Low-temperature thermal pre-treatment of municipal wastewater sludge : Process optimization and effects on solubilization and anaerobic degradation

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Laleh Nazari
  • Zhongshun Yuan
  • Domenico Santoro
  • Siva Sarathy
  • Dang Ho
  • Damien Batstone
  • Madhumita B. Ray

Detail(s)

Original languageEnglish
Pages (from-to)111-123
Journal / PublicationWater Research
Volume113
Publication statusPublished - 2017
Externally publishedYes

Abstract

The present study examines the relationship between the degree of solubilization and biodegradability of wastewater sludge in anaerobic digestion as a result of low-temperature thermal pre-treatment. The main effect of thermal pre-treatment is the disintegration of cell membranes and thus solubilization of organic compounds. There is an established correlation between chemical oxygen demand (COD) solubilization and temperature of thermal pre-treatment, but results of thermal pre-treatment in terms of biodegradability are not well understood. Aiming to determine the impact of low temperature treatments on biogas production, the thermal pre-treatment process was first optimized based on an experimental design study on waste activated sludge in batch mode. The optimum temperature, reaction time and pH of the process were determined to be 80 °C, 5 h and pH 10, respectively. All three factors had a strong individual effect (p < 0.001), with a significant interaction effect for temp. pH2(p = 0.002). Thermal pre-treatments, carried out on seven different municipal wastewater sludges at the above optimum operating conditions, produced increased COD solubilization of 18.3 ± 7.5% and VSS reduction of 27.7 ± 12.3% compared to the untreated sludges. The solubilization of proteins was significantly higher than carbohydrates. Methane produced in biochemical methane potential (BMP) tests, indicated initial higher rates (p = 0.0013) for the thermally treated samples (khydup to 5 times higher), although the ultimate methane yields were not significantly affected by the treatment. © 2017 Elsevier Ltd

Research Area(s)

  • Degradability, Methane production rate, Process optimization, Solubilization, Thermal treatment, Waste activated sludge

Bibliographic Note

Publication details (e.g. title, author(s), publication statuses and dates) are captured on an “AS IS” and “AS AVAILABLE” basis at the time of record harvesting from the data source. Suggestions for further amendments or supplementary information can be sent to lbscholars@cityu.edu.hk.

Citation Format(s)

Low-temperature thermal pre-treatment of municipal wastewater sludge: Process optimization and effects on solubilization and anaerobic degradation. / Nazari, Laleh; Yuan, Zhongshun; Santoro, Domenico et al.
In: Water Research, Vol. 113, 2017, p. 111-123.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review