## 1 Introduction  
Pyrolysis is a degradative technique for producing energy from biomasses, in the absence of oxygen [1], and represents an example of a Circular Economy System. Pyrolysis process generates two types of wastes: (i) a carbon-based material that could be used in different pathways (such as production of carbon activated materials) and (ii) a \"pyroligneous liquor\" (PL) composed by water, alcohols, organic acids, phenols, aldehydes, ketones, esters, furan and pyran derivatives, hydrocarbons, and nitrogen compounds [2]. According to the Italian Law, PL represents an environmental risk due to its composition so remediation of the waste is required. Among other clean-up technologies, phytoremediation entails a set of natural processes of polluted water treatment based on how the soil-vegetation system can behave as a natural filter for water purification. Compared to traditional practices, phytoremediation requires larger surfaces, but leads to lower employment of energy and technology, and is more sustainable under an economic point of view [3].  
Moreover, plants used for remediation of wastewater produce a relevant biomass that is of great interest for energy production and heavy metal recovery for industrial purposes [4; 5; 6; 7; 8]. Phytoremediation of PL can be achieved using constructed wetlands (CWs) that are based on the interactions of plants and the associated microflora living in the rhizosphere [9]. For improving the efficiency of CWs, bioaugmentation could be a possibility to accelerate the establishment of microflora to remediate hard degradable industrial pollutants, such as PL [10]. Among the microflora in direct contact with a root system, Arbuscular Mycorrhiziae (AM) are an example of important symbiosis involving fungi and plants, resulting in a nutritional exchange in which fungi improve the mineral nutrition of plants and receive photosyntates [11]. AM fungi (AMF) can act as biofilters, reducing abiotic stresses in plants due to organic compounds such as insecticides [12], aromatic hydrocarbons and polycyclic aromatic hydrocarbons [13; 14; 15; 16]. Moreover, the interaction between plants and AMF plays an active role in heavy metals stresses and accumulation [17; 18; 19; 20]. Despite the wide range of research applications of AMF in CWs [21], little is known about the remediation of PL.  
Bioaugmentation can also be performed by adding bacteria that directly or indirectly interact with plants: as previously reported, specific bacterial strains can promote symbiosis between plant roots and AMF [22; 23]. Moreover, selected rhizobacteria can degrade total petroleum hydrocarbon effluent [24], organic chemicals [25], heavy metals [26], and contribute to nitrification [27] and denitrification [28].  
Bacteria living in rhizosphere with beneficial effects on the plant development and health (the so-called Plant Growth- Promoting Bacteria or PGPB) can promote plant growth by producing plant hormones, solubilizing phosphate, producing enzymes such as the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase to alleviate biotic and abiotic stresses [29; 30].  
Here, we report on the results obtained in a CW, using _Phragmites australis_ inoculated with a pool of AMF and a PGPB strain, to remediate PL polluted waters.