24 rowsCompared to the conventional N-D, ammonium assimilation (AA) is a short-step metabolic process ...

The total nitrogen removal efficiency was enhanced (93.11%) and the start-up time was shortened from 98 to 67 days. ... This increases the surface area of gravel balls and enables them to accumulate microorganisms and provide integrated aerobic, anaerobic, and anoxic environments in the different sections of the ball-shaped gravel [16 ...

Microorganisms can transform nitrogen compounds as reactive and toxic as nitric oxide or as inert and harmless as dinitrogen gas. Microbial transformations of …

Biological nitrogen removal (BNR) technologies are the most effective approaches for the remediation of environmental nitrogen pollutants from wastewater treatment plants (WWTPs). Presently, research is going on to elucidate the structure and function of BNR microbial communities and optimizing BNR treatment systems to …

Many wastewater treatment facilities rely on chemicals for tertiary treatment, however, biological nitrogen removal practices are much more environmentally friendly and cost effective. Therefore, interest in biological treatment is increasing. Biological approaches take advantage of specific groups of microorganisms involved in nitrogen cycling ...

An aerobic denitrification strain, Pseudomonas balearica RAD-17, was identified and showed efficient inorganic nitrogen removal ability. The average NO3−-N, NO2−-N, and total ammonium nitrogen (TAN) removal rate (>95% removal efficiency) in a batch test was 6.22 mg/(L∙h), 6.30 mg/(L∙h), and 1.56 mg/(L∙h), respectively. Meanwhile, optimal …

The sequence of anaerobic-anoxic-anaerobic-aerobic processes, which provides the efficiency of wastewater treatment for removal of organic pollutants of 90-95 %, ammonium nitrogen 97-99 % and ...

This phenomenon reduced the average ammonium nitrogen removal rate from 95.0 to 70.7%, and the average total nitrogen removal rate decreased from 81.3 to 43.6%, respectively.

The best nitrogen removal was achieved at the condition of high ammonia concentration without organic carbon, with obtained the nitrogen removal loading rate of 2.2 g N/(L·d) and the nitrogen removal percentage of 92%. ... These microorganisms could utilize amino acids in EPS [43], resulting in the decreased concentration of amino …

Many different aerobic and anaerobic biological processes and treatment schemes are available for transforming organics and/or removing nitrogen from domestic wastewaters. Significant reductions in oxygen requirements and absence of a need for organics for nitrogen reduction are often indicated as advantageous for using the newer …

This study investigated the effects of NZVI on both nitrogen and phosphorus removal and microorganisms in activated sludge. The following conclusions were drawn based on the results. The addition of lower concentration of NZVI particles (20 and 50 mg/L) showed no measurable effect on nitrogen removal, however, when the …

Traditional biological nitrogen removal technologies usually involve a two-step process with different types of microbes, autotrophic nitrifying bacteria, and …

Abstract. Nitrogen has traditionally been removed from wastewater by nitrification and denitrification processes, in which organic carbon has been used as an electron donor during denitrification. However, some wastewaters contain low concentrations of organic carbon, which may require external organic carbon supply, …

The nitrogen removal alliance formed by the salt-tolerant anammox bacterium (Candidatus Kuenenia) and denitrifying bacteria (unclassified SBR1031 and …

In this research, the effect of low-concentration methanol on the functional microorganisms and nitrogen removal and recovery in the CANON system is investigated. The result shows that the anaerobic ammonium-oxidizing bacteria (AnAOB) was suppressed with low-concentration methanol addition, and the phylum Planctomycetes was hidden.

N removal in wetlands is achieved via coupled bio-physio-chemical processes that include mineralisation, nitrification, denitrification, anaerobic ammonium oxidation (anammox), biomass ...

Nitrogen removal by microorganisms in constructed wetlands is a critical step. This removal process occurs through different steps such as amination, aerobic ammonia oxidation, nitrite oxidation, anoxic denitrification, heterotrophic nitrification, and aerobic denitrification in constructed wetlands.

Oxygen or air is supplied for microorganisms via membrane micropores, the microorganisms attach to the membrane surface and grow into biofilm. In contrast to conventional BA systems, there are two significant differences in MABAR. ... To further analyze the microbial populations contributing to the nitrogen removal, the phylotypes …

Nitrogen-cycling microorganisms play key roles at the intersection of microbiology and wastewater engineering. In addition to the well-studied ammonia …

3.2. Nitrogen removal performances3.2.1. Nitrogen removal efficiency. The variations in the levels of nitrogen species (i.e., TN, NO 2 –-N, NO 3 −-N, and NH 4 +-N) in the ammonium-rich landfill leachates via the AO-M and AO-N processes listed in Table 1.Even though the feed water included the high NH 4 +-N concentrations, the nitrogen …

Microorganisms are one of the major components of biofilms. The structure of the microbial community exerts substantial effects on its function. ... As a representation of functional differences of the nitrogen removal, the significantly different functional patterns of level 3 KOs are displayed in Fig. 8 b and c. Glycerolipid metabolism ...

This study evaluated and compared microbial communities and water quality changes from WWTPs worldwide by meta-analysis of published high-throughput sequencing data. Six …

Biological nutrient removal is an integral part of a wastewater treatment plant. However, the microorganism responsible for nutrient removal is susceptible to inhibition by external toxicants such as heavy metals which have the potential to completely inhibit biological nutrient removal. The inhibition is a result of the interaction between heavy …

A likely scenario was that the microorganisms formed a community inside the pores, following activation and immobilization. EDX analysis was performed on the base point and the microorganisms expected point, and the results are shown in Table 1.Carbon and sulfur were lower in the microorganisms expected point compared to base point; …

The discovery of heterotrophic nitrification-aerobic denitrification (HN-AD) microorganisms has opened a new window for wastewater treatment. The underlying mechanism of HN-AD, however, is not fully understood because of the phylogenetic diversity of HN-AD microbes. The isolation and characterization of new HN-AD microorganisms …

Biological nutrient removal (BNR) removes total nitrogen (TN) and total phosphorus (TP) from wastewater through the use of microorganisms under different environmental conditions in the treatment process (Metcalf and Eddy, 2003). Nitrogen Removal . Total effluent nitrogen comprises ammonia, nitrate, particulate organic nitrogen, and soluble …

Different organic matters have different effects on the nitrogen removal performance of partial nitritation and anammox (PN/A) biofilm system. In this study, the effects of adding soluble starch, ethanol, and sodium acetate on the functional microorganisms and nitrogen removal in the PN/A biofilm system are investigated.

Biological nitrogen removal proceeds slowly because the microorganisms responsible for the elimination reactions grow slowly. In addition, the operational control …

Encapsulating microorganisms is promising to enhance biological nitrogen removal (BNR) in wastewater, with benefits of increased efficiency, reduced inhibition, and improved stability. Encapsulation technology has advanced, with recent findings in new encapsulation materials, pure and enrichment culture studies with novel nitrogen-converting ...

It is possible that the community structure of microorganisms that can utilize BDPs gradually stabilizes, resulting in an improvement of nitrogen removal performance over time. When the HRT was decreased from 24 h to 16 h, the average removal rate of TN was 84.44 % at steady state in the PBS reactor which was similar to the PCL reactor's ...