Application of superparamagnetic mesoporous silicates on naproxen removal

Abstract

Adsorption of Naproxen (NAX), non-steroidal anti-inflammatory drug (NSAID), by using superparamagnetic hexagonal mesoporous silicates (HMS-SP) in synthetic wastewater at high concentration (0.5 – 10 mg/L) was investigated. Five different types of adsorbents were synthesized by surfactant templating method, and modified surface functional group with silanol, 3-aminopropyltriethoxy-, 3-mercaptopropyl-, phenyltrimethoxy- and butyronitrile- groups by co-condensation method that denoted as HMS-SP, A-HMS-SP, M-HMS-SP, P-HMS-SP and N-HMS-SP, respectively. Kinetic adsorptions of all synthesized adsorbents were fitted well with pseudo-second-order equation. Adsorption isotherms were best matched with linear model, Fruendlich model and Langmuir model. P-HMS-SP had highest adsorption capacity following with M-HMS-SP, N-HMS-SP, HMS-SP and A-HMS-SP, but still lower than PAC. Hydrophobic adsorbents had higher adsorption capacity of NAX than hydrophilic adsorbents. High Gradient Magnetic Separation filter (HGMS filter) was applied to separate adsorbent particle from treated water. Effect of bed depth, flow rate, surface area of stainless filer and concentration of particle influenced on the breakthrough curve. The breakthrough time was increasing by extending bed depth of stainless filter and decreasing flow rate and particle concentration. Moreover, application of BDST model can be matched with HGMS filter, due to high correlation coefficient. Nevertheless, BDST model cannot apply with changing flow rate and particle concentration. Electrostatic interaction can affect NAX adsorption capacities of adsorbents, except for A-HMS-SP and HMS-SP. High Gradient Magnetic Separation filter (HGMS filter) was applied to separate adsorbent particle from treated water. Effect of bed depth, flow rate, surface area of stainless filer and concentration of particle influenced on the breakthrough curve. The breakthrough time was increasing by extending bed depth of stainless filter and decreasing flow rate and particle concentration. Moreover, application of BDST model can be matched with HGMS filter, due to high correlation coefficient. Nevertheless, BDST model cannot apply with changing flow rate and particle concentration.