The challenges of mainstream deammonification process for municipal used water treatment

Abstract

The deammonification process combining partial nitritation and anaerobic ammonium oxidation has been considered as a viable option for energy-efficient used water treatment. So far, many full-scale sidestream deammonification plants handling high-ammonia used water have been in successful operation since Anammox bacteria were first discovered in the 1990s. However, large-scale application of this process for treating municipal used water with low ammonia concentration has rarely been reported. Compared to the sidestream deammonification process, the mainstream deammonification process for municipal used water treatment faces three main challenges, i.e., (i) high COD/N ratio leading to denitrifiers outcompeting Anammox bacteria, (ii) numerous difficulties in selective retention of ammonia-oxidizing bacteria (AOB) over nitrite-oxidizing bacteria (NOB), and (iii) sufficient accumulation of Anammox bacteria. Therefore, this paper attempts to provide a detailed analysis of these challenges and possible solutions towards sustainable mainstream deammonification process.

Deterioration of the anammox process at decreasing temperatures and long SRTs

“…One of the biggest challenges for implementation of this technology in the waterline of a sewage treatment plant is the temperature of the wastewater; in moderate climates the wastewater temperature reaches 10°C during winter. Lab-and pilot-scale research on the mainstream application of anammox is currently pursued worldwide [9][10][11][12]. These studies usually focus on the full PN/A processes or actual wastewater, making it difficult to evaluate the exact contribution of the anammox conversion as well as the intrinsic impact of temperature on the anammox population.…”

One-stage deammonification start-up control using ion-selective electrodes (ISE) sensor

“…Collected samples were filtered with syringe filters, pore size 1.2Pm and after that ammonia, nitrite and nitrate nitrogen concentrations were measured using Hach photometric cuvette tests: LCK303 (2 -47 mg N-NH 4 + /dm 3 ), LCK342 (range 0.6 -6 mg N-NO 2 -/dm 3 ) and LCK340 (range 5 -35 mg N-NO 3 -/dm 3 ) and a DR3900 spectrophotometer. Total suspended solids (TSS) and volatile suspended solids (VSS) concentrations were determined using direct weight method according to Standard Methods guideline.…”

“…centrate water from sludge dewatering), named as side-stream treatment. Robust deammonification in cold streams with low ammonium concentration, such as municipal wastewater (mainstream treatment), is still subject of intense research and should be considered as an infancy stage so far [3][4][5][6]. Until 2014, there was over 100 full-scale side-stream installations, where 88% of them was in one-stage reactor configuration, which means that partial nitritation and Anammox (PN/Anammox) processes occur in a single reactor [7].…”

Status, Challenges, and Perspectives of Mainstream Nitritation–Anammox for Wastewater Treatment

“…To decrease COD/N ratio and save energy, A-B configuration has been proposed, in which A-stage serves as a pretreatment process for organic removal, via either anaerobic treatment or a COD-concentration step and is followed by a B-stage for nitrogen removal. The COD-concentration step can be achieved by physical (e.g., sieving), chemical (e.g., precipitation), or biological (e.g., high-rate activated sludge treatment, HRAS) (Lotti et al, 2015;Xu et al, 2015).…”

“…The interest in nitritation-anammox treatment has grown in the past two decades from start-of-art research to real-world applications, resulting in a large number of journal articles. There have been several excellent reviews of sidestream applications of nitritation-anammox processes Van Hulle et al, 2010;Vlaeminck et al, 2012), the incorporation of anammox into mainstream BNR (Delgado Vela et al, 2015), key factors affecting anammox growth and nitrite production under mainstream conditions (Ma et al, 2016), and technical challenges and bottlenecks of mainstream applications (Cao et al, 2017;Xu et al, 2015). However, very few have focused on the current research progress and application status, and control and operational issues of the mainstream nitritation-anammox process.…”