A novel characterization of alginate-attapulgite-calcium carbonate (AAC) gel adsorption in bacterial biodegradation of used engine oil (UEO)

Abstract

Biodegradation of used engine oil (UEO) that pollutes the environment is attracting increasing attention. The aim of this study was to characterize the adsorption of used engine oil (UEO) and the immobilization of UEO biodegraders in Ochrobacterium intermedium LMG 3301 and Ochrobacterium intermedium LMG 3301 plus Bacillus paramycoides MCCC1A04098 (BC) using alginate-attapulgite-calcium carbonate (AAC). Twenty AAC beads were tested separately in 20 mL of soil water extract (SWE) and hexane containing 1% UEO for their adsorptive capacities of UEO in 50-mL capped flasks. The results showed that the UEO removal efficiency (%RE) was bead-number dependent, recording a maximum of 83 ± 0.32% in SWE, and 11.50 ± 0.52% in hexane correlating with the highest number of AAC-granules (20 beads). The 1st order kinetics in SWE showed a UEO adsorption rate, K₁ (h⁻¹), of 0.11–0.15 h⁻¹ correlating with 20 AAC-granules and 1, 2, 3 and 4% (w/v) UEO. The intra-particle diffusion kinetic model suggested that intra-diffusion was the main mode of mass transfer in AAC granules. The microscopic study and 2,3,5-triphenyltetrazolium chloride (TTC) positive stain showed that bacteria grew well in AAC. This result demonstrates that this matrix can be applied in the formulation of novel adsorptive granular formulas for bioremediation of UEO.

Keywords:

• Sodium alginate-attapulgite-CaCO3 (AAC)
• sodium alginate-CaCO3 (AC)
• adsorption
• used engine oil (UEO)
• 2,3,5-triphenyltetrazolium chloride (TTC)
• scanning electron microscope (SEM)

Authors’ contributions

Izeddin Abdalla Elhamrouni certifies that he has fully participated in conducting the experiments and making extensive contributions to write and review the manuscript. Mohd Yusoff Ishak contributed with valuable comments on the intellectual content and final approval of the manuscript. Wan Lutfi Wan Johari and Normala Halimoon contributed in revising the final version of the manuscript.

Disclosure statement

We confirm that there are no conflicts of interest to declare as related with this draft result manuscript. And the manuscript has been read and approved by all named authors. The order of authors listed in the manuscript has been approved by all of us. No part of this paper has been published or submitted elsewhere.

Data availability statement

The data that support the findings reported in this study are available at: https://drive.google.com/file/d/1zSt8MYe0scL2hFBE478AWEtI9vb3jAPH/view?usp=sharing, file password: aaaa2014.

Additional information

Funding

This project was funded by Faculty of Forestry and Environment, UPM.