Degradation of 2,4-Dichlorophenol by Ethylenediamine-N,N′-disuccinic Acid-Modified Photo-Fenton System: Effects of Chemical Compounds Present in Natural Waters

Gilles Mailhot,Shuangfei Wang,Ying Huang,Wenyu Huang,Hongfei Lin

doi:10.3390/pr9010029

Abstract

This paper describes a study of the treatment of 2,4-dichlorophenol (2,4-DCP) with an ethylenediamine-N,N′-disuccinic-acid (EDDS)-modified photo-Fenton system in ultrapure water and different natural waters. The results showed that the EDDS-modified photo-Fenton system is adequate for 2,4-DCP degradation. Compared with a medium containing a single organic pollutant, the removal of pollutants in a more complex medium consisting of two organic compounds is slower by around 25 to 50% as a function of the organic pollutant. Moreover, 2,4-DCP can be further effectively degraded in the presence of organic materials and various inorganic ions. However, the photodegradation of 2,4-DCP in different natural waters, including natural lake water, effluent from domestic sewage treatment plants, and secondary effluent from pulp and paper mill wastewaters, is inhibited. Chemical compounds present in natural waters have different influences on the degradation of 2,4-DCP by adopting the EDDS-modified photo-Fenton system. In any case, the results obtained in this work show that the EDDS-modified photo-Fenton system can effectively degrade pollutants in a natural water body, which makes it a promising technology for treating pollutants in natural water bodies.

Highlights

Advanced oxidation processes (AOPs) can effectively oxidize organic pollutants in water using active free radicals [1], which have been adopted to degrade pollutants from many types of wastewaters, such as tannery wastewaters and pharmaceutical wastewaters [2,3]
The influence of different initial concencentrations of 2,4-DCP on the photochemical experiment was studied while keeping the trations of 2,4-DCP on the photochemical experiment was studied while keeping the other other reaction parameters unchanged
From our results (Figure 6a), we show that the 2,4-DCP degradation efficiency deFrom our results (Figure 6a), we show that the 2,4-DCP degradation efficiency decreased slightly at the chloride concentration up to 7.10 g/L, and the process continued to creased slightly at the chloride concentration up to 7.10 g/L, and the process continued to exhibit a significant degradation efficiency

Summary

Introduction

Advanced oxidation processes (AOPs) can effectively oxidize organic pollutants in water using active free radicals [1], which have been adopted to degrade pollutants from many types of wastewaters, such as tannery wastewaters and pharmaceutical wastewaters [2,3]. The efficiency of the photo-Fenton process has been proven by many previous studies, most of which were carried out at an acidic pH value [8,9,10]. The introduction of chelating agents, especially organic carboxylic acid into the Fenton reaction, proved to be an effective method for broadening the applicable pH values. Several different organic carboxylic acids, such as citric acid, oxalic acid, NTA, and EDTA, were used to modify the Fenton process and proved to be efficient [11,12,13,14]. Ethylenediamine-N,N 0 -disuccinic-acid (EDDS), a biodegradable isomer of EDTA, was used as a chelating agent in homogeneous and heterogeneous Fenton and photo-Fenton systems in our previous studies [15,16,17,18]

Methods

Results

Conclusion