JIANGLi-hua,ZHUOGui-hua,CHENXi-mei,et al.Effects of Chemical Agent Combined with High Temperature on Hydrolysis of Sludge with Low Organic Content[J].China Water & Wastewater,2022,38(19):86-92.
Effects of Chemical Agent Combined with High Temperature on Hydrolysis of Sludge with Low Organic Content
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第38卷
Number:
第19期
Page:
86-92
Column:
Date of publication:
2022-10-01
- Keywords:
- sludge with low organic content; thermophilic hydrolysis; combined pretreatment; anaerobic digestion; dissolution of organic matter
- Abstract:
- Anaerobic digestion is one of the main strategies to facilitate sludge stabilization and energy recovery. The biological nutrient removal process is widely applied in wastewater treatment plants in southern China, and the widespread low content of influent organic matter results in the low content of sludge organic matter (VS/TS < 0.6). In this paper, the typical sludge with low organic content in southern China was first pretreated with chemical agents including NaOH, Ca(OH)2 and CaCl2 combined with thermophilic hydrolysis at 120 ℃ for 0.5 h. Then, the sludge was used as the substrate for mesophilic anaerobic digestion. The addition of chemical agents combined with thermophilic hydrolysis promoted the release of soluble organic carbon (SOC), soluble sugar and soluble protein, and increased the cumulative methane production. In the process of thermophilic hydrolysis pretreatment, the efficiency of chemical agents for dissolution of organic matters in descending order was NaOH, Ca(OH)2 and CaCl2. In the subsequent anaerobic digestion process, since CaCl2 promoted the proportion of carbohydrates in SCOD, the degradation efficiencies of total chemical oxygen demand (TCOD) and total sugar were obviously improved after dosing CaCl2 combined with thermophilic hydrolysis. The degradation of TCOD was 25 326 mg/L, and the degradation of total sugar accounted for the highest proportion of the degraded TCOD (87.7%), so the cumulative methane production of CaCl2 among the three agents was the highest (183.1 mL/gVS). The addition of CaCl2 combined with thermophilic hydrolysis pretreatment was more effective to enhance the anaerobic biogas production performance of low organic sludge than NaOH and Ca(OH)2.
Last Update:
2022-10-01