Use of nitrifying and denitrifying bacteria to remove ammonia from waste water had been studied for a long time due to their high efficiency and low cost. Nitrifying bacteria not only grow slowly but also require high concentration of oxygen to facilitate the nitrifying process. Moreover, the followed denitrifying process needs the supply of adequate carbon sources for denitrifying bacteria to avoid greenhouse gas emission from the system. It shows the operational control to remove ammonia from waste water would be very difficult. Therefore, it is important to study the physiological and biochemical characteristics of those nitrifying and denitrifying bacteria closely. In 1995, Mulder discovered the disappearance of ammonium at the expense of nitrate and nitrogen production from their denitrifying pilot plant in the Netherlands, then van de Graaf verified an ANAMMOX reaction in the laboratory. Further studies that have revealed the combination of aerobic nitrification and anaerobic ammonium oxidation is more efficient to remove ammonia than most conventional methods. The ANAMMOX process is performed by a group of Planctomycete which involves the oxidation of ammonia anaerobically with nitrite as the final electron acceptor to yield gaseous nitrogen. Since this process is no need of supply external carbon source and oxygen, the ANAMMOX system can offer the advantages of less cost, less microbial contamination and less N2O and NO emission to the environment. This study is to summarize the bacterial species diversity, distribution in nature, their physiological characteristics, and potential biochemical pathways of those nitrogen converting microorganisms. In addition, several novel nitrogen removal technologies are also discussed for further understanding of the process optimization under both aerobic and anaerobic conditions.

Despite the environmental significance of microbial manganese reduction, the molecular mechanism of microbial manganese respiration remains poorly understood. Soluble Mn(III) has been recently found to be a dominant soluble species in aquatic systems, yet little is known about the identity of microbial populations catalyzing Mn(III) reduction in the environment nor the molecular mechanism of Mn(III) respiration. In this research, a suite of Mn(III) reduction-deficient mutant strains were isolated, including Mn(III) reduction-deficient mutant strain Mn3-1 that also displayed the ability to reduce soluble organic-Fe(III), but not solid Fe(III) oxides, demonstrating for the first time that the reduction of soluble organic-Fe(III) and solid Fe(III) oxides proceed through electron transport pathways with at least one distinct component. This work also shows that the electron transport pathway for Mn(III) reduction in S. oneidensis shares many of the electron transport components of Fe(III) and Mn(IV) reduction pathways and that Mn(IV) reduction to Mn(II) proceeds step-wise through two one-electron transfer reactions with Mn(III) as a transient intermediate. Finally, sediment incubations were carried out to enrich for NH4+ oxidizing- Mn(III) reducing consortia. The Mn(III) reducing consortium was found to be dominated by an electrogenic Ochrobactrum sp. and a Shewanella sp. The isolated Shewanella strain is able to oxidize acetate with Mn(III) as electron acceptor, an activity never observed before in a metal-reducing member of the Shewanella genus.

Humans have dramatically increased the amount of reactive nitrogen cycling through the biosphere. In coastal systems, excess nitrogen can lead to negative impacts. Thus, it is crucial to understand how nitrogen is cycled within, and eventually removed from, marine systems and the variables that regulate these processes. Sediment denitrification (the microbial conversion of nitrate (NO3^-) to dinitrogen (N2) gas) and water column nitrification (the two step oxidation of ammonium (NH4^+) to nitrite (NO2^-) and then nitrate (NO3^-)) rates were quantified along an in situ gradient of environmental conditions from an estuary to the continental shelf off Rhode Island, USA. Sediment net denitrification rates were directly measured over multiple seasonal cycles using the N2/Ar technique. Denitrification rates ranged from 20-75 μmol m^-2 hr^-1 (mean 44±4), indicating that this process removes ~5% of total reactive nitrogen entering the North Atlantic shelf region per year. Based on model results, these rates also represented a three-fold decrease in sediment nitrogen removal in New England continental shelf sediments over the past century. A literature review of marine water column nitrification observations were compiled to evaluate how ammonium, nitrite, and total oxidation rates vary worldwide. Rates of ammonium, nitrite, and total oxidation differed among estuary, continental shelf, and open ocean environments (p<0.05). This review highlights that as we continue to study marine "nitrification," it is necessary to consider both individual oxidation processes and environment type. Water column ammonium and nitrite oxidation rates were measured using stable isotope tracers off Rhode Island. At all study sites, nitrite oxidation rates (0-99 nM d^-1) outpaced ammonium oxidation rates (0-20 nM d^-1). These oxidation processes responded in dissimilar ways to in situ water column conditions (depth, salinity, dissolved oxygen, and pH), and these relationships varied with location. Nitrous oxide (N2O) production rates up to 10 times higher than ammonium oxidation indicated that ammonium oxidation may be underestimated if this byproduct is not measured. For the first time, the link between sediment metabolism and water column nitrification was also examined, and the results highlight the importance of benthic-pelagic coupling as controlling factor of water column ammonium and nitrite oxidation. / 2019-04-30T00:00:00Z

