Seeding of foundry sand containing phenol resin with micro-organisms, to biodegrade the phenol, by animating the sand in an inclined rotating conduit and spraying with an aqueous suspension of the micro-organisms

摘要

Seeding with micro-organisms of foundry sand particularly containing at least one phenol resin as binder comprises (a) continuously introducing sand; (b) progressively animating the sand; (c) spraying an aqueous suspension of the micro-organisms onto the sand; (d) extracting the seeded sand by the low point of the conduit. The seeding with micro-organisms of a foundry sand particularly containing at least one phenol resin as a binder, the micro-organisms being able to degrade the binder, consists of: (a) continuously introducing the sand by a high point of a cylindrical inclined and rotating conduit; (b) progressively animating the sand with a mixing movement in the conduit from the high point to a low point; (c) spraying an aqueous suspension of the micro-organisms onto the sand on at least a part of its trajectory in order to seed it with the micro-organisms; (d) extracting the seeded sand by the low point of the conduit. Advantageously the micro-organisms used are aerobic and of the numerous heterotrophic micro-organisms ( bacteria, fungi and yeast) known for their capacity to degrade phenol. The aqueous suspension may also include a nutrient, such as nitrogen, phosphorus or potassium, for the micro-organism.