Removal Efficiencies Of NH4 Research Articles

Aerobic biodegradation of 2,6-dichlorophenol in a nitrifying granular sludge reactor: System performance and microbial community evolution

In the present study, the changes in nitrification performance, microbial products, and microbial community were evaluated in a nitrifying granular sludge (NGS) system for co-metabolic degradation of 2,6-dichlorophenol (2,6-DCP). After the 90-d acclimation period, the removal efficiencies of NH4+-N and 2,6-DCP reached 99.8 % and 99.9 %, respectively. The presence of 2,6-DCP caused the NGS to release more protein-like substances to protect the NGS from toxic environments. The activities of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria in the NGS were enhanced in the presence of 2,6-DCP, and the enhancement of AOB activity improved the co-metabolism ability of NGS. The increase in nitrification capacity might have been a positive effect of 2,6-DCP co-metabolic biodegradation. Moreover, Amaricoccus and Acidovorax were the main strains involved after long-term operation in the degradation of 2,6-DCP in the NGS sequencing batch reactor.

Systematic effects of Fe doping on the activity of V2O5/TiO2-carbon nanotube catalyst for NH3-SCR of NOx

The present investigation concentrates on the reduction of NOx emissions, the indirect greenhouse gases, which generate ozone by reacting with the atmosphere. A series of composite catalytic support (TiO2-CNTs) with a constant TiO2-CNT ratio prepared by precipitation method was utilized to synthesize Fe-modified V2O5/TiO2-CNT catalyst for selective catalytic reduction (SCR) of NOx with ammonia (NH3). The structural and surface characteristics of the prepared catalyst were investigated by using Brunauer–Emmett–Teller surface area measurement, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope, and temperature-programmed desorption (TPD) techniques. In terms of catalytic activity, VFe3TiC10 catalyst showed better SCR performance having a NOx conversion efficiency of 95% and 98% at 250 °C and 300 °C, respectively. The improved performance could be attributed to high surface chemisorbed oxygen on the surface of the catalyst by the added Fe species which promotes the SCR activity. The catalytic activity results depicted that the addition of CNTs to TiO2 support enhanced the SCR activity of the catalyst at low reaction temperatures and it also provides better resistance to SO2. In addition, the effects of Fe modification on the NH3 removal efficiency of the catalyst were also investigated.

Enhanced nutrient removal of simultaneous partial nitrification, denitrification and phosphorus removal (SPNDPR) in a single-stage anaerobic/micro-aerobic sequencing batch reactor for treating real sewage with low carbon/nitrogen

The feasibility of simultaneous partial nitrification, denitrification and phosphorus removal (SPNDPR) process was investigated in a single-stage anaerobic/micro-aerobic sequencing batch reactor for treating real sewage. Partial nitrification was maintained with average nitrite accumulation ratio of 90.3% during 266 days’ operation. Removal efficiencies for NH4+-N (96.3%), total inorganic nitrogen (81.4%), and phosphorus (91.0%) were stably obtained when treated real sewage with low carbon/nitrogen (3.4), with simultaneous partial nitrification and denitrification efficiency of 73.1%. The mechanism analysis revealed that denitrifying glycogen-accumulating organisms (DGAOs) and denitrifying polyphosphate-accumulating organisms (DPAOs) played the main roles in N-removal and P-removal, respectively. Nitrite pathway and optimized use of the organic carbon available in the sewage were keys for the successful performance. Further microbial community illustrating that DGAOs Candidatus_Competibacter, DPAOs Dechloromonas, and ammonia-oxidizing bacteria Nitrosomonadaceae were main functional groups. Notably, sludge granulation was formed under long-term synchronous low dissolved oxygen and low sludge loading conditions, avoiding sludge bulking.

Intensified simultaneous nitrification and denitrification performance in integrated packed bed bioreactors using PHBV with different dosing methods.

To explore an effective approach of simultaneous nitrification and denitrification in wastewater with low C/N ratios, integrated packed bed bioreactors based on poly(3-hydroxybutyrate-hydroxyvalerate) (PHBV) with different dosing methods were designed. The removal efficiency of NH4+-N in bioreactor with aeration was 88.62%, and higher NO3--N removal efficiency was observed in bioreactor filled with grainy PHBV (95.21%) than bioreactor filled with strip PHBV (93.34%). Microbial study indicated that microbes harboring amoA and nirS genes preferred to attach on the surface of ceramsite, and significant differences in microbial community compositions at phylum and genus levels were observed. To summarize, it is feasible to utilize grainy PHBV for simultaneous and efficient removal of NH4+-N and NO3--N from wastewater with low C/N ratios.

