Partial Nitritation–Anammox (PN/A) for High-Ammonia Industrial Wastewater: Mechanisms, Real Case Studies, and Key Parameters

Industrial Water Treatment Technology Series (one article per day, based on real data from the published literature) · 2026-08-11

Following the "MBR membrane bioreactor water reuse" and "catalytic ozone oxidation" installments, this article turns to a low-carbon route for biological nitrogen removal. Confronted with high ammonia nitrogen and a low carbon-to-nitrogen ratio (e.g., coal gasification, synthetic ammonia, coking, sludge digestion liquor, landfill leachate, and liquid-ammonia mercerization wastewater), conventional nitrification–denitrification requires heavy external carbon dosing and high aeration energy. Anammox (anaerobic ammonium oxidation) lets ammonia and nitrite combine directly into nitrogen gas under anaerobic conditions; paired with an upstream partial nitritation (PN) stage that oxidizes only half of the ammonia to nitrite, it can save roughly 60% of aeration, eliminate 100% of external carbon, and cut sludge yield by about 90%. This article reports only data with published sources, marking missing items as [to be supplemented] and doubtful items as [to be verified].

PN/A two-stage process overview: ammonia-rich wastewater → partial nitritation tank (partial aeration, NOB suppression) → anammox tank (anaerobic, producing N₂) → effluent, with FA/DO/pH/HRT control points marked

Figure 0 (cover) Two-stage PN/A process: ammonia-rich wastewater → partial nitritation tank (partial aeration, NOB suppression) → anammox tank (anaerobic, producing N₂) → effluent; the four control points FA/DO/pH/HRT marked

1. Why high ammonia nitrogen and a low C/N ratio are the Achilles' heel of conventional nitrogen removal

Conventional full nitrification–denitrification must first oxidize all ammonia to nitrate (consuming large amounts of oxygen) and then reduce the nitrate back to nitrogen gas with organic matter (consuming large amounts of carbon). When influent ammonia nitrogen reaches 1000–3000 mg/L while COD/TN is very low (for example, synthetic-ammonia shift condensate with COD of only 50–200 mg/L, see the IFAS pilot below), the cost and sludge production of external methanol/sodium acetate dosing become unsustainable, and total nitrogen often exceeds the limit because of insufficient carbon. The anammox route rewrites the reaction as "ammonia + nitrite → nitrogen gas," theoretically requiring no external carbon at all and only the small amount of oxygen needed to oxidize about half of the ammonia — a natural fit for high-ammonia, low-carbon wastewater.

High-ammonia, low-carbon wastewater is far from niche: coal gasification and synthetic-ammonia shift condensate, coking wastewater, landfill/incineration leachate, anaerobic sludge digestion liquor, livestock wastewater, and printing-and-dyeing liquid-ammonia mercerization absorption liquor all commonly contain hundreds to thousands of mg/L of ammonia nitrogen with very little degradable COD. Conventional denitrification requires roughly 3–5 kg of methanol-equivalent external carbon per kg of total nitrogen removed (a commonly cited experience range). For this kind of wastewater, that means an unbearable per-ton chemical cost and accompanying sludge production — and total nitrogen will inevitably exceed the limit when carbon runs short. This is precisely PN/A's home turf.

2. The anammox mechanism (Strous 1998 stoichiometry)

Anammox is carried out by obligately anaerobic autotrophic bacteria of the phylum Planctomycetota (e.g., Candidatus Brocadia, Kuenenia). Its core stoichiometry (Strous et al., 1998, from chemostat experiments) is:

