Pengolahan Air Limbah Domestik Tipe Greyewater Menggunakan Reaktor Upflow Anaerobic Sludge Blanket ( UASB)

Abstract

ABSTRACT Semarang City dispose 94,06 % of their domestic greywater into drainage and 5,94 % of them into the ground. This violated Perda Jateng No 5 tahun 2012 about Wastewater Quality Standard because greywater contains 155-1400 mg COD/L and BOD 125-673 mg/L. The contribution of COD disposal is 0.98 to 8.80 g/person/day and BOD is 0.79 to 4.24 g/person/day. Upflow Anaerobic Sludge Blanket (UASB) is an alternative process to treat greywater. Its working principle is distributing the wastewater in the reactor with upward direction of flow through the sludge blanket with specific hydraulic retention time (HRT). Laboratory scale research using artificial greywater was conducted in 64 days with 5 units of transparent fiber column-shaped UASB reactor with diameter of 10.16 cm and a height of 100 cm, and the outlet’s height was 60 cm. Reactors were operated at variations concentration of 155 mg/L-1400 mg/L; HRT 4-12 hours; upflow (Vup) 0.05 m/jam-0,15m/jam, and Hydraulic 3 2 Loading Rate (HLR) 0.05 to 0.15. m /m /jam. An optimum COD removal efficiency of 48.01 to 77.34% was obtained at 8 hours HRT with with influent COD of 827-867 mg/L. Based on Regression Models the largest BOD and COD removal efficiency were 72.35% and 74.43% thus were achieved at the load concentration 910 mg/L and 962.50 mg/L respectively. BOD5 elimination kinetics model resulted the degradation rate constant (k) of 0.11/h for loads from 473.76 to 643.10 mg/L and COD removal kinetics model resulted the degradation rate constant (k) of 0.10/h to 960 loads -1480 mg/L. Research using greywater from domestic wastewater in Semarang at mean COD load of 603.03 mg/L (566.67 to 633.33 mg/L) resulted in the greatest efficiency of 70.84% (from 62.86 to 80.00%). Whereas the average BOD5 load of 328.44, mg/L (299.78 to 341.57 mg/L) obtained an average efficiency of 69.25% (61.71 to 75.62%). At BOD5 load of 297-312 mg/L, reactor resulted better efficiency on greywater in comparison to artificial greywater. COD and BOD removal efficiency has significant relationship with hydraulic capacity (HRT, flowrate, Vup, HLR) and the influent concentration. Increasing of HRT decreased flowrate, Vup and HLR, however increasing removal efficiency and vice versa. Reactor performed better efficiency removal when applied with real greywater compared than artificial greywater. Biogas pontenty of those reactor was 1 mL/0.06 g/m3 COD eliminated. Based on these results, UASB reactor can be used as one solution to carry out the management and control of receiving water bodies. Further studies on UASB are needed to be implemented in order to obtain the height of the column for practical needs. Keywords : Greywater, UASB, HLR, Vup and HRT xxxi