Electrochemically-assisted ammonia recovery from wastewater using a floating electrode

2017 ◽  
Vol 75 (8) ◽  
pp. 1804-1811 ◽  
Author(s):  
Tim H. Muster ◽  
Johannes Jermakka
Keyword(s):  
Ammonia Oxidation ◽  
Ammonia Concentration ◽  
Ammonia Removal ◽  
Synthetic Wastewater ◽  
Environmental Waters ◽  
Air Interface ◽  
High Ammonia ◽  
Ammonia Recovery ◽  
Anodic Reactions ◽  
Floating Electrode

This work presents and explores a novel methodology for the removal and recovery of ammonia from wastewater based upon two mechanisms: electrochemical oxidation and a previously unreported electrochemically-assisted surface transfer mechanism. Recovery of ammonia is enabled by placing a porous cathodic electrode at the wastewater-air interface. In this configuration, the cathode creates local alkalinity and an electric field that draws ammonium ions towards the wastewater-air interface, resulting in near-linear reductions of dissolved ammonium irrespective of concentration. This approach leads to significant ammonia recovery without the need for ion-exchange membranes. In addition, anodic reactions that simultaneously occur at depth in the wastewater induce ammonia oxidation in accordance with proven mechanisms. The floating electrode approach offers improved ammonia removal efficiency in comparison to electrooxidation. Trials conducted on synthetic wastewater (900 mg NH4+-N l−1) and filtered anaerobic centrate (560 mg NH4+-N l−1) demonstrated ammonia concentration decreases up to 216 mg l−1 hr−1 and 110 mg l−1 hr−1, respectively, under the application of 5 mA cm−2 current density. The technology would be best used to treat municipal and industrial wastewaters possessing high ammonia concentration, including anaerobic digester centrate and urine, and offers potential to assist in removing ammonia from environmental waters.

Model experiments on improving nitrogen removal in laboratory scale subsurface constructed wetlands by enhancing the anaerobic ammonia oxidation

2007 ◽  
Vol 56 (3) ◽  
pp. 145-150 ◽  
Author(s):  
D. Paredes ◽  
P. Kuschk ◽  
F. Stange ◽  
R.A. Müller ◽  
H. Köser
Keyword(s):  
Nitrogen Removal ◽  
Ammonia Oxidation ◽  
Operating Conditions ◽  
Laboratory Scale ◽  
Synthetic Wastewater ◽  
Scale Model ◽  
Model Experiments ◽  
Anaerobic Ammonia Oxidation ◽  
High Ammonia ◽  
Process Strategy

Anaerobic ammonia oxidation (Anammox) has been identified as a new general process-strategy for nitrogen removal in wastewater treatment. In order to evaluate the role and effects of the Anammox process in wetlands, laboratory-scale model experiments were performed with planted fixed bed reactors. A reactor (planted with Juncus effusus) was fed with synthetic wastewater containing 150–200 mg L−1 NH+4 and 75–480 mg L−1 NO−2. Under these operating conditions, the plants were affected by the high ammonia and nitrite concentrations and the nitrogen removal rate fell within the same range of 45–49 mg N d−1 (equivalent to 0.64–0.70 g Nm−2d−1) as already reported by other authors. In order to stimulate the rate of nitrogen conversion, the planted reactor was inoculated with Anammox biomass. As a result, the rate of nitrogen removal was increased 4–5-fold and the toxic effects on the plants also disappeared. The results show that, in principle, subsurface flow wetlands can also function as an “Anammox bioreactor”. However, the design of a complete process for the treatment of waters with a high ammonia load and, in particular, the realisation of simple technical solutions for partial nitrification have still to be developed.