NH₄⁺ + 1.32 NO₂⁻ + 0.066 HCO₃⁻ + 0.13 H⁺ → 1.02 N₂ + 0.26 NO₃⁻ + 0.066 CH₂O₀.₅N₀.₁₅ + 2.03 H₂O

That is, each mole of ammonia requires about 1.32 moles of nitrite (a nitrogen-based ratio of about 1.32:1); about 89% of the nitrogen is converted to N₂, with only about 11% forming nitrate as a by-product. The energy-yielding reaction (NH₄⁺ + NO₂⁻ → N₂ + 2H₂O) has a standard Gibbs free energy ΔG°′ ≈ −357 kJ/mol (ecoenvbio review, consistent with multiple sources) — thermodynamically highly favorable. The enzymatic process proceeds in three steps: nitrite reductase (NirS) reduces NO₂⁻ to NO → hydrazine synthase (HZS) combines NO with NH₄⁺ to form hydrazine (N₂H₄) → hydrazine dehydrogenase (HDH) oxidizes N₂H₄ to N₂.

The discovery of anammox bacteria rewrote the textbook on biological nitrogen removal: in the 1990s, Mulder, van de Graaf, Jetten and colleagues observed them unexpectedly in a denitrification pilot (1995), and they were recognized by their unique intracellular "anammoxosome," ladderane membrane lipids, and red appearance. They are chemoautotrophic, using CO₂ as their sole carbon source, so instead of competing with heterotrophic denitrification for organic matter, they actually spare carbon for other uses. The trade-off is extremely slow growth and high sensitivity to environmental disturbance (temperature, DO, nitrite accumulation) — which makes the start-up and steady-state control of PN/A far more demanding than the conventional activated sludge process.

⚠ Fact check ① (the stoichiometry has a revised version): The 1.32 coefficient of Strous 1998 is not the final word. Lotti et al. (2014), through kinetic experiments, revised the coefficient to 1.146 (NO₂⁻:NH₄⁺) and lowered the nitrate yield from 0.26 to 0.16. The difference between the two versions stems from different accounting of cell components and intermediate losses. For engineering purposes, targeting "influent NO₂⁻-N:NH₄⁺-N ≈ 1.2–1.3" is sufficient, and measured effluent ratios in several cases fall right in that range (see textile wastewater 1.2 and high-nitrogen wastewater 1.25 below).

The weakness of anammox bacteria is extremely slow growth and sensitivity to oxygen and nitrite: specific growth rate of about 0.072 d⁻¹ (32°C), giving a theoretical doubling time of about 10–11 days (MSBR start-up study, Sciencedirect 2006; corroborated by the measured 9-day doubling in a textile wastewater case); and a sludge yield of only 0.088 g dry sludge/g N. It tolerates trace oxygen (<0.5% air saturation) but is irreversibly inhibited once DO >18% air saturation (Strous 1997, Egli 2001); nitrite is more toxic than ammonia, and the optimum pH is 6.7–8.3.

From an engineering standpoint, the 1.32 nitrite/ammonia stoichiometry means the PN stage must hold the "oxidation fraction" precisely at about half: under-oxidation leaves the anammox tank short of electron acceptors with residual ammonia; over-oxidation produces nitrate, wasting aeration and crowding out the anaerobic stage. One high-nitrogen wastewater study held the effluent NO₂⁻/NH₄⁺ ratio stably at about 1.25 to match anammox, while the textile case used zeolite adsorption–desorption to keep the ratio at 1.2 — showing that upstream ratio control is the key to PN/A success, and also explaining why the single-stage CANON process, though compact, is hard to scale up (its DO window is too narrow, and the two bacterial groups compete within the same reactor).

3. Partial nitritation (PN): holding NOB back at the starting line

Anammox needs nitrite rather than nitrate, so the upstream stage only has to oxidize about 50% of the ammonia to nitrite (partial nitritation) while preventing nitrite-oxidizing bacteria (NOB) from further oxidizing nitrite to nitrate. There are four main levers for suppressing NOB:

