Multivariate optimization and modeling of gas refinery oily wastewaters treatment utilizing activated carbon as high throughput adsorbent

Hamed Bagheri ¹ ( Ph.D. student, Department of Chemical Engineering, Marvdasht Branch, Islamic Azad University, Marvdasht, Iran )
Bizhan Honarvar ² ( Associate Professor, Department of Chemical Engineering, Marvdasht Branch, Islamic Azad University, Marvdasht, Iran )
Nadia Esfandiari ³ ( Associate Professor, Department of Chemical Engineering, Marvdasht Branch, Islamic Azad University, Marvdasht, Iran )
Zahra Arab Aboosadi ⁴ ( Associate Professor, Department of Chemical Engineering, Marvdasht Branch, Islamic Azad University, Marvdasht, Iran )

Submited date : 2022-08-02 Accepted date : 2024-02-14

Keywords: Activated Carbon, Gas refinery wastewaters, Multivariate optimization, Response surface method,

Abstract :

Abstract

Introduction: Adsorption-based methods for treatment of oily wastewaters are well-known, cost-effective, and efficient method. However, to reach an efficient treatment process, adsorption process should be optimized. The response surface method (RSM) is an appropriate method due to the evaluation of factors interactions, reducing the number of experimental runs, and consequently, time- and cost-saving.

Methods: The specific surface area of adsorbent as one of the most important factors that affect the adsorption yield was calculated by BET&BJH, revealing a specific surface area as high as 897 m2 g-1 for the adsorbent. The factors affecting the COD removal including adsorbent dosage, treatment time, temperature, and pH were optimized by multivariate optimization utilizing Design-Expert software by a response surface method (21 runs) for two types of wastewater of gas refineries.

Findings: The method showed a COD removal of 93.0% and 87.0% for wastewaters' collected output and input of the gravity pool of the API, in turn. Moreover, the kinetic studies were performed for both collected wastewaters, which revealed that the adsorption process followed the first-order kinetics for the COD removal from the input wastewater of the gravity pool of the API and a zero-order model for the COD removal from its output wastewater.

Conclusion: Based on the results, developed process showed excellent potential for the treatment of real gas refinery wastewaters, hence, the authors strongly recommended its use for this aim on a large scale.