In the field of biomass gasification for distributed power generation, ENEA and Sotacarbo are developing several activities on demonstration plant scale in order to test gasification technologies for combined production of synthesis gas and electric power in medium and small-scale industrial plants. The Sotacarbo pilot platform has been built up to test different plant solutions at different operating conditions; therefore, a very flexible and simple layout has been designed and constructed. Both demonstration and pilot plants are based on an up-draft, air-blown and fixed-bed gasification process, suitable to be fed with both Biomass and Agro-Industrial Residues. This paper presents recent activities associated to develop-ment of syngas clean up and waste water management systems, related to the operation of a pilot plant for the conversion of biomass and agro-industrial residues into syngas, electrical and thermal power. The pilot plant is composed of an up-draft, air-blown 2.5MWth fixed-bed gasifier, a concurrent wet scrubber for syngas clean up and a flare. The plant is also equipped with a chemical and physical water treatment plant. The waste water treatment line is equipped with an oil skimmer in order to minimize the water sent to the final treat-ment and to recover part of the effluents that are recirculated to the scrubber. The Sotacarbo pilot platform has been built up to test different plant solutions at different operating condi-tions; therefore, a very flexible and simple layout has been designed and constructed. In this study wastewater treatment process performance is also evaluated, indeed the process has been implemented with new components in order to minimize water consumption and sludge disposal and treat water contaminated by tar appropriately. As a result, feeding in particular agro-industrial residues may represent a good opportunity to exploit/promote distributed generation systems that can be part of a new energy paradigm in a framework of circular economy especially in conditions of insularity or in rural areas not grid connected.