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prod 2017-237b équipe EA BIOmE AGROSUP; National audience; Résumé de la brochure: Dans une société où il devient urgent de réduire l'empreinte environnementale des activités humaines, la première étape est de pouvoir faire un diagnostic de la qualité de notre environnement et des différentes matrices le constituant (eau, sol, atmosphère, déchets). Les microorganismes, de par leur petite taille, leur énorme diversité taxonomique et génétique, leur réactivité aux perturbations ainsi que par leur forte implication dans les cycles biogéochimiques gérant les flux de matière et d'énergie, sont des candidats incontournables pour élaborer ce diagnostic. Ceci est d'autant plus vrai que depuis une vingtaine d'années les fortes évolutions méthodologiques dans le domaine de la biologie moléculaire ont permis de sublimer les techniques d'étude de ces microorganismes dans l'environnement. Le présent ouvrage décrit : dans un premier chapitre les différentes techniques relevant de la microbiologie moléculaire capable de caractériser l'abondance, la diversité, l'activité et les potentialités fonctionnelles des communautés microbiennes indigènes de diverses matrices environnementales (eau, sol, atmosphère, déchets). Neuf fiches techniques viennent en appui de ce chapitre et expliquent l'intérêt et les limites des indicateurs qui en découlent ; le deuxième chapitre est constitué des fiches applications illustrant des utilisations réelles de ces techniques pour évaluer ou remédier à l'impact des activités humaines (agricoles, industrielles, urbaines) sur les différentes matrices environnementales ; le troisième chapitre présente le caractère opérationnel de ces outils biologiques pouvant répondre à diverses questions environnementales. Mots-clés : DIAGNOSTIC ENVIRONNEMENTAL, ATMOSPHERE, SOL, EAU, DECHET, MICROORGANISME Éditeur : ADEME Date de mise en ligne : novembre 2017 Date d'édition : octobre 2017 Langue : FR EAN imprimé : 9791029704857 EAN électronique : 9791029704864 Type de support : Imprimé/A4 Cible(s) concernée(s) : Recherche et Innovation, Entreprises et Monde Agricole Public : Bureaux d'études, Entreprises et fédérations professionnelles, Agriculture et Forêt, Collectivités territoriales, Enseignants

Sewage sludge contains a huge diversity of organic contaminants including pharmaceuticals (1). These compounds may interact with the organo-mineral environment prevailing in such complex matrix through various sorption/complexation mechanisms. These interactions could be modified by the treatment applied to sludge and this reactivity modification could thus influence the contaminants fate after sludge disposal onto soil. In order to study the impact of sludge treatments on the fate of pharmaceuticals after sludge spreading on soil, we have conducted lab-scale leaching experiments with 4 types of sludge sampled on an industrial sludge treatment line including anaerobic digestion, drying and composting. Batch and column assays (based on EU standards XP CEN ISO/TS 21268-1, XP CEN ISO/TS 21268-2, XP CEN/TS 14997 et XP CEN ISO/TS 21268-3) and lysimeters experiments were conducted to assess contaminant release from 4 sludge: a thickened sludge (S), the same sludge after anaerobic digestion (DS), then after drying (DDS) and finally composted with green wastes (C-DDS). The release was also assessed from soil-sludge mixtures. Carbamazepin (CBZ), ciprofloxacin (CIP), sulfamethoxazole (SMX) and ibuprofen (IBP) were quantified in the raw and treated samples and in the leachates of the assays. CIP and IBP transfer from a non-contaminated soil was also assessed by means of laboratory column experiments. CIP was present at the highest concentration in the 4 sludge samples, the three other compounds were present at concentration around and below 100 μg/kgDM. During all the leaching experiments, only CIP, CBZ and IBP were detected. Experiments carried out on sludge showed that different sludge treatments can lead to different contaminant releases. Indeed, the dried anaerobic digested sludge and the composted sludge led to a better retention of CIP and CBZ as shown during batch and column experiments. Sludge thickening and composting led to a greater retention of IBP as shown in batch experiments. However, the sludge exhibited the same behavior in column experiments concerning IBP. In addition, CIP was neither detected in batch nor in column experiments carried out with soil-sludge mixtures whereas IBP and CBZ were either quantified or detected. In batch experiments IBP was quantified in leachates coming from soil-DS mixture and only detected in leachates of other mixtures. Under the same batch conditions, CBZ was quantified in each leachate with a lower level in the soil-C-DDS. In the column experiments, IBP was quantified in all soil-sludge mixtures as well as CBZ. In addition, column experiments with the non-contaminated soil showed that IBP can migrate in soil. But, a fraction of IBP seemed irreversibly sorbed to the soil. On the contrary, CIP showed no migration in laboratory column experiments. In lysimeter vessel under unsaturated conditions, CIP was not detected in leachates. IBP was quantified in only one leachate coming from the lysimeter filled with the soil-DS mixture and was also detected in some other leachates. CBZ was quantified in all leachates, the lowest concentration was found for the soil-compost mixture. These results confirmed what was already observed during batch and column experiments: CIP is highly retained in soils whereas IBP and CBZ can be mobilized. These results are also in accordance with results obtained on field-experiment where CBZ and IBP were detected at low frequency in the soil-leachates (2). According to the concentrations found in the raw and treated sludge, it seems that ibuprofen is preferentially released compared to carbamazepin and ciprofloxacin. Ciprofloxacin is highly retained in the soil. Ibuprofen release is nevertheless moderate. The releases of ciprofloxacin and carbamazepin are lower is the case of compost supply.

International audience

While many urban authorities in Europe are confronted both with increasing demands by urban dwellers for allotment gardens, vacant urban soil tends to be scarce and/or polluted by past industrial activities. A possible solution for local authorities could therefore be to promote rooftop gardening. Little technical information exists however on certain forms of rooftop urban agriculture, called Z-Farming. In 2012, a pilot experiment was run in Paris (France). Simple and cheap systems of rooftop gardening were tested on a rooftop, using as crop substrates only local urban organic waste so as to contribute to the urban metabolism. Production levels, physical and chemical evolution of substrates and heavy metal contents in cropping substrates and edible vegetables were measured. Available results show (i) high levels of crop production compared to the reduced use of inputs, and (ii) very low levels of heavy metal pollutants in the edible parts of the crops. These encouraging results allow us to consider that rooftop gardening is possible. It will nevertheless be necessary to identify more precisely the types of roof that can be used, and to assess more fully the generic result of the low level of pollution, as well as the global sustainability of these cropping systems.