活性污泥及其与秸秆共基质的厌氧消化特性

摘要

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∶1 and 10∶ 1,respectively.When SRT were 10 and 15 d,the cumulative biogas productions from co-substrates were 5818.0 and 9026.0 mL,respectively,15.3％ and 14.0％ higher than those of the mono-substrate (i.e.4930.0 and 7760.0 mL),respectively.The maximal (ψ)(CH4) from co-substrates was 69.3％,15.4％ higher than that of single substrate (maximum 58.61％).The removal rates of CODC,were 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 than 215.6,213.5 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.%为分析秸秆对污泥厌氧消化特性的影响,在中温[(35土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15d,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(NH4+-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 mL,比活性污泥单基质的沼气产量(4 930.0、7 760.0 mL)分别提高了15.3％、14.0％;共基质所产沼气中((ψ)(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(NH4+-N)分别为278.5和254.9 mg/L,单基质平均ρ(NH4+-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.