Efficiency Of Fabricated CNT-IPSF/Fe3O4 Nanocomposites In Removal Of Phenanthrenes From Contaminated Water

摘要

The increased demand for oil to supply the needs of industry and motorists has exposed the water sources to one of the greatest threats. The removal of selective organic pollutants such as phenanthrenes in aqueous solution was investigated by adsorption process on fabricated CNT-IPSF/Fe3O4 nanocomposites. Characterization of products confirmed the synthesis of individual nanomaterials in the nanocomposites. The SEM image of prepared CNTs showed configuration with abundant threadlike entities whose TEMs further confirmed evidence for formation of MWCNTs. The silica modified magnetite (Fe3O4.SiO2) nanoparticles had clear, distinct and spherical shaped nanoparticles arranged in a 2-D closed packed manner. The XRD diffraction pattern showed well crystalline magnetite silica NPs with particle size 22.4 nm from the Debye-Scherrer equation. The SEM'EDAX analysis revealed large quantities of dispersive magnetite NPs with moderately uniform and cubic structures in the fabricated CNT-IPSF/Fe3O4 nanocomposites. Adsorption parameters were optimized at adsorbent dose (6 mg/20ml), contact time (40 mins), pHPZC (4.5) and pH 5. Adsorption kinetics followed pseudo second order kinetics while the adsorption isotherm favored was Freundlich isotherms. The nanocomposites were not largely affected by of counter PAHs as its removal efficiency was 42.2 % and 40.8 % in the presence of naphthalene and anthracene respectively. This was replicated in its application in phenanthrenes removal from industrial wastewater in which the nanocomposites showed 63 % phenanthrenes removal. The trend for the studied desorption solvents was acetone > hexane > methanol which had 47 %, 42 % and 22 % removal efficiency respectively. The adsorption-desorption cycles involved a small volume of phenanthrene concentrates being recovered with gradual decrease in adsorption capacity for phenanthrene from 33.46 - 28.68 'g/g after three cycles. The desorption efficiency of phenanthrenes increased from to 49.81 to 56.98 wt.% implying that the developed nanocomposites could be advantageously be reused several times in removal of toxic phenanthrenes from industrial waste water.