Date of Award

7-1-2018

Thesis Type

phd

Document Type

Thesis (Restricted Access)

Divisions

science

Department

Faculty of Science

Institution

University of Malaya

Abstract

In this study, three new adsorbents were synthesized, free fatty acids from hydrolysis of triacylglycerol of palm cooking oil functionalized magnetic nanoparticles (MNP@FFAs-PCO), free fatty acids from waste palm cooking oil functionalized magnetic nanoparticles (MNP@FFAs-WPCO) and free fatty acids from waste palm cooking oil functionalized magnetic nanoparticles immobilized on the surface of the graphene oxide (MNP@FFAs-WPCO-GO) for the preconcentration and remediation of organic pollutants from various sample matrices. The structure of MNP@FFAs-PCO and MNP@FFAs-WPCO were characterized by XRD, TEM, FT-IR, FESEM, VSM, EDX, BET, TGA analyses and water contact angle measurement. The obtained results prove the successful synthesis of these adsorbents. Furthermore, it was also revealed that MNP@FFAs-WPCO has a larger surface area and higher hydrophobicity compared to MNP@FFAs-PCO. The synthesized MNP@FFAs-PCO and MNP@FFAs-WPCO were used as adsorbent for magnetic solid phase extraction (MSPE) of polycyclic aromatic hydrocarbons (PAHs) and for the removal of oil from aqueous media. The MNP@FFAs-PCO and MNP@FFAs-WPCO showed a low limit of detection (LOD) ranging from 0.01 to 0.05 ng mL-1 and 0.001 to 0.05 ng mL-1, respectively and limit of quantification (LOQ) in the range of 0.03-0.16 ng mL-1 and 0.004-0.2 ng mL-1, respectively. The application of MNP@FFAs-PCO and MNP@FFAs-WPCO were successfully studied on the leachate and sludge from a landfill site. The MNP@FFAs-PCO recorded good recovery (81.1-119.3%) with satisfactory precision (%RSD: 3.1–13.6) while MNP@FFAs-WPCO showed satisfactory recovery (72.3–119.9%) with acceptable precision (%RSD: 4.8–11.8). The MNP@FFAs-PCO and MNP@FFAs-WPCO were also found to be able to adsorb 3.50 times and 4.31 times of oil higher than their own weight, respectively. In this study, it was found that MNP@FFAs-WPCO showed an excellent MSPE performance as it provided lower LOD for all selected PAHs and good oil sorption capacity in comparison with the performance MNP@FFAs-PCO. The third adsorbent, MNP@FFAs-WPCO-GO was characterized by FT-IR, XRD, FESEM, TGA, TEM, VSM and EDX analyses to confirm its structure. It was successfully applied as a MSPE adsorbent for simultaneous separation of selected PAHs and phthalate esters (PAEs). It has good performance with low LODs ranging from 0.02 – 0.93 ng mL-1 for PAHs and 0.56 – 0.97 ng mL-1 for PAEs with LOQs in the range of 0.07 to 3.10 ng mL-1 for PAHs and 1.86 to 3.20 ng mL-1 for PAEs. The MNP@FFAs-WPCO-GO was successfully studied on apple, cabbage and landfill sludge samples. High recoveries (81.5 – 118.2% for PAEs) and (86.7 – 118.8% for PAHs) with satisfactory precision (%RSD: 2.1 to 9.9 for PAEs, 1.5 to 11.0 for PAHs) were obtained.

Note

Thesis (PhD) - Faculty of Science, University of Malaya, 2018.

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