CaO对高浓度污泥厌氧消化性能的影响机理及动力学分析

为解决高固体浓度污泥厌氧消化水解速率慢的问题，采用CaO对高固体浓度污泥进行碱解预处理。采用粒径分析及溶解性COD、蛋白质和多糖浓度监测考察碱解预处理前后污泥物理化学特性的变化，评估碱解预处理对高固体浓度污泥厌氧消化产甲烷潜力及有机物降解规律的影响，研究不同碱量下EPS、细胞壁和细胞膜破解程度对厌氧消化性能的影响机理，分析厌氧消化过程的动力学特性。结果显示:CaO碱解预处理高固体浓度污泥后，污泥粒径变化不明显，而溶解性COD、蛋白质和多糖的浓度均有增加；碱解预处理的破解程度随着碱投加量的增加而增加；碱解预处理后，高固体浓度厌氧消化的累积甲烷产率提升了22.9%~34.8%；分析机理低碱量预处理时只能释放EPS中的有机质，从而促进厌氧消化的累积甲烷产率，而高碱量预处理时，EPS内的有机质和胞内聚合物都得到释放，使累积甲烷产率增加。动力学研究结果表明:碱解预处理可以显著提高污泥甲烷产率，加快厌氧消化速率，并明显缩短延滞期。

INFLUENCE MECHANISM AND KINETIC STUDY OF CaO PRETREATMENT ON HIGH-SOLID SLUDGE ANAEROBIC DIGESTION PERFORMANCE

To resolve the problem of low hydrolysis rate of high-solid waste activated sludge during anaerobic digestion process, CaO was used to disintegrate high-solid sludge. Physical and chemical characters of sludge before and after alkaline pretreatment were evaluated in terms of particle size, and soluble COD, protein, carbohydrate. Effect of alkaline pretreatment on cumulative methane yield and organism decomposition during high-solid anaerobic digestion process were also studied. The influence mechanism of EPS, cell wall and cell membrane cracking degree on anaerobic digestion performance under different alkali levels were studied. The results indicated that after the CaO pretreatment, the particle size of sludge was hardly changed, and the concentrations of SCOD, soluble protein and carbohydrate showed an obvious increase trend. The disintegration degree increased with the dosage of CaO. After alkaline pretreatment, the cumulative methane yield increased by 22.9%~34.8%. The mechanism discussion results showed that only organic matters in EPS could be released during low-alkali pretreatment, which promoted the cumulative methane yield, while organic matters in EPS and intracellular polymers were both released during high-alkali pretreatment, which led to the increase of cumulative methane yield. Kinetics study results showed that alkaline pretreatment could not only enhance methane yield, but also accelerate the anaerobic digestion and shorten the inhibitory stage.