Abstract:
To study the effect of pulp powder for granulation in an expanded granular sludge bed (EGSB) reactor. Wastewater in this experiment was real wastewater from piggery. The influent COD content was 2,500 mg/L. on average. In the experiment with 4 EGSB reactors, the Pulp powder concentrations employed were 0, 1,500, 2,000 and 3,000 mg./g.SS, respectively. The organic loading rate varied by 1, 2 and 3.5 kg.COD/m3-day. The upflow velocity was varied 2, 4 and 7 m/hr. The experiments were carried out in 156 days. The result showed that 4 reactors have the COD removal of over 91.5 percent. The sludge in reactor with Pulp powder 2,000 mg/g.SS was sludge granulation observed faster than reactor without Pulp powder. The granules were initially observed on Day 31 and Day 59, respectively. About 40% of granular sludge had their size between 0.15-1.23 mm. in diameter. The Specific Methanogenic activity (SMA) for reactor 1, 2, 3 and 4 values was 0.08, 0.15, 0.29 and 0.11 gCOD-gCH4/gVSS-d., respectively. The SEM showed that a granule from all reactors was mostly composed of Methanothrix-like species.The result shows that the Pulp powder, Organic loading rate and Upflow velocity which enhanced sludge granulation, efficiency and decrease period for startup system. The most promising for the Pulp powder concentrations addition was 2,000 mg./g.SS.