Optimizing linear alkyl benzene sulfonate removal using Fenton oxidation process in Taguchi Method

Abstract

Linear alkyl benzene sulfonate (LAS), which is the most common used anionic surfactant in detergents manufacturing, can discharge onto water resources through wastewater and causes change in taste and odor, disruption in water treatment processes, aquatics death, and oxygen transfer limitation. Accordingly, this article investigates to optimize LAS removal using Fenton oxidation process in Taguchi Method for the first time. LAS removal using Fenton oxidation was perused experimentally in a lab-scale reactor. In order to save relevant costs, 25 runs were qualified to specify the optimum conditions of Fenton oxidation using Taguchi method by Minitab 16 software. Sampling and testing procedures were executed based on the standard methods for the examination of water and wastewater. The optimum conditions included 900 mg/L hydrogen peroxide, 170 mg/L ferrous ion, pH of 4 and the reaction time of 20 min. Fenton oxidation, as a second order reaction with the rate coefficient of 0.0152 L/mg ⋅ min, provided 86.5% efficiency for LAS removal in the optimum conditions. Despite Fenton oxidation appeared as a high efficiency process in LAS removal, low removal efficiency of chemical oxygen demand corresponding with LAS affirmed its partial degradation.

Optimization of Ultrasonication Process for the Degradation of Linear Alkyl Benzene Sulfonic Acid by Response Surface Methodology

“…The results of this study were compared with literature about the detergent degradation by advanced oxidation processes. Khorsandi et al reported LAS concentration decrease from 25 to 3.38 mg L −1 with Fenton oxidation (900 mg L −1 hydrogen peroxide, 170 mg L −1 ferrous ion, pH 4 and a reaction time of 120 min). They showed that LAS degradation by Fenton oxidation has apparently high efficiency but the low COD degradation efficiency corresponding to LAS indicates its incomplete decomposition.…”

“…[1] There are many studies in the literature about the treatment of surfactants such as adsorption, [2,3] electrochemical coagulation, [4] electrochemical oxidation, [5] photochemical treatment, [6] sonication, [7] wet air oxidation, [8] photodegradation and ozonation, [9] anaerobic degradation, [10,11] functionalized multi-walled carbon nanotubes, [12] photosynthesis, [13] combined electrochemical and photocatalytic process, [14] and Fenton oxidation. [15] The number of studies on the degradation of LABSA using the sonication process is limited. Ultrasonic energy produced by sound waves, which are out of hearing range (20 kHz to 500 MHz), has been used commonly in the fields of engineering, science and medicine for many years.…”

“…There are many studies in the literature about the treatment of surfactants such as adsorption, electrochemical coagulation, electrochemical oxidation, photochemical treatment, sonication, wet air oxidation, photodegradation and ozonation, anaerobic degradation, functionalized multi‐walled carbon nanotubes, photosynthesis, combined electrochemical and photocatalytic process, and Fenton oxidation …”