High-Performance Macroporous Free-Standing Microbial Fuel Cell Anode Derived from Grape for Efficient Power Generation and Brewery Wastewater Treatment.

Microbial fuel cells (MFCs) have the potential to directly convert the chemical energy in organic matter into electrical energy, making them a promising technology for achieving sustainable energy production alongside wastewater treatment. However, the low extracellular electron transfer (EET) rates and limited bacteria loading capacity of MFCs anode materials present challenges in achieving high power output. In this study, three-dimensionally heteroatom-doped carbonized grape (CG) monoliths with a macroporous structure were successfully fabricated using a facile and low-cost route and employed as independent anodes in MFCs for treating brewery wastewater. The CG obtained at 900 °C (CG-900) exhibited excellent biocompatibility. When integrated into MFCs, these units initiated electricity generation a mere 1.8 days after inoculation and swiftly reached a peak output voltage of 658 mV, demonstrating an exceptional areal power density of 3.71 W m-2. The porous structure of the CG-900 anode facilitated efficient ion transport and microbial community succession, ensuring sustained operational excellence. Remarkably, even when nutrition was interrupted for 30 days, the voltage swiftly returned to its original level. Moreover, the CG-900 anode exhibited a superior capacity for accommodating electricigens, boasting a notably higher abundance of Geobacter spp. (87.1%) compared to carbon cloth (CC, 63.0%). Most notably, when treating brewery wastewater, the CG-900 anode achieved a maximum power density of 3.52 W m-2, accompanied by remarkable treatment efficiency, with a COD removal rate of 85.5%. This study provides a facile and low-cost synthesis technique for fabricating high-performance MFC anodes for use in microbial energy harvesting.

Application of Metal-Organic Frameworks (MOFs) in Environmental Biosystems.

Metal-organic frameworks (MOFs) are crystalline materials that are formed by self-assembling organic linkers and metal ions with large specific areas and pore volumes. Their chemical tunability, structural diversity, and tailor-ability make them adaptive to decorate many substrate materials, such as biomass-derived carbon materials, and competitive in many environmental biosystems, such as biofuel cells, bioelectrocatalysts, microbial metal reduction, and fermentation systems. In this review, we surmised the recent progress of MOFs and MOF-derived materials and their applications in environmental biosystems. The behavior of MOFs and MOF-derived materials in different environmental biosystems and their influences on performance are described. The inherent mechanisms will guide the rational design of MOF-related materials and lead to a better understanding of their interaction with biocomponents.

Influence of thermally activated peroxodisulfate pretreatment on gaseous emission, dissolved organic matter and maturity evolution during spiramycin fermentation residue composting.

Aerobic composting combined with appropriate pretreatment is promising to achieve the utilization of antibiotics fermentation residues (AFRs). This research studied the effect of thermally activated peroxodisulfate (TAP) pretreatment on greenhouse gas (GHGs) emission, dissolved organic matter (DOM) and maturity evaluation during spiramycin fermentation residue (SFR) composting. Three treatments were conducted from co-composting of SFR and wheat straw, while 90% and 99.9% residual spirmycin removal pretreatment SFR by TAP were provided and compared with raw SFR. The cumulative CO2 and NH3 emissions increased by 17.2% and 30.8% after TAP pretreatment removed 99.9% residual spiramycin in SFR, while the cumulative CH4 and N2O emission decreased by 34.0% and 5.27%, respectively. The DOM, humic acid (HA)/fulvic acid (FA) and NH4+/NO3- analysis confirmed that the composting maturity was improved with the increasing of HA and NO3- content by TAP pretreatment.

High-performance free-standing microbial fuel cell anode derived from Chinese date for enhanced electron transfer rates.

Traditional anode materials have disadvantages like low specific surface area and poor electrical conductivity. Herein, carbonized Chinese dates (CCD) were synthesized as microbial fuel cells (MFC) anodes. The obtained materials exhibited excellent biocompatibility with fast start-up (within one day) and charge transfer (Rct 4.0 Ω). Their porous structure allows efficient ion transport and microbial community succession, favorable for long-term operation. The biomass analysis shows that CCD anodes can load higher weight of biomass. High-throughput sequencing (16S rRNA) discovered that CCD anode can enrich Geobacter spp., with highest abundance of 73.4%, much higher than carbon felt (CF, 39.2%). Benefit from these properties, the MFC with CCD anodes possess a maximum power density of 12.17 W m-3 (1.62 times of commercial carbon felt). In all, the CCD anode exhibits high performance with low cost and easy fabrication, certificating it a promising candidate for an ideal MFC anode material.

Nanomaterials Facilitating Microbial Extracellular Electron Transfer at Interfaces.

