White certificates for energy efficiency interventions and benefits for employ of innovative technologies involve operating costs reduction, that favours the return on investment.
Evaporation is a very efficient technology for wastewater treatment, but with high operating costs due to building materials and considerable thermal energy needs. Careful feasibility studies define the choice of more convenient evaporation technology (hot water or vapour, mechanical steam recompression, heat pump) for each different case, evaluating the application of devices, as creation of vacuum in ebullition chamber and employ of more evaporation tanks (multiple effects), that facilitate the return on investment thanks to energy saving.
The UASB (Up-flow Anaerobic Sludge Blanket) biological technology can be applied to wastewater with a high COD (Chemical Oxygen Demand) level, as that of food, chemical and pharmaceutical industries. It allows not only to lower pollutants concentration in effluents, obtaining a treated water recyclable in working process, but also to generate energy: bacteria composing the sludge blanket, indeed, digest carbon, producing biogas.
The process of treatment of digestate from biomass plants for COD, heavy metals and nitrogen removal, allows at the same time a valorization of effluent through the recycling of its liquid and solid by-products, that can be used as soil fertilizers and improvers or combustibles for power generation.
Reverse osmosis and MBR mobile treatment units have spread for water desalination and potabilization in rural communities or in emergency situations. Connection with a photovoltaic panels system make the plants, remotely monitorable, energy autonomous.
One of main problem of reverse osmosis and nanofiltration plants is the creation of mineral scaling, causing a slowing down of filtering action and in consequence also a growth of energy consumptions. An innovative technology is able to prevent the event, optimizing the output of desalination processes: it allows indeed to recover over 90% of water, to reduce until to 60% concentrate to dispose, to minimize or avoid antiscalant chemicals use and to lower energy consumptions.
