Effect Of Ammonia Nitrogen Research Articles

Effect of dissolved oxygen and ammonia nitrogen on Culter alburnus: Physiology, biochemistry, and molecular analyses

Culter alburnus (topmouth culter)is an economically valuable freshwater fish. However, its insufficient tolerance to dissolved oxygen (DO) and ammonia nitrogen (AN) hinders its industrialisation. 360 experimental fish (4.87 ± 1.10 g) were placed in breathing chambers (oxygen level was 0.70–6.50 mg/L) or water tanks (control AN, 0 mg/L; low AN, 8 mg/L; high AN, 16 mg/L). This study analysed the effects of DO and AN on C. alburnus at physiological, biochemical, and molecular levels. (1) Physiology level: the floating point, coma critical point, and coma point at 20 °C group were significantly higher than those at 30 °C. The oxygen consumption rate of C. alburnus at 20 °C, 25 °C, and 30 °C was (256.65 ± 25.87), (470.47 ± 83.84), and (520.87 ± 55.40) mg/kg.h. The LC50 of AN after 96 h was 24.13 mg/L, and the safe concentration was 2.41 mg/L. The survival rate in the high AN group was significantly lower than that in the other two groups. (2) Biochemistry level: The change curves of antioxidant enzyme activity in the liver tissue under hypoxic stress reached a maximum at 12 h and then decreased. In addition, the increase and decrease in enzyme activity (except malondialdehyde) in the high AN group was lower than that in the low AN group. (3) Molecular level: the angiotensin-converting enzyme and carboxypeptidase genes were the major differentially expressed genes (DEGs) in hypoxic stress, and the DEGs were mainly enriched in the ABC transporter signal transduction pathway. In addition, the serum/glucocorticoid-regulated kinase, stearoyl-CoA desaturase, and 3-hydroxy-3-methylglutaryl-coenzyme A reductase genes were among the major DEGs under high AN stress. The DEGs were mainly enriched in steroid biosynthesis or glycine, serine, and threonine metabolism transporter signal transduction pathways. In summary, it is necessary to focus on the DO and AN during C. alburnus breeding.

Effects of Ammonia Nitrogen, Nitrite and pH on Embryo In Vitro Incubation of Red Crayfish

As an important economic aquatic animal, red crayfish’s reproduction and incubation can affect its breeding efficiency. With aquaculture developing, the study of factors affecting aquaculture species growth has gradually become an important research direction. To study the effects of ammonia nitrogen, nitrite and pH on red crayfish embryos, the In Vitro incubation experiment of red crayfish embryos was conducted. The residual module was used to design the embryo counting method of red crayfish. And different ammonia nitrogen, nitrite and PH gradients were set to analyze the hatching rate and emergence rate of red crayfish’s embryo development.When conducting research method performance testing, the training loss value of the research method decreased to 84 after 200 iterations. On the 6th day in an ammonia nitrogen environment, the number of water microbiota was only 4.74 M. The emergence rate of red crayfish decreases to a lower level when the ammonia nitrogen concentration is above 0.6 mg/L. The emergence rate of red crayfish decreased with the increase of nitrite concentration, and decreased to 0 when the nitrite concentration reached 1.25 mg/L. When the pH value of water body is 8.1, the emergence rate of red crayfish reaches the highest value of 68.92%. Ammonia nitrogen and nitrite concentration will inhibit the In Vitro hatching of crayfish embryos, and the appropriate PH value can improve the emergence rate of crayfish hatching In Vitro.

Effects of ammonia nitrogen and organic carbon availability on microbial community structure and ecological interactions in a full-scale partial nitritation and anammox (PN/A) system

