Dissolved organic matter mitigates the toxicity of silver nanoparticles to freshwater algae: Effects on oxidative stress and membrane function.

The mechanisms underlying the destruction of cell membranes by silver nanoparticles (AgNPs) in the presence of dissolved organic matter (DOM) remain unclear despite extensive studies on the toxicity of AgNPs to the cell membranes of aquatic organisms. This study investigated the impact of dissolved humic acid (DHA) on the toxicity of AgNPs and silver ions (Ag) to Chlorella vulgaris cell membranes. Specifically, this research examined the alterations in membrane lipid peroxidation, cell membrane permeability, fatty acid (FA) profiles, membrane fluidity, and ultrastructural changes in algal cells resulting from Ag and AgNPs, both in the absence and presence of DHA, as well as the potential cytoprotective effect of DHA.

A High-Quality Mixed Matrix Membrane with Nanosheets Assembled and Uniformly Dispersed Fillers for Ethanol Recovery.

A high-quality filler within mixed matrix membranes, coupled with uniform dispersity, endows a high-efficiency transfer pathway for the significant improvement on separation performance. In this work, a zeolite-typed MCM-22 filler is reported that is doped into polydimethylsiloxane (PDMS) matrix by ultrafast photo-curing technique. The unique structure of nanosheets assembly layer by layer endows the continuous transfer channels towards penetrate molecules because of the inter-connective nanosheets within PDMS matrix.

Design of PDMS/PAN composite membranes with ultra-interfacial stability layer integration.

The interfacial interaction between the selective layer and porous substrate directly determines the separation performance and service lifetime of functional composite membranes. Till now, almost all reported polymeric selective layers are physically in contact with the substrate, which is unsatisfactory for long-term operation. Herein, we introduced a functional composite membrane with ultra-interfacial stability layer integration between the polydimethylsiloxane selective layer and polyacrylonitrile substrate, where a facile light-triggered copolymerization achieved their covalent bonding.

Single Cobalt Atoms Immobilized on Palladium-Based Nanosheets as 2D Single-Atom Alloy for Efficient Hydrogen Evolution Reaction.

Single-atom alloys (SAAs) display excellent electrocatalytic performance by overcoming the scaling relationships in alloys. However, due to the lack of a unique structure engineering design, it is difficult to obtain SAAs with a high specific surface area to expose more active sites. Herein, single Co atoms are immobilized on Pd metallene (Pdm) support to obtain Co/Pdm through the design of the engineered morphology of Pd, realizing the preparation of ultra-thin 2D SAA.

Research on Impact Resistance of Reinforced Concrete Beams Strengthened with Carbon Fiber Reinforced Polymer Grid and Engineered Cementitious Composites.

When reinforced concrete structures are subjected to impact loads, they may suddenly yield or fail, or even collapse as a whole. In this paper, the impact resistance of reinforced concrete (RC) beams strengthened with carbon fiber reinforced polymer (CFRP) grid and engineered cementitious composites (ECC) was studied. Drop hammer impact tests were conducted on eight beams, then the finite element model was used to simulate the impact test, finally a simplified two-degree-of-freedom (TDOF) model was proposed for CFRP grid reinforced ECC layer strengthened RC beams under impact loading.

A Particle-Driven, Ultrafast-Cured Strategy for Tuning the Network Cavity Size of Membranes with Outstanding Pervaporation Performance.

Poly(dimethylsiloxane) (PDMS) membranes are widely used for bioethanol separation. However, the network cavity size of PDMS membranes is generally smaller than the ethanol kinetic radius (0.225 nm), which limits the transport of ethanol molecules and weakens the pervaporation performance.

Chlorella vulgaris on the cathode promoted the performance of sediment microbial fuel cells for electrogenesis and pollutant removal.

The lack of electron acceptors in cathode has limited the widespread application of sediment microbial fuel cells (SMFCs). In this study, Chlorella vulgaris (C. vulgaris) was added to the cathode to produce oxygen as an electron acceptor.

Untangling the nitrate removal pathways for a constructed wetland- sponge iron coupled system and the impacts of sponge iron on a wetland ecosystem.

Sponge iron (s-Fe) is a potential alternative electron donor for nitrate reduction. To gain insight into the mechanism of denitrification in a constructed wetland- sponge iron coupled system (CW-Fe system), the removal performance and reduction characteristics of nitrate in constructed wetlands (CWs) with and without s-Fe application were compared. Results indicated that s-Fe intensified the removal of nitrate with a 6h-HRT.

Bioenergy generation and simultaneous nitrate and phosphorus removal in a pyrite-based constructed wetland-microbial fuel cell.

This study investigates the performance of a pyrite-based constructed wetland-microbial fuel cell (PCW-MFC) in chemical oxygen demand (COD), nitrate (NO-N), total inorganic nitrogen (TIN), and total phosphorus (TP) removal and bioelectricity generation, and explores the mechanisms involved. Four microcosms were used: a constructed wetland (CW), a pyrite-based constructed wetland (PCW), a constructed wetland-microbial fuel cell (CW-MFC), and a PCW-MFC. After 180 days' operation, the PCW-MFC exhibited enhanced simultaneous nitrate and phosphorus removal and bioelectricity output.

