Research

Jump to: Review

17 pages, 2567 KiB

Open AccessArticle

Use of High-Frequency Ultrasound Waves for Boiler Water Demineralization/Desalination Treatment

by Yago Fraga Ferreira Brandão, Leonardo Bandeira dos Santos, Gleice Paula de Araújo, Leonildo Pereira Pedrosa Júnior, Benjamim Francisco da Costa Neto, Rita de Cássia Freire Soares da Silva, Mohand Benachour, Attilio Converti, Leonie Asfora Sarubbo and Valdemir Alexandre dos Santos

Energies 2022, 15(12), 4431; https://0-doi-org.brum.beds.ac.uk/10.3390/en15124431 - 17 Jun 2022

Cited by 2 | Viewed by 1656

Abstract

Isolated ultrasonic vibrations were used to treat feed water from a 20 bar steam-producing water tube boiler. Physical treatments such as ultrasounds and reverse osmosis (RO) are recommended as the most eco-friendly for this purpose. A novel bench-scale prototype delivering 6 L/h of [...] Read more.

Isolated ultrasonic vibrations were used to treat feed water from a 20 bar steam-producing water tube boiler. Physical treatments such as ultrasounds and reverse osmosis (RO) are recommended as the most eco-friendly for this purpose. A novel bench-scale prototype delivering 6 L/h of treated water was designed and built. The ultrasonic atomization of raw water with 1.7 MHz piezoelectric transducers and subsequent humidification and dehumidification of drag airflow was the innovating sequence of operations used as a treatment technique. To ensure greater humidification capacity to the drag air, the energy available from the thermal inertia of the liquid column (raw water) in the prototype vaporization chamber was used to heat this air flow. After a single pass of raw water through the bench-scale prototype, a 98.0% reduction in conductivity and a 99.0% decrease in the content of total dissolved solids were obtained at a drag air temperature of 70 °C. Compared to RO, two of the main advantages of the proposed ultrasonic wave method are the elimination of the use of chemical agents in the pre-treatment phase and a significant reduction in maintenance costs by membrane replacement. Full article

(This article belongs to the Special Issue Environmental Biotechnology for Green Energy)

► Show Figures

Figure 1

12 pages, 2102 KiB

Open AccessArticle

Environmental Valorization of Rice Waste as Adsorbent Material for the Removal of Nitrates from Water

by Michela Mazzoccoli, Elisabetta Arato and Cristina Moliner

Energies 2022, 15(7), 2605; https://0-doi-org.brum.beds.ac.uk/10.3390/en15072605 - 02 Apr 2022

Cited by 2 | Viewed by 1325

Abstract

An innovative water-treatment process consisting in reducing the nitrate concentration by using an active silica filter obtained from ashes produced during rice-straw thermal treatment has been developed by the LIFE LIBERNITRATE project. A life-cycle assessment (LCA) was carried out to evaluate the environmental [...] Read more.

An innovative water-treatment process consisting in reducing the nitrate concentration by using an active silica filter obtained from ashes produced during rice-straw thermal treatment has been developed by the LIFE LIBERNITRATE project. A life-cycle assessment (LCA) was carried out to evaluate the environmental impacts of this innovative process, from the production of ashes and extraction and activation of silica to the water treatment. These results were compared to the environmental impact derived from the use of bottled water, instead of tap water, where traditional water treatments (i.e., reverse osmosis) may not be available due to the high installation and operating costs. The comparison showed that the proposed innovative process could contribute to reducing the environmental impact in almost all analyzed impact categories (from 20% for photochemical oxidation to 90% for abiotic depletion) with respect to the use of bottled water. In addition, if conveniently optimized (for example reducing the amount of active silica used per day), the innovative process could further reduce the ecological footprint and be more eco-friendly than the use of bottled water and could be applied to treating water in small towns where reverse osmosis may not be installed. The LCA proved that the innovative process could contribute to reducing the environmental impact of water-treatment technologies resulting in lower environmental indicators with respect to the use of bottled water. Full article

(This article belongs to the Special Issue Environmental Biotechnology for Green Energy)

► Show Figures

Figure 1

12 pages, 2531 KiB

Open AccessArticle

Immobilizing Enzymes on a Commercial Polymer: Performance Analysis of a GOx-Laccase Based Enzymatic Biofuel Cell Assembly

by Dario Pelosi, Linda Barelli, Nicolò Montegiove, Eleonora Calzoni, Alessio Cesaretti, Alessandro Di Michele, Carla Emiliani and Luca Gammaitoni

Energies 2022, 15(6), 2182; https://0-doi-org.brum.beds.ac.uk/10.3390/en15062182 - 16 Mar 2022

Cited by 5 | Viewed by 2466

Abstract

Enzymatic Biofuel Cell (EBC) represents a promising green source since it is capable of harvesting electricity from renewable and abundantly available biofuels using enzymes as catalysts. Nevertheless, nowadays long-term stability and low power output are currently the main concerns. To this end, several [...] Read more.