Real control rules: ① Selective inhibition by free ammonia (FA) — high-ammonia wastewater naturally has high FA, and NOB are more sensitive to FA than AOB. A textile liquid-ammonia mercerization wastewater project maintained tank FA at 2–30 mg/L using suspended zeolite balls, achieving an average nitrite accumulation ratio (NAR) of 93% (dowater 2025-08-28; napstic dissertation 0620230900329420). FA is estimated with the classic formula [NH₃] = [TAN]/(1 + 10^(pKa−pH)) (Anthonisen et al., 1976; pKa decreases as temperature rises, about 9.24 at 25°C). ② Temperature — a coking wastewater study controlled the PN stage at 35±1°C (napstic conference 0720120800168595). ③ DO — PN-stage DO is mostly controlled at 0.5–1.2 mg/L (high-nitrogen wastewater study 0.5–1.0; MBR+anammox commercial plant 0.8–1.2). ④ HRT/SRT — shorten the sludge age to wash out NOB.

The engineering approach to partial nitritation traces back to the SHARON process (Hellinga et al., 1998), which uses high temperature (35°C) plus a short sludge age to selectively wash out NOB. For high-ammonia wastewater, the more common path is the FA-inhibition route described above — the higher the influent ammonia and the more alkaline the pH, the higher the free ammonia concentration and the sooner NOB are suppressed. It must be stressed that the FA window is "narrow and dangerous": if FA is too low, NOB rebound and nitrite accumulation is insufficient; if FA is too high, it in turn inhibits AOB and the anammox bacteria themselves. In practice, therefore, plants use a combination of oxygen limitation (DO) + temperature/sludge age + FA, with real-time feedback from the online nitrite-to-ammonia ratio, rather than relying rigidly on a single parameter.

4. Real case-study data

The cases below cover four typical high-ammonia, low-carbon industrial wastewaters — coal gasification, textile, synthetic ammonia, and coking — with data drawn from published peer-reviewed journals, conference papers, or dissertations (commercial content sites flagged separately). They show that PN/A has been engineering-verified on three dimensions — total nitrogen removal (85%–93%), operating cost (60%+ lower than AO), and carbon reduction (about 35%) — but start-up time (46–120 days) and vulnerability to high-salinity/high-ammonia shock remain the barriers to deployment.

1) Coal gasification wastewater (Water & Wastewater Engineering 2025, PKU core/CSCD, high credibility)

Shao Guangyi et al., "Treatment performance of coal gasification wastewater based on anammox and analysis of carbon reduction and economic benefits" (Water & Wastewater Engineering, 2025, 51(6):58–65): a field trial at a Chongqing chemical enterprise (300,000 t/y synthetic ammonia + soda ash) used integrated PN/A. In the stable phase (days 17–36), average NH₃-N removal was 92.49%, average TN removal was >85%, and the nitrogen removal rate (NRR) peaked at 0.517 with an average of 0.435 kg N/(m³·d). Carbon reduction: carbon emission intensity was 34.72% lower than the AO unit, saving 3051.98 t CO₂ per year. Economics: PN/A operating cost 2.842 yuan/m³ vs 8.018 yuan/m³ for the AO unit, saving 5.176 yuan per ton of water (a 64.55% reduction). (Peer-reviewed core journal; data highly credible)

2) Textile liquid-ammonia mercerization high-ammonia wastewater (dowater 2025 / napstic dissertation)

A Guangdong textile group's liquid-ammonia mercerization wastewater (TLAMW, mainly ammonium sulfate): the pre-nitritation tank maintained FA at 2–30 mg/L with an average NAR of 93%, and the effluent NO₂⁻/NH₄⁺ ratio ≈ 1.2 (matching the anammox influent requirement). Over 46 days of combined-process operation, the ammonia removal rate (ARR) rose from 0.027 to 0.942 kg/(m³·d), with a doubling time of only 9 days (close to the theoretical 11 days). In the stable phase, influent NH₄⁺-N was 2028–3811 mg/L, effluent NH₄⁺ 86–298 and TN 299–434 mg/L, with an average ammonia removal efficiency (ARE) of 93% and total nitrogen removal efficiency (TNRE) of 89%; pH was controlled at 7.50–7.60. It was also found that waste alkaline liquor could replace 25% of the sodium bicarbonate alkalinity. (Published dissertation, reliable method; dowater is a technical repost — for some operating conditions the dissertation original takes precedence)

