Adsorption and photodegradation of micropollutant in wastewater by photocatalyst TiO2/rice husk biochar.

With the acceleration of global industrialization, organic pollutants have become a threat to ecological safety and human health. This work prepared TiO2/rice husk biochar (TiO2/BC) for removal of bisphenol A (BA) micropollutant in wastewater. Experiment results revealed a low BA removal efficiency by TiO2/BC was observed at 34.5% under the dark environment. However, the removal rate of BA by UV light-assisted TiO2/BC significantly increased to 97.6% in 1 h. The results also demonstrated that the removal performance of BA using TiO2/BC was 2.1times higher than that of commercial TiO2 (46.4%). Besides, the removal efficiency of BA by reused TiO2/BC after eight cycles slightly decreased by 12.8%, demonstrating the excellent properties of the prepared composite. TiO2/BC also exhibited high removal efficiency of BA (over 89%) from the synthetic wastewater sample, indicating the potential utilization of composite for removing BA in wastewater. This work provides a new way to turn biomass waste into useful material and effective method to remove micropollutant BA.

Current application of seaweed waste for composting and biochar: A review.

To address the origins of ocean acidification, seaweed aquaculture is emerging as a key biosequestration strategy. Nevertheless, seaweed biomass is involved in developing food and animal feed, whereas seaweed waste from commercial hydrocolloid extraction is dumped in landfills, which together limit the carbon cycle and carbon sequestration. This work sought to evaluate the production, properties, and applications of seaweed compost and biochar to strengthen the "carbon sink" implications of aquaculture sectors. Due to their unique characteristics, the production of seaweed-derived biochar and compost, as well as their existing applications, are distinct when compared to terrestrial biomass. This paper outlines the benefits of composting and biochar production as well as proposes ideas and perspectives to overcome technical shortcomings. If properly synchronized, progression in the aquaculture sector, composting, and biochar production, potentially promote various Sustainable Development Goals.

Oxidative annulation of acetophenones and 2-aminobenzothiazoles catalyzed by reusable nickel-doped LaMnO3 perovskites.

Synthesis of imidazole[2,1-b]benzothiazoles often suffers from the use of pre-functionalized substrates and/or homogeneous, non-recyclable catalytic systems. Herein we report a method for direct coupling of acetophenones and 2-aminobenzothiazoles in the presence of reusable perovskites, namely LaMn0.95Ni0.05O3. Imidazole[2,1-b]benzothiazoles were obtained in moderate to good yields and contained an array of useful functionalities. Control experiments indicated that the perovskites played pivotal roles in halogenation and condensation steps.

Recent Progress on Functionalized Graphene Quantum Dots and Their Nanocomposites for Enhanced Gas Sensing Applications.

Gas-sensing technology has witnessed significant advancements that have been driven by the emergence of graphene quantum dots (GQDs) and their tailored nanocomposites. This comprehensive review surveys the recent progress made in the construction methods and applications of functionalized GQDs and GQD-based nanocomposites for gas sensing. The gas-sensing mechanisms, based on the Fermi-level control and charge carrier depletion layer theory, are briefly explained through the formation of heterojunctions and the adsorption/desorption principle. Furthermore, this review explores the enhancements achieved through the incorporation of GQDs into nanocomposites with diverse matrices, including polymers, metal oxides, and 2D materials. We also provide an overview of the key progress in various hazardous gas sensing applications using functionalized GQDs and GQD-based nanocomposites, focusing on key detection parameters such as sensitivity, selectivity, stability, response and recovery time, repeatability, and limit of detection (LOD). According to the most recent data, the normally reported values for the LOD of various toxic gases using GQD-based sensors are in the range of 1-10 ppm. Remarkably, some GQD-based sensors exhibit extremely low detection limits, such as N-GQDs/SnO2 (0.01 ppb for formaldehyde) and GQD@SnO2 (0.10 ppb for NO2). This review provides an up-to-date perspective on the evolving landscape of functionalized GQDs and their nanocomposites as pivotal components in the development of advanced gas sensors.

Antibacterial Activity of Copper Nanoparticles-Chitosan Composite against Vibrio parahaemolyticus.