Enzymatic Biofuel Cell (EBC) represents a promising green source since it is capable of harvesting electricity from renewable and abundantly available biofuels using enzymes as catalysts. Nevertheless, nowadays long-term stability and low power output are currently the main concerns. To this end, several research studies focus on using complex tridimensional and highly expensive nanostructures as electrode support for enzymes. This increases cell performance whilst drastically reducing the economic feasibility needed for industrial viability. Thus, this paper analyzes a novel flow-based EBC consisting of covalent immobilized GOx (bioanode) and Laccase (biocathode) on a commercial flat conductive polymer. A suitable immobilization technique based on covalent ligands is carried out to enhance EBC durability. The experimental characterization demonstrates that the cell generates power over three weeks, reaching 590 mV and 2.41 µW cm⁻² as maximum open circuit voltage and power density, respectively. The most significant contributions of this configuration are definitely ease of implementation, low cost, high scalability, and reproducibility. Therefore, such a design can be considered a step forward in the viable EBC industrialization process for a wide range of applications. Full article

(This article belongs to the Special Issue Environmental Biotechnology for Green Energy)

► Show Figures

Graphical abstract

12 pages, 1145 KiB

Open AccessArticle

In Situ Transesterification of Microbial Biomass for Biolubricant Production Catalyzed by Heteropolyacid Supported on Niobium

by Savienne M. F. E. Zorn, Ana Paula T. da Silva, Eduardo H. Bredda, Heitor B. S. Bento, Guilherme A. Pedro, Ana Karine F. Carvalho, Messias Borges Silva and Patrícia C. M. Da Rós

Energies 2022, 15(4), 1591; https://0-doi-org.brum.beds.ac.uk/10.3390/en15041591 - 21 Feb 2022

Cited by 2 | Viewed by 1731

Abstract

Lubricants are substances of the foremost importance in the modern world, as they are essential to the proper functioning of various mechanisms. Most lubricants, however, are still made from petroleum fractions. I light of this, and due to various environmental problems, the search [...] Read more.

Lubricants are substances of the foremost importance in the modern world, as they are essential to the proper functioning of various mechanisms. Most lubricants, however, are still made from petroleum fractions. I light of this, and due to various environmental problems, the search for feasible biolubricants has become essential. This study obtained biolubricants through the in situ transesterification of microbial biomass, containing at least 20 wt% of lipids. The following two distinct biomasses were evaluated: the marine microalgae, Dunaliella salina, and the consortium of microalgae-fungi, Scenedesmus obliquus and Mucor circinelloides. Microbial oil from both biomasses presented a fatty acid profile with high amounts of oleic acid. The oil of D. salina had a lower content of polyunsaturated fatty acids relative to the microbial consortium profile, which indicates that this is a good configuration for increasing biolubricant oxidation resistance. The catalyst used was a Keggin-structure heteropolyacid supported on niobium, H₃PMo₁₂O₄₀/Nb₂O₅, activated at 150 °C, which had high transesterification yields, notwithstanding the feedstocks, which were rich in free fatty acids. The performed transesterification reactions resulted in excellent yields, up to 97.58% and 96.80%, for marine microalgae and the consortium, respectively, after 6 h at 250 °C, with 10 wt% of catalyst (related to the lipid amount). As such, the (H₃PMo₁₂O₄₀/Nb₂O₅) catalyst could become an attractive option for producing biolubricants from microbial biomass. Full article

(This article belongs to the Special Issue Environmental Biotechnology for Green Energy)

► Show Figures

Figure 1

15 pages, 5179 KiB

Open AccessArticle

A Study of the Pyrolysis Products of Kraft Lignin

by Matteo Borella, Alessandro A. Casazza, Gabriella Garbarino, Paola Riani and Guido Busca

Energies 2022, 15(3), 991; https://0-doi-org.brum.beds.ac.uk/10.3390/en15030991 - 28 Jan 2022

Cited by 4 | Viewed by 2334

Abstract

In order to valorize lignin wastes to produce useful aromatic compounds, the thermal degradation pyrolysis of Kraft lignin in the absence of catalysts has been investigated at 350, 450, and 550 °C. The high content of sulfur in the fresh sample led to [...] Read more.

