Combined Digestion Landfill Leachate with Septage

• Main Authors: Bian, Feng-Yi, 邊逢沂
• Other Authors: Lin Chiu-Yue
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/86822531631765932643

碩士 === 逢甲大學 === 土木及水利工程研究所 === 85 === This paper examines the operating parameters and treatment efficiency in digesting landfill leachate with septage. The leachate and septage, both fromTaichung City which having a population of 800,000, were combined and treatedby anaerobic digestion. Three lab-scale CSTR digesters ( Continuous Flow Sirred Tank Reactor, 4-L working volume for each ) were used and operated at 35±1℃. Septage and leachate were mixed at the ratio of 1:1, 2:1 and 3:1 on the basis of COD. For each digester, the solids retention times (SRT) werecontrolled at 20, 10, and 5.3 days. The organic loading and volatile solidsloading ranged from 0.3-1.4 kg COD / m3-day and 0.79-3.7 kg / m3-day,respectively. According to experimental results, combined treatment enhanced the treatment efficeiency. For the same SRT, a higher ratio of septage increased the removal efficiencies of total COD, ammonia nitrogen and totalphosphorus (T-P). However, the removal efficiencies of volatile solids (VS),saccharide and protein decreased. Septage enhanced 40％ reduction of NH3 -N inthe leachate, which had a concentration up to 477 mg/L. When the organicloading reached 0.315 kg COD / m3- day ( septage/leachate =3:1 ) based on SRT20 days, the removal efficiencies of total COD, NH3 -N, T-P, VS, saccharides and proteins were 86, 69, 86, 28, 82 and 80％, respectively. At the organic loading of 1.159 kg COD / m3-day ( septage/leachate =3:1 ) and at SRT 5.3 days,the removal efficiencies of total COD,NH3 -N, T-P, VS,saccharide and proteinwere 76, 53, 75, 12, 75 and 72％, respectively. The dewaterability ofdigested sludge was also determined. Aseries of batch tests with serum bottles was used to study the effects ofheavy metal ions on the VFA degradation and methane production. The increment of VFA degradation and methane production efficiencies at the metallicconcentration of 33 mg Fe+3 /L ( 1.37~1.80 mg Fe+3 /g- VSS ), 1 mg Mn+2/L ( 0.05~0.08 mg Mn+2 /g-VSS ), 29 mg Zn+2 /L ( 1.20~1.58 mg Zn+2 /g-VSS ), 12 mg Ni+2 /L （0.49~0.66 mg Ni+2 /g-VSS） and 56 mg Cu+2 /L （2.32~2.54mg Cu+2 /g-VSS）, respectively. The kinetic parameters of the 3 reactors were respectively Vmax 3.1, 2.7 and 2.5 mg-COD/mg VS-day; Ks 120, 93 and 86mg-COD/L; Yg 0.018, 0.026 and 0.042 mg-VS/mg-COD; Kd 0.024, 0.032 and 0.046 1/day。