46 Results Found

Low C/N wastewater results from a wide range of factors that significantly harm the environment. They include insufficient carbon sources, low denitrification efficiency, and ${\mathrm{NH}}_4^{+}$-N concentrations in low C/N wastewater that are too high to be treated...

Partial nitrification (PN) is an effective process for treating high-strength ammonium wastewater with a low COD/N (chemical oxygen demand/total nitrogen) ratio; this is because the cooperative interaction with denitrification or anammox can result i...

This work investigated the roles of sludge micropowder addition in microbial structure and partial nitrification and denitrification (PND) in an extended filamentous aerobic granular sludge-sequencing batch reactor (AGS-SBR) using high-ammonia wastew...

This study investigated the ecological selection and enrichment of anaerobic ammonium-oxidizing bacteria (AnAOB) driven by endogenous carbon cycling in a low-oxygen SBR biofilm system without external carbon addition. The system was operated using dr...

Pickle wastewater is a highly saline organic effluent that poses a significant ecological risk. In this study, a sequencing batch biofilm reactor (SBBR) was used to treat such wastewater, and a denitrification system capable of simultaneously removin...

A nitrification inhibitor is an effective tool that can be used to reduce the loss of nitrogen (N) and improve crop yields. Most studies have focused on the changes in the soil N mineralization process that may influence the dynamics of soil inorgani...

Using actual domestic wastewater as the research object, nitrogen compounds and their combinations were added to different nitrification (partial nitrification, full nitrification) processes to investigate nitrous oxide (N₂O) emission and its nitrifi...

Anaerobic ammonium oxidation (anammox) technologies have attracted substantial interest due to their advantages over traditional biological nitrogen removal processes, including high efficiency and low energy demand. Currently, multiple side-stream a...

Mature landfill leachate is a complex and highly polluted effluent with a large amount of ammonia nitrogen, toxic components and low biodegradability. Its COD/N and BOD₅/COD ratios are low, which is not suitable for traditional nitrification and deni...

Nitrous oxide (N₂O) is a greenhouse gas contributing to ozone layer depletion and climate change. Wastewater treatment plants (WWTPs) contribute significantly to the global anthropogenic N₂O emissions. The main factors affecting N₂O emissions are the...

Previous studies have highlighted the salinization caused by the use of seawater to flush toilets and industrial wastewater entering the urban wastewater systems in coastal areas. Thus, in this study, the effect of salinity on N₂O emissions during th...

In recent years, the simultaneous partial nitrification, anammox, and denitrification (SNAD) process has attracted considerable attention due to its advantages such as low energy consumption and low sludge production. This study investigated the long...

In a biological treatment process, hydraulic retention time (HRT) has a certain effect on the operation of the reactor. This study investigated the effect of HRT on carbon sequestration in a two-stage anaerobic ammonium oxidation (anammox) process us...

Nitrogen is a main contaminant of wastewater worldwide. Novel processes for nitrogen removal have been developed over the last several decades. One of these is the partial nitritation process. This process includes the oxidation of ammonium to nitrit...

This study investigated the nitrogen removal performance of a three-stage AO reactor for refractory TN and the changes in microbial community structure within the activated sludge system under varying sodium chloride concentration conditions. Under a...

Simultaneous partial nitrification, anammox, denitrification, and fermentation (SNADF) is a novel process achieving simultaneous advanced sludge reduction and nitrogen removal. The influence of low temperatures on the SNADF reactor was explored to fa...

Anaerobic digestion (AD) produces useful biogas and waste streams with high levels of dissolved methane (CH₄) and ammonium (NH₄⁺), among other nutrients. Membrane biofilm reactors (MBfRs), which support dissolved methane oxidation in the same reactor...

The aim of this study was to explore the effect of biochar on N₂O emissions in soils with different pH levels. Soils with five pH levels (4.0, 5.1, 5.8, 6.6, and 7.2) were incubated in two conditions, with 0% biochar (CK) and 1% biochar (BC), for 23...

Massachusetts Bay in the northeastern United States is highly vulnerable to ocean acidification (OA) due to reduced buffering capacity from significant freshwater inputs. We hypothesize that acidification varies across temporal and spatial scales, wi...

The construction of an anaerobic digester coupled with post-digestion low-level aeration for agricultural wastewater treatment is described. The digester employs underwater speakers to accelerate the anaerobic digestion process while retaining solids...

Nitrification is a key process governing nitrogen (N) loss and greenhouse gas emissions in agricultural soils, and its regulation is strongly influenced by both chemical inhibitors and soil properties. Copper (Cu), a metal cofactor that is crucial fo...

Novel technologies such as partial nitritation (PN) and partial denitritation (PDN) could be combined with the anammox-based process in order to alleviate energy input. The former combination, also noted as deammonification, has been intensively stud...

The partial nitritation (PN)–anammox (PN/A) process offers a sustainable alternative to nitrogen management in wastewater treatment, addressing the high costs and increasing the low eco-friendliness associated with traditional nitrification/den...