In order to valorize lignin wastes to produce useful aromatic compounds, the thermal degradation pyrolysis of Kraft lignin in the absence of catalysts has been investigated at 350, 450, and 550 °C. The high content of sulfur in the fresh sample led to the formation of S-containing compounds in products whose evolution in the gas phase was monitored through GC-MS analysis. Pyrolytic gas is rich in CH₄, CO, CO₂, and H₂S with the presence of other sulfur compounds in smaller amounts (i.e., CH₃SH, CH₃-S-CH₃, SO₂, COS, and CS₂). Biochar morphology and elemental composition have been investigated by means of SEM and EDX. The carbon content reaches ~90% after pyrolysis at 550 °C, while the oxygen content showed a decreasing trend with increasing temperature. From GC-MS analysis, bio-oil resulted rich in alkyl-alkoxy phenols, together with (alkyl)dihydroxy benzenes and minor amounts of hydrocarbons and sulfur compounds. NaOH/H₂O and EtOH/H₂O extraction were performed with the aim of extracting phenolic-like compounds. Sodium hydroxide solution allowed a better but still incomplete extraction of phenolic compounds, leaving a bio-oil richer in sulfur. Full article

(This article belongs to the Special Issue Environmental Biotechnology for Green Energy)

► Show Figures

Figure 1

18 pages, 6193 KiB

Open AccessArticle

Physicochemical Upgrading of a Biodetergent for Application in the Industrial Energy Sector

by Charles Bronzo B. Farias, Rita de Cássia F. Soares da Silva, Fabíola Carolina G. Almeida, Attilio Converti, Valdemir A. dos Santos and Leonie A. Sarubbo

Energies 2022, 15(2), 463; https://0-doi-org.brum.beds.ac.uk/10.3390/en15020463 - 10 Jan 2022

Cited by 2 | Viewed by 2034

Abstract

In the industries across the petroleum chain and those involved in energy generation, the use of petroderivatives as fuel oils is common. To clean parts, equipment and environments contaminated by hydrocarbons, they use expensive, toxic products, bringing risks to the environment as well [...] Read more.

In the industries across the petroleum chain and those involved in energy generation, the use of petroderivatives as fuel oils is common. To clean parts, equipment and environments contaminated by hydrocarbons, they use expensive, toxic products, bringing risks to the environment as well as to workers’ health. Thus, the aim of this study was to check the stability of a biodetergent prepared using atoxic substances for large-scale production and industrial energy sector application. The relationship between volume (4 to 10 L) and stirring time (5 to 10 min) of the formulation at 3200 rpm and 80 °C was evaluated. The hydrophilic lipophilic balance (HLB), long-term stability (365 days), toxicity and efficiency of low-sulfur, viscous fuel oil removal from metal pieces and floors were investigated. The interaction among operating conditions was shown to influence the features of the product, which achieved approximately 100% stability after a stirring time of 7 min. The emulsion HBL index varied between 4.3 and 11.0. The biodetergent maintained its physicochemical properties during its 365 days of storage and showed high efficiency, removing 100% of the OCB1 impregnated on the metallic surfaces and floors tested. The formulation showed reliability in scale up when submitted to the study of physicochemical factors in the productive process, and safe application, by reducing risks for workers’ health and environment. Full article

(This article belongs to the Special Issue Environmental Biotechnology for Green Energy)

► Show Figures

Graphical abstract

15 pages, 2023 KiB

Open AccessArticle

Flushing of Soils Highly Contaminated with Cd Using Various Washing Agents Derived from Sewage Sludge

by Barbara K. Klik, Dorota Kulikowska and Zygmunt M. Gusiatin

Energies 2022, 15(1), 349; https://0-doi-org.brum.beds.ac.uk/10.3390/en15010349 - 04 Jan 2022

Cited by 2 | Viewed by 1337

Abstract

The suitability of sewage-sludge derived washing agents (SS_WAs) (dissolved organic matter DOM; humic-like substances HLS; soluble humic substances SHS), was assessed for removing Cd from highly contaminated (300 mg/kg) sandy clay loam and clay. The soils were remediated via column flushing at two [...] Read more.

