Evaluation of the production of alginate-like exopolysaccharides (ALE) and tryptophan in aerobic granular sludge systems
- PDF / 1,878,519 Bytes
- 12 Pages / 595.276 x 790.866 pts Page_size
- 116 Downloads / 159 Views
RESEARCH PAPER
Evaluation of the production of alginate‑like exopolysaccharides (ALE) and tryptophan in aerobic granular sludge systems Silvio Luiz de Sousa Rollemberg1 · Amanda Ferreira dos Santos1 · Tasso Jorge Tavares Ferreira1 · Paulo Igor Milen Firmino1 · André Bezerra dos Santos1 Received: 13 June 2020 / Accepted: 25 August 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract The engineering and microbiological aspects involved in the production of alginate-like exopolysaccharides (ALE) and tryptophan (TRY) in aerobic granular sludge systems were evaluated. The inclusion of short anoxic phase (A/O/A cycle–anaerobic, oxic, and anoxic phase) and the control of sludge retention time (SRT ≈ 10 days) proved to be an important strategy to increase the content of these bioproducts in granules. The substrate concentration also has a relevant impact on the production of ALE and TRY. The results of the microbiological analysis showed that slow-growing heterotrophic microbial groups (i.e., PAOs and GAOs) might be associated with the production of ALE, and the EPS-producing fermentative bacteria might be associated with the TRY production. The preliminary economic evaluation indicated the potential of ALE recovery in AGS systems in decreasing the OPEX (operational expenditure) of the treatment, especially for larger sewage treatment plants or industrial wastewaters with a high organic load. Keywords Aerobic granular sludge (AGS) · Resource recovery · Alginate-like exopolysaccharides (ALE) · Tryptophan (TRY)
Introduction The aerobic granular sludge (AGS) system is considered one of the most promising biological wastewater treatment technology of the twenty-first century [1] due to the high capacity of pollutants removal in a single reactor, good settling ability of the developed biomass, strong and compact microbial structure, resource recovery possibilities, etc. [2]. These systems have been implemented in new wastewater treatment plants (WWTPs) and even in constructed facilities (upgraded) by using the existing structures [3]. Compared to activated sludge, AGS presents a significant reduction in footprint (50–75%), power consumption (20–50%), and reduction in operating costs (20–25%). Concerning other Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00449-020-02439-w) contains supplementary material, which is available to authorized users. * André Bezerra dos Santos [email protected] 1
Department of Hydraulic and Environmental Engineering, Federal University of Ceará, Campus do Pici, Bloco 713. Pici., Fortaleza, CE 60455‑900, Brazil
compact treatment options, such as membrane bioreactor (MBR), the energy demand of AGS is about 35–70% lower [2]. However, a yield coefficient (Y) of 0.35 g VSS/g COD was found for aerobic granules [4], indicating an excess sludge production six times higher than the values found in anaerobic reactors [5]. Moreover, recent papers are reporting the low digestibility of discharged aerobic granular sludge, impairing t
Data Loading...
