Blanket development in a malting wastewater anerobic treatment

A 3 m(3) pilot UASB reactor was operated with malting wastewater. In order to find the aggregation characteristics, the sludge concentration profile w as determined throughout time. Reactor behaviour concerning the physical pr operties of the sludge can be evaluated using this procedure. Moreover, org anic load per VSS can be calculated from this profile. The organic load bas ed per VSS is more accurate as a design parameter than the volumetric load. Under the study conditions imposed the COD removal efficiencies achieved w ere about 85%. Organic loads of 0.6-0.7 kg COD/(kgVSS.d) were reached. Afte r operating at 30 degreesC, temperatures of 28 degreesC and 15 degreesC wer e tested, showing no decrease in COD removal efficiency. At week 15 the pre sence of granules was verified, and after that, sludge concentrations of 30 -35 kg VSS/m(3) were measured at the bottom of the reactor. The SVI of the granular sludge decreased to values below 20 mL/gVSS. The settlement veloci ty was 10 m/h, which is much greater than the recommended values for the se ttlement zone; therefore, no problems are to be expected in the settler reg arding the sludge sedimentation. The biomass yield coefficient obtained was 0.10 gVSS/gCOD in agreement with literature values for brewering effluent.