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Cofermenting Algal Biomass with Municipal Primary Solids to Enhance Carboxylate Production
Author(s) -
Romenesko Taylor,
Coats Erik R.
Publication year - 2018
Publication title -
water environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 73
eISSN - 1554-7531
pISSN - 1061-4303
DOI - 10.2175/106143017x15131012188105
Subject(s) - biomass (ecology) , environmental science , carboxylate , primary (astronomy) , production (economics) , waste management , environmental engineering , chemistry , pulp and paper industry , engineering , ecology , biology , economics , physics , macroeconomics , astronomy , stereochemistry
As water resource recovery facilities (WRRFs) implement biological nutrient removal (BNR) processes to remove excess wastewater nutrients, carboxylic acid demands increase; resource recovery processes (e.g., struvite, polyhydroxyalkanoate production) also demand carboxylates. In this regard, interest in algae to achieve tertiary treatment creates a new intraWRRF fermentation substrate. Indeed, fermentation potential tests indicated that algal augmentation could prove beneficial; carboxylate concentrations increased 31 % over primary solids. However, unexpectedly, and disproving a key research hypothesis, algal augmentation in a fed‐batch fermenter decreased the production of carboxylic acids (26–34% at SRTs of 5–7 d); preliminary analyses suggest heterotrophic algae consumed carboxylates. Disproving a second research hypothesis, algal biomass did not significantly diversify carboxylate speciation. Finally, and unexpectedly, algal fermentation realized significant ammonia removal (39–96 % at SRTs of 5–7 d). Although decreased carboxylate yield is not desired, reduced ammonia load could potentially decrease WRRF energy demands and decrease carboxylic acid demands to achieve denitrification.