Aerobic and Anaerobic Digestion of Septage

• Main Authors: Chou, Jen, 周仁
• Other Authors: Chiu-Yue Lin
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/31093385236250809448

碩士 === 逢甲大學 === 土木及水利工程研究所 === 85 === Two digesters, aerobic and anaerobic, were used to treat septage with sludge retention time (SRT) of 30, 20, 15, 10 and 5.3 days. At SRT of 30 days or organic loading of 178 g-COD/m3. day, the removal efficiencies of VS (volatilesolids), COD (Chemical Oxygen Demand), NH3-N (Ammonia), T-p (Total Phosphorus),saccharide and protein were respectively higher than 43, 89, 90, 77, 64 and 52percent for aerobic digestion, and higher than 40, 84, 57, 65, 65 and 57 percent for anaerobic digestion. The removal rates of COD, NH3-N, totalphosphorus, saccharide and protein were 159, 10.8, 0.6, 5 and 2.4 g /m3.day foraerobic digestion, and 150, 8, 0.4, 5 and 2.6 g-COD/m3.day for anaerobicdigestion at SRT of 30, 20, 15, 10 and 5.3 days, respectively. The treatmentefficiency of aerobic digestion was better than that of an aerobic digestion.The dewaterability of digested sludge was determined by capillary suction time(CST). The CSTs were respectively 19, 15, 12.5, 10.2 and 33 seconds for aerobicdigestion, and 67, 31, 28, 24 and 72 seconds for anaerobic digestion for thefive SRTs. The nondegradable portion of VSS (Volatile Suspended Solides) wasapproximately 49.6 percent of the initial total VSS concentration, resultingin the removal efficiency of VSS of lower than 50 percent. The Kb (batchreaction rate for degradable VSS) was 0.132 per day.The kinetic parameters were calculated using Monod model for anaerobicdigestion and the values of Vmax, Ks, Yg and Kd were 3.34 day-1, 236 mg COD/L,0.3 mg VSS/mg COD and 0.014 day-1, respectively. A series of batch tests withserum bottle was used to analyze the effects of heavy metals on the VFA degradation and methane production. The dosages at 45 mg Cu+2/L, 12 mg Ni+2/ L,29 mg Zn+2/L, 33 mg Fe+3/L and 1.4 mg Mn+2/L can promote VFA degradation andenhance methane production efficiency for anaerobic digested sludge with SRTof 5.3 days.