The Selectivity of Different Sized Catalysts on DOM Fractional Removal during the Catalytic Ozonation of Municipal Sewage

Chendong Shuang,Ji Wu,Aimin Li,Cheng Wang

doi:10.3390/catal9010014

Abstract

Dissolved organic matter (DOM) is a typical kind of pollutant with a complex composition, and different advanced treatments demonstrate different abilities toward its fractional removal. Hence, it is necessary to analyze the fraction of DOM that remains when using advanced treatments. In this paper, ozonation was used to deal with the biological effluents and comparisons of the catalytic ozonation with different particle sizes of γ-Al2O3 were made. The results of these comparisons indicated that the catalysts were active in improving the removal of DOM and γ-Al2O3 with different particle sizes can selectively remove DOM. The result of fluorescence showed that a decrease in the catalyst particle size contributes to a significant decrease in the fluorescence intensity, except for tryptophan-like substances. Meanwhile, DOM fractions with large molecular weights could be decomposed into small molecules by ozonation, resulting in increased hydrophilicity. However, the use of a catalyst in ozonation increased the removal of hydrophilic components. Additionally, a smaller catalyst particle size increased the removal of hydrophilic components. The results of catalyst analysis implied that the surface hydroxyl groups of catalyst γ-Al2O3 and the diffusion of DOM in the catalyst γ-Al2O3 played important roles in the ozonation catalytic process for the removal of DOM.

Highlights

In the past few decades, the problem of water pollution has received increasing attention around the world [1]
This study investigated the effect of γ-Al2 O3 with different particle sizes on Dissolved organic matter (DOM)
Ozonation substantially reduced the intensities of the fluorescence of the examined DOM fractions by Excitation-emission matrix (EEM)

Summary

Introduction

In the past few decades, the problem of water pollution has received increasing attention around the world [1]. Dissolved organic matter (DOM) in the biological effluents are typical kind of pollutants with complex compositions [3], some of which cause threats to both human health and aquatic ecosystems because of problems such as bacteria reproduction [4] and disinfection by-products (DBPs) formation [5]. These DOMs are generally refractory since the conventional biological methods, coagulation and adsorption are ineffective due to its non-biodegradability, higher hydrophilicity, and lower molecular weight [6].

Methods

Results

Conclusion