Effects of stepwise thermal hydrolysis and solid-liquid separation on three different sludge organic matter solubilization and biodegradability

Yang, Dongyuan; Dai, Xiaohu; Song, Liang; Dai, Lingling; Dong, Bin

doi:10.1016/j.biortech.2019.121753

Cited by 27 publications

(3 citation statements)

References 35 publications

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“…Most of the current studies preferred combining high temperature with short time for anaerobic digestion pretreatment. ,, For example, in the study by Yang et al, three dewatered sludges were pretreated at 160 °C for 90 min before anaerobic digestion. However, the methane production potential of the sludge pretreated for a prolonged contact time at a low temperature could be superior to that treated at a high temperature with a short contact time.…”

Section: Resultsmentioning

confidence: 99%

“…The profiles and the maximum methane production values could reach the same level as that of high-organic content sludges. 14,15,23,33 For instance, in the study by Toutian et al, 14 the biomethane potential of the thermally hydrolyzed waste active sludge (the VS of the sludge was 73.4% TS) at temperatures of 90−170 °C was around 170.26−301.73 mL/gVS. The results demonstrated that low-temperature thermal hydrolysis is an efficient pretreatment for the anaerobic digestion of sludge with a low organic content.…”

Section: Resultsmentioning

confidence: 99%

“…However, most of the previous studies preferred to increase the temperature of thermal hydrolysis pretreatment to achieve better efficiency, ,− which requires a high energy input and largely reduces the overall profit ability of the process . A recent study revealed that a high methane yield was obtained from the sludge treated hydrothermally at 150–190 °C, with the yield increasing by 18–31% compared with that of the control group.…”

Section: Introductionmentioning

confidence: 99%

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Enhanced Deep Utilization of Low-Organic Content Sludge by Processing Time-Extended Low-Temperature Thermal Pretreatment

Liu

Wang³

et al. 2021

ACS Omega

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Anaerobic digestion is an important way for maintaining sewage sludge stability, reduction, and resource recovery. However, the low organic content generally limits methane production. Recently, thermal hydrolysis has been widely used for sludge pretreatment to improve the anaerobic digestion efficiency. Generally, an increased temperature is preferred to enhance the solubility of organic matters in the sludge. However, high energy requirement comes with increased temperature. Application of low-temperature thermal treatment could overcome this drawback. However, the appropriate low-temperature pretreatment time is still uncertain. In this study, an extended contact time with low thermal pretreatment (90 °C) was chosen to realize a more efficient and economical digestion process of low-organic content sludge. The results demonstrated that the solubilization of proteins and carbohydrates was significantly promoted by the contact time-extended thermal hydrolysis pretreatment. The following anaerobic digestion efficiency of low-organic content sludge was also dramatically improved with the prolonged contact time. The maximum methane production could reach around 294.73 mL/gVS after 36 h of 90 °C treatment, which was 5.56 times that of the untreated groups. Additionally, based on the energy balance calculation, extending the thermal hydrolysis time resulted in a more economically feasible anaerobic digestion than increasing the temperature. The dewatering properties and the stability of the heavy metals were also reinforced, implying the advanced deep utilization of the digested low-organic content sludge. In conclusion, sludge pretreated by low-temperature thermal hydrolysis with a prolonged contact time could be more effective for low-organic content sludge treatment and disposal.

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