Prodn. of floatable materials for absorption beds - by carbonising pre-expanded grain, esp. useful in anaerobic waste water treatment plants

摘要

Prodn. is effected by carbonising pre-expanded natural 'fruits' (esp. grains) at 180-450 deg.C. The starting material is popcorn, puffed wheat or puffed rice. Carbonisation is effected in the presence of air, opt. in a closed vessel to form a moulded prod. USE - The floatable materials are esp. useful as biomass carriers in biological (esp. anaerobic) waste-water treatment plants. They may also be used as packing materials in columns, trickle units and adsorption or absorption beds, as biofilter materials, as hydroponic culture substrates, as insulating materials, as fillers for plastics, foams, bricks and concrete, and as carriers for catalysts and 'active agents'