Electrolytic removal of ammonia from aqueous phase by Pt/Ti anode

2013 ◽  
Vol 67 (11) ◽  
pp. 2451-2457 ◽  
Author(s):  
Liang Li ◽  
Yuanxing Huang ◽  
Yan Liu ◽  
Yangyang Li
Keyword(s):  
Ammonia Oxidation ◽  
Removal Rate ◽  
Treatment Plant ◽  
Chloride Concentration ◽  
Ammonia Concentration ◽  
Ammonia Removal ◽  
Direct Oxidation ◽  
Indirect Oxidation ◽  
Zero Order Kinetics ◽  
Secondary Clarifier

This study investigated the mechanism and kinetic modeling of electrolytic degradation of ammonia with Pt/Ti anode. The results show that ammonia oxidation from direct oxidation or indirect oxidation with hydroxyl radicals was slow but can be observed under pH 9 and high initial ammonia concentration of 1,050 mg N L−1. Indirect oxidation with HOCl was the mechanism for the chloride-mediated electrolytic removal of ammonia. In this process, pH between 3 and 9 had little effect on the ammonia removal rate, but current density (j) and chloride concentration ([Cl−]) showed a linear relationship with ammonia removal rate within the range of 3.8–15.4 mA cm−2 and 30–300 mg L−1, respectively. The ammonia removal could be described by a pseudo-zero order kinetics with a mathematic equation of k = 0.0003 × [Cl−] × j − 0.076. Treatment of the actual wastewater effluent from a secondary clarifier in a local wastewater treatment plant showed an ammonia removal rate of 0.8 mg N L−1 h−1 and energy cost of 14 kJ per mg N ammonia.

Effect of Aeration on Fresh and Aged Municipal Solid Waste in a Simulated Landfill Bioreactor

2004 ◽  
Vol 39 (3) ◽  
pp. 223-229 ◽  
Author(s):  
Mostafa A. Warith ◽  
Graham J. Takata
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Ammonia Concentration ◽  
Air Injection ◽  
Bioreactor Landfills ◽  
Time To Stabilization ◽  
High Ammonia ◽  
Simulated Landfill ◽  
Term Monitoring

Abstract Municipal solid waste (MSW) is slow to stabilize under conventional anaerobic landfill conditions, demanding long-term monitoring and pollution control. Provision of aerobic conditions offers several advantages including accelerated leachate stabilization, increased landfill airspace recovery and a reduction in greenhouse gas emissions. Air injection was applied over 130 days to bench-scale bioreactors containing fresh and aged MSW representative of newly constructed and pre-existing landfill conditions. In the fresh MSW simulation bioreactors, aeration reduced the average time to stabilization of leachate pH by 46 days, TSS by 42 days, TDS by 84 days, BOD5 by 46 days and COD by 32 days. In addition, final leachate concentrations were consistently lower in aerated test cells. There was no indication of a gradual decrease in the concentration of ammonia, and it is likely this high ammonia concentration would continue to be problematic in bioreactor landfill applications. This study focussed only on biodegradability of organics in the solid waste. The concentrations of the nonreactive or conservative substances such as chloride and/or heavy metals remain in the bioreactor landfills due to the continuous recirculation of leachate. The results of this study demonstrate the potential for air injection to accelerate stabilization of municipal solid waste, with greatest influence on fresh waste with a high biodegradable organic fraction.

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

2019 ◽  
Vol 5 (2) ◽  
pp. 383-396 ◽  
Author(s):  
Anna Patrícya Florentino ◽  
Ahmed Sharaf ◽  
Lei Zhang ◽  
Yang Liu
Keyword(s):  
Activated Carbon ◽  
Hydrogen Exchange ◽  
Granular Activated Carbon ◽  
Ammonia Concentration ◽  
Anaerobic Digesters ◽  
Ammonia Inhibition ◽  
High Ammonia

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.

Nitrification preservation in activated sludge during curative bulking chlorination

2003 ◽  
Vol 47 (11) ◽  
pp. 85-92 ◽  
Author(s):  
E. Cotteux ◽  
P. Duchene
Keyword(s):  
Activated Sludge ◽  
Pilot Plant ◽  
Wastewater Treatment Plants ◽  
Oxygen Uptake Rate ◽  
Ammonia Concentration ◽  
Synthetic Wastewater ◽  
Biological Wastewater Treatment ◽  
Simple Method ◽  
Method Of Measurement ◽  
The Impact