Nutrient availability significantly impacts microbial biosynthesis, cell growth, and cell cycle progression. In this study, a full-scale plug-flow partial nitritation/anammox (PN/A) system was used to investigate variations in the microbial community structure in both immobilized carriers and flocs, as well as a gradual decrease in nutrient availability from upstream to downstream. We found that reduced ammonia nitrogen (from 150.4 to 30.6 mg/L) and organic carbon (from 415.7 to 342.8 mg/L) availability significantly lowered microbial diversity and altered microbial communities in biofilms other than flocs from upstream to downstream. The abundance of all anammox bacteria increased by 1.97 times, from 3.25×1010 to 6.40×1010 copies per gram of wet sludge, in the biofilm core microbiome. Furthermore, from upstream to downstream, taxa with lower ribosomal RNA operon copy numbers were consistently enriched in both biofilm and floc communities, indicating that slow-growing microorganisms are more likely to be enriched in low-nutrient environments. Rare taxa with a relative abundance of less than 0.1% exhibited unique metabolic functions, including amino acid, carbohydrate, cofactor, and vitamin metabolisms, which was inferred by PICRUST2 and persisted across the nutrient gradient in both the biofilm and floc communities. Despite their low abundance, they may play important roles in mediating the stability and function of the PN/A system. Overall, the results demonstrate the impact of a naturally formed ammonia nitrogen and organic carbon gradient in a full-scale plug-flow PN/A installation on nutrient availability and its effects on microbial diversity, community composition, and microbial interactions, which expands our fundamental understanding of this energy-efficient and promising biotechnology for treating high-strength ammonium wastewater.

The effect of ammonia nitrogen, nitrite and pH on artificial incubation of red claw crayfish Cherax quadricarinatus eggs and growth of juveniles

The effect of ammonia nitrogen, nitrite and <scp>pH</scp> on artificial incubation of red claw crayfish <i>Cherax quadricarinatus</i> eggs and growth of juveniles

Effect of ammonia nitrogen and microorganisms on the elevated nitrogenous biochemical oxygen demand (NBOD) levels in the Yeongsan river in Gwangju

Effect of ammonia nitrogen and microorganisms on the elevated nitrogenous biochemical oxygen demand (NBOD) levels in the Yeongsan river in Gwangju

Adsorption of levofloxacin on natural zeolite: effects of ammonia nitrogen and humic acid.

The persistence of antibiotics in sewage treatment plants in recent years has become a serious problem. Meanwhile, humic acid and ammonia nitrogen are widely distributed in natural reservoirs and might influence the sorption, migration and transformation of antibiotics. In this study, natural zeolite (NZ) was evaluated as an adsorbent for the removal of levofloxacin (LEV). The physical and chemical properties of NZ before and after adsorption were characterized by various analytical techniques to develop the mechanism. The effects of ammonia nitrogen and humic acid (HA) on the interfacial behavior of LEV on NZ were explored. Comparative experiments revealed that LEV adsorption on NZ involved electrostatic interactions and ion exchange, and the adsorption processes were well fitted by the Langmuir isotherm model and pseudosecond-order kinetic model. The maximum experimental adsorption capacity of LEV was 22.17 mg·g-1 at pH 6.5. The presence of ammonia nitrogen and HA significantly suppressed the adsorption of LEV due to competitive adsorption, and the adsorption capacity decreased 58 and 46%, respectively. It is obvious that low concentrations of ammonia nitrogen and HA are conducive to improving the treatment effect of sewage. This study demonstrates that NZ is a promising and efficient material for LEV adsorption.

Comparison of immune defense and antioxidant capacity between broodstock and hybrid offspring of juvenile shrimp (Macrobrachium nipponense): Response to acute ammonia stress

Ammonia is a major environmental pollutant in the aquatic system that poses a great threat to the health of shrimp. Macrobrachium nipponense, as one of the large-yield farmed shrimp, is facing germplasm degradation. Genetic improvement through hybridization is one of the effective methods to solve this problem. However, there are few studies on the effects of ammonia nitrogen on the germplasm resources of M.nipponense. In this study, the broodstock populations (Dianshan, DS) and hybrid offspring (DS ♀×CD [Changjiang, CJ ♂×Dongting, DT ♀], SCD) were exposed to 0, 5, or 20mg/L of ammonia for 96h. The survival rate of the SCD group was greater than the DS group, although there were no significant differences in weight gain rate and length gain rate (p>0.05). The number of positive cells and apoptosis rates in the DS group were significantly greater than in the SCD group after ammonia exposure (p<0.05). As the ammonia concentration increased, the antioxidant enzyme activities in the SCD group were significantly higher than DS group, while the hepatotoxicity enzyme activities in the SCD group were significantly lower than DS group (p<0.05). The trends in the expression of antioxidant- and immune-related genes were generally consistent with the activities of antioxidant enzymes. Our study found that the hybrid population had stronger stress resistance than their parent populations at the same ammonia concentration. This study confirms our speculation that hybrid population has a greater advantage in antioxidant immunity, which also provides reference for the follow-up study of chronic ammonia toxicity.

