Overcoming ammonia inhibition in anaerobic blackwater treatment with granular activated carbon: the role of electroactive microorganisms

Abstract

Methanogenesis and enrichment of microorganisms capable of interspecies electron and/or hydrogen exchange was investigated with addition of granular activated carbon (GAC) to batch anaerobic digesters treating vacuum collected blackwater with high ammonia concentration.

A high‐rate anaerobic biofilm reactor for biomethane recovery from source‐separated blackwater at ambient temperature

“…Due to the hydrolysis and decomposition of proteins and other particulate organic content, ammonia could be released during the blackwater digestion (Florentino et al., 2019; Gao et al., 2018), leading to a higher TAN concentration in the treated effluent than that of influent (~1,000 mg/L). As shown in Figure 7, the average TAN concentration in stage 1 was about 1,300 mg/L, while in stage 2, it increased to around 1,500 mg/L.…”

“…Dang et al (2016) observed 13 times higher methane production rate at high OLR of 8.5 g COD/L-d in a carbon-cloth amended anaerobic bioreactor fed with dog food. However, to date, few studies have been conducted on supplementing conductive materials in biomethane recovery from blackwater (Florentino et al, 2019;Xu et al, 2019). Granular activated carbon (GAC) addition has been utilized in batch tests for concentrated blackwater digestion which demonstrated 19% increase in biochemical methane potential (BMP) (Florentino et al, 2019).…”

“…The highest organic loading rate (OLR) of 4.87 g COD/L‐d for blackwater mono‐digestion so far was achieved in a mesophilic UASB reactor (Gao, Zhang, Guo, Zhang, & Liu, 2019). However, due to low biodegradability of blackwater as well as the potential of free ammonia inhibition (Florentino, Sharaf, Zhang, & Liu, 2019; Gao, Zhang, Florentino, & Liu, 2018), only few studies could achieve OLRs higher than 1.0 g COD/L‐d (Abdel‐Shafy, El‐Khateeb, Regelsberger, El‐Sheikh, & Shehata, 2009; Moges et al., 2018; van Voorthuizen, Zwijnenburg, van der Meer, & Temmink, 2008), while mostly ranged from 0.3 to 1.0 g COD/L‐d (De Graaff et al., 2010; Gao, Guo, Zhang, Zhang, & Liu, 2019; Kujawa‐Roeleveld, Elmitwalli, & Zeeman, 2006; Luostarinen et al., 2007; Meulman, Zeeman, & Buisman, 2008; Tervahauta, Bryant, Leal, Buisman, & Zeeman, 2014; Wendland et al., 2007; Zamalloa et al., 2013). Blackwater is mostly discharged at ambient temperatures, while digestion efficiency could be further limited by low hydrolysis rate and low methanogenic activity without heating (Zhang, Hendrickx, Kampman, Temmink, & Zeeman, 2013).…”

“…However, to date, few studies have been conducted on supplementing conductive materials in biomethane recovery from blackwater (Florentino et al., 2019; Xu et al., 2019). Granular activated carbon (GAC) addition has been utilized in batch tests for concentrated blackwater digestion which demonstrated 19% increase in biochemical methane potential (BMP) (Florentino et al., 2019). The results also showed a microbial community shift toward syntrophic bacteria and methanogenic archaea, such as the enrichment of Geobacteraceae family and Methanosarcina , which likely participated in DIET (Florentino et al., 2019).…”

“…Granular activated carbon (GAC) addition has been utilized in batch tests for concentrated blackwater digestion which demonstrated 19% increase in biochemical methane potential (BMP) (Florentino et al., 2019). The results also showed a microbial community shift toward syntrophic bacteria and methanogenic archaea, such as the enrichment of Geobacteraceae family and Methanosarcina , which likely participated in DIET (Florentino et al., 2019). However, these studies were conducted in batch BMP test, which has left open a wide research gap in understanding the impacts of conductive material addition on the performance of different anaerobic reactors under continuous mode.…”