Technical Bulletin No. 0020: Summary of Trickling Filter Treatment of Alkaline Pulping Waste Waters

Due to its wide spread and effective use for treating domestic sewage, the trickling filter has, in recent years, been used experimentally and otherwise in the treatment of a number of trade wastes. Previous publications of the National Council (National Council releases No.1 and No.4) deal with the use of this device for the treatment of waste sulfite liquor. In the attached report is summarized a number of pilot plant operations in which the trickling filter is used to treat various alkaline pulping wastes including strawboard, kraft mill and rag mill wastes. In the case of none of these wastes can the use of the trickling filter as a treatment method be considered practical. This is due largely to the fact that until some means of stimulating filter activity is found, current low efficiencies would necessitate filter construction on a scale comparable in magnitude to the mill construction itself.