关键词: Anaerobic digestion Excess sludge Gas production Hydrothermal pre-treatment Lysozyme

Mesh : Muramidase / metabolism Sewage / chemistry Anaerobiosis Waste Disposal, Fluid / methods Methane Hydrolysis

来  源:   DOI:10.1016/j.jes.2023.10.001

Abstract:
Anaerobic digestion (AD) is widely employed for sludge stabilization and waste reduction. However, the slow hydrolysis process hinders methane production and leads to prolonged sludge issues. In this study, an efficient and eco-friendly lysozyme pre-treatment method was utilized to address these challenges. By optimizing lysozyme dosage, hydrolysis and cell lysis were maximized. Furthermore, lysozyme combined with hydrothermal pretreatment enhanced overall efficiency. Results indicate that: (1) When lysozyme dosage reached 90 mg/g TS after 240 min of pretreatment, SCOD, soluble polysaccharides, and protein content reached their maxima at 855.00, 44.09, and 204.86 mg/L, respectively. This represented an increase of 85.87%, 365.58%, and 259.21% compared to the untreated sludge. Three-dimensional fluorescence spectroscopy revealed the highest fluorescence intensity in the IV region (soluble microbial product), promoting microbial metabolic activity. (2) Lysozyme combined with hydrothermal pretreatment significantly increased SCOD, soluble proteins, and polysaccharide release from sludge, reducing SCOD release time. Orthogonal experiments identified Group 3 as the most effective for SCOD and soluble polysaccharide release, while Group 9 released the most soluble proteins. The significance order of factors influencing SCOD, soluble proteins, and polysaccharide release is hydrothermal temperature > hydrothermal time > enzymatic digestion time.(3) The lysozyme-assisted hydrothermal pretreatment group exhibited the fastest release and the highest SCOD concentration of 8,135.00 mg/L during anaerobic digestion. Maximum SCOD consumption and cumulative gas production increased by 95.89% and 130.58%, respectively, compared to the control group, allowing gas production to conclude 3 days earlier.
摘要:
厌氧消化(AD)广泛用于污泥稳定和废物减少。然而,缓慢的水解过程阻碍了甲烷的产生,并导致长期的污泥问题。在这项研究中,一种高效和环保的溶菌酶预处理方法被用来解决这些挑战。通过优化溶菌酶用量,水解和细胞裂解最大化。此外,溶菌酶结合水热预处理提高了整体效率。结果表明:(1)当溶菌酶用量达到90mg/gTS时,预处理240min,SCOD,可溶性多糖,蛋白质含量在855.00、44.09和204.86mg/L达到最大值,分别。这代表了85.87%的增长,365.58%,与未处理污泥相比,为259.21%。三维荧光光谱显示,IV区(可溶性微生物产物)的荧光强度最高,促进微生物代谢活动。(2)溶菌酶结合水热预处理显著增加了SCOD,可溶性蛋白质,和从污泥中释放的多糖,减少SCOD释放时间。正交实验确定第3组对SCOD和可溶性多糖释放最有效,而第9组释放了最可溶性的蛋白质。影响SCOD的因素的重要性顺序,可溶性蛋白质,多糖释放量为水热温度>水热时间>酶解时间。(3)溶菌酶辅助水热预处理组在厌氧消化过程中释放最快,SCOD浓度最高,为8,135.00mg/L。最大SCOD消耗量和累计产气量分别增加95.89%和130.58%,分别,与对照组相比,允许天然气生产提前3天结束。
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