Series of Combined Pretreatment Can Affect the Solubilization of Waste-Activated Sludge

Alsayed Mostafa, Min-Gyun Kim, Seongwon Im, Mo-Kwon Lee, Seoktae Kang and Dong-Hoon Kim
Additional contact information
Alsayed Mostafa: Department of Civil Engineering, Inha University, 100 Inharo, Nam-gu, Incheon 22212, Korea
Min-Gyun Kim: Department of Civil Engineering, Inha University, 100 Inharo, Nam-gu, Incheon 22212, Korea
Seongwon Im: Department of Civil Engineering, Inha University, 100 Inharo, Nam-gu, Incheon 22212, Korea
Mo-Kwon Lee: Department of Civil Engineering, Inha University, 100 Inharo, Nam-gu, Incheon 22212, Korea
Seoktae Kang: Department of Civil and Environmental Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea
Dong-Hoon Kim: Department of Civil Engineering, Inha University, 100 Inharo, Nam-gu, Incheon 22212, Korea

Energies, 2020, vol. 13, issue 16, 1-11

Abstract: Various pretreatment methods have been combined and employed for maximizing the solubilization of waste-activated sludge (WAS). However, the question “by changing the series of applied combined pretreatments (CPs), can the solubilization efficiency of WAS be affected?” has never been addressed. In this study, firstly, thermal (T), alkaline (A), and ultrasonic (U) pretreatments were individually applied at broad strengths (T = 80–120 °C for 30 min, A = pH 9–12, and U = 5–60 min at 300 W). Then, pretreatment conditions that caused similar solubilization (13.0%) (120 °C, pH 11, and 30 min for T, A, and U, respectively), were adopted for CP with reverse sequences of T&A, U&A, and T&U. A similar disintegration degree was observed in U→A and A→U, while a meaningful difference was found in T&A and T&U: T→A (28.3%), A→T (42.9%), T→U (22.9%), and U→T (27.1%). The difference in pretreatment series also affected the characteristics of soluble matters, which was analyzed by excitation emission matrix and molecular weight distribution. Due to these differences, the highest methane yield of 68.8% (based on (chemical oxygen demand) COD input ) was achieved at A→T, compared to T→A (62.3%). Our results suggested a simple strategy for increasing solubilization, at the same expense of energy, which might be beneficial in the following treatment process, such as dewatering and transportation.

Keywords: combined pretreatment; sequence; waste-activated sludge; solubilization; methane yield; anaerobic digestion (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2020
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (2)

Downloads: (external link)
https://www.mdpi.com/1996-1073/13/16/4165/pdf (application/pdf)
https://www.mdpi.com/1996-1073/13/16/4165/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:13:y:2020:i:16:p:4165-:d:397797

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().