Ammonia-nitrogen removal by breakpoint chlorination

Pressley, Thomas A.; Bishop, Dolloff F.; Roan, Stephanie G.

doi:10.1021/es60066a006

Cited by 245 publications

(135 citation statements)

References 5 publications

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“…The HOCl further reacts with NH 3 and produces N 2 [10]. It has been also reported that Ti/TiO 2 -RuO 2 anode can efficiently remove NH 3 with the appropriate amount of Cl -concentration in the electrolyte [11].…”

Section: Nitrate Removal Using Electrochemically Produced Hoclmentioning

confidence: 98%

Influence of Operational Parameters on Rapid Nitrate Removal Using an Electrochemical Flow Cell

Ashadullah¹,

Kishimoto²

2016

IJESD

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Abstract-Nitrate contamination is a great concern all over the world. However, the conventional biological processes like the modified Ludzack-Ettinger process are time-consuming. Accordingly, a rapid process for nitrate removal is desired. We conceived an electrochemical process for rapid removal of nitrate, which contained electrochemical reduction of nitrate to ammonia and electrochemical break-point chlorination of ammonia. In this research, we investigated effects of operational parameters such as volumetric electric charge, flow rate and chloride ion concentration on electrochemical nitrate removal. A hand-made divided flow cell with a copper mesh cathode, a platinum-coated titanium anode and a cation exchange membrane as a separator was developed as well as applied to the treatment of synthetic water containing 1.42 mM of nitrate at various volumetric electric charges, flow rates and chloride ion concentrations. As a result, it was observed that the flow cell operated at a flow rate of 20 mL/min, chloride ion concentration of 800 mg/L, volumetric electric charge of 5,100 C/L and at pH 7 successfully removed nitrate from 1.42 mM to 0.43 mM without ammonia and nitrite accumulation within 1 minute contact time. Consequently, the electrochemical technique was thought to be feasible for the rapid removal of nitrate from water streams.Index Terms-Break-point chlorination, biological process, electrochemical process, nitrate contamination.

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Section: Nitrate Removal Using Electrochemically Produced Hoclmentioning

confidence: 98%

Influence of Operational Parameters on Rapid Nitrate Removal Using an Electrochemical Flow Cell

Ashadullah¹,

Kishimoto²

2016

IJESD

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“…Approximately 14 percent of the oxidized ammonium and urea in the buffered groundwater samples treated with hypochlorite formed nitrate, while in the unbuffered samples (pH Ͻ 4) ~7 percent of the oxidized ammonium and urea formed nitrate. Pressley et al (1972) indicated that nitrate production was pH-dependent and that lowering the pH to 6 reduced nitrate formation to approximately 1 percent.…”

Section: Bench-scale Experimentsmentioning

confidence: 99%

A chemox treatment for urea- and ammonium-contaminated groundwater

Spalding¹,

Khan²,

Exner³

2005

Remediation

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In a pilot project performed at a fertilizer manufacturing facility, a one-step chemical oxidation technique successfully treated urea-and ammonium-contaminated groundwater. The oxidation reaction occurred in an 1,100-gallon batch reactor. The contaminated inflow was buffered by the metered addition of sodium bicarbonate solution and subsequently treated with sodium hypochlorite in an 8:1 weight ratio of Cl 2 :N. In an instantaneous reaction, the urea and ammonium-N were completely oxidized to nitrogen gas that was vented to the atmosphere during mixing. The pH of the reactor discharge was ~6.5. Sodium sulfite was used to reduce residual hypochlorite in the reactor effluent to chloride to provide process water with characteristics suitable for discharge. Oxidation rates were similar with different strengths of hypochlorite; however, a 5 to 6 percent sodium hypochlorite (as Cl 2 ) solution was the most stable.

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“…When the chlorine dosage exceeds approximately ten times the concentration of ammonia nitrogen by weight, a process known as the breakpoint reaction occurs (76). By a series of reactions most of the ammonia nitrogen is oxidized to nitrous oxide or nitrogen gas.…”

Section: Chlorine Species In Solutionmentioning

confidence: 99%

Environmental health sciences center task force review on halogenated organics in drinking water

Deinzer¹,

Schaumburg²,

Klein³

1978

Environ Health Perspect

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The disinfection of drinking water by chlorination has in recent years come under closer scrutiny because of the potential hazards associated with the production of stable chlorinated organic chemicals. Organic chemical contaminants are common to all water supplies and it is now well-established that chlorinated by-products are obtained under conditions of disinfection, or during tertiary treatment of sewage whose products can ultimately find their way into drinking water supplies. Naturally occurring humic substances which are invariably present in drinking waters are probably the source of chloroform and other halogenated methanes, and chloroform has shown up in every water supply investigated thus far. The Environmental Protection Agency is charged with the responsibility of assessing the public health effects resulting from the consumption of contaminated drinking water. It has specifically undertaken the task of determining whether organic contaminants or their chlorinated derivatives have a special impact, and if so, what alternatives there are to protect the consumer against bacterial and viral diseases that are transmitted through infected drinking waters. The impetus to look at these chemicals is not entirely without some prima facie evidence of potential trouble. Epidemiological studies suggested a higher incidence of cancer along the lower Mississippi River where the contamination from organic chemicals is particularly high. The conclusions from these studies have, to be sure, not gone unchallenged. The task of assessing the effects of chemicals in the drinking water is a difficult one. It includes many variables, including differences in water supplies and the temporal relationship between contamination and consumption of the finished product. It must also take into account the relative importance of the effects from these chemicals in comparison to those from occupational exposure, ingestion of contaminated foods, inhalation of polluted air, and many others. The susceptibility of different age, genetic, and ethnic groups within the population must also be carefully considered. The present review discusses: the reasons for disinfection; the general occurrence of chlorinated organics in drinking water; the chemistry in the synthesis of chlorinated organics under aqueous conditions; and alternatives to chlorine for disinfection.

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Ammonia-nitrogen removal by breakpoint chlorination

Cited by 245 publications

References 5 publications

Influence of Operational Parameters on Rapid Nitrate Removal Using an Electrochemical Flow Cell

Influence of Operational Parameters on Rapid Nitrate Removal Using an Electrochemical Flow Cell

A chemox treatment for urea- and ammonium-contaminated groundwater

Environmental health sciences center task force review on halogenated organics in drinking water

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