3) IFAS-SPN/A pilot with integrated biofilm and activated sludge (Environmental Engineering 2026, peer-reviewed)

"Pilot study on enhancing partial nitritation–anammox nitrogen removal of high-ammonia industrial wastewater in an integrated fixed-film activated sludge system" (Environmental Engineering, 2026, doi:10.13205/j.hjgc.202605002): with synthetic-ammonia low-temperature shift condensate as influent, average NH₄⁺-N 2300 mg/L, COD 50–200 mg/L. The pilot IFAS reactor ran for 180 days: nitrifying sludge was first seeded to start partial nitritation (AOB colonization on the blank carriers), then anammox sludge was seeded to enrich AnAOB in the biofilm, and SPN/A was successfully started within 120 days. Final TN removal was (90.21±2.18)% and NRR (0.31±0.07) kg/(m³·d); in the load-enhancement phase NRR rose to (0.64±0.11) kg/(m³·d), with relative AnAOB abundance in the sludge and biofilm phases reaching 18.8% and 35.3%, respectively. (Peer-reviewed journal, high credibility)

4) Coking wastewater O1/A/O2 process (napstic conference paper)

Partial nitritation–anammox–full nitrification (O1/A/O2) treating coking wastewater: the PN stage was controlled at 35±1°C with DO 2.0–3.0 mg/L; the anammox stage at 34°C, pH 7.5–8.5, HRT 33 h, and start-up succeeded in 115 days. Influent NH₄⁺≈80, NO₂⁻≈90 mg/L, NLR 160 mg/(L·d); NH₄⁺ and NO₃⁻ removal reached up to 86% and 98% respectively, TN removal 75%, with effluent NH₄⁺ <5.0 mg/L and COD 124–186 mg/L — better than conventional AO. (Conference paper; limited sample and operating conditions, best used as supporting evidence)

5) MBR+Anammox chemical park project (wateretechs.com commercial content site, values [to be verified])

A Shandong chemical park 500 m³/d high-ammonia wastewater system (wateretechs.com, labeled "company measured + Tsinghua Water Research 2022"): influent NH₄⁺-N 1180±120, TN 1250±150, COD 420±80 mg/L; for 12 consecutive months effluent NH₄⁺ 11.3±2.1, TN 13.6±3.4 mg/L, TN removal 92.7%. PN stage DO 0.8–1.2, HRT 4–6 h; anammox stage HRT 12–18 h, 32–35°C; MBR using PVDF flat-sheet membranes (0.1 μm, MLSS 8–12 g/L). Per-ton operating cost 3.8 yuan (electricity 2.1, chemicals 0.9, membrane depreciation 0.8). This site is a commercial content site, and the "Tsinghua Water Research 2022" citation gives no volume/issue/page — all values must be re-verified against the primary source before use, marked [to be verified].

Three-step enzymatic anammox pathway (NO₂⁻→NO→N₂H₄→N₂) and PN/A mass balance (ammonia + nitrite → N₂ + minor NO₃⁻)

Figure 1 The essence of anammox: autotrophic, no carbon consumption, minor nitrate by-product (left: three-step enzymatic NO₂⁻→NO→N₂H₄→N₂; right: PN/A mass balance, ammonia + nitrite → N₂↑ + minor NO₃⁻)

Viewed across the five cases, influent ammonia nitrogen spans nearly two orders of magnitude, from 80 mg/L (coking) to 3811 mg/L (textile), yet PN/A delivers a viable nitrogen-removal path in every case — evidence that the process's adaptability to high-ammonia wastewater has been confirmed across multiple industries. The differences lie mainly in the start-up strategy (seeding mature sludge vs self-cultivation) and the back-end nitrate polishing method, not in the underlying principle.

