Patricia García-Muñoz

Trends in the Intensification of the Fenton Process for Wastewater Treatment: An Overview

The implementation of increasingly stringent regulations for wastewater discharge has enforced research efforts toward either the implementation of novel treatments or the improvement of those presently available. The literature on the use of Fenton oxidation in wastewater treatment has established this method as one of the most effective and suitable process for the abatement of recalcitrant water pollutants. However, despite the many advantages of the conventional Fenton process, there are issues relative to pH modulation, the cost associated to H2O2 and catalyst consumption as well as to sludge disposal that limit a more extended full-scale application. In recent years, several solutions have been developed for the sake of improving Fenton (or Fenton-like) oxidation as a cost-effective technology. This paper presents a thorough review on the different ways of intensifying the Fenton by using radiation, electrochemistry, and/or heterogeneous catalysts, as well as by optimizing the main operating conditions in the conventional homogeneous system. The application of these enhanced technologies to synthetic and real industrial wastewaters is described and discussed.

An overview on the application of advanced oxidation processes for the removal of naphthenic acids from water

ABSTRACT Although the exploitation of new energy sources like oil sand or shale may efficiently relieve the urgency of energy shortage, it can also have significant and adverse environmental impacts since huge volumes of oil-containing wastewaters are produced yearly worldwide due to such activities. Naphthenic acids (NAs), which are reported to be bio-recalcitrant due to their structural complexity and toxicity, are the main harmful components of oil shale fracking processes and oil sand process-affected waters. Identification techniques are being continuously improved to deal with the growing analytical need for traditional NAs and emerging ones like oxy-, aromatic, and diamondoid NAs. Meanwhile, treatment approaches focused on technical solutions have been investigated in the past decades. Among these, advanced oxidation processes are the most studied. Different oxidizing agents, like ozone, hydrogen peroxide, and persulfate, among others, have been used, giving rise to a diversity of techniques. The current work presents an updated overview of these techniques with regard to their application for the removal of NAs from water.