria rhodina MAMB-05 (VMSM and M3) were evaluated to determine their effectiveness in removing Ag(I) ions from synthetic solutions. Both biomass types obtained good results in the biosorption process with maximum biosorption capacities (qm) for the Langmuir model of 34.67 and 39.23 mg Ag(I)/g dry biomass for M3 and VMSM, respectively. The biomass was characterized by X-ray microfluorescence and Fourier-transform-infrared spectroscopy (FT-IR). After the biosorption process, the mechanisms involved in biosorption were studied by FT-IR, X-ray diffraction (XRD), Field Emission Scanning Microscopy/Energy Dispersive X-ray Analysis (FESEM/EDX) and Ultraviolet-Visible Spectrophotometry. The results demonstrated the participation of various mechanisms in the retention of silver on biomass (bioadsorption, complexation, ion exchange, covalent bonding) that resulted in the formation of silver chloride nanoparticles (AgCl-NPs) and silver nanoparticles (AgNPs). The sizes of AgCl-NPs (chlorargyrite) according to the Debye-Scherrer equation were 19.29 nm (VMSM biomass) and 24.9 nm for the M3 type. For AgNPs the crystal size was between 1.5 and 0.8 nm for VMSM and M3 respectively. Furthermore, it was found that an undetermined fraction of the silver nanoparticles after biosorption remained in solution, which could be advantageous for their recovery.


Asunto(s)
Nanopartículas del Metal , Plata , Antibacterianos , Ascomicetos , Biomasa , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X
20.
Environ Technol ; 42(8): 1165-1178, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31475614

RESUMEN

World's energy consumption has doubled in the last four decades, this demand has been covered by the usage of fossil fuels; which are an important source of greenhouse gases emissions, entailing climate change. An efficient less polluting management alternative is the anaerobic digestion (AD) process which generates biogas derived from organic matter. The methane contained at the biogas is considered a biofuel that can generate electricity and heat through its combustion. Biochemical Methane Potential (BMP) essays are standardized methodologies carried out to estimate the energy potential of an organic residue. After performing a BMP test for 13 residual biomass samples, it can be concluded that fresh livestock rumen and manure were the best substrates to generate higher biogas yields; ranging from 1119-1669 ml/g VSadded, with high methane content (65%

Asunto(s)
Biocombustibles , Metano , Anaerobiosis , Animales , Biomasa , Estiércol , Porcinos
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