Ghafari, Mohsen, Ghafari

Mohsen Ghafari is a senior R&D engineer at Evoqua Water Technologies. His focus area is emerging contaminants including 1,4-dioxane and PFAS. He...

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About Ghafari, Mohsen

Mohsen Ghafari is a senior R&D engineer at Evoqua Water Technologies. His focus area is emerging contaminants including 1,4-dioxane and PFAS. He received his PhD degree in Environmental Engineering from University at Buffalo in 2018, where he worked on developing novel polymeric adsorbents for water treatment and air pollution control.

Ghafari, Mohsen

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Description: Evaluation of Different Advanced Oxidation Processes (AOPs) for Removal of...

Evaluation of Different Advanced Oxidation Processes (AOPs) for Removal of 1,4-Dioxane in Textile Wastewater

Abstract

1,4-dioxane, which is widely used in various industrial processes, is one of the major recalcitrant and toxic contaminants. Several states in the US have established drinking water and groundwater guidelines as low as 0.3 ppb for 1,4-dioxane. Therefore, to address the industrial need to meet the regulatory standards for their discharge, investigation of efficient and cost-effective technologies is required. Advanced oxidation processes (AOPs) have shown promises in removing 1,4-dioxane from waste streams. However, the success of these processes depends on the water matrix. In many water and wastewater streams, 1,4-dioxane is accompanied by a background of organic substances, with a concentration significantly higher than the 1,4-dioxane. In these water-treatment applications, a selective method for the oxidation of 1,4-dioxane would be advantageous. A high selectivity treatment process versus other organics reduces operation cost and/or equipment footprint. In this study, several AOPs have been tested on a textile wastewater containing 350-450 ppm total organic carbon (TOC) and 12-14 ppm 1,4-dioxane to evaluate 1,4-dioxane destruction. The Fenton's process, electrochemical oxidation (EOX), and peroxone process (mixture of hydrogen peroxide and ozone) were investigated in 2-L batch reactors. UV + H2O2 was not included in this study due to low UV transmittance of the wastewater that would result in an inefficient destruction of 1,4-dioxane. Among the tested processes, peroxone was found to be the most efficient treatment technology by eliminating 1,4-dioxane from the wastewater to near non-detect levels in 2 hr (Figure 1), while Fenton's reaction (Figure 2) required up to 140 hr to reach that level. EOX was able to remove only 41% of 1,4-dioxane after 10 hr of reaction (Figure 3). Peroxone was the most selective oxidation process. TOC destruction was less than 30% while achieving > 99% destruction of 1,4-dioxane. The higher selectivity of peroxone process compared to the other AOPs should reduce the chemical usage as well as the reaction time. In the next step, process optimization will be performed by improving ozone mass transfer and solubility in addition to reducing the hydrogen peroxide dosing to minimize the capital and operating costs.

Several advanced oxidation processes (AOPs) were tested on a textile wastewater to evaluate 1,4-dioxane destruction. Peroxone was found to be the most efficient treatment technology by almost complete destruction of 1,4-dioxane in 2 h, while Fenton's reaction required up to 140 h and electrochemical oxidation (EOX) removed only 41% of 1,4-dioxane after 10 h of reaction. Peroxone was also the most selective process by achieving > 99% 1,4-dioxane destruction while reducing TOC by only 30%.

SpeakerGhafari, Mohsen

Presentation time

09:00:00

09:25:00

Session time

08:30:00

09:30:00

TopicIntermediate Level, Industrial Issues and Treatment Technologies, Microconstituents and Contaminants of Emerging Concern (Non-PFAS), Research and Innovation

Author(s)

Ghafari, Mohsen

Author(s)Mohsen Ghafari1; Joshua Griffis2; Thomas K. Mallmann3; Simon Dukes4; Ben Sattertfield, George Gu

Author affiliation(s)Evoqua Water Technologies, LLC, Pittsburgh, PA1; Evoqua Water Technologies, LLC, Pittsburgh, PA2; Evoqua Water Technologies, LLC, Pittsburgh, PA3; Evoqua Water Technologies, LLC, Pittsburgh, PA4

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2022

DOI10.2175/193864718825158513

Volume / Issue

Content sourceWEFTEC

Word count15

Base text size -

Ghafari, Mohsen

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