Anion-exchange membrane-separated electrochemical cells enable the use of sacrificial anodes for hydrogen peroxide detection with enhanced dynamic ranges

Recent advances in rare earth ion-doped upconversion nanomaterials: From design to their applications in food safety analysis

The misuse of chemicals in agricultural systems and food production leads to an increase in contaminants in food, which ultimately has adverse effects on human health. This situation has prompted a demand for sophisticated detection technologies with rapid and sensitive features, as concerns over food safety and quality have grown around the globe. The rare earth ion-doped upconversion nanoparticle (UCNP)-based sensor has emerged as an innovative and promising approach for detecting and analyzing food contaminants due to its superior photophysical properties, including low autofluorescence background, deep penetration of light, low toxicity, and minimal photodamage to the biological samples. The aim of this review was to discuss an outline of the applications of UCNPs to detect contaminants in food matrices, with particular attention on the determination of heavy metals, pesticides, pathogenic bacteria, mycotoxins, and antibiotics. The review briefly discusses the mechanism of upconversion (UC) luminescence, the synthesis, modification, functionality of UCNPs, as well as the detection principles for the design of UC biosensors. Furthermore, because current UCNP research on food safety detection is still at an early stage, this review identifies several bottlenecks that must be overcome in UCNPs and discusses the future prospects for its application in the field of food analysis.

Desalination and Detoxification of Textile Wastewater by Novel Photocatalytic Electrolysis Membrane Reactor for Ecosafe Hydroponic Farming

In this study, a novel photoelectrocatalytic membrane (PECM) reactor was tested as an option for the desalination, disinfection, and detoxification of biologically treated textile wastewater (BTTWW), with the aim to reuse it in hydroponic farming. The anionic ion exchange (IEX) process was used before PECM treatment to remove toxic residual dyes. The toxicity evaluation for every effluent was carried out using the Vibrio fischeri, Microtox^® test protocol. The disinfection effect of the PECM reactor was studied against E. coli. After PECM treatment, the 78.7% toxicity level of the BTTWW was reduced to 14.6%. However, photocatalytic desalination during treatment was found to be slow (2.5 mg L^-1 min^-1 at 1 V potential). The reactor demonstrated approximately 52% COD and 63% TOC removal efficiency. The effects of wastewater reuse on hydroponic production were comparatively investigated by following the growth of the lettuce plant. A detrimental effect was observed on the lettuce plant by the reuse of BTTWW, while no negative impact was reported using the PECM treated textile wastewater. In addition, all macro/micronutrient elements in the PECM treated textile wastewater were recovered by hydroponic farming, and the PECM treatment may be an eco-safe wastewater reuse method for crop irrigation.

Green electrochemical synthesis of silver sulfadiazine microcrystals

Electrochemical synthesis of silver sulfadiazine (AgSD) microcrystals was carried out galvanostatically in a special two-electrode cell equipped with a sacrificial silver rod anode and a stainless steel plate cathode. The cell used in this work consists of a small cylindrical chamber containing aqueous sulfadiazine/sodium nitrate as the anode compartment inside a larger cylindrical chamber containing nitric acid solution as the cathode compartment. The ionic connection of two chambers is carried out through a solvent surface layer. In this study, the effect of the experimental parameters such as applied current density and sodium nitrate concentration as well as nitric acid concentration on the yield and energy consumption of AgSD is discussed. The proposed method is fast and green and has unique features including synthesis in a single step, and no need for a metal salt.