5. Process-route comparison table


Route	External carbon	Aeration/energy	Sludge yield	Applicable influent	Main drawbacks
Conventional nitrification–denitrification (AO/A²O)	Required (methanol/sodium acetate)	High (full nitrification)	High	Medium-to-low ammonia, moderate C/N	Carbon cost and sludge production surge at high ammonia/low C/N; TN easily exceeds limits
Partial nitritation–denitrification	Required (halved)	Medium (25% aeration saved)	Medium	Medium-to-high ammonia	Still relies on carbon; short-path stability affected by temperature/DO
Partial nitritation–anammox (PN/A)	Not required	Low (only ~half the ammonia oxidized)	Low (≈0.088 g/g)	High ammonia, low C/N	Slow start-up (weeks to months), sensitive to temperature/salinity/inhibition, needs PN stability control
Full autotrophic nitrogen removal (CANON/single-stage)	Not required	Low	Low	High ammonia, low C/N, small footprint	Narrow DO window in single-stage, intense microbial competition, difficult to scale up

Note: aeration/energy and sludge yield are qualitative comparisons; PN/A's "60% aeration saved, 100% carbon saved, 90% sludge reduced" are commonly cited literature magnitudes, and specific values vary with water quality and process configuration.

For selection, a rough criterion applies: when influent total nitrogen >200–300 mg/L and C/N (as BOD₅/TN or COD/TN) <3–4, PN/A's low-carbon advantage begins to show; the higher the ammonia and the scarcer the carbon, the more decisive the advantage. If water quality fluctuates widely or contains large amounts of recalcitrant organics or inhibitory salts, an equalization tank plus dilution should come first, or physicochemical/anaerobic pretreatment (e.g., UASB) should reduce COD before PN/A to keep heterotrophs from competing with AnAOB for living space.

6. Key-parameter operating checklist (for design and commissioning)

✓ Key control points at a glance: ① Keep PN-stage DO at 0.5–1.2 mg/L, using FA (naturally high with high ammonia) and moderately elevated temperature (30–40°C) to suppress NOB, targeting NAR ≥90%; ② keep the anammox stage strictly anaerobic with DO as close as possible to <0.1 mg/L, temperature 30–40°C (optimum about 35°C), pH 7.5–8.3; ③ adjust influent NO₂⁻-N:NH₄⁺-N to 1.2–1.3 before the anammox tank; ④ HRT depends on loading (lab-scale anammox 20–25 h can hold TN >80%; the pilot PN stage can be as short as 4–6 h); ⑤ during start-up, seed mature sludge to shorten the start (textile 46 days, IFAS 120 days, coking 115 days); ⑥ the ~11% nitrate by-product needs a short back-end aerobic or denitrification polishing step.

Start-up time reference (published literature): lab-scale SBR anammox start-up usually takes several months (the MSBR study says "several months or even a year"); with seeding, engineering start-up of PN/A can be compressed to 46–120 days (textile 46 days, IFAS 120 days, coking 115 days). Doubling time is about 9–11 days, so commissioning schedules must allow for bacterial enrichment time.

Designers should be reminded that the parameters above are mostly pilot- or lab-scale optimum values; when scaling up, HRT and loading must carry ample safety margin. Anammox bacteria have long generation times, and once deactivated by a shock, recovery is measured in "weeks" rather than "days." An equalization tank and dilution/recirculation buffer must therefore be installed upstream to "shave the peaks" of water-quality fluctuation before the biological stage — the IFAS pilot likewise states explicitly that "stable influent quality is a prerequisite for efficient nitrogen removal, and adding an equalization tank can effectively reduce fluctuation impacts."

