ADVANCED OXIDATION PROCESSES: RECENT ACHIEVEMENTS AND PERSPECTIVES Humic acids extracted from compost as amendments for Fenton treatment of diesel-contaminated soil Daniela Zingaretti 1 & Miguel Angel Lominchar 2 & Iason Verginelli 1 & Aurora Santos 2 & Renato Baciocchi 1 Received: 3 October 2019 /Accepted: 24 February 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract In this study, we investigate the performance of a Fenton-like process carried out adding as amendments humic acids extracted from compost obtained from organic wastes. Namely, Fenton-like lab-scale tests with different dosages of the extracted humic acids and traditional stabilizing agent (KH 2 PO 4 ) were performed on a diesel-contaminated soil collected in a former gasoline station. The performed tests showed a beneficial effect of the extracted humic acids on the hydrogen peroxide stability. Namely, the H 2 O 2 lifetime in the tests carried out without the addition of any amendments proved to be quite limited, resulting equal to around 1 h. The adoption of the extracted humic acids alone entailed a limited increase of the hydrogen peroxide stability that anyhow was detected in solution for 24 h using 10 g/L of extracted HA. When the humic acids (10 g/L) were used in combination with KH 2 PO 4 (8.2 g/L), the hydrogen peroxide lifetime increased up to around 150 h. A beneficial effect of the humic acids extracted from compost for a Fenton-like process was also observed in terms of diesel removal. Namely, without any amendment, a contaminant removal of around 55% was observed. Using KH 2 PO 4 or HA alone, the contaminant removal raised up to around 75% while using the traditional stabilizer together with the humic acids extracted from compost, it was possible to remove up to 90% of the initial diesel content of the soil. Keywords Contaminated sites . In situ chemical oxidation . Fenton-like . Diesel . Humic acids . Compost Introduction Contamination, which is recognized as a threat to soil and water quality and to the wider environment (Bardos et al. 2016), is a common issue around the world and it is in- cluded within the 17 Sustainable Development Goals set by the United Nations; namely, Goal 3.9 is “by 2030” to “substantially reduce the number of deaths and illnesses from hazardous chemicals and air, water and soil pollution and contamination” (UN 2015). Different risk mitigation strategies can be deployed: these can be grouped in those aimed at targeting the contamination plume and those aimed at targeting the source of contamination. The for- mer ones include vertical cutoff walls (Takai et al. 2016), pump and treat (Guo et al. 2019a, b), and permeable re- active barriers (Obiri-Nyarko et al. 2014). The latter ones include different physico-chemical or biological ap- proaches, such as air sparging (Chang et al. 2019) or bioventing (Mosco and Zytner 2017). Advanced oxidation processes (AOPs) are widely used for the in situ treatment of contaminated sites. Namely, AOPs are applied in the frame of the so-called in situ chemical oxidation (ISCO) approaches, which rely on the delivery of different oxidants into the subsurface, aimed at targeting a variety of organic contaminants in the source of contamination (ITRC 2005; Siegrist et al. 2011), most commonly in the saturated zone. Oxidant delivery is commonly accomplished through permeation by vertical direct-push injection probes or flushing by vertical groundwater wells (Baciocchi et al. 2014). Commonly applied oxidants include potassium permanga- nate, activated sodium or potassium persulfate, and catalysed Responsible editor: Vítor Pais Vilar * Daniela Zingaretti zingaretti@ing.uniroma2.it 1 Department of Civil Engineering and Computer Science Engineering, Laboratory of Environmental Engineering, University of Rome “Tor Vergata”, Rome, RM, Italy 2 Chemical Engineering Department, University Complutense of Madrid, Spain, Madrid, Spain Environmental Science and Pollution Research https://doi.org/10.1007/s11356-020-08221-5