Development and optimisation of VFA driven DEAMOX process for treatment of strong nitrogenous anaerobic effluents

Abstract

The recently proposed DEAMOX (DEnitrifying AMmonium OXidation) process combines the anammox reaction with autotrophic denitrifying conditions using sulphide as an electron donor for the production of nitrite from nitrate within an anaerobic biofilm. This paper firstly presents a feasibility study of the DEAMOX process using synthetic (ammonia + nitrate) wastewater where sulphide is replaced by volatile fatty acids (VFA) as a more widespread electron donor for partial denitrification. Under the influent N-NH+4/N-NO3(-) and COD/N-NO3(-) ratios of 1 and 2.3, respectively, the typical efficiencies of ammonia removal were around 40% (no matter whether a VFA mixture or only acetate were used) for nitrogen loading rates (NLR) up to 1236 mg N/l/d. This parameter increased to 80% by increasing the influent COD/N-NO3(-) ratio to 3.48 and decreasing the influent N-NH4 +/N-NO3(-) ratio to 0.29. As a result, the total nitrogen removal increased to 95%. The proposed process was further tested with typical strong nitrogenous effluent such as reject water (total N, 530-566 mg N/l; total COD, 1530-1780 mg/l) after thermophilic sludge anaerobic digestion. For this, the raw wastewater was split and partially ( approximately 50%) fed to a nitrifying reactor (to generate nitrate) and the remaining part ( approximately 50%) was directed to the DEAMOX reactor where this stream was mixed with the nitrified effluent. Stable process performance up to NLR of 1,243 mg N/l/d in the DEAMOX reactor was achieved resulting in 40, 100, and 66% removal of ammonia, NOx(-), and total nitrogen, respectively.

Primary sludge fermentate as carbon source for mainstream partial denitrification–anammox (PdNA)

“…Accumulation of nitrite via PdN has been previously reported in the literature (van Rijn et al, 1996; Wilderer et al, 1987). Several factors have been investigated in terms of their effect on PdN efficiency including carbon‐to‐nitrogen (C/N) ratio (Cao et al, 2013), carbon source (Du et al, 2017; Kalyuzhnyi et al, 2008), pH (Almeida et al, 1995; Thomsen et al, 1994), temperature (Du et al, 2017), and nitrate concentration (Du et al, 2017; Le et al, 2019b). Recently, residual nitrate concentration was found to be an essential factor for PdN selection in mixed cultures with acetate (Le et al, 2019a) or glycerol (Campolong et al, 2019) as carbon sources.…”

Nitrate residual as a key parameter to efficiently control partial denitrification coupling with anammox

“…In addition, such savings can be achieved without any need for NOB out‐selection, unlike mainstream deammonification. Initially, PdN‐AnAOB concept was proposed in sidestream treatment referred as DEnitrifying AMmonium OXidation (DEAMOX) which was designed to combine the AnAOB reaction with partial denitrification using sulfide (Kalyuzhnyi, Gladchenko, Mulder, & Versprille, ), acetate (Kalyuzhnyi, Gladchenko, Kang, Mulder, & Versprille, ), or glycerol (Sharp, Niemiec, Khunjar, Galst, & Deur, ) as an electron donor. Mainstream application of PdN‐AnAOB has been getting more attention recently (Cao, Peng, Du, & Wang, ; Du et al, ; Ma, Qian, Yuan, Yuan, & Peng, ; Niemiec, Sharp, & Duer, ).…”

Nitrate and nitrite inhibition of methanogenesis during denitrification in granular biofilms and digested domestic sludges

“…to NO 2 -. This is achieved by partial nitifrication (nitritation) with AOB followed by anammox (van Dongen et al 2001) or partial denitrification to nitrite followed by anammox (Kalyuzhnyi et al 2008;Sumino et al 2006).…”