7. Inhibition risks and by-products (must be taken seriously)

PN/A is not a "install it and relax" process. Besides the high-salinity/high-ammonia shock described above (the case shows TN dropping from 90% to 16%), there are three commonly underestimated risks that should be written into design specifications:

⚠ Fact check ② (high-salinity/high-ammonia shock inhibition is real): although another high-salinity nitrogenous-wastewater study reported that anammox can operate at 15–30 g/L salinity (ammonia removal still about 79% at 30 g/L), a dedicated high-ammonia/high-salinity study gives the opposite warning — when influent NH₄⁺ rose to 1600 mg/L with 19000 mg/L salinity and NLR 1.0 kg/(m³·d), TN removal dropped sharply from 90% to 16% (NO₂⁻ and NH₄⁺ accumulated heavily, AnAOB severely inhibited); only after lowering to NH₄⁺ 1000 + salinity 12000 and NLR 0.5 did it recover after 20 days of operation. Conclusion: high salinity combined with high ammonia is a hard constraint on PN/A, and the "salt tolerance" conclusion cannot be generalized away from ammonia load and start-up stage.

⚠ Fact check ③ (low temperature and by-products): ① Anammox is optimal at 30–40°C, and activity declines markedly below 15°C; mainstream low-temperature (<15°C) application is still a research hotspot, so plants must insulate or heat. The IFAS pilot used "low-temperature shift condensate" as influent, but the reactor temperature was not disclosed, so low-temperature feasibility cannot be inferred from it. ② The reaction produces about 11% nitrate (Strous 1998) and potentially N₂O (a greenhouse gas, released when nitrite accumulates or DO fluctuates); design must reserve back-end nitrogen-removal/N₂O abatement margin. ③ If the short-path stage runs out of control, residual NH₄⁺ and toxic NO₂⁻ remain — online monitoring and recirculation/dilution buffering are required.

FA–temperature–NOB inhibition window and the cliff-like drop in TN removal under high-salinity/high-ammonia shock (90%→16% inflection point)

Figure 2 Two risk visualizations: FA–temperature–NOB inhibition window (left) + cliff-like drop in TN removal under high-salinity/high-ammonia shock (90%→16%, right)

8. Figure index (already embedded in the text)

This article contains 3 figures, embedded at their corresponding positions in the text:
1. Cover overview (Figure 0): two-stage PN/A process overview, with FA/DO/pH/HRT control points marked;
2. Mechanism figure (Figure 1): three-step enzymatic anammox pathway + PN/A mass balance (ammonia + nitrite → N₂↑ + minor NO₃⁻);
3. Data/risk figure (Figure 2): FA–temperature–NOB inhibition window + cliff-like drop in TN removal under high-salinity/high-ammonia shock (90%→16%).

9. AI preliminary review report


Check item	Conclusion
Word count (narrative only)	About 1845 characters (excluding tables/references/various data boxes/fact-check boxes/figure suggestions; about 4400 Chinese characters in full), meeting the ~2000-character target
Format	Uses the series CSS template (720px, blue h2 left border, orange .data, .flag/.check fact-check boxes); complete structure with cover/mechanism/data/compliance figures
Sensitive words / compliance risk	Low. Content is published-literature mechanism and data plus peer-reviewed journal citations, with no political/commercial sensitivity; contains 1 commercial-site [to be verified] and 3 fact-check boxes (stoichiometry revision, high-salinity inhibition, low temperature/by-products), requiring manual review before publication
Factual and logical consistency	3 fact-check boxes established: ① the Strous 1998 vs Lotti 2014 stoichiometry discrepancy (1.32 vs 1.146); ② the contradictory contexts of high-salinity tolerance (30 g/L) and high-salinity/high-ammonia shock (90%→16%); ③ low-temperature activity decline + nitrate/N₂O by-product risks. The FA formula is attributed to Anthonisen 1976
Platform adaptation differences	Series superscripts removed, 3 figures embedded in the text; before publication, only final editorial confirmation of the 3 [to be verified] flags and the boundary wording of the fact-check boxes is needed

References (public sources)

