METHOD FOR RECOVERING PARTICULATE AND SCAVENGING FORMALDEHYDE

摘要

A thin film mem- brane filtration system (50) recovers particulate from the waste water stream (66) of a wood panel fabrica- tion process to a desired concentration of approxi- mately 30-50 % solid by weight. The high concen- tration level enables im- proved transport or dispo- sal. Rather than discard the concentrate, however, the concentrate is added into subsequent wood pan- el "particle board" batches at a rate of approximately 0.5 to 0.65 gallons per 1000 pounds of wood pro- duct. The concentrate re- duces press time, serves as a scavenger for tying up formaldehyde and serves as a resin extender for strengthening internal bonds of fabricated pan- els. The membranes (54) capture the particulate into an accumulated concentrate, while passing permeate output to a recycle water stream (80).