Application of montmorillonite/octadecylamine nanoparticles in the removal of textile dye from aqueous solutions: Modeling, kinetic, and equilibrium studies

In the study, the proliferation of industries has been associated with an increase in the production of industrial wastewater and subsequent environmental pollution, wherein dyes emerge as prominent pollutants. The characteristics of nanoclay modified with octadecylamine, were elucidated throughvarious techniques, including Field Emission Scanning Electron Microscopy/Energy Dispersive Spectroscopy (FE-SEM/EDS), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), X-ray Diffraction (XRD), and Brunauer-Emmett-Teller Surface Area Analysis (BET). The research delved into the impact of variables such as pH, initial dye concentration, adsorbent dose, temperature, and ultrasonication time on the removal of Acid Black 1 (AB1) through an ultrasonic process, employing a central composite design (CCD). Optimal conditions for the adsorption process were determined: pH at 5.46, adsorbent mass at 4 mg/30 mL, initial dye concentration at 20 mg/L, ultrasound time at 20 min, and temperature at 50 °C, resulting in a remarkable 96.49% adsorption efficiency. The fitting of experimental equilibrium data to different isotherm models, including Langmuir, Freundlich, and Temkin, indicated thatthe Freundlich model was the most suitable. Analysis of the adsorption data with various kinetic models such as pseudo-first and second-order models, and intraparticle diffusion models, revealed the applicability of the second-order equation model. A thermodynamic study unveiled that the adsorption process was spontaneous and endothermic. In conclusion, the study highlights the significant capability ofmontmorillonite nanoclay modified with octadecylamine in removing AB1 dye, rendering it a viable option for wastewater treatment.

Safeguarding drinking water: A brief insight on characteristics, treatments and risk assessment of contamination

Water pollution stands as a critical worldwide concern, bearing extensive repercussions that extend to human health and the natural ecosystem. The sources of water pollution can be diverse, arising from natural processes and human activities and the pollutants may range from chemical and biological agents to physical and radiological contaminants. The contamination of water disrupts the natural functioning of the system, leading to both immediate and prolonged health problems. Various technologies and procedures, ranging from conventional to advanced, have been developed to eliminate water impurities, with the choice depending on the type and level of contamination. Assessing risks is a crucial element in guaranteeing the safety of drinking water. Till now, research is continuing the removal of contaminates for the sake of supplying safe drinking water. The study examined physical, inorganic, organic, biological and radiological contaminants in drinking water. It looked at where these contaminants come from, their characteristics, the impact they have and successful methods used in real-world situations to clean the contaminated water. Risk assessment methodologies associated with the use of unsafe drinking water as future directives are also taken into consideration in the present study for the benefit of public concern. The manuscript introduces a comprehensive study on water pollution, focusing on assessing and mitigating risks associated with physical, inorganic, organic, biological and radiological contaminants in drinking water, with a novel emphasis on future directives and sustainable solutions for public safety.

Catalytic Processes for Water and Wastewater Treatment

Water and wastewater treatment still face significant challenges today [...]

Sulfur and nitrogen co-doped magnetic biochar coupled with hydroxylamine for high-efficiency of persulfate activation and mechanism study

Biochar has recently become a central issue in advanced oxidation processes (AOPs) based on peroxydisulfate (PDS) activation. However, the PDS activation by biochar must be improved. In this study, S, N co-doped magnetic biochar (IBC) was prepared by a simple impregnation-pyrolysis method using Eichhornia crassipes stems with inherent sulfur and nitrogen as the raw materials for biochar. The reductant hydroxylamine (HA) was employed to further enhance PDS activation by the IBC for organic pollutant degradation. Incorporating HA in PDS activation over IBC significantly improved its compatibility with complex water, catalytic degradation, stability performance, and mineralization rate of organic pollutants. The outstanding performance of the HA/PDS/IBC system for organic degradation was due to the increased free radicals SO₄^·-, O₂^·-, and non-radical ¹O₂ generated, as well as the electrons transferred between IBC, PDS, and organic pollutants, which were verified by electron paramagnetic resonance (EPR) detection and electrochemical characterizations. Furthermore, HA-enhanced Fe(III)/Fe(II) cycling, surface functional groups, and S and N doping contributed to the generation of reactive oxygen species (ROS). Moreover, the toxicity assessment indicated that the toxicity of the degradation intermediates decreased. Therefore, this research proposes a new insight into the enhanced degradation of pollutants by increasing PDS activation using biochar-based catalytic materials.