Persulfate Application for Landfill Leachate Treatment: Current Status and Challenges

Landfill Leachate (LL) is considered an important environmental burden, being a high-strength wastewater with high organic load, considerable toxicity, dark color, as well as high concentrations of ammonium and dissolved solids. These characteristics render LL a difficult effluent to treat. Nowadays, the application of persulfate, as a novel treatment strategy, is increasing in the treatment of contaminated waters. LL has recently received great attention from researchers as a challenge for the performance evaluation of persulfate-based processes. This chapter focuses on describing LL treatment by persulfate-based processes as a hazardous wastewater. LL characterization and persulfate chemistry are introduced in the current chapter. Several persulfate activation methods and their applications on LL treatment have been discussed in detail. The following sections present LL persulfate-mediated treatment by different activation methods. (I) Homogeneous persulfate activation by transition metals, (II) heterogeneous persulfate activation by transition metals, (III) persulfate activation by high energy input (microwaves, heat, ultraviolet, and ultrasound), and (IV) other persulfate activation methods. Furthermore, a reflection on the current status, literature, and challenges of persulfate application for LL treatment is included. The topics included in this chapter can serve as a comprehensive guide for environmental engineers, in the successful development of persulfate application for LL treatment.