The bulking that occurs in biological wastewater treatment plants using activated sludge is very often controlled by the injection of sodium hypochlorite into the return activated sludge (RAS) stream. In the present study undertaken at two pilot plants fed with synthetic wastewater, the impact of the pass frequency of the sludge at the chlorine dosing point on the nitrifying flora is analysed. The pass frequency is one for the pilot plant 1 and two for the pilot plant 2. A dose of chlorine of 4.85 ± 0.05 g/kg/MLVSS per day was applied at both pilots. The preservative effect on nitrifying activity of the lowest concentration of chlorine at the dosing point and therefore of the highest pass frequency was evidenced. Among other tools, a simple method of measurement of the oxygen uptake rate enabled us to monitor the effect of chlorination on nitrification before recording an increase in the ammonia concentration in the bulking.

scholarly journals Impact of the increased active surface of the platinum catalyst on the total ammonia recovery coefficient

2009 ◽  
Vol 45 (1) ◽  
pp. 69-78 ◽  
Author(s):  
B. Trumic ◽  
D. Stankovic ◽  
V. Trujic
Keyword(s):  
Ammonia Oxidation ◽  
Platinum Catalyst ◽  
Platinum Catalysts ◽  
Active Surface ◽  
Specific Design ◽  
Recovery Coefficient ◽  
Design Efficiency ◽  
Industrial Environment ◽  
Ammonia Recovery ◽  
Total Ammonia

In order to increase the active surface of platinum catalysts for ammonia oxidation and on the basis of theoretic considerations and tests in industrial environment, we have finally decided on their specific design. Efficiency on the newly designed catalyst was checked in industrial circumstances. A comparative analysis of the total ammonia recovery coefficient between the mentioned new catalysts and previously applied platinum catalysts was carried out. All advantages of catalysts with increased active surfaces were confirmed and a new method of their manufacturing process was selected.

Biodegradation of aniline

1997 ◽  
Vol 36 (10) ◽  
pp. 53-63 ◽  
Author(s):  
Shabbir H. Gheewala ◽  
Ajit P. Annachhatre
Keyword(s):  
Activated Sludge ◽  
Ammonia Oxidation ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Inhibitory Effect ◽  
Synthetic Wastewater ◽  
Nitrifying Bacteria ◽  
Aquatic Life ◽  
Oxidation Rates ◽  
Batch Tests

Discharge of aniline to the environment must be controlled as aniline is toxic to aquatic life and also exerts additional oxygen demand due to nitrification reaction involved during its biodegradation. Organic carbonaceous removal by heterotrophs during aniline biodegradation releases NH4+ which is the substrate for autotrophic nitrifying bacteria. However, aniline is toxic to nitrifying bacteria and severely inhibits their activity. Accordingly, batch and continuous studies were conducted to assess the biodegradation of aniline and its inhibitory effect on nitrification. Synthetic wastewater was used as feed with aniline as sole carbon source for mixed microbial population. Experiments were conducted at ambient temperatures of 30–32°C. An aerobic activated sludge Unit was operated at an HRT of about 13 hours and SRT of about 12 days. Biomass from aerobic activated sludge process treating domestic wastewater was acclimatized to synthetic wastewater Containing aniline. Removal efficiencies more than 95% were obtained for feed aniline concentrations upto 350 mg/l with insignificant inhibition of nitrification due to aniline. Ammonia oxidation rates of about 20–115 mgNH4N/l/d were observed. Batch tests were carried out to test the inhibitory effects of high initial aniline concentrations on nitritication. Carbonaceous removal by heterotrophs proceeded rapidly within 4–6 hours with nitrification picking up as soon as aniline concentration dropped below 3–4 mg/l. For higher initial aniline concentration more than 250 mg/l, complete nitrification did not take place even after aniline Concentration dropped below 3–4 mg/l.

Photocatalytic Degradation of High Ammonia Concentration Water Solutions by TiO2

2005 ◽  
Vol 95 (5) ◽  
pp. 335-343 ◽  
Author(s):  
Sandro Maria Murgia ◽  
Antonio Poletti ◽  
Roberta Selvaggi
Keyword(s):  
Photocatalytic Degradation ◽  
Ammonia Concentration ◽  
Water Solutions ◽  
High Ammonia
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