Denitrification performance of Pseudomonas fluorescens Z03 immobilized by graphene oxide-modified polyvinyl-alcohol and sodium alginate gel beads at low temperature.

Improving the effect of microbial denitrification under low-temperature conditions has been a popular focus of research in recent years. In this study, graphene oxide (GO)-modified polyvinyl-alcohol (PVA) and sodium alginate (SA) (GO/PVA–SA) gel beads were used as a heterotrophic nitrification–aerobic denitrification (HN–AD) bacteria (Pseudomonas fluorescens Z03) carrier to enhance nitrogen removal efficiency levels at low temperatures (6–8°C). The removal efficiency of and and the variations in concentrations of extracellular polymeric substances (EPS) under different GO doses (0.03–0.15 g l−1) were studied. The results indicated that the addition of GO can improve the efficiency of nitrogen removal, and the highest removal efficiency level and highest carbohydrate, protein, and total EPS content levels (50.28 mg, 132.78 mg and 183.06 mg (g GO/PVA–SA gel)−1, respectively) were obtained with 0.15 g l−1 GO. The simplified Monod model accurately predicted the nitrogen removal efficiency level. These findings suggested that the application of GO serves as an effective means to enhance nitrogen removal by stimulating the activity of HN–AD bacteria.

Microbial and isotopomer analysis of N2O generation pathways in ammonia removal biofilters

Ammonia removal biofilters can be a potential source of nitrous oxide (N2O) production as a result of microbial nitrification and denitrification. In this study, these two N2O generation pathways was quantified using isotopic site preference values (SP, 33‰ for nitrification and 0‰ for denitrification) in a 204-d operation. Tests with two moisture conditions (45% and 55%) and three inlet NH3 concentrations (35, 18 and 0 ppmv) were performed. A 55+% NH3 removal efficiency was achieved in biofilters with 35 and 18 ppmv ammonia supply, but no significant difference (p > 0.05) was found between the moisture treatments. Results showed that biofilters were clearly net sources of N2O, and biofilters with higher moisture content generated significantly (p < 0.05) higher N2O concentration. The N2O generation did not stop even after the biofilters were terminated. The percentage of inlet NH3–N converted into N2O–N were 5.2%, 8.5% for biofilters with 45% moisture content, and 14.8%, 10.8% for those with 55% moisture content. Gene abundance of amoA and nosZ in packing materials (taken on days 64, 107, 140, 180 and 204) increased due to NH3 input reaching the highest on day 140 and then decreased in response to reduced NH3 supply on day 180 and 204. The changes of SP values suggested a shift between nitrification and denitrification with regard to N2O generation. Overall, the nitrification was the dominant pathway for N2O generation, but uncertainty exits as well. This study confirmed that NH3-loaded biofilters were net sources of N2O, and use of SP-N2O may be helpful in better understanding the processes responsible for such emissions.

Enhancing the water flux and biological treatment in bilateral influent submerged FOMBR via applying the strategy of intermittent discharging salt

ABSTRACT The forward osmotic membrane bioreactor (FOMBR) is an emerging innovative technology with broad application prospects in the field of wastewater treatment. Its application is severely limited by concentration polarization, salinity accumulation, and evident water flux decline. Gradual salinity accumulation to a maximum conductivity of 19.7 mS cm−1 under continuous flow operation suppressed the activities of sludge and biodegradation efficiencies. The employment of the regulation of intermittent supernatant discharge was first investigated to alleviate inhibition caused via accumulated salinity in the bioreactor, and bilateral influent was examined with respect to the performance of the FOMBR. The preferable condition to be applied was FO orientation mode (i.e. active layer facing feed) with spacers added to the surface. Given the decreased salt concentration with 2 L of the supernatant removed per day, the water flux declined more slowly and sludge activities were recovered. When compared to the performance without discharging supernatant, the strategy of controlling salinity could improve the removal efficiencies of NH4 +-N, PO4 3--P, and total organic carbon (TOC) by 15.1, 14.3, and 2.3%, respectively. Additionally, the sludge in the intermittent supernatant discharge bioreactor exhibited better sludge property, larger sludge particle size, and recovered sludge activities with the mixed liquid suspended solids (MLSS) stable at around 4.90 g L−1. Therefore, regulation of intermittent salt discharge and controlling the salinity concentration in bioreactor can be employed as an effective method to deal with concentration polarization and salinity accumulation in the FOMBR.

