15 th International Conference on Environmental Science and Technology Rhodes, Greece, 31 August to 2 September 2017 CEST2017_00542 Lab-scale investigation on remediation of sediments contaminated with hydrocarbons by using super-expanded graphite. Masi S. 1 , Calace S. 1 , Mazzone G. 1 , Caivano M. 1 , Buchicchio A. 1 , Pascale S. 1 , Bianco G. 2 , Caniani D. 1 * 1Università della Basilicata, Scuola di Ingegneria, Viale dell’Ateneo Lucano 10 - Potenza, Italy 2 Università della Basilicata, Dipartimento di Scienze, Viale dell’Ateneo Lucano 10 - Potenza, Italy *corresponding author: Donatella Caniani e-mail: donatella.caniani@unibas.it Abstract In view of necessity to develop simple, rapid, and efficient methods for monitoring and removal contaminants from soil, a new graphene-based material is presented for treatment of hydrocarbon-contaminated soils. Lab-scale experiments on three soil matrices featured by increasing granulometry were carried to evaluate graphene adsorption capability, as removal efficiency. Soil samples, firstly contaminated with different quantities of mineral exhausted oil up to final concentrations of 12500, 25000, 50000 mgkg -1 , respectively, were treated with opportune amount of graphene. Results show as the removal efficiency of graphene is directly proportional to contamination level of the soil. Particularly, the best removal efficiency (87.04%) was reached during treatment of gravel samples at maximum contamination level using the highest dosage of graphene, even though good results (80.83%) were also achieved using lower graphene/pollutant ratio. Moreover, graphene at ratio 1/10 showed worse removal efficiencies in treating sea (81.17%) and silica sand (63.52%) than gravel. In this study, also the thermal regeneration was investigated in order to evaluate a possible reuse of graphene with subsequent technical and economic advantages. Graphene- technique proves to be technologically and economically competitive with other currently used technologies, revealing the best choice for the remediation of hydrocarbon-contaminated soils. Keywords: contaminated sediments, hydrocarbons, remediation, super-expanded graphite 1. Introduction In the last century, the industrial development has led to spread of wealth, contributing to environmental pollution. In Europe, three million potentially contaminated sites have been counted, of which 10% (300,000 sites) need remediation (EEA, 2015). There are a lot of pollutant agents resulting from the production and use of synthetic products, but only after decades their dangerousness has been acknowledged. Particularly, petroleum products represent more than 50% of soil contaminants (EEA, 2015). Hydrocarbons pollution of soil and water is usually due to accidental spills, losses from tanks or pipelines, mismanagement of storage sites or landfills for industrial waste. The soil pollution represents a critical issue for technicians and researchers because of its difficulty of treatment. In view of necessity to develop simple, rapid, and efficient methods for monitoring and removal these contaminants from soil, a broad spectrum of technologies is available to remove or to degrade hydrocarbons. In this paper, a lab-scale experimentation was carried out to remove hydrocarbons from contaminated soils, using super-expanded graphite as innovative material characterized by high specific surface and adsorption capacity (Zhu et al., 2010). To our knowledge, the use of graphene in soil remediation is not enough investigated in the scientific literature. Therefore, to enlarge the available literature on soil and water remediation, laboratory tests were performed, to evaluate the maximum adsorption capacity in several experimental conditions (i.e., granulometry, graphene/pollutant ratio, contact time, and pollutant concentration). The main objective of this work is to treat different types of solid matrix, artificially contaminated with exhausted lubricating oil, using super- expanded graphite as adsorbent. The aim is to achieve high levels of removal by means of reduced quantities of graphite. In this way, it is possible to introduce a new remediation technology which is technologically and economically competitive. 2. Materials and methods 2.1. Properties of graphene The promising applications of super-expanded graphite arise from its particular structural properties. Graphene is a nanomaterial mainly used to treat water contaminated with hydrocarbons, producing excellent results (Wang et al., 2013; Mehdinia et al., 2015). Particularly, it is an innovative material with elevated transparency and a large specific surface area (2630 m 2 g -1 ). Moreover, the mechanical resistance is 200 times greater than steel, the flexibility is comparable to that of rubber, the thermal conductivity is twice than that of diamond, the electrical conductivity is higher to any other material and the apparent density is from 2.3 to 9 gl -1 .