Effect of ammonia nitrogen on the detoxification metabolic pathway of cuttlefish (Sepia pharaonis)

The goal of this research was to explore the detoxification metabolic pathway and regulatory mechanism of the cuttlefish (Sepia pharaonis) under ammonia nitrogen stress. This study investigated the ammonia and urea contents in the hemolymph and liver and the amino acid contents in the liver using high-performance liquid chromatography (HPLC) and examined the changes in the activities and mRNA expression of key enzymes in the ammonia nitrogen metabolic pathway under different ammonia nitrogen stress concentrations (1 mg/L, 3 mg/L, 6 mg/L and 12 mg/L). The main conclusion was that the key indices of the urea metabolic pathway showed obvious time-concentration effects under ammonia nitrogen stress. An ornithine-urea cycle metabolic pathway was confirmed to exist in cuttlefish at the transcriptional and metabolic levels. Under low ammonia nitrogen stress, cuttlefish can detoxify ammonia nitrogen into urea through urea metabolism. However, the metabolic pathway of the urea cycle is inhibited under high ammonia nitrogen stress (≥12 mg/L). Second, under ammonia nitrogen stress, the contents of glutamine, taurine, proline, glycine (except under high concentration stress), citrulline and tyrosine in the liver tissue increased significantly (P < 0.05). Aspartic acid and alanine initially increased and then decreased with the concentration of ammonia nitrogen. In summary, under ammonia nitrogen stress, cuttlefish may utilize the urea and amino acid metabolic pathways. Converting ammonia nitrogen to urea and amino acids (glutamine, taurine, proline, glycine, aspartic acid, alanine, citrulline and tyrosine) reduces the ammonia nitrogen content in the body. However, under high ammonia nitrogen stress, the urea cycle pathway and some amino acid metabolic pathways (such as aspartic acid and alanine) are inhibited.

Simulation of Denitrification Process of Calcium Nitrate Combined with Low Oxygen Aeration Based on Double Logarithm Mode

In situ remediation of sediment pollution is an important measure for the treatment of urban black-odorous water. In this study, the process of calcium nitrate dosing and low oxygen aeration was used to repair the sediment of black-odorous water body in a glass container. The variation trend and removal efficiency of ammonia nitrogen and nitrate nitrogen in sediment and overlying water were investigated during the process. By establishing the double logarithm model of calcium nitrate sediment repair process, the change law of ammonia nitrogen and nitrate nitrogen content in sediment under different calcium nitrate dosing conditions was studied, and the denitrification process of different calcium nitrate dosing and low oxygen aeration was simulated. The results showed that by establishing the double logarithm model of calcium nitrate sediment remediation process, when the dosage of calcium nitrate was 6%, the inhibition rate of calcium nitrate on nitrate nitrogen release was the largest. The stable inhibitory concentration of nitrate nitrogen was 11.65 mg/g, and the stable inhibited concentration of ammonia nitrogen was 382.95 mg/kg. The stable inhibitory concentration of nitrate nitrogen and ammonia nitrogen in overlying water was 8.34 mg/L and 16.47 mg/L. Moreover, excessive calcium nitrate (8%) may increase the risk of microbial ecological environment in sediment and weaken the inhibitory effect. The optimum parameters were the calcium nitrate dosage of 6%, the reaction time of 21 days, and the aeration rate of 30 mL/min. Under these conditions, the removal effect of ammonia nitrogen in sediment and overlying water was further improved, and the concentration of nitrate nitrogen was effectively controlled. The stable inhibitory content of nitrate nitrogen in sediment was 5.55 mg/g, and the stable inhibitory content of ammonia nitrogen was 982.79 mg/kg. The stable inhibitory concentration of nitrate nitrogen and ammonia nitrogen in overlying water was 6.55 mg/L and 118.20 mg/L. Based on a simulation, this study provides important technical support for the formulation of a refined endogenous pollution control scheme by controlling the process of calcium nitrate remediation and low oxygen aeration.

