Combination tanning mechanism inspired environmentally benign catalyst for efficient degradation of tetracycline

Abstract

The utilization of chelation reaction between metals and tannins is a common tanning method in leather chemistry. Herein, a novel combination tanning mechanism inspired environmentally benign catalyst (CMBT-Fe0) was synthesized by immobilizing Fe nanoparticles onto bayberry tannin (BT) grafted chitosan microfibers (CM). The obtained catalyst featured a well-defined microfibrous structure, on which Fe0 nanoparticles were highly dispersed to exhibit exceptional catalytic activity for the degradation of tetracycline (TC). The catalytic activity of CMBT-Fe0 was 1.72 times higher than that of the commercial Fe0 nanoparticles without immobilization, with 95.03% of TC degraded within 90.0 min. The CMBT-Fe0 catalysts were recycled 6 times, with the removal rate of TC maintained at 82.56%. Furthermore, a possible mechanism responsible for the catalytic removal of TC was provided by analyzing the catalytic degradation products via liquid chromatography-mass spectrometry. Therefore, our investigation successfully developed efficient catalysts to address the concerned environmental issue of antibiotic pollution. Graphical Abstract

Construction of Waste Paper-Chitosan-Based Membranes with pH-Tunable Surface Charge for Efficient Separation of Oil-in-Water Emulsion and Dye

“…As global industries expand rapidly, the severity of water pollution is escalating. , Among various pollutants, water-insoluble oils and water-soluble organic dyes are viewed as the primary contaminants in wastewater, posing significant threats to both the environment and human health. − So far, numerous technologies, including adsorption, − photocatalysis, − chemical oxidation, , biological methods, ion exchange, and membrane separation − have been undertaken to address oil–water separation and dye removal from wastewater. Noteworthily, owing to the increasing complexity of wastewater, traditional single-treatment technology has become inadequate for meeting current demands. − Fortunately, membrane adsorption–separation technology has recently emerged as an effective method for treating complex wastewater containing oil and dyes. − This method combines the benefits of adsorption and membrane separation, providing advantages like simple operation, low energy usage, and high efficiency. ,, Based on this, numerous membranes have been developed with special wettability, particularly superhydrophilic and underwater superoleophobic features, along with abundant adsorption sites for simultaneously removing dyes and separating oil–water mixtures. ,− However, the majority of these adsorption–separation membranes are made from nonrenewable resources and are nonbiodegradable, potentially causing secondary environmental pollution after their service life .…”