Electrochemically active bacteria can transport their metabolically generated electrons to anodes, or accept electrons from cathodes to synthesize high-value chemicals and fuels, via a process known as extracellular electron transfer (EET). Harnessing of this microbial EET process has led to the development of microbial bio-electrochemical systems (BESs), which can achieve the interconversion of electrical and chemical energy and enable electricity generation, hydrogen production, electrosynthesis, wastewater treatment, desalination, water and soil remediation, and sensing. Here, the focus is on the current understanding of the microbial EET process occurring at both the bacteria-electrode interface and the biotic interface, as well as some attempts to improve the EET by using various nanomaterials. The behavior of nanomaterials in different EET routes and their influence on the performance of BESs are described. The inherent mechanisms will guide rational design of EET-related materials and lead to a better understanding of EET mechanisms.

Fuel-Driven Dissipative Self-Assembly of a Supra-Amphiphile in Batch Reactor.

Dissipative self-assembly is an intriguing but challenging research topic in chemistry, materials science, physics, and biology because most functional self-assembly in nature, such as the organization and operation of cells, is actually an out-of-equilibrium system driven by energy dissipation. In this article, we successfully fabricated an I2-responsive supra-amphiphile by a PEGylated poly(amino acid) and realize its dissipative self-assembly in batch reactor by coupling it with the redox reaction between NaIO3 and thiourea, in which I2 is an intermediate product. The formation and dissipative self-assembly of the supra-amphiphile can be repeatedly initiated by adding the mixture of NaIO3 and thiourea, which herein acts as "chemical fuel", while the lifetime of the transient nanostructures formed by the dissipative self-assembly is easily tuned by altering thiourea concentration in the "chemical fuel". Furthermore, as an application demo, the dissipative self-assembly of the supra-amphiphile is examined to control dispersion of multiwalled carbon nanotubes in water, exhibiting a good performance of organic pollutant removal.

FeS2 Nanoparticles Decorated Graphene as Microbial-Fuel-Cell Anode Achieving High Power Density.

Microbial fuel cells (MFCs) have received great attention worldwide due to their potential in recovering electrical energy from waste and inexhaustible biomass. Unfortunately, the difficulty of achieving the high power, especially in real samples, remains a bottleneck for their practical applications. Herein, FeS2 nanoparticles decorated graphene is fabricated via a simple hydrothermal reaction. The FeS2 nanoparticles decorated graphene anode not only benefits bacterial adhesion and enrichment of electrochemically active Geobacter species on the electrode surface but also promotes efficient extracellular electron transfer, thus giving rise to a fast start-up time of 2 d, an unprecedented power density of 3220 mW m-2 and a remarkable current density of 3.06 A m-2 in the acetate-feeding and mixed bacteria-based MFCs. Most importantly, the FeS2 nanoparticles decorated graphene anode successfully achieves a power density of 310 mW m-2 with simultaneous removal of 1319 ± 28 mg L-1 chemical oxygen demand in effluents from a beer factory wastewater. The characteristics of improved power generation and enhanced pollutant removal efficiency opens the door toward development of high-performance MFCs via rational anode design for practical application.

[Laboratory study of surface electromyography and electrocardiogram in assessing dynamic workload].

OBJECTIVE: To investigate the use of surface electromyography (sEMG) and electrocardiogram (ECG) in evaluation of dynamic workload. METHODS: Through controlling the speed and gradient, 8 subjects ran on the treadmill power machine to simulate the dynamic work. The sEMG signal of anterior tibial muscle (AT) and gastrocnemius muscle (GC) of right lower limb and ECG signal were recorded. The root mean square value (RMS), median frequency (MF), mean power frequency (MPF), heart rate (HR), standard deviation of all normal to normal intervals (SDNN) and Borg scores were analyzed. RESULTS: In the five sports, with the speed increasing, all the values of RMS increased in the AT and GC (P < 0.01). With the gradient increasing, the values of RMS increased in the GC (P < 0.01) while the values of RMS of AT had a trend of decrease (P > 0.05). In all five sports, both the values of MF and MPF in AT and GC were lowest in B sports. Compared to A sport, most of the values of MF and MPF increased in C, D, E sports (P < 0.01), with a highest value in the D sport. Compared with A sport, the HR of B, C, D, E sports significantly increased (P < 0.01), and the highest heart rate was found in B sport, however, the values of SDNN significantly decreased. With the increased speed and gradient, the scores of Borg scale significantly increased. CONCLUSION: In the evaluation of dynamic workload, RMS and HR appear to be good indexes. However, in terms of stress reaction to dynamic workload, MF and MPF are more sensitive.