Effects of ammonia nitrogen on early growth and survival of the ‘Zebra 2’ strain of the manila clam ( Ruditapes philippinarum )

The ‘Zebra 2’ strain of the Manila clam (Ruditapes philippinarum) is a newly bred for aquaculture in the low temperature Bohai and Yellow seas in northern China. The goal of this study was to determine the tolerance of ‘Zebra 2’ clams at early developmental stages to total ammonia nitrogen (TAN) under acute stress and continuous subacute stress levels. ‘Zebra 2’ were cultured under TAN stress at water salinity of 27–28, temperature of 21–28°C and pH of 8.0–8.2. Survival rate and production of clams from the fertilized egg to juvenile stages were measured. The acute stress test revealed that the median effective concentrations of TAN for hatchability and deformity of fertilized eggs at 24 h were 7.08 and 15.12 mg/L, with the unionized ammonia (UIA) at 0.22 and 0.36 mg/L respectively. The 50% lethal concentrations for D-shaped larvae (shell length 101.50 μm), umbo larvae (179.67 μm) and juveniles (610.50 μm) at 96 h were 3.28, 48.90 and 57.57 mg/L, with UIA at 0.10, 2.08 and 2.99 mg/L respectively. These results suggested that the ‘Zebra 2’ clams hatching and D-shaped larvae stages were most sensitive to TAN and that the tolerance significantly increased after the umbo larval stage. In the continuous subacute stress test, ‘Zebra 2’ juveniles were observed under all the treatments after 53 days of exposure to TAN stress at 5.45 mg/L (0.23 mg/L UIA). The maximal acceptable toxicant concentration of UIA used to determine the mortality rate, yield and relative yield was ranged from 0.12 to 0.23 mg/L. These findings suggested that maintaining TAN <0.22 mg/L and UIA ≤0.021 mg/L at seawater pH ≤8.5, salinity ≥25 and water temperature ≤25°C would improve larval rearing of ‘Zebra 2’ clams.

The mechanisms of conventional pollutants adsorption by modified granular steel slag

This study was performed to investigate the removal of phosphorus, nitrogen, ammonia and dissolved organic matter (DOM) from domestic wastewater using modified granular steel slag (GSS) as adsorbent. The modification methods include acid modification, alkalinity modification and thermal modification. The GSS modified at 800°C for 1 h was easier to hydrolyze Ca&lt;sup&gt;2+&lt;/sup&gt;, which could promote the precipitation of phosphates and the ion exchange process of ammonia. Therefore, the adsorptive capacity of GSS for phosphates and ammonia could be significantly improved by the thermal treatment. The acid-modified GSS promoted the adsorption capacity of nitrates by increasing surface protonation, specific surface area and pore size. The highest nitrates adsorption capacity was obtained when GSS was immersed in 1 mol/L HCl solution for 24 h. The presence of nitrates inhibited the adsorption of phosphates by GSS because the adsorption of nitrates and phosphates by GSS depended largely on electrostatic attraction and intermolecular force, and the competition between them reduced the adsorption capacity. Ammonia can promote the hydrolysis of metal ions on the surface of GSS, increase the concentration of metal ions in solution and promote the formation of phosphate precipitation, but ammonia also competed with phosphate for active sites on the surface of GSS. The effect of ammonia nitrogen on phosphate adsorption was the result of the interaction of the two mechanisms. For domestic wastewater, the thermally modified GSS showed the best adsorption rate of total phosphorus and total nitrogen, and the acid-modified GSS had better adsorption capacity for organic matter. The thermally modified GSS had a good application effect in laboratory subsurface flow constructed wetlands.

Effect of Nitrogen on Magnesium Modified Biochar Adsorption to Phosphorus

The effect of ammonia-nitrogen in water on phosphorus removal by magnesium modified biochar (MBC) was developed to increase the utilization of wetland plants. The crystal structures were measured by X-ray powder diffraction (XRD). MBC was prepared using reed as the biomass feedstock, which was modified with magnesium chloride. The raw biochar (BC) was prepared as a control. The removal of phosphate from solution using four different methods, i.e. MBC, BC, BC, and MgCl2 solutions (BC+Mg2+) and MgCl2 solutions (Mg2+), under different nitrogen to phosphorus molar ratios and initial phosphorus concentrations was investigated in batch experiments. The results demonstrated that the phosphorus removal efficiency of the four treatment methods, which followed the order of MBC>>BC+Mg2+≈Mg2+>BC. NH4+ in the solution, promoted