An Automatic Bench-scale Unit for Clarification of Animal Wastewater by Dual Means of Cohesion and Ultrafiltration

For the purpose of clarifying animal wastewater, an automatic administration with inorganic cohesion and ultrafiltration was tried. As an inorganic agglutinant, 0.385g Ferric Trichloride was added to 1g total suspended solids of slurry. The ultrafiltration module, which had the membrane made of vacant string tubes of poly sulfon, had an effective membrane area 1.0m2. Maximum tolerable pressure of the module was 3kg/cm2. For an automatic operation of the unit, a programmable controller PL 40-III was used. The administration procedure was as follows; Pumping up of the wastewater and addition of agglutinant solution-Agitation (circulation) of the slurry in the tank-Pumping out to the sedimentation tank-Sedimenting administration-Drainage of the muddy slurry-Ultrafiltration of the supernatant-Reverse cleansing of the filter. The unit worked according to the program. During the experimental operation, original sewage, supernatant after inorganic cohesion, and filtrate after ultrafiltration were sampled, and the loads of organic matters were analyzed. Indices of the filtrate compared with those of the original slurry changed as follows; pH 7.5 to 3.0, T-S 290mg/l to 450mg/l, T-SS 150mg/l to 0mg/l, COD 120mg/l to 26mg/l, BOD 210mg 30mg/l, and transparence 2.6cm to more than 30cm.