In this paper a new dataset of Polychlorinated Dibenzo-p-Dioxin and Dibenzofuran (PCDD/Fs) half-lives in soil is presented. Data derive from a greenhouse experiment performed with an aged contaminated soil under semi-field conditions, obtained from a National Relevance Site (SIN) located in Northern Italy (SIN Brescia-Caffaro). Ten different treatments (combination of seven plant species with different soil conditions) were considered together with the respective controls (soil without plants). The ability of the plants to stimulate the biodegradation of these compounds was evaluated measuring the PCDD/F concentration reduction in soil over a period of 18 months. The formation of new bound residues was excluded by using roots as passive sampler of bioaccessible concentrations. The best treatment which significantly reduced PCDD/F concentrations in soil was the one with Festuca arundinacea (about 11%-24% reduction, depending on the congener). These decreases reflected in half-lives ranging from 2.5 to 5.8 years. Simulations performed with a dynamic air-vegetation-soil model (SoilPlusVeg) confirmed that these half-lives were substantially due to biodegradation rather than other loss processes. Since no coherent PCDD/F degradation half-life datasets are currently available for soil, they could contribute to substantially improve the predictions of soil remediation time, long-range transport and food chain transfer of these chemicals using multimedia fate models.

This chapter will focus on the potential role of safe microorganisms as biocleaning agents in the removal of altered or undesirable organic substances on historical wall paintings. Selected microbes can be adopted as biological cleaners to reduce and remove deterioration ageing phenomena, environmental pollutants and altered by-products of past intervention of restorations. The aim is to offer a comprehensive view on the role and potentiality of virtuous microorganisms pro- biocleaning of altered historical wall paintings. We also report four case studies in the CH restoration field, carried out in the last 25 years, with the innovative use of bacteria and different delivery systems, focusing the attention on the preliminary diagnosis and the monitoring of the whole process. The CH field represents a great challenge and Science and Art link together the work of conservator scientists and historians with researchers and scientists, sharing their diverse expertises and joining the knowledges to the preservation and the conservation of our artistic patrimony.

This chapter will focus on the role of microorganisms in the removal of nitrates and sulfates on artistic stoneworks. The main groups of microbes and their metabolisms involved in bioremoval methods for the preservation and protection of cultural artifacts are reported. The aim is to offer a comprehensive view on the role and potentiality of virtuous microorganisms in the biocleaning and bioremoval of black crusts and salts altering CH stoneworks. We highlight the importance of the use of the selected microorganisms and the adoption of adequate carriers for the anaerobic metabolism of nitrate and sulfate reducers to be applied on the altered stone surfaces. The following characteristics of the delivery system are of great importance: the ability to guarantee water content for microbes, the absence of toxicity for the environment, no negative effects to the stone surfaces, easy to prepare, to apply, and to remove from different stone surfaces at the end of the treatment. We report an overview of the last 30 years on the biocleaning processes including diagnostic studies of the alterations, the assessment of associated risks, the effectiveness and efficacy of the proposed method, and the evaluation in terms of economic and environmental sustainability.