Forward ultra-low emission for power plants via wet electrostatic precipitators and newly developed demisters: Filterable and condensable particulate matters

Coal-fired power plants (CFPPs) install wet electrostatic precipitators (WESPs) or/and demisters as end control devices along with wet flue gas desulfurization (WFGD) systems to meet the ultra-low emission standards in China. This study comprehensively explores the influence of these end control devices on filterable particulate matter (FPM) and condensable particulate matter (CPM) emissions, based on field measurements and chemical analyses of collected samples. The field study was conducted in two typical CFPPs, one equipped with WESPs and the other with newly developed demisters (NDDs). With respect to FPM and filterable PM2.5, the WESP removal efficiency was 96 ± 3% and 92 ± 2%, respectively, and that of NDD was 62 ± 6% and 51 ± 5%, respectively. However, for some unconventional pollutants, the NDD removal efficiency was 60 ± 8% for CPM, which was higher than that of WESP (42 ± 10%); the removal efficiencies of HCl, SO3, and NH3 during the WESP were 78 ± 8%, 44 ± 11%, and 30 ± 5%, respectively, while they were 69 ± 16%, 58 ± 9%, and 60 ± 7%, respectively, when equipped with the NDD. Chemical composition analysis of the obtained samples revealed that the relative content of SO42− in FPM2.5 increased from 12–17% to 14–33% on using end control devices (WESP or NDD). Moreover, SO42− was the major ion component in CPM with relative ratios increasing from 15–35% to 21–59%. The mass ratio of FPM2.5 in FPMs, as well as the relative mass ratio of CPMs, in total particulate matter increased at the outlets of both control devices. The obtained results imply that both WESP and NDD effectively remove FPM and CPM to meet the ultra-low emission standards, respectively. Thus, more attention should be paid to emissions of CPM and FPM2.5 in pollution control technologies.

Application Research on Deodorization Effect of Domestic Waste by One Microbial Deodorizer

In order to assess the deodorization effect of the selected microbial deodorizer, one garbage truck and three refuse transfer stations were used for our investigation. The removal efficiency of NH3, H2S and odor concentration from domestic wastes was studied. The results showed that the concentration of NH3 was decreased by 90.9% and the concentration of odor was decreased by 92.8% when spraying deodorant in the garbage truck. In the three refuse transfer stations, the average removal rates of NH3 and the odor concentration were 66.7% and 34.7%, respectively. Good deodorizing effects of the selected microbial deodorizer were obtained in this research.

Meat processing wastewater Phycoremediation by Botryococcus sp.: a biokinetic study and a techno-economic analysis

ABSTRACT The current study was carried out to investigate the biokinetic model of Botryococcus sp. in removing NH4 + and PO4 3- from meat processing wastewater. The removal efficiency of NH4 + ranged from 89.74% to 99.03% and from 92.39% to 99.93% for PO4 3-. The biokinetic coefficients of NH4 + were = 1.72 mg NH4 + mg−1 chl a d−1 and = 52.29 mgL−1. The biokinetic coefficients of PO4 3- were as follows; = 1.13 mg PO4 3- mg−1 chl a d−1 and = 44.45 mg/L. The techno-economic analysis indicated that the fixed capital estimate will cost USD 920,500 with an annual operating 7920 h/year.

Evaluation of a pilot-scale scrubber for the mitigation of NH3 emissions from laboratory animal house in the presence of different oxidants

