Co-application of activated carbon and compost to contaminated soils: Toxic elements mobility and PAH degradation and availability

28 páginas, 6 tablas y 2 figurasThis work assesses the suitability of three commercial activated carbons (AC) and their combination with olive mill waste compost (AC+C) as amendments for the remediation of two different contaminated soils. The treatments were applied to a mining soil and their ability to immobilize trace elements was evaluated. Besides, the efficiency of the amendments to degrade and reduce the availability of polycyclic aromatic hydrocarbons (PAH) was investigated in a soil from a wood creosote treatment plant. To this aim, trace elements mobility and PAH degradation and availability were evaluated. Ecotoxicological assays were performed to assess potential toxicity risks in the untreated and the amended soils. In the mining soil, the AC were able to immobilize metals and As but the AC+C treatments were more effective than AC. In the PAH-polluted soil, AC treatments promoted the degradation of high molecular weight PAH but the AC+C amendments further enhanced the degradation of total PAH and reduced the availability of those with 3-rings. The ecotoxicological tests demonstrated an improvement of soil quality when AC and compost were applied together. In conclusion, the co-application of AC and compost reduces the mobility of potentially toxic elements in the polluted mine soil and enhances PAH degradation and reduces PAH availability in the creosote-contaminated soil.This work was financially supported by the Ministry of Economy and Competitiveness of Spain, projects CTM2013-47874-C2-R and CTM2013-48697-C2-2. CGD was supported by a postdoctoral contract (Juan de la Cierva FJCI-2015-23543) from the Spanish Ministry of Economy and Competitiveness.Peer reviewe