活性污泥及其与秸秆共基质的厌氧消化特性

Characteristics of Anaerobic Digestion of Activated Sludge and Co-Substrates with Waste Straw

为分析秸秆对污泥厌氧消化特性的影响,在中温〔(35±1)℃〕条件下,研究了活性污泥单基质及其与秸秆共基质在SRT(固体停留时间)分别为10和15 d,以及C/N(质量比)分别为5.5∶1、10.0∶1的情况下,厌氧消化产沼气量及其组分、ρ(NH_4^+-N)、ρ(TP)、ρ(CODCr)及ρ(VFA)〔以ρ(乙酸)计,其中VFA为挥发性短链脂肪酸〕的变化特性.结果表明:活性污泥-秸秆共基质厌氧消化在SRT为10、15 d时,累积沼气产量为5 818.0、9 026.0 m L,比活性污泥单基质的沼气产量(4 930.0、7 760.0 m L)分别提高了15.3%、14.0%;共基质所产沼气中φ(CH4)最高为69.3%,比活性污泥单基质高出15.4%.此外,在SRT为10和15 d时,活性污泥-秸秆共基质厌氧消化CODCr去除率分别为25.0%和28.0%,优于单基质的10.2%和13.1%;共基质平均ρ(NH_4^+-N)分别为278.5和254.9 mg/L,单基质平均ρ(NH_4^+-N)分别为215.6和213.5 mg/L;活性污泥-秸秆共基质平均ρ(TP)分别为168.6和175.9 mg/L,高于活性污泥单基质的129.2和152.2 mg/L.共基质有利于厌氧消化液中有机物的提高,从而增加ρ(VFA)、提高甲烷产量.研究显示,共基质可优化厌氧消化底物的C/N,促进厌氧消化反应,提高产气量.

In order to investigate the characteristics of anaerobic digestion of activated sludge and co-substrates with waste straw,anaerobic digestion with activated sludge and co-substrates with waste straw was conducted under mesophilic condition（35 ± 1） ℃ with solid retention time（SRT） of 10 and 15 d.The variation characteristics of biogas production and composition,ρ（NH4＋-N）,ρ（TP）,ρ（CODCr） and ρ（VFA） were investigated with the C/N（mass ratio） of mono-substrate of sewage sludge and co-substrates set at 5.5∶ 1and 10∶ 1,respectively.When SRT were 10 and 15 d,the cumulative biogas productions from co-substrates were 5818.0 and 9026.0m L,respectively,15.3% and 14.0% higher than those of the mono-substrate（i.e.4930.0 and 7760.0 m L）,respectively.The maximal φ（CH4） from co-substrates was 69.3%,15.4% higher than that of single substrate（maximum 58.61%）.The removal rates of CODCrwere 25.0% and 28.0% of co-substrates during two SRT,better than those of mono-substrate（which only had 10.2% and 13.1%）.The average ρ（NH4＋-N） and ρ（TP） of co-substrates were 278.5,254.9 mg/L and 168.6,175.9 mg/L,which were higher than215.6,213.5 mg/L and 129.2,152.2 mg/L of mono-substrate.Co-substrates can optimize C/N of substrates and promote the performance of anaerobic digestion and biogas production.