As shown in Action B3 in the proposal, trials at laboratory scale have been carried out in CTAEX for the reduction of sewage sludge heavy metals with fly ash from ENCE biomass factory. Sewage sludge was previously characterize in their heavy metals and fertilizing fractions (N, P and K).

<p style="text-align: justify;"> Essays of direct filtration of sewage sludge over fly ash column and mixture of the two components and later phases separations have been carried out.</p> <p style="text-align: justify;"> &nbsp;</p> <p style="text-align: justify;"> Results show a high adsorption capacity of fly ash, but both interesting fractions are retained in the solid fraction. A selective adsorption is required to separate both fractions and their subsequent separate utilization.&nbsp;</p> <p style="text-align: justify;"> &nbsp;</p> <p style="text-align: justify;"> A new battery of trials are set out by modifying extractive conditions (pH, temperature, extracting agents, etc.), always with a view of its technical viability at prototype scale.</p> <div> &nbsp;</div>