Soil is a vital and largely non-renewable (in the 50-100 years timescale) resource increasingly under pressure, which performs a number of key environmental, social and economic functions vital for life, but increasingly threatened by a range of human activities, causing its degradation. Unfortunately this problem is aggravated due to diffuse contamination, which in most cases result in damage or loss of several functions of soil, groundwater contamination and possible transfer of pollutants to humans.

In the EU 1.5 M polluted sites have been estimated, and in Russia and the New Independent States (NIS) the number is at least comparable, due to former military sites, machinery repair, fuel stations, and industrial production sites. Heavy metals, PCB, chlorinated hydrocarbons, pesticides and nitrates lead to severe consequences on the environment, the agricultural production system and human health (gastrointestinal, respiratory diseases, blood exchange disorders, oncological diseases).

Soil clean-up is a difficult operation with very high costs, varying from 59 to 109 billion €/ha, irrespective of the degree of contamination and technology applied. The most generally used method to address land pollutants is to excavate and remove the polluted land, which is then treated or transported to a landfill at another location. Apart from being costly, this method results in a heavy environmental load and many times not financial or technically feasible. The development of new technologies for the removal of poisons from the soil has thus become a priority. Further research has been carried out in the field of bioremediation, phytoremediation and sorption based methods as alternative method to excavation.

CLEANSOIL aims to develop an economically friendly sound alternative to enable the on-site/in-situ treatment of hazardous substances, by means of adsorption mechanisms. Based on its simplicity, it is specially targeted for large areas of polluted land, and highly recommended when the removal is not applicable (under buildings, roads, railroads, etc), as it causes minimum disturbance.

The method consists of several inserted cords connecting a multitude of sorbent material-containing sockets inside the same number of parallel horizontal holes drilled in the ground. After a sufficient period of time the sorbents absorb the pollutants to the desired remediation effect, the system is removed and the sorbent regenerated for further application.

The proposed project will investigate and clearly define the potential applications of the CLEANSOIL system. By making the necessary adaptations, selective systems for each kind of contaminant will be established, which will allow to offer solutions for large contaminated areas at moderate costs. Still further applied research is required in order to adapt the method to different soil conditions and contamination problems. With these aim, tests will be conducted for selection of the most suitable sorbents and reactive agents for the removal of a wide range of pollutant compounds in conjunction with studies of soil geological properties and the hydraulic characteristics.

• to develop and to test an innovative, simple, easy to handle, applicable under existing infrastructures and cost-effective on-site and in-situ soil remediation method able to achieve a degree of soil remediation that allows its reutilisation for different purposes
• to contribute to the development of methods for the remediation of contaminated soils up to the restoration of its vital functions applicable both in the EU and the NIS
• to gather deeper knowledge on pollutants adsorption processes in soils, by finding the most suitable sorbent materials and bacteria able to remove different pollutants in different soils
• to strengthen the exchange of knowledge between EU and NIS scientists in an area of mutual interest

During the three years duration project, the research work comprising the 8 work packages have been developed according to the figure below. During the first work package (WP1), the problem in its environmental, social and economic dimensions for the involved countries will be defined, and a set of parameters and for the evaluation of the project progress and results established. Further, a detailed specification of the situation in the targeted areas where the CLEANSOIL system will be implemented will be carried out (WP2). This research will be the base for identifying appropriate sorbents for each specific pollutant source in WP3, which will be tested at laboratory scale soil column experiments in order to define the most relevant design parameters for the system. In WP4, based on the already established local conditions, the system will be designed and dimensioned and a complete sampling test programme developed. According to the design, in WP5 the CLEANSOIL concept will be constructed at the selected sites, and the system will be operated. Samples from the soil, the groundwater and the soil solution water, as well as the sorbents will be periodically analysed. In WP6 the CLEANSOIL performance will be evaluated based on the data compiled during the field tests. The values obtained after the treatment will be compared to the initial concentrations and to the fixed objectives. After the end of the testing period, the system will be removed definitely. Based on that, a study on the economic, technical and environmental feasibility of the whole system will be developed.
In parallel to the above mentioned activities dissemination tasks (WP7) will be held in order to raise public awareness about the problems and the solutions offered by CLEANSOIL (communication with relevant stakeholders, presentations, publications, conferences).