Abstract: The present invention is intended for the technical field of organic waste fermentation and makes it possible to increase methane production yields by anaerobic fermentation from lignocellulose materials of plant origin. The invention concerns a new composition based on a superabsorbent polymer and iron for accelerating the degradation of this type of organic waste, as well as a process for using it.

Abstract: The present invention relates to the technical field of treating urban and industrial saline sludges in general and more specifically the “conditioning” thereof before it is removed through the appropriate channels. The drying composition of the invention makes it possible to easily transport and store saline sludges, namely all sludges comprising even small quantities of salts made up of inorganic anions, in particular chlorides, and cations such as sodium, potassium, calcium and magnesium. Said drying composition is characterized in that it comprises: —at least 50% and up to 99% by weight of a superabsorbent polymer—and from 1% to 99% by weight of a flocculant polymer. It makes it possible to dry saline sludges by significantly reducing the quantity of superabsorbent required to achieve said outcome. The invention also relates to the use of the composition for conditioning saline sludges.