Journal
CHEMOSPHERE
Volume 186, Issue -, Pages 864-872Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.chemosphere.2017.08.017
Keywords
Alkaline sludge fermentation; Alkali types; Short chain fatty acids (SCFAs); Sludge retention time (SRI); Microbial community structure
Categories
Funding
- National Key Science and Technology Special Projects of water pollution control and management [2015ZX07218001]
- Fundamental Research Funds for the Central Universities [310829151074]
Ask authors/readers for more resources
The effects of two alkali agents, NaOH and Ca(OH)(2), on enhancing waste activated sludge (WAS) fermentation and short chain fatty acids (SCFAs) accumulation were studied in semi-continuous stirred tank reactors (semi-CSTR) at different sludge retention time (SRT) (2-10 d). The optimum SRT for SCFAs accumulation of NaOH and Ca(OH)(2) adding system was 8 d and 10 d, respectively. Results showed that the average organics yields including soluble chemical oxygen demand (SCOD), protein, and carbohydrate in the NaOH system were as almost twice as that in the Ca(OH)(2) system. For Ca(OH)(2) system, sludge hydrolysis and protein acidification efficiencies were negatively affected by Ca2+ precipitation, which was revealed by the decrease of Ca2+ concentration, the rise of zeta potential and better sludge dewaterability in Ca(OH)(2) system. In addition, Firmicutes, Proteobacteria and Actinobacteria were the main microbial functional groups in both types of alkali systems. NaOH system obtained higher microbial quantities which led to better acidification. For application, however, Ca(OH)(2) was more economically feasible owning to its lower price and better dewaterability of residual sludge. (C) 2017 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available