Sub-theme
2. Promoting Water Efficiency, Productivity and Services
Topic
2-4. Wastewater treatment and reuse
Body
MO solution is a common acidic anion dye of mono azo compounds, which belongs to carcinogenic azo dyes. It can harm aquatic organisms, lead to rapid heart rate, quadriplegia and other symptoms. It is water-soluble and chemically stable, which is difficult to effectively remove. Adsorption has been used to remove azo dyes from water and industrial effluents because of its ability to remove high and low concentrations of dyes while being easy to design, environmentally friendly, and low-cost. In this experiment, magnetic ferric oxide nanoparticles were prepared by coprecipitation method, and then magnetic mesoporous silica nanoparticles were synthesized by sol-gel method by coating silica shells on magnetic ferric oxide nanoparticles. A series of characterization tests such as TEM, VSM, XRD, XPS and BET were used to investigate the structure and properties of the synthesized magnetic mesoporous silica nanoparticles. Then a series of simulation experiments were conducted to explore the influence of environmental factors (PH, temperature, time, dosage, initial concentration, coexistence ions) on the adsorption of magnetic mesoporous silica nanoparticles and the adsorption properties of the adsorbent. The experimental results show that: The adsorption kinetics of magnetic mesoporous silica nanoparticles for MO followed pseudo-first-order kinetics, and the isothermal adsorption model followed Freundlich adsorption isotherm model. The adsorption of the adsorbent was optimal under the conditions of PH=2, T=45℃, t=30min, and the adsorption rate reached 295.74mg/g. Much higher than biochar 6mg/g, bentonite 36.67mg/g. The unit adsorption capacity of magnetic mesoporous silica nanoparticles can still reach 83% after repeated for 4 times, and the reusability is relatively strong. In addition, VSM characterization results show that magnetic mesoporous silica nanoparticles have strong magnetism and are easy to be separated from waste water, which meets the requirements of environmental protection materials. This study provides a new idea for the adsorption of MO dye wastewater by mesoporous nanoparticles, and reveals the great prospect of mesoporous nanoparticles for the removal of dye wastewater.