Weak washwater from a pulp mill, evaporator condensate from the spent liquor recovery system, and paper machine white water effluents were treated over a 17 month period in a secondary treatment plant consisting of 2 aeration basins. One basin was equipped with two 75 hp aerators and the other with six 25 hp aerators. Piping was designed to permit series and parallel operation of the two basins, and provisions were made to recycle treated waste. Series operation was superior to parallel operation for the wastes treated. The two 75 hp aerators were much more efficient in both mixing and aeration capacity than the smaller 25 hp units. An 80% BOD reduction in the system was achieved at a loading of 2.2 lbs BOD/hp-hr equivalent to a daily load of 16,000 lbs BOD. Total operating costs are discussed.

Laboratory scale experiments in a 2 ton/hour experimental unit with peaches, pears, and apricots demonstrated that peel softened by hot solutions of sodium hydroxide can be removed efficiently by a series of rotating rubber discs. The quality of the peeled fruit prepared with the experimental unit compared favorably with fruit peeled in the conventional manner by commercial equipment, while peeling losses for all three fruits in the experimental unit were the same or slightly lower than those resulting from commercial peeling. During experimental peeling of peach halves, volume of wastewater discharged was 34.5 gallons per ton of pitted peaches as compared to 547 gallons per ton for conventional commercial peeling.