The invention discloses a method for preparing a modified composite biological filler and belongs to the technical field of
environmental protection. According to the method,
polyvinyl chloride polyhedral hollow spheres serve as a carrier, are subjected to compound-
acid oxidation and then are subjected to
acrylic acid grafting modification; through introducing oxo polar groups, the
surface roughness and microbial film hanging performance are improved, the specific surface area and microbial attachment area are increased; due to adsorption removal capability of
zeolite,
vermiculite and
activated charcoal to
wastewater, luffa cylindrica is subjected to carbonizing treatment and then is compounded with the
zeolite and the
vermiculite, and FeAl precipitates are adsorbed; FeAl
oxide doped composite
powder is prepared through high-temperature
calcination, so as to further improve the adsorption removal capability; meanwhile, due to biological film
growth promoting action of Fe, the film hanging time is shortened; and finally, the composite
powder is stuck to surfaces of the modified
polyvinyl chloride polyhedral hollow spheres treated with
polyvinyl alcohol, so as to prepare the modified composite biological filler. The prepared modified composite biological filler has the advantages that the stability is good, the specific surface area is large, the surface is rough, and biological films are difficult in falling-off.