The Early Mortality Syndrome (EMS) caused by Vibrio parahaemolyticus has recently resulted in a serious loss in shrimp farms in the Mekong delta, Vietnam. Here, antibacterial activity of copper nanoparticles-chitosan composite (CuCS) against V. parahaemolyticus was investigated. Copper nanoparticles were synthesized using L-ascorbic acid as a green reducing agent and chitosan as a biopolymer matrix and stabilizing agent. The physical properties of CuCS were evaluated. Next, antibacterial activity of 2.5, 5.0, 10.0 ppm CuCS against V. parahaemolyticus inoculated in a sterilized shrimp-pond water was examined. CuCS at 2.5 ppm eliminated 91.47% and 95.26% of V. parahaemolyticus after 2 and 4 h of exposure, respectively. Complete elimination was attained following 2 h of 5.0 ppm CuCS exposure. A complete elimination of V. parahaemolyticus in a real EMS-infected shrimp-pond water was also described. This study is the first to report the antibacterial activity of CuCS against V. parahaemolyticus, an important pathogen in shrimp industry in the Mekong delta, Vietnam.

Alternative pathways to α,ß-unsaturated ketones via direct oxidative coupling transformation using Sr-doped LaCoO3 perovskite catalyst.

A strontium-doped lanthanum cobaltite perovskite material was prepared, and used as a recyclable and effective heterogeneous catalyst for the direct oxidative coupling of alkenes with aromatic aldehydes to produce α,ß-unsaturated ketones. The reaction afforded high yields in the presence of di-tert-butylperoxide as oxidant. Single oxides or salts of strontium, lanthanum and cobalt, and the undoped perovskite offered a lower catalytic activity than the strontium-doped perovskite. Benzaldehyde could be replaced by benzyl alcohol, dibenzyl ether, 2-oxo-2-phenylacetaldehyde, 2-bromoacetophenone or (dimethoxymethyl) benzene in the oxidative coupling reaction with alkenes. To our best knowledge, reactions between these starting materials with alkenes are new and unknown in the literature.

Synthesis of triphenylpyridines via an oxidative cyclization reaction using Sr-doped LaCoO3 perovskite as a recyclable heterogeneous catalyst.

An La0.6Sr0.4CoO3 strontium-doped lanthanum cobaltite perovskite was prepared via a gelation and calcination approach and used as a heterogeneous catalyst for the synthesis of triphenylpyridines via the cyclization reaction between ketoximes and phenylacetic acids. The transformation proceeded via the oxidative functionalization of the sp3 C-H bond in phenylacetic acid. The La0.6Sr0.4CoO3 catalyst demonstrated a superior performance to that of the pristine LaCoCO3 as well as a series of homogeneous and heterogeneous catalysts. Furthermore, the La0.6Sr0.4CoO3 catalyst was facilely recovered and reused without considerable decline in its catalytic efficiency. To the best of our knowledge, the combination of ketoximes with easily available phenylacetic acids is novel.

In vitro activity of colistin in antimicrobial combination against carbapenem-resistant Acinetobacter baumannii isolated from patients with ventilator-associated pneumonia in Vietnam.

Acinetobacter baumannii has become one of the major infection threats in intensive care units (ICUs) globally. Since 2008, A. baumannii has been the leading cause of ventilator-associated pneumonia (VAP) in our ICU at an infectious disease hospital in southern Vietnam. The emergence of this pathogen in our setting is consistent with the persistence of a specific clone exhibiting resistance to carbapenems. Antimicrobial combinations may be a strategy to treat infections caused by these carbapenem-resistant A. baumannii. Therefore, we assessed potential antimicrobial combinations against local carbapenem-resistant A. baumannii by measuring in vitro interactions of colistin with four antimicrobials that are locally certified for treating VAP. We first performed antimicrobial susceptibility testing and multilocus variable number tandem repeat analysis (MLVA) genotyping on 74 A. baumannii isolated from quantitative tracheal aspirates from patients with VAP over an 18-month period. These 74 isolates could be subdivided into 21 main clusters by MLVA and >80 % were resistant to carbapenems. We selected 56 representative isolates for in vitro combination synergy testing. Synergy was observed in four (7 %), seven (13 %), 20 (36 %) and 38 (68 %) isolates with combinations of colistin with ceftazidime, ceftriaxone, imipenem and meropenem, respectively. Notably, more carbapenem-resistant A. baumannii isolates (36/43; 84 %) exhibited synergistic activity with a combination of colistin and meropenem than carbapenem-susceptible A. baumannii isolates (2/13; 15 %) (P = 0.023; Fisher's exact test). Our findings suggest that combinations of colistin and meropenem should be considered when treating carbapenem-resistant A. baumannii infections in Vietnam, and we advocate clinical trials investigating combination therapy for VAP.