Removal of oil and heavy metals from wastewater sludge using surfactant-enhanced oil removal (SEOR) from plant-based / Nur Amalina Mohd Sulong

Petroleum is the most significant energy source and raw material for the chemical
industry. The increasing trends of petroleum industries and the high demand of the
production capacity directly leads to the oil pollution generation problems as well as
environmental problems which accumulated a large volume of oily wastewater sludge
due to high content of petroleum hydrocarbon (PHC). In order to overcome the oily
wastewater sludge problems generated, the initiative study was developed to minimize
this issue by treating the oily wastewater sludge in terms of oil and heavy metals
removal using plant-based surfactant in surfactant-enhanced oil removal (SEOR). In
this study, the sodium lauryl sulfoacetate (SLSA) and cocamidopropyl betaine (CAPB)
plant-based surfactant derived from palm oil were used for SEOR process. Based on
the research finding, oily wastewater sludge has significant amount of volatile matters
(32.22 wt%) which consists of hazardous polycyclic aromatic hydrocarbons (PAHs)
that needs to be removed from oily wastewater sludge. The critical micelle
concentration (CMC) of SLSA and CAPB plant-based surfactant was 125 mg/L and 33
mg/L via simplified colorimetric method and conductivity method. The treatment of
oily wastewater sludge showed that the significant amount of oil removal observed in
SLSA and CAPB plant-based surfactant at concentration of 1000 mg/L with 85.40%
and 87.26% respectively. Moreover, it deduced that the CAPB surfactant illustrated the
significant amount of metal removal on mercury (Hg) and lead (Pb) that rangely about
38.46% and 26.91% respectively as compared to SLSA surfactant (3.53% and 6.95%
respectively) at plant-based surfactant concentration of 1000 mg/L. This finding shows
the potential of CAPB surfactant in enhancing the oil and heavy metals removal from
oily wastewater sludge. The SLSA and CAPB plant-based surfactant clearly
distinguished the best operating condition at reaction temperature of 50oC for 20
minutes in terms of oil and heavy metals removal. These results obtained for SLSA and
CAPB plant-based was verified by using statistical data analysis via Polynomial
Regression.