Advanced Removal of Dyes with Tuning Carbon/TiO2 Composite Properties

This study evaluates the removal of several dyes with different charge properties, i.e., anionic (Acid Red 88), cationic (Basic Red 13), and neutral (Basic Red 5) using transition metal-doped TiO2 supported on a high-surface-area activated carbon. Experimental results confirm the successful deposition of TiO2 and the derivatives (Zr-, Cu-, and Ce-doped samples) on the surface of the activated carbon material and the development of extended heterojunctions with improved electronic properties. Incorporating a small percentage of dopants significantly improves the adsorption properties of the composites towards the three dyes evaluated, preferentially for sample AC/TiO2_Zr. Similarly, the photodegradation efficiency highly depends on the nature of the composite evaluated and the characteristics of the dye. Sample AC/TiO2_Zr demonstrates the best overall removal efficiency for Acid Red 88 and Basic Red 5—83% and 63%, respectively. This promising performance must simultaneously be attributed to a dual mechanism, i.e., adsorption and photodegradation. Notably, the AC/TiO2_Ce outperformed the other catalysts in eliminating Basic Red 13 (74%/6 h). A possible Acid Red 88 degradation mechanism using AC/TiO2_Zr was proposed. This study shows that the removal efficiency of AC/TiO2 composites strongly depends on both the material and pollutant.This research was supported by Štefan Schwarz Postdoc Fellowship No. 2022/OV1/010, the Marie Curie Programme H2020-MSCA-RISE-2016-NANOMED No. 734641, and APVV-19-0302 projects. J.S.-A. acknowledges financial support from MCIN/AEI/10.13039/501100011033 and EU NextGeneration/PRTR (Project PCI2020-111968/ERANET-M/3D-Photocat), MCIN (Project PID2019-108453GB-C21), and Conselleria de Innovación, Universidades, Ciencia y Sociedad Digital, Generalitat Valenciana (Project CIPROM/2021/022)

A Review on Adsorbable Organic Halogens Treatment Technologies: Approaches and Application

Halogen-containing organic substances have a detrimental and toxic impact on the environment and human health due to their high stability, carcinogenic effects, and ability to accumulate when ingested. The production and release of these substances have significantly increased in recent decades, resulting in a lack of effective treatment technologies. Adsorbable organic halogens (AOX), a specific parameter used to monitor pollution, represents the total amount of chlorinated, brominated, and iodinated organics that can be adsorbed on activated carbon from various environments. This paper provides an overview of selected articles from the past three decades (1990–2023) focusing on the primary natural and industrial sources of AOX. It also evaluates different determination techniques and a variety of removal approaches based on biological, physical, chemical, and combined processes. Additionally, the limitations and efficiency of these approaches are briefly characterized. While biochemical and physical methods have been limited by financial constraints and reduced efficiency, biological, chemical, and physicochemical techniques have shown significant potential in improving water quality. This knowledge can be valuable for the development of alternative water treatment techniques and underscores the importance of sustainable water usage

A ‘Turn-On’ Carbamazepine Sensing Using a Luminescent SiO₂/-(CH₂)₃NH₂/-C₆H₅ + Rh6G System

Carbamazepine is a crucial medication used to treat nervous system disorders, and its low level of absorption in the human body suggests that a significant amount of it may be present in sewage water. Consequently, this pioneering research deals with the synthesis and application of a luminescent sensor based on rhodamine 6 G-modified bifunctional silica particles for the determination of carbamazepine. The sensing material was fabricated in one step by the sol–gel technique and the dye was adsorbed onto the surface from an alcohol solution. The composition, morphology and size of functionalized silica particles were determined by physico-chemical methods. The material’s features provide the possibility of its application as a sensing material for carbamazepine determination at a variety of concentrations. The sensor possesses a linear response towards carbamazepine in the concentration range of 0.8–200.0 μM with a limit of detection (LOD) of 17.9 μM and a limit of quantification (LOQ) of 59.7 μM and has demonstrated reliable quantification over a wide range of concentrations, from therapeutic to high fatal concentrations. Additionally, the sensing mechanism has been proposed, which involves the formation of hydrogen bonding between carbamazepine and Rhodamine 6G immobilized bifunctional silica particles