Effects of nZVI dosing on the improvement in the contaminant removal performance of constructed wetlands under the dye stress.

In this study, different dosages of nanoscale zero-valent iron (nZVI) were used to improve the nitrogen removal efficiency in CWs under different C/N ratios and dye stress conditions. The addition of nZVI enhanced the dye and nitrogen removal efficiencies in constructed wetlands (CWs) through chemical reduction and biological denitrification processes. However, total nitrogen (TN) and dye removal efficiencies firstly increased and then decreased with the increases of the nZVI dosage and influent COD/N (C/N) ratio.

Micro-aeration with hollow fiber membrane enhanced the nitrogen removal in constructed wetlands.

The nitrogen removal efficiency in constructed wetlands (CWs) was largely affected by the dissolved oxygen (DO). In this study, micro-aeration with different numbers of hollow fiber membrane modules (HFMEs) was adopted to increase the oxygen availability and improve the nitrogen removal efficiency in CWs under different air temperatures and different hydraulic retention time (HRT). Compared to the plant oxygen release (ROL) of wetland plants and traditional mechanical aeration, HFME increased the oxygen availability and enhanced the nitrogen removal efficiency in CWs.

Modified solid carbon sources with nitrate adsorption capability combined with nZVI improve the denitrification performance of constructed wetlands.

In this study, various modified agricultural wastes (modified canna leaves (MCL), modified rice straw (MRS) and modified peanut shells (MPS)) as solid carbon sources (SCSs) were used to remove nitrate in constructed wetlands (CWs). Then, modified SCSs combined with nZVI (SCSN) as co-electrons further enhanced both heterotrophic denitrification (HD) and autotrophic denitrification (AD) performance of CWs. The results showed that NO-N removal efficiencies in CWs with SCSNs (75.

The Ultrafast and Continuous Fabrication of a Polydimethylsiloxane Membrane by Ultraviolet-Induced Polymerization.

The polydimethylsiloxane (PDMS) membrane commonly used for separation of biobutanol from fermentation broth fails to meet demand owing to its discontinuous and polluting thermal fabrication. Now, an UV-induced polymerization strategy is proposed to realize the ultrafast and continuous fabrication of the PDMS membrane. UV-crosslinking of synthesized methacrylate-functionalized PDMS (MA-PDMS) is complete within 30 s.

Mechanism and performance of trace metal removal by continuous-flow constructed wetlands coupled with a micro-electric field.

Constructed wetlands coupled with a micro-electric field (CW-MEF) is a novel and efficient water treatment technology. The objective of this study was to investigate the mechanism and performance of trace metals (TMs) removal for CW-MEF systems during summer and winter. The mass distribution of TMs in plants and biofilms, physiological indices of wetland plants, and bacterial community structures on electrodes and in the rhizospheres were analyzed as well as to explore further the TM removal mechanism.

Formaldehyde assimilation through coordination of the glyoxylate pathway and the tricarboxylic acid cycle in broad bean roots.

Formaldehyde (HCHO) assimilation in broad bean (Vicia faba L. cv. YD) roots was investigated using C-labeled HCHO followed by C-NMR analysis.

Montmorillonite supported nanoscale zero-valent iron immobilized in sodium alginate (SA/Mt-NZVI) enhanced the nitrogen removal in vertical flow constructed wetlands (VFCWs).

Lacking of electron donor generally causes the low denitrification performance of constructed wetlands (CWs). Montmorillonite supported nanoscale zero-valent iron immobilized in sodium alginate (SA/Mt-NZVI) as novel electron donor-acceptor compounds were added in the denitrification zone of vertical flow constructed wetlands (VFCWs) to enhance the nitrogen removal. The key factors of the SA/Mt-NZVI dosage, the hydraulic retention time (HRT) of VFCWs, and the C/N ratios of influent were explored.

Intensified heterotrophic denitrification in constructed wetlands using four solid carbon sources: Denitrification efficiency and bacterial community structure.

Biodenitrification using solid carbon sources is a cost-effective way for nitrate removal. In the study, wheat straw, cotton, poly(butylene succinate), and newspaper was chosen as the carbon source to compare the denitrification efficiency and bacterial communities in constructed wetlands. Parameters including COD, NO-N, NO-N and total nitrogen (TN) were analyzed.

Performance enhancement of a polydimethylsiloxane membrane for effective -butanol pervaporation by bonding multi-silyl-functional MCM-41.

In the current work, MCM-41/polydimethylsiloxane (PDMS) mixed matrix membrane (MMM) was prepared for effective -butanol pervaporation from a model aqueous solution. In order to improve the compatibility between MCM-41 and PDMS, different types of silane coupling agents including -propyltrimethoxysilane (PTMS), -octyltrimethoxysilane (OTMS), -dodecyltrimethoxysilane (DTMS) and -hexadecyltrimethoxysilane (HDTMS) were used to modify the MCM-41. The results showed that the highest -butanol separation performance was achieved by bonding 20 wt% of PTMS-modified MCM-41 with PDMS.