Rare earth element (REE) mining exerts profound impacts on aquatic ecosystems, yet the microbial community responses and water quality under such stress remain underexplored. In this study, the surface (0.2 m) and subsurface (1.0 m) water along a spa...

Water from anaerobic sludge dewatering (reject water that is recycled to the inlet main process treatment) from the Knarrdalstrand municipal wastewater treatment plant in Porsgrunn, Norway, contains 2.4 g/L of total chemical oxygen demand (TCOD) and...

In order to understand the mechanisms of microbial growth on waste polyurethane sponge materials, their effectiveness as biomass carriers in domestic sewage with increased ammonium nitrogen content treatment was assessed. Comparative experiments were...

The anammox process is considered as a revolutionary new denitrification technology. In this study, the anammox process was started in a single-stage moving bed biofilm reactor (MBBR) and the mechanism of excess removal of ammonia nitrogen was studie...

Soil nitrogen (N) is critical for crop yield. Although previous studies have shown that straw return enhances soil mineral N availability, the response of soil aggregate microbes to straw return and its impact on soil mineral N availability remains u...

Cool-climate maize fields are characterized by low soil temperatures, strong seasonal hydrothermal fluctuations, and peat-influenced soil profiles, which may lead to patterns of nitrogen (N) cycling distinct from those in conventional agricultural so...

A comprehensive hydrochemical, stable isotope and microbial analyses characterisation has been performed to evaluate the sources of groundwater, nitrogen pollution and degradation processes occurring in an industrial polluted coastal aquifer in the f...

To date, the management of high-strength wastewater represents a serious problem. This work aims to evaluate the performance on chemical pollutants and on sludge production of one of the two full-scale thermophilic membrane bioreactors (ThMBRs) curre...

De novo granulation of autochthonous microorganisms of water and wastewater reduces the start-up periods for cultivating aerobic granular sludge (AGS) and enrichment of degrading strains. However, it has not been demonstrated using refractory carbon...

Nitrous oxide (N₂O), as one of the important greenhouse gases in the atmosphere, has a significant impact on global climate change. Its emissions are significantly regulated by land use changes, especially in ecologically fragile semi-arid areas. How...

The study of two-stage partial nitrification–anaerobic ammonium oxidation (PN/A) reactors, which are advantageous in engineering applications, still lacks research on process kinetics. Therefore, in this study, the start-up performance and proc...

Given increasingly prominent environmental issues, there is a pressing need to satisfy more stringent emission standards for wastewater treatment plants (WWTP) while concurrently prioritizing energy conservation; a new up-flow layered nitrogen remova...

To address the bottleneck of poor biological nitrogen removal efficiency caused by the extremely low carbon-to-nitrogen (C/N) ratio of domestic sewage in alpine plateau regions, this study used Hordeum vulgare var. coeleste L., a characteristic crop...

The aim of this 15-month study was to evaluate and compare two partially saturated (PS) vertical flow (VF) wetlands for total nitrogen (TN) removal. The PS VF wetlands, evaluated in duplicate, were added with corncob (CC) in two different heights of...

Mature landfill leachates are characterized by high levels of ammoniacal nitrogen which must be reduced for discharge in the sewer system and further treatment in municipal wastewater treatment plants. The use of anammox-based processes can allow for...

Deammonification, which is based on partial nitritation and anammox (PN/A), is a well-established sidestream treatment for nitrogen removal. However, transferring deammonification to mainstream wastewater treatment remains challenging due to low temp...

Denitrification and nitrification are two pivotal microbial processes relating to N₂O emissions. However, the difference in N₂O emission fluxes and N₂O-producing bacteria between a karst (KA) and non-karst area (NKA) remains unclear. The objective of...

Groundwater nitrate (NO₃⁻) pollution sources and in situ attenuation were investigated in Kisumu city and Kano plains. Samples from 62 groundwater wells consisting of shallow wells (hand dug, depth <10 m) and boreholes (machine drilled, depth >...

Decentralized graywater treatment using nature-based systems represents a sustainable, low-energy alternative to centralized wastewater technologies, particularly in water-scarce regions. This study evaluates the performance of a rain-garden-based co...

Anammox is a promising approach for biological nitrogen removal, but the differences in microbial community structure across different systems and their response mechanisms to environmental factors remain unclear. In this study, 206 microbial samples...

Planting a deep-rooted green manure (GM) (more than 1.0 m depth) greatly improves soil fertility and reduces the loss of nutrients. However, few studies have examined the response of soil nitrogen (N) distribution in the soil profile and subsoil N re...

Zinc oxide nanoparticles (ZnO NPs) are widely used and exposed to the soil environment, but their effect on soil nitrous oxide (N₂O) emissions remains unclear. In this study, a microcosm experiment was conducted to explore the effects of different Zn...

Nitrous oxide (N₂O) is recognized as a potent greenhouse gas, and 60% of atmospheric N₂O emissions come from cropland soils. Potassium (K) is an important fertilizer for rice paddy fields. K fertilizer decreased the abundance of functional genes medi...