The removal of contaminants of emerging concern (CECs) has become a hot research topic in the field of environmental engineering in recent years. In this work, a simple pyrolysis method was designed to prepare a high-performance biochar-loaded zero-valent copper (CuC) material for the catalytic degradation of antibiotics ENR by PMS. The results showed that 10 mg/L of ENR was completely removed within 30 min at an initial pH of 3, CuC 0.3 g/L, and PMS 2 mmol/L. Further studies confirmed that the reactive oxygen species (ROS) involved in ENR degradation are ·OH, ·, 1O2, and . Among them, 1O2 played a major role in degradation, whereas · played a key role in the indirect generation of 1O2. On the one hand, CuC adsorbed and activated PMS to generate ·OH, · and ·. · was unstable and reacted rapidly with H2O and ·OH to generate large amounts of 1O2. On the other hand, both the self-decomposition of PMS and direct activation of PMS by C=O on biochar also generated 1O2. Five byproducts were generated during degradation and eventually mineralized to CO2, H2O, , and F−. This study provides a facile strategy and new insights into the biochar-loaded zero-valent transition-metal-catalyzed PMS degradation of CECs.
In this paper, an advanced statistical physics adsorption model (double-layer model with two energies) is successfully established. On the basis of this model, statistical thermodynamic functions (e.g., entropy (S), Gibbs free enthalpy (G), and internal energy (Eint)), pore size distribution (PSD), and site energy distribution (SED) functions were successfully developed and applied to investigate the adsorption mechanisms of nanopore-structured ashitaba waste-based activated carbons (AWAC) and walnut shell-based activated carbons (WSAC) on Congo red (CR) and methylene blue (MB) dyes in aqueous solutions. Statistical thermodynamic results indicated that the adsorption reactions involved in this study are entropy-increasing, endothermic, and spontaneous in nature. Furthermore, PSD and SED described the heterogeneity of these adsorbents in terms of geometry or structure and energy and illustrated that the aforementioned adsorption processes are endothermic physisorption. All in all, this study contributed to broadening the understanding of the adsorption mechanisms of dye molecules onto biomass-based activated carbons.
The contamination of urban rivers substantially threatens urban ecology, public health, and general progress. Addressing this matter is complex and challenging, particularly in tidal rivers. After investigating the climate conditions, population, and distribution of rivers and pollution in Sanya, China, a hydraulic and water quality model was built for Sanya utilizing InfoWorks ICM, and a comprehensive remediation approach was proposed. The implementation of this scheme led to a substantial decrease in point and non-point sources of pollution. In particular, COD, NH3-N, and TP were reduced by 87.00%, 84.01%, and 74.24%, respectively, from point source pollution. Point source pollution was well-managed north of the bridge, with a reduction rate close to 40% for non-point source pollution. This research confirmed that pollutants are only temporarily retained in the river at high tide and are discharged as the tide recedes, thus having a limited impact on long-term pollution discharge. This research provides valuable references for applying water environment models and the comprehensive treatment of tidal river pollution. The final plan scheme is to significantly improve the water quality of Sanya’s rivers by effectively controlling the discharge of pollutants while achieving considerable cost savings of approximately CNY 1.7 billion.
To substitute fossil resources, it is necessary to investigate the conversion of biomass into 1,2-propanediol (1,2-PDO) as a high-value-added chemical. The Pt/deAl-Beta@Mg(OH)2 catalytic system is designed to obtain a higher 1,2-PDO production yield. The optimal yield of 1,2-PDO is 34.1%. The unique shell-core structure of the catalyst demonstrates stability, with a catalytic yield of over 30% after three times of use. The primary process path from glucose to 1,2-PDO, glucose-hexitol-1,2-PDO, is speculated by the experiments of intermediate product selectivity. The alkaline catalytic mechanism of the reaction process is elucidated by studying catalyst characterization and analyzing different time courses of products. The introduction of Mg(OH)2 improves the target yield by promoting the isomerization from glucose to fructose and retro-aldol condensation (RAC) conversion, with pseudo-yield increases of 76.1% and 42.1%, respectively. By studying the processes of producing lactic acid and 1,2-PDO from glucose, the glucose hydrogenolysis flow chart is improved, which is of great significance for accurately controlling 1,2-PDO production in industrial applications. The metal, acid, and alkali synergistic catalytic system constructed in this paper can provide a theoretical basis and route reference for applying biomass conversion technology in practice.
About Me
Jiang Zhao's research interests include water and wastewater treatment.
Jiang Zhao's research interests include water and wastewater treatment.