Introduction

Unlike free oil which floats on surface of water, emulsified oil is difficult to remove. Barley straw is cheap and an abundantly available biomass which has the ability to undergo ion-exchange and adsorption. The purpose of this study is to determine the effect of contact time, agitation speed and initial oil concentration on the oil uptake by barley straw and to determine the kinetics of oil adsorption by applying suitable kinetic models.

Experimental

In this study, two types of barley straw were used; raw barley straw (RBS) and surfactant treated barley straw (SBS). For the adsorption experiment, a measured amount of adsorbent and known concentration and volume of synthetic emulsified oil effluent was agitated together at a selected temperature in a 250 mL Erlenmeyer flask and was withdrawn at pre selected times for analysis.

Results and Discussion

The study was conducted with initial oil concentration of 7000 mg L-1 in water where RBS and SBS were separately suspended in the flasks. It can be generalized that kinetic adsorption of oil consists of two significant phases: a primary rapid phase and a slow second phase. As for adsorption kinetic model, the kinetic data showed that the RBS treatment fitted pseudo first-order whereas the SBS inclined towards pseudo second-order model.

Conclusion

This study demonstrated that barley straw has a potential to be used as an effective adsorbent for the treatment of emulsified oil wastewater.