Degradation of urea, ammonia and nitrite in moving bed biofilters operated at different feed loadings

Ahnen, Mathis von; Pedersen, Lars‐Flemming; Pedersen, Palle; Dalsgaard, Anne Johanne Tang

doi:10.1016/j.aquaeng.2015.10.004

Cited by 37 publications

(10 citation statements)

References 37 publications

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“…It can be removed through biological decomposition to ammonia, [ 25 ] but this noxious gas is subsequently discharged into the atmosphere as a pollutant, impairing air quality and causing health risks. Therefore, various other methods have been suggested to eliminate urea from wastewater, including enzymatic and nonenzymatic hydrolysis, [ 26–28 ] biodegradation, [ 29,30 ] oxidation with strong oxidants, [ 31 ] adsorption, [ 32,33 ] and catalytic decomposition in aqueous solutions. [ 26,34 ] Different catalysts have been applied for the chemical decomposition of urea, such as Pt/SiO 2 , [ 31,35 ] as well as polymorphs of Al 2 O 3 [ 27 ] and TiO 2 , [ 36 ] but it can also be degraded by electrochemical oxidation.…”

Section: Introductionmentioning

confidence: 99%

Advances in Catalytic Electrooxidation of Urea: A Review

et al. 2021

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The urea oxidation reaction (UOR) is technologically important for the development of a renewable energy infrastructure. Urea electrolysis (UE) can be used to produce hydrogen much more cost‐effectively than water electrolysis, as it theoretically requires 93% less energy. Urea can also be used as fuel in direct urea fuel cells (DUFCs), instead of H2, and thus serve as an efficient hydrogen carrier. This review addresses the UOR in neutral, acidic, and alkaline electrolytes, with special emphasis on the latter. Recent developments in Ni‐based catalysts for urea oxidation (UO) in alkaline electrolytes are discussed in detail, highlighting proposed reaction mechanisms and intermediates, based on experimental and computational results. Various catalytic designs used to mitigate the UO kinetic barriers, including the use of transition metal oxides and alloys, as well as tailored surface support materials, and discuss their application in UE and DUFCs are presented. The significant challenges impeding advances in urea electrocatalysis, in addition to emerging research areas in this field, are also discussed.

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Section: Introductionmentioning

confidence: 99%

Advances in Catalytic Electrooxidation of Urea: A Review

et al. 2021

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“…In the 6th week, water samples were collected from all tanks at the outflow shortly before feeding and 12 h post-feeding. Total ammonia-nitrogen (TAN), nitrite-N and nitrate-N were determined according to the methods described by von Ahnen et al (2015). The PAA concentration and degradation were determined in the surface water of the pulse and continuous treatment groups according to the DPD (N,N-diethyl-p-phenylendiamine sulfate salt) photometric method described by Pedersen et al (2009).…”

Section: Water Parameter Measurementmentioning

confidence: 99%

Pulse versus continuous peracetic acid applications: Effects on rainbow trout performance, biofilm formation and water quality

Liu

Straus

Pedersen³

et al. 2017

Aquacultural Engineering

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a b s t r a c tPeracetic acid (PAA) products are being introduced to aquaculture as sustainable disinfectants. Two strategies are used to apply PAA: high dose pulse applications, or low dose continuous application. In the present study, their impacts on fish health and water quality were investigated in triplicate flowthrough tanks stocked with rainbow trout. The gentler and shorter water cortisol increase measured along twice-per-week pulse applications of 1 mg L −1 PAA indicated a progressive adaptation of fish. In contrast, the continuous application of 0.2 mg L −1 PAA caused no stress to fish. Meanwhile, no mortality and no impact on growth or innate cellular immunity were observed. The pulse applications restricted biofilm formation, and partially inhibited nitrification. Additionally, the highest oxygen concentration and stable pH were observed. In contrast, the continuous application promoted biofilm formation, and caused a pH increase and intermediate oxygen concentration. The contrast was probably due to different susceptibility of microbes to PAA-induced oxidative stress. To summarize, pulse PAA applications cause minor stress in fish, but have advantages over continuous application by ensuring better water quality.

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“…Vários são os micro-organismos capazes de produzir ATP através da hidrólise da ureia (VON AHNEN et al, 2015). A força próton motriz ou potencial eletroquímico (∆p) é que controla a geração da energia (Eq.…”

Section: Mecanismos Energéticos De Bactérias Ureolíticasunclassified

Bioprecipitação De Carbonato De Cálcio Por Bactérias Ureolíticas E Suas Aplicações

Reis¹,

Rodrigues²,

Soares³

et al. 2017

Enci Bio

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RESUMOA biomineralização é uma alteração química em um ambiente através de atividade microbiana que resulta na precipitação de minerais, sendo um fenômeno amplamente distribuído na natureza. Na precipitação de carbonato de cálcio induzida microbiologicamente (MICP, do inglês microbially induced calcium carbonate precipitation), a urease apresenta papel importante ao hidrolisar a ureia, por uma grande variedade de micro-organismos capazes de produzir elevados níveis desta enzima. Existem diferentes polimorfos do cristal de carbonato de cálcio e a estrutura que é formada depende do tipo da fonte de cálcio utilizada, período de incubação e atividades metabólicas referentes à espécie microbiana avaliada. A MICP é uma alternativa promissora e ambientalmente amigável para as tecnologias de remediação atuais e convencionais capazes de resolverem problemas ambientais em campos multidisciplinares. Várias aplicações como aumento da qualidade e da melhoria das propriedades de materiais de construção, remoção de metais potencialmente tóxicos e radionucleotídeos e sequestro de dióxido de carbono atmosférico têm sido discutidas. PALAVRAS-CHAVE: Biomoneralização, carbonato de cálcio, construção civil, MICP, urease. CALCIUM CARBONATE BIOPRECIPITATION BY UREOLYTIC BACTERIA AND ITS APPLICATIONSABSTRACT Biomineralization is a chemical change in environment through the microbial activity that results in the precipitation of minerals, being a phenomenon widely spread in nature. In microbially induced carbonate precipitation (MICP), ureases plays an important role in hydrolyzing urea by a large variety of microorganisms capable of producing high levels of this enzyme. There are different polymorphs of calcium carbonate crystal and the structure that is formed depends on the type of calcium used, the incubation time and metabolic activities of the evaluated microbrial species.

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Degradation of urea, ammonia and nitrite in moving bed biofilters operated at different feed loadings

Cited by 37 publications

References 37 publications

Advances in Catalytic Electrooxidation of Urea: A Review

Advances in Catalytic Electrooxidation of Urea: A Review

Pulse versus continuous peracetic acid applications: Effects on rainbow trout performance, biofilm formation and water quality

Bioprecipitação De Carbonato De Cálcio Por Bactérias Ureolíticas E Suas Aplicações

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