The exhaust air expelled from laboratory animal housing systems is the main source of the NH3 emissions to the atmosphere. On this basis and regarding the environmental impact of NH3 emissions, more insights into the air scrubbers as one of the ways to mitigate the NH3 emission from animal houses are needed. The detailed evaluation of a pilot chemical scrubber system was performed for the elimination of NH3 gas by various oxidants such as NaOCl, H2O2, and KMnO4 over a two months period. The removal performance and elimination capacity were applied as technical indexes for appraisal of pilot-scale function against off-gases. Also, the influence of empty bed residential time (EBRT) and pH of scrubbing solution on the chemical scrubber acting mechanism was investigated. The obtained results indicated that the removal efficiency and elimination capacity of NH3 by scrubber in the presence of H2O2 had more robustness against changes of mass loading rate and empty bed residential time (EBRT) than other oxidants, with a removal efficiency of 99.31 % to 88.12 % in EBRTs of 12.81 to 1.6 s, respectively. Furthermore, for the economic assessment of the oxidants, the oxidant-consumed (mg)/NH3-removed (mg) fraction was obtained for oxidants, which was 7.5–9.2, 1.35–2.5, and 11.5–12.4 for NaClO, H2O2, and KMnO4, respectively. On this basis, employing the hydrogen peroxide oxidant can be beneficial in terms of economic viewpoint. Ultimately, chemical scrubber along with H2O2 oxidant seems to be a more efficient applicable NH3 mitigating method in treating waste gas of animal house.

Isolation and niche characteristics in simultaneous nitrification and denitrification application of an aerobic denitrifier, Acinetobacter sp. YS2

The ecological niche of aerobic denitrifiers in activated sludge is little studied, but this determines the performance of these bacteria in reactors. Acinetobacter sp. YS2 isolated from a treatment process for petrochemical wastewater and showed excellent nitrogen removal performance. In the nitrification and denitrification process, the removal efficiencies of NH4+-N and NO3−-N were 87.81% and 88.20% at 24 h, respectively, and nitrogen balance analysis indicated that the proportions of nitrogen removal by gaseous nitrogen were 37.58% and 46.45%, respectively. During simultaneous nitrification and denitrification (SND) treatment of synthetic petrochemical wastewater in a sequencing batch reactor (SBR), aerobic denitrifiers became the dominant species and the proportion reached 87.44% in the microbial community. The removal efficiencies of NH4+-N and TN were 99.46% and 80.36% over 5 days, respectively. This research has shown that aerobic denitrifiers can become the dominant species in the applications of SND treatment for petrochemical wastewater.

Aimed at building a healthy living environment: An analysis of performance of Clean-Air Heat Pump system for ammonia removal

Clean-Air Heat Pump (CAHP) is an innovative system which combines a desiccant wheel with a heat pump which can improve indoor air quality during the process of hygro-thermal control without using additional energy. It is verified that organic gaseous pollutants in air can be effectively removed by the CAHP in our previous research papers but whether the air purification capability of the CAHP is equally effective for inorganic pollutants is unknown. Therefore, in this paper, the removal of ammonia (NH3)-one typical inorganic pollutant by the CAHP was focused, and the effects of regeneration air temperature of the rotor and NH3 concentration on NH3 removal were elaborated analyzed. The results showed that NH3 could not be continuously removed when the adsorbent-silica gel in the CAHP was regenerated by low-temperature thermal energy like 60 °C. A higher regeneration air temperature, possibly more than 90 °C, was required, in which case NH3 removal and desorption efficiencies reached 86.5% and 93.8% when the NH3 concentration was 2.5 ppm. Even if the NH3 concentration in process air was increased to 7.1 ppm, the air cleaning efficiency was still maintained above 67%.

Impact Persulfate on COD Analyze and Possibility Use it as Oxidant of Leachate

In this research, the performance of persulfate (PS) for the removal the chemical oxygen demand (COD) of raw leachate landfill was studied. The experiments were conducted in a batch reactor. The effects pH (2-11), PS/COD ratio (2-10), and reaction time (0-240 min) on the removal of leachate landfill. The Maximum removal efficiencies of COD and NH3 at optimize operational conditions (pH 4, PS/COD ratio: 6 and reaction time: 45 min) were 48.33% and 45.83%, respectively.

