盐度对剩余污泥与浓缩渗滤液厌氧共消化的影响

Impact of Salinity on Anaerobic Co-digestion of Excess Sludge and Concentrated Leachate

通过连续流和序批式厌氧消化试验探究盐度对剩余污泥与浓缩渗滤液厌氧共消化性能的影响机理。连续流厌氧消化试验表明,当反应器中盐度从5 g/L提高至30 g/L时,COD去除率由94.3%降至66.2%,总挥发性脂肪酸(TVFAs)累积量(以COD计)由23.4 mg/L增长至2261 mg/L,CH_(4)产量降低了86.8%,污泥絮体结构逐渐被破坏,表面粗糙程度不断增大,反应器性能不断下降。序批式厌氧消化试验表明,在剩余污泥与浓缩渗滤液厌氧共消化过程中,适量的盐度促进了增溶阶段可溶性蛋白质和多糖的释放,强化了水解阶段大分子有机物向氨基酸与单糖的转化过程,TVFAs浓度升高,促进了酸化阶段,但抑制了产甲烷菌的活性,CH4产量急剧下降。

The impact of salinity on the anaerobic co-digestion of excess sludge and concentrated leachate was examined through continuous-flow and sequencing batch anaerobic digestion experiments.The continuous-flow anaerobic digestion test demonstrated that COD removal efficiency declined from 94.3%to 66.2%as the salinity in the reactor increased from 5 g/L to 30 g/L.Concurrently,the accumulation of total volatile fatty acids(TVFAs)expressed in COD rose significantly from 23.4 mg/L to 2261 mg/L,while methane production experienced a substantial decrease of 86.8%.Additionally,the floc structure of the sludge was progressively disrupted,leading to an increase in surface roughness and a corresponding decline in reactor performance.The sequencing batch anaerobic digestion test demonstrated that an appropriate salinity facilitated the release of soluble proteins and polysaccharides during the solubilization phase,enhanced the conversion of macromolecular organic compounds into amino acids and monosaccharides in the hydrolysis phase,increased TVFAs concentrations,promoted the acidification,while simultaneously inhibiting methanogenic activity in the anaerobic co-digestion process involving excess sludge and concentrated leachate.Consequently,methane production experienced a significant decline.