No description available.

published_or_final_version / Civil Engineering / Master / Master of Philosophy

As concentrações de carbono inorgânico e compostos sulfurados a partir das quais pode haver melhoria ou inibição do processo ANAMMOX variam muito na literatura especializada. Características como o tipo de efluente, inóculo, reator, temperatura, pH e tempo de detenção hidráulica influenciam as respostas obtidas em cada trabalho. A presente pesquisa teve como objetivo encontrar uma relação ideal entre as concentrações de bicarbonato e sulfeto utilizadas pelas bactérias responsáveis pelo processo. Para isso, na etapa 1, tentou-se enriquecer biomassa ANAMMOX em um reator contínuo de leito fixo utilizando lodo de uma lagoa aerada proveniente da ETE da indústria \"Incofap\", fabricante de ração animal no município de Araraquara (São Paulo). Posteriormente, na etapa 2, para encontrar a relação ideal entre bicarbonato e sulfeto, optou-se por utilizar reatores em batelada inoculados com lodo proveniente de um reator experimental ANAMMOX previamente enriquecido. Tais reatores foram alimentados com substrato sintético contendo a mesma concentração de nitrogênio amoniacal e nitrito (70 mgN/l), enquanto variou-se as concentrações de bicarbonato (5 - 125mgHCO3-/l) e sulfeto (0 - 32 mgS2-/l) por meio de um planejamento fatorial 2 x 2. Concluiuse, na etapa 1, que o lodo da \"Incofap\" possui grande potencial para processos de nitrificação parcial e desnitrificação heterotrófica, desde que condições de microaeração e estrita anaerobiose, respectivamente, sejam satisfeitas. Enquanto isso, na etapa 2, concluiu-se que qualquer presença de sulfeto no meio prejudica o processo ANAMMOX e quanto mais próximo da razão teórica estiver a concentração de bicarbonato, melhor é a atividade microbiana. / The concentrations of inorganic carbon and sulfur compounds from which there may be improvement or inhibition of the ANAMMOX process vary greatly in the literature. Characteristics such as the type of effluent, inoculum, reactor, temperature, pH and time of hydraulic detention influence the responses obtained in each work. The present research had as objective to find an ideal relation between the concentrations of bicarbonate and sulfide used by the bacteria responsible for the process. For this, in step 1, we tried to enrich ANAMMOX biomass in a continuous bed reactor using sludge from an aerated lagoon from the WWTP of the industry \"Incofap\", animal feed manufacturer in the city of Araraquara (São Paulo). Later, in step 2, to find the ideal relationship between bicarbonate and sulfide, we decided to use batch reactors inoculated with sludge from a previously enriched ANAMMOX experimental reactor. These reactors were fed with synthetic substract containing the same concentration of ammonium nitrogen and nitrite (70 mgN/l), while varying the concentrations of bicarbonate (5 - 125 mgHCO3-/l) and sulfide (0 - 32 mgS2-/l ) by means of a 2 x 2 factorial design. In stage 1, it was concluded that the \"Incofap\" sludge has great potential for partial nitrification and heterotrophic denitrification, provided that microaeration conditions and strict anaerobiosis are respectively satisfied. Meanwhile, in step 2, it was concluded that any presence of sulfide in the medium impairs the ANAMMOX process and the closer to the theoretical ratio is the bicarbonate concentration, better is the microbial activity.

No description available.