The suitability of sewage-sludge derived washing agents (SS_WAs) (dissolved organic matter DOM; humic-like substances HLS; soluble humic substances SHS), was assessed for removing Cd from highly contaminated (300 mg/kg) sandy clay loam and clay. The soils were remediated via column flushing at two flow rates, 0.5 and 1.0 mL/min. The stability of the flow velocity (FV) depended on the type of SS_WA and decreased in the following order: DOM > HLS > SHS. Cd was most effectively removed during the first hours of flushing, and the process proceeded with a first-order kinetics. The overall process efficiency was higher at flow rate of 1.0 mL/min than at 0.5 mL/min and ranged from 65.7 (SHS) to 75.5% (DOM) for the sandy clay loam and from 64.7% (SHS) to 67.8% (DOM) for the clay. However, all SS_WAs at both flow rates removed the most mobile Cd fraction (F1) with an efficiency above 90%. Flushing improved soil characteristics in terms of the content of organic matter, humic substances and nutrients. Among all SS_WAs, DOM was the most suitable for remediation of highly Cd-contaminated soils due to high efficiency of Cd removal, the high stability of its FV during flushing and the simple manner of DOM recovery from sewage sludge. Full article

(This article belongs to the Special Issue Environmental Biotechnology for Green Energy)

► Show Figures

Graphical abstract

11 pages, 1747 KiB

Open AccessArticle

Recycling of Blast Furnace and Coal Slags in Aided Phytostabilisation of Soils Highly Polluted with Heavy Metals

by Maja Radziemska, Justyna Dzięcioł, Zygmunt M. Gusiatin, Agnieszka Bęś, Wojciech Sas, Andrzej Głuchowski, Beata Gawryszewska, Zbigniew Mazur and Martin Brtnicky

Energies 2021, 14(14), 4300; https://0-doi-org.brum.beds.ac.uk/10.3390/en14144300 - 16 Jul 2021

Cited by 1 | Viewed by 1620

Abstract

(1) Background: The growing demand for developing new methods of degraded land remediation is linked to the need to improve the soil environment, including post-industrial soils. Biological methods such as the aided phytostabilisation technique are the most common methods applied to achieve effective [...] Read more.

(1) Background: The growing demand for developing new methods of degraded land remediation is linked to the need to improve the soil environment, including post-industrial soils. Biological methods such as the aided phytostabilisation technique are the most common methods applied to achieve effective remediation. This study aimed to determine the technical potential of methods using novel or yet not used soil amendments, such as blast furnace slag (BFS) and coal slag (CS), with Dactylis glomerata L. as a test plant. (2) Methods: The experiment was conducted on post-industrial area soil with high concentrations of Cu (761 mg/kg), Cd (23.9 mg/kg), Pb (13,539 mg/kg) and Zn (8683 mg/kg). The heavy metal content in roots and the above-ground parts of plants and soil was determined by flame atomic absorption spectrometry. (3) Results: The addition of BFS to the soil was the most effective in increasing Dactylis glomerata L. biomass yield. The Cu, Cd, Pb, and Zn concentrations were higher in the roots than in the above-ground parts of the plants. BFS and CS induced a considerable increase in soil pH, compared to the control treatment. The addition of BFS also produced the greatest significant decrease in the Pb content in soil following the phytostabilisation process. (4) Conclusions: In view of the above, the use of BFS in the aided phytostabilisation in soils contaminated with high levels of Cu, Cd, Pb, and Zn can be recommended for larger-scale in situ projects. Full article

(This article belongs to the Special Issue Environmental Biotechnology for Green Energy)

► Show Figures

Figure 1

Review

Jump to: Research

20 pages, 17507 KiB

Open AccessReview

Use of Hydrogen as Fuel: A Trend of the 21st Century

by Charles Bronzo Barbosa Farias, Robson Carmelo Santos Barreiros, Milena Fernandes da Silva, Alessandro Alberto Casazza, Attilio Converti and Leonie Asfora Sarubbo

Energies 2022, 15(1), 311; https://doi.org/10.3390/en15010311 - 03 Jan 2022

Cited by 51 | Viewed by 7302

Abstract

The unbridled use of fossil fuels is a serious problem that has become increasingly evident over the years. As such fuels contribute considerably to environmental pollution, there is a need to find new, sustainable sources of energy with low emissions of greenhouse gases. [...] Read more.

The unbridled use of fossil fuels is a serious problem that has become increasingly evident over the years. As such fuels contribute considerably to environmental pollution, there is a need to find new, sustainable sources of energy with low emissions of greenhouse gases. Climate change poses a substantial challenge for the scientific community. Thus, the use of renewable energy through technologies that offer maximum efficiency with minimal pollution and carbon emissions has become a major goal. Technology related to the use of hydrogen as a fuel is one of the most promising solutions for future systems of clean energy. The aim of the present review was to provide an overview of elements related to the potential use of hydrogen as an alternative energy source, considering its specific chemical and physical characteristics as well as prospects for an increase in the participation of hydrogen fuel in the world energy matrix. Full article

(This article belongs to the Special Issue Environmental Biotechnology for Green Energy)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Environmental Biotechnology for Green Energy

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Published Papers (9 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI