Mechanism of visible light enhances microbial degradation of Bisphenol A

Clearing the path: Unraveling bisphenol a removal and degradation mechanisms for a cleaner future

Bisphenol A (BPA) is a prevalent chemical found in a range of consumer goods, which has raised worries about its possible health hazards. Comprehending the breakdown pathways of BPA is essential for evaluating its environmental consequences and addressing associated concerns. This review emphasizes the significance of studying the degradation/removal of BPA, with a specific focus on both natural and artificial routes. It explores natural processes such as photolysis, hydrolysis, and biodegradation, as well as manmade methods including advanced oxidation processes (AOPs) and enzymatic degradation. Examining the decomposition of BPA helps to understand how it behaves in the environment, providing valuable information for managing risks and addressing pollution. Furthermore, comprehending degradation mechanisms aids in the creation of more secure substitutes and regulatory actions to reduce BPA exposure and safeguard human health. This review emphasizes the need of promptly addressing this environmental and public health concern through the research of BPA degradation.

Assembly strategies for microbe-material hybrid systems in solar energy conversion

Microbe-material hybrid systems which facilitate the solar-driven synthesis of high-value chemicals, harness the unique capabilities of microbes, maintaining the high-selectivity catalytic abilities, while concurrently incorporating exogenous materials to confer novel functionalities. The effective assembly of both components is essential for the overall functionality of microbe-material hybrid systems. Herein, we conducted a critical review of microbe-material hybrid systems for solar energy conversion focusing on the perspective of interface assembly strategies between microbes and materials, which are categorized into five types: cell uptake, intracellular synthesis, extracellular mineralization, electrostatic adsorption, and cell encapsulation. Moreover, this review elucidates the mechanisms by which microbe-material hybrid systems convert elementary substrates, such as carbon dioxide, nitrogen, and water, into high-value chemicals or materials for energy generation.

Constructing a Type-II CdS/Bi2MoO6 Heterostructure: Promoting Photocatalytic Degradation of Contaminants

Constructing a heterostructure is regarded as one of the most favorable approaches to attaining the separation ability of photogenerated carriers and strengthening photocatalysis efficiency. In this study, a CdS/Bi2MoO6 type-II heterostructure was constructed through a hydrothermal technique. The photocatalytic test result shows that the degradation efficiency of rhodamine B (RhB) and tetracycline (TC) over CS/BMO-1 was 100 and 92% under visible light, respectively, which is the highest compared to other samples. The exceptional photocatalytic efficiency is principally associated with generating an inherent electric field within a type-II heterostructure, effectively restraining the recombination of photogenerated electron hole pairs. The intermediate products during the photocatalytic degradation of RhB and TC were identified through liquid chromatography-mass spectrometry, and the hypotheses were formulated regarding the corresponding photodegradation mechanisms. Furthermore, the outcomes of capture tests exhibited that the primary active species were •O2- and h+, and a mechanism of the photocatalytic degradation procedure has been proposed.

Microalgal-bacterial consortia for the treatment of livestock wastewater: Removal of pollutants, interaction mechanisms, influencing factors, and prospects for application

The livestock sector is responsible for a significant amount of wastewater globally. The microalgal-bacterial consortium (MBC) treatment has gained increasing attention as it is able to eliminate pollutants to yield value-added microalgal products. This review offers a critical discussion of the source of pollutants from livestock wastewater and the environmental impact of these pollutants. It also discusses the interactions between microalgae and bacteria in treatment systems and natural habitats in detail. The effects on MBC on the removal of various pollutants (conventional and emerging) are highlighted, focusing specifically on analysis of the removal mechanisms. Notably, the various influencing factors are classified into internal, external, and operating factors, and the mutual feedback relationships between them and the target (removal efficiency and biomass) have been thoroughly analysed. Finally, a wastewater recycling treatment model based on MBC is proposed for the construction of a green livestock farm, and the application value of various microalgal products has been analysed. The overall aim was to indicate that the use of MBC can provide cost-effective and eco-friendly approaches for the treatment of livestock wastewater, thereby advancing the path toward a promising microalgal-bacterial-based technology.

Fabrication of chitin based hydrophilic hyper-crosslinked porous polymer for efficiently removing bisphenol A from water

Water pollution caused by bisphenol A (BPA) has become the world problem. Designing and preparing cost-effective and biodegradable sorbents for the effectively adsorptive removal of bisphenol A from wastewater is of immense significance. Herein, a natural polysaccharide (chitin) was used as raw materials to be grafted with styrene (GS), then crosslinked with α,α'-dichloro-p-xylene (DCX) to form the hyper-crosslinked polymer (labeled as CGS@DCX). The CGS@DCX showed high adsorptive affinity for bisphenol A, with adsorption capacity of 441 mg g-1. Various studies gave an insight into the adsorption process, demonstrating that the highly efficient adsorption of BPA by the CGS@DCX is mainly based on the π-π stacking, hydrogen-bond interaction, polar interaction and pore adsorption. Moreover, the CGS@DCX had high chemical stability, good reusability (9 cycles) and fast adsorption kinetics (10 min) for adsorption of BPA. This work provides a promising strategy for the design and synthesis of novel yet eco-friendly sorbents to solve environmental problems.

Chemical bonding and facet modulating of p-n heterojunction enable vectorial charge transfer for enhanced photocatalysis

Heterojunctions have been proved to be the promising photocatalysts for hazardous contaminants removal, but the inferior interfacial contact, low carrier mobility and random carrier diffusion seriously hamper the photoactivity improvement of the conventional heterojunctions. Herein, SO chemically bonded p-n oriented heterostructure is fabricated via selectively anchoring of p-type Ag2S nanoparticles on the lateral facet of n-type Bi4TaO8Cl nanosheet. Such a p-n heterojunction engineering on specific facet of Bi4TaO8Cl semiconductor derives ingenious double internal electric field (IEF), which not only effectively creates the spatially separated oxidation and reduction sites, but also delivers the powerful driving forces for impactful spatial directed photocarrier transfer along the cascade path. Additionally, our experimental and theoretical analyses jointly signify that the interfacial SO bond could serve as an efficient atomic-level interfacial channel, which is conducive to encouraging the vectorial charge separation and migration kinetic. As a result, the Ag2S/Bi4TaO8Cl oriented heterojunction exhibits significantly enhanced visible light driven photocatalytic redox ability for tetracycline oxidation and hexavalent chromium reduction than those of single component and the traditional random/mixed heterojunctions. This study could provide a deeper insight into the synergistic effects of multi-IEF modulation and interfacial chemical bond bridging on optimizing the photogenerated carrier behaviors.

Intimate coupling of gC3N4/CdS semiconductor on eco-friendly biocarrier loofah sponge for enhanced detoxification of ciprofloxacin

Ciprofloxacin is one of the antibiotics predominantly used to treat bacterial infections, however excess usage, and release of antibiotic from various sources to the environment can cause severe risks to human health since it was considered as emerging pollutant. This study deals with the intimately coupled photocatalysis and biodegradation (ICPB) of ciprofloxacin using gC3N4/CdS photocatalytic semiconductor and eco-friendly renewable loofah sponge as biocarrier in the ICPB. The photocatalyst gC3N4/CdS was prepared and their synergistic photocatalytic degradation of ciprofloxacin were assessed and the results shows that gC3N4/CdS (20%) exhibit 79% degradation efficiency in 36 h. Further ICPB exhibited enhanced ciprofloxacin degradation 95% at 36 h. The 62.4% and 81.1% of chemical oxygen demand (COD) removal was obtained in the photocatalysis and ICPB respectively. Enhanced degradation of ciprofloxacin and COD removal was due to the synergetic photoelectrons generated from the gC3N4/CdS (20%) transferred to the bacterial communities which intensely mineralize the degradation products produced from the photocatalysis process. Furthermore, production of hydroxyl •OH and superoxide radical anion O2• were identified actively involved in the degradation of ciprofloxacin. The biocarrier loofah sponge provided favourable environment to the bacterial communities for the formation of biofilm and production of extracellular polymeric substances (EPS). Excess quantity of EPS production in the ICPB helps in the prevention of toxicity of photocatalyst to bacterial communities as well as facilitate the extracellular electron transfer process. This work provides a novel path for enhanced degradation of ciprofloxacin using eco-friendly, low cost and renewable biocarrier loofah sponge in the ICPB system.