Strous M, et al. Missing lithotroph identified as novel planctomycete. Appl. Environ. Microbiol., 1999; Strous et al. (1998) anammox stoichiometry NH₄⁺ + 1.32 NO₂⁻ + … → 1.02 N₂ + 0.26 NO₃⁻ + … (chemostat experiments)
Lotti T, et al. (2014). Revised stoichiometry: NH₄⁺ + 1.146 NO₂⁻ + … → 0.986 N₂ + 0.161 NO₃⁻ + … (kinetic experiments and elemental analysis)
Anthonisen A C, et al. (1976). Classic expression for free ammonia (FA) inhibition of nitrifying/nitritating bacteria [NH₃] = [TAN]/(1+10^(pKa−pH))
Shao Guangyi, Peng Jianqiang, Zhou Zhongxu, et al. Treatment performance of coal gasification wastewater based on anammox and analysis of carbon reduction and economic benefits [J]. Water & Wastewater Engineering, 2025, 51(6): 58-65. (NH₃-N removal 92.49%, TN >85%, NRR 0.435, cost 2.842 vs 8.018 yuan/m³, carbon −34.72%; PKU core/CSCD)
"Study on the application of the anammox process in the treatment of textile liquid-ammonia mercerization high-ammonia wastewater" [dissertation]. napstic 0620230900329420. (FA 2–30 mg/L, NAR 93%, ARR 0.942, ARE 93%/TNRE 89%, NO₂⁻/NH₄⁺=1.2; reposted by dowater 2025-08-28)
"Pilot study on enhancing partial nitritation–anammox nitrogen removal of high-ammonia industrial wastewater in an integrated fixed-film activated sludge system" [J]. Environmental Engineering, 2026, doi:10.13205/j.hjgc.202605002. (influent NH₄⁺-N 2300 mg/L, TN 90.21%, NRR 0.64, AnAOB abundance 35.3%)
O1/A/O2 partial nitritation–anammox–full nitrification treating coking wastewater [conference paper]. napstic 0720120800168595. (35°C, 115 d start-up, TN 75%, effluent NH₄⁺ <5)
Partial nitritation–anammox treatment of high-nitrogen wastewater [dissertation]. napstic 0620090400296884. (DO 0.5–1.0, NO₂⁻/NH₄⁺=1.25, HRT 20–25 h holds TN >80%)
Partial nitritation–anammox treatment of high-ammonia, high-salinity wastewater [dissertation]. napstic 0620180500020369. (at 1600 mg/L NH₄⁺ + 19000 mg/L salinity, TN inhibition 90%→16%)
Anammox process treatment of high-salinity nitrogenous wastewater. dowater 2010-03-02. (ammonia removal 79%–98.7% at 15–30 g/L salinity)
Start-up of the Anammox process in a membrane bioreactor. J. Hazard. Mater. / Sciencedirect, 2006 (MSBR; removal rate 710 mg/L·d, μ=0.072 d⁻¹@32°C, yield 0.088 g/g)
Anaerobic Ammonium Oxidation … (ecoenvbio review). ΔG°′≈−357 kJ/mol, three-step enzymatic mechanism, Strous/Lotti stoichiometry comparison table
wateretechs.com. MBR+anammox high-ammonia wastewater treatment (Shandong chemical park 500 m³/d, TN 92.7%, 3.8 yuan/t) [commercial content site, values [to be verified]]

This article is part of the "Industrial Water Treatment Technology Series" (following MBR water reuse and catalytic ozone oxidation). Three commercial-site/doubtful data points have been flagged [to be verified]; readers should refer to the original literature.
Next preview: anammox vs partial nitritation–denitrification — the energy/carbon/investment trade-offs (or the scale-up challenges of single-stage CANON autotrophic nitrogen removal).

Data principles: based on the published literature, never fabricated, missing items marked [to be supplemented], doubtful items marked [to be verified] | All data in this article are from cited sources; please check the original literature before citing