As concentrações de carbono inorgânico e compostos sulfurados a partir das quais pode haver melhoria ou inibição do processo ANAMMOX variam muito na literatura especializada. Características como o tipo de efluente, inóculo, reator, temperatura, pH e tempo de detenção hidráulica influenciam as respostas obtidas em cada trabalho. A presente pesquisa teve como objetivo encontrar uma relação ideal entre as concentrações de bicarbonato e sulfeto utilizadas pelas bactérias responsáveis pelo processo. Para isso, na etapa 1, tentou-se enriquecer biomassa ANAMMOX em um reator contínuo de leito fixo utilizando lodo de uma lagoa aerada proveniente da ETE da indústria \"Incofap\", fabricante de ração animal no município de Araraquara (São Paulo). Posteriormente, na etapa 2, para encontrar a relação ideal entre bicarbonato e sulfeto, optou-se por utilizar reatores em batelada inoculados com lodo proveniente de um reator experimental ANAMMOX previamente enriquecido. Tais reatores foram alimentados com substrato sintético contendo a mesma concentração de nitrogênio amoniacal e nitrito (70 mgN/l), enquanto variou-se as concentrações de bicarbonato (5 - 125mgHCO3-/l) e sulfeto (0 - 32 mgS2-/l) por meio de um planejamento fatorial 2 x 2. Concluiuse, na etapa 1, que o lodo da \"Incofap\" possui grande potencial para processos de nitrificação parcial e desnitrificação heterotrófica, desde que condições de microaeração e estrita anaerobiose, respectivamente, sejam satisfeitas. Enquanto isso, na etapa 2, concluiu-se que qualquer presença de sulfeto no meio prejudica o processo ANAMMOX e quanto mais próximo da razão teórica estiver a concentração de bicarbonato, melhor é a atividade microbiana. / The concentrations of inorganic carbon and sulfur compounds from which there may be improvement or inhibition of the ANAMMOX process vary greatly in the literature. Characteristics such as the type of effluent, inoculum, reactor, temperature, pH and time of hydraulic detention influence the responses obtained in each work. The present research had as objective to find an ideal relation between the concentrations of bicarbonate and sulfide used by the bacteria responsible for the process. For this, in step 1, we tried to enrich ANAMMOX biomass in a continuous bed reactor using sludge from an aerated lagoon from the WWTP of the industry \"Incofap\", animal feed manufacturer in the city of Araraquara (São Paulo). Later, in step 2, to find the ideal relationship between bicarbonate and sulfide, we decided to use batch reactors inoculated with sludge from a previously enriched ANAMMOX experimental reactor. These reactors were fed with synthetic substract containing the same concentration of ammonium nitrogen and nitrite (70 mgN/l), while varying the concentrations of bicarbonate (5 - 125 mgHCO3-/l) and sulfide (0 - 32 mgS2-/l ) by means of a 2 x 2 factorial design. In stage 1, it was concluded that the \"Incofap\" sludge has great potential for partial nitrification and heterotrophic denitrification, provided that microaeration conditions and strict anaerobiosis are respectively satisfied. Meanwhile, in step 2, it was concluded that any presence of sulfide in the medium impairs the ANAMMOX process and the closer to the theoretical ratio is the bicarbonate concentration, better is the microbial activity.

The presence of nutrients, such as nitrogenous compounds, in wastewater can pose serious environmental concerns to water systems leading to reduced water quality and potential risks to the public health. Nutrient removal in conventional wastewater treatment systems is becoming increasingly more costly due to the extensive energy requirements and high aeration costs. Anaerobic ammonium oxidation (Anammox) is an alternative method for nutrient removal which can reduce overall treatment costs due to less aeration requirements and less sludge production. Anammox process can be implemented with other innovative technologies, such as membrane aerated biofilm reactors (MABR) to achieve effective and sustainable nutrient removal. A major challenge associated with Anammox process is effective control of nitrite oxidizing bacteria (NOB). High temperature in wastewater treatment systems can promote Anammox bacterial growth and inhibit NOB activity. This research aims to investigate the feasibility of integrating Anammox processes with MABR technologies and to examine the effects of high temperature aeration supplied to MABR systems on Anammox bacterial growth and NOB suppression. The nitrogen removal by Anammox bacteria in a lab-scaled MABR is examined to determine the impact of aeration temperature on inhibition of NOB. / Thesis / Master of Applied Science (MASc)

In an effort to develop cost-effective technologies for the removal of ammonium nitrogen from dairy waste, a novel biological wastewater treatment process, utilizing anaerobic ammonium oxidation (anammox), referred to as Oxygen-Limited Autotrophic Nitrification and Denitrification (OLAND) was examined. Due to the potential use of OLAND-based systems in dairy manure management, a detailed water quality assessment of a modern dairy farm manure treatment-system was conducted. The Johnson Highland Dairy Farm, Glade Spring, Virginia, was selected for this assessment and a comprehensive analysis of the wastewater characteristics throughout the confined animal feeding operation was completed. The results suggest that ammonia concentrations in the anaerobic storage facility was high enough to justify use of treatment technologies that reduce ammonia loads in stored dairy waste. A lightly loaded Fixed Film Bioreactor (FFBR), in which the OLAND process was desired to occur, was then constructed in the laboratory and monitored over 51 days. Of particular interest was the time taken to achieve stable performance of this OLAND system. Furthermore, a protocol was developed to determine whether OLAND based metabolism was occurring. Ammonium nitrogen removal efficiency in the FFBR throughout the 51-day monitoring period was high, averaging approximately 95 % for the length of the study. From day 32 to 51, simultaneous removal of both ammonium and nitrite with a low level of concomitant nitrate production was observed, a key indicator of possible anammox activity. Stoichiometric ratios calculated for the FFBR compared favorably with those already established for OLAND systems. The developed protocol, incorporating anaerobic and aerobic batch experiments, to verify the occurrence of OLAND based metabolism did not yield expected results and described poorly what was being observed in the FFBR. Volatilization of ammonia during the experimental test was suspected and should be controlled when the protocol is performed in the future. / Master of Science