The Influence of Meteorological Variables on Air Pollutants Improvement using Hibiscus Cannabinus L. Kenaf Filter

Bauxite mining activities has led to serious consequences towards humans and environment in term of water pollution, air pollution and has extensively damaged the ecosystem of aquatic life. This study investigates the performance of Hibiscus Cannabinus L. (Kenaf) fibres in improving air pollutants. The influence of meteorological conditions i.e. temperature and wind speed, as well as the thickness of Kenaf fibre filter on the concentration of PM10, NH3, NO2 , and Cl2 after the Kenaf fiber treatment is established. The bauxite sample was collected near Kuantan Port, Pahang and a prototype was fabricated to test ability of the Kenaf fibres in improving air quality. Wind speed and temperature was modified to be similar as the actual conditions on site. The study found that the Kenaf fibre filter improved the concentration of PM10, NH3, NO2 , and Cl2 efficiently after air treatment. Two layers of Kenaf fiber filter showed better performance in removing air pollutants as compared to one-layer filter. One-layer filter is capable to improve 16% to 43% of PM10, NH3, NO2 , andCl2 concentration, whereas as high as 70% of pollutants can be removed when two-layer filter is utilized. The removal efficiencies of NH3 , NO2 , Cl2 and PM10 (with Kenaf) increased from 33%, 17%, 38% and 75% to 60%, 67%, 73% and 85% respectively when the wind speed increased from 900 rpm to 1200 rpm. In contrast, the percentages of removal decreased when higher temperature was applied. The removal of PM10, NH3, NO2 , andCl2 decreased from 75%, 60%, 69% and 41% to 57%, 50%, 65% and 39% respectively when the temperature was increased from 27 °C to 32 °C.

Control of Sludge Bulking Caused by Unknown Reason Through FeCl3 Coupled with Biochemical Methods

Filamentous bulking could commonly influence effluent water quality in sewage treatment plants. Existing technologies are slowly effective, time consuming, and poorly adaptable. For now, enhancing organics substrates (COD) and dissolved oxygen (DO) concentration, adding FeCl3 into the reactor, and maintaining alternant aeration conditions are common methods to control filamentous bulking, but the effects of coupling techniques on the control of bulking are rarely reported. In this study, the filamentous bulking resulting from unintentionally erupted Candidatus Saccharibacteria was controlled by FeCl3 coupled with biochemical methods, which transforming step-feed A/O processes to the SBR process in the emergency by increasing DO to (7.45±0.49) mg·L-1 during aeration, enhancing COD to (332.73±106.06) mg·L-1, and adding FeCl3 into the reactor to set the starting concentration to 120 mg·L-1. As the results showed, FeCl3 coupled with the biochemical method quickly counteracted the bulking sludge mainly composed of Candidatus Saccharibacteria caused by unknown reason, while the Sludge Volume Index dropped from 274 mL·g-1 to 56 mL·g-1 within 14 days. The relative abundance of Candidatus Saccharibacteria decreased from 97.64% to 32.67% at the genus level because FeCl3 coupled with the biochemical method inhibited growth of Candidatus Saccharibacteria. Meanwhile, effluents of both COD and PO43--P met the effluent requirements of the I-A discharge standard in China and removal efficiency of NH4+-N increased from 65.33% to 74.65%. The results showed that FeCl3 coupled with the biochemical method exhibited good performance in the control of bulking caused by unknown reasons.

Start-up of the Simultaneous Nitrification, Anammox, and Denitrification (SNAD) Reactor and Efficacy of a Small Amount of Organic Carbon

In perspective of the issue of how to begin simultaneous nitrification, anammox, and denitrification (SNAD) rapidly, the sequencing batch biofilm reactor (SBBR) was adopted to enrich ammonia-oxidizing bacteria (AOB) and anammox bacteria (AnAOB) rapidly and to inhibit nitrite-oxidizing bacteria (NOB) after three phases (67 days) of culture, and the impacts of different low carbon-nitrogen ratios (COD/N) on denitrification performance of the process were investigated. The results showed that preventing the accumulation of nitrite (NO2−-N) was the key to start SNAD successfully. The removal efficiencies of ammonia nitrogen (NH4+-N) and total nitrogen (TN) in the system can reach more than 99% and 90%, respectively. Corresponding to COD/N = 0, 1 and 2, removal efficiencies of NH4+-N were 99.6%, 99.5%, and 98.5% respectively and removal efficiencies of TN were 93.8%, 97.2%, and 98.1%, respectively; the total nitrogen removal rate (TNRR) was greater than 0.29 kg N m−3 day−1. It indicates that the presence of a small amount of COD is beneficial to the denitrification of NO3−-N without affecting the effect of simultaneous nitrification and anaerobic ammonium oxidation, which further improves the efficiency of nitrogen removal. High-throughput sequencing analysis showed that the ratios of AOB, AnAOB, and denitrifying bacteria were 7.3%, 20.1%, and 7.66%, respectively. Candidatus Kuenenia was the only genus of the SNAD reactor with anaerobic ammonium oxidation. AOB, Anammox, and heterotrophic denitrifying bacteria were present in the system, while ammonia oxidation and anaerobic ammonium oxidation played a dominant role in the denitrification process.

Struvite pyrolysate cycling technology assisted by thermal hydrolysis pretreatment to recover ammonium nitrogen from composting leachate

Abstract Composting leachate containing high concentrations of nitrogen imposes a significant burden on aquatic environment. Struvite crystallization to recover ammonium nitrogen from composting leachate is limited by the inefficient capture of organic nitrogen and excessive magnesium and phosphate input. To cope with these challenges, struvite pyrolysate cycling technology coupled with a thermal hydrolysis pretreatment was investigated to recover ammonium nitrogen from composting leachate. Struvite and its pyrolysate were characterized by SEM-EDX, FTIR, and particle size analyzer. The optimal conversion rate of nitrogen in composting leachate with thermal hydrolysis-assisted was obtained at 180 °C for 75 min, achieving an NH4+-N to total nitrogen proportion of 82.2%. The optimal parameters for struvite pyrolysate generation were found to be: molar ratio of hydroxyl to NH4+-N of 1:1, heating temperature of 110 °C, and holding time of 3 h. SEM-EDX analysis revealed that the principal struvite pyrolysate was MgNaPO4·7H2O. When the struvite pyrolysate was reprocessed as novel magnesium and phosphate sources, the removal efficiency of NH4+-N decreased from 98.3 ± 1.3% in the first cycle to 78.1 ± 1.0% in the fifth cycle. FTIR analysis indicated the increase in the impurities content of struvite pyrolysate and the decrease in active phosphorus and magnesium sources. Particle size analysis suggested ammonium precipitation was restricted by the crystal growth size. An economic analysis demonstrated that 59.0% of processing costs could be saved by cycling struvite pyrolysate compared with a non-cycling process.

A fast start-up of the organotrophic anammox process inoculated with constructed wetland sediment

Organotrophic anaerobic ammonium oxidation (anammox) bacteria can utilize small volatile fatty acids with nitrate as electron acceptors with less energy consumption and no biomass production. To achieve a faster and stable start-up of organotrophic anammox process, in this study, the growth of organotrophic anammox bacteria seeded from hybrid constructed wetland (CW) sediment under different TOC/TN ratios and different chloramphenicol concentrations were investigated. The incubation study was conducted at the TOC/TN ratio = 0.0375–0.1 or 0.1–0.2 for the period of over five months by using serum bottles. The anammox bacteria revealed a higher activity when the TOC/TN ratio was 0.1, with the removal efficiency of NH4+-N (60–80%) and NO2−-N (~100%). The relative abundances of anammox in the incubated CW sediment were about 30% higher in comparison with the municipal waste water treatment plant sludge, suggesting the CW sediment could be a viable source for the enrichment of organotrophic anammox bacteria. On the contrary, the continuous addition of 50 mg/L chloramphenicol completely inhibited the anammox activity in our study. Following the results of the batch tests, Candidatus Brocadia caroliniensis was successfully enriched with the CW sediment in an auto-controlled SBR for the period of 40 days.

Investigation of ammonia stripping with a hydrodynamic cavitation reactor.

Ammonia is a commonly used compound in the domestic and industrial fields. If ammonia found in wastewater after use is not treated, even at low concentrations it may cause toxic effects in the receiving environment. In this study, a hydrodynamic cavitation reactor (HDC) was designed with the aim of removing ammonia. The effect of parameters like different cavitation numbers, airflow, temperature and initial concentration on NH3 removal was researched. The potential of hydrodynamic cavitation for removal of volatile gases, like NH3, was assessed with the aid of two film theory mathematical equations. Experimental studies were performed at fixed pH = 11. Under the conditions of 0.12 cavitation number, 25 L/min airflow, 30 °C temperature and 2500 mg/L initial concentration, in 24 h 98.4% NH3 removal efficiency was achieved. With the same experimental conditions without any air, the HDC reactor provided 89.5% NH3 removal at the end of 24 h. The HDC reactor is very effective for the removal of volatile gases from wastewater and it was concluded that even in the absence of aeration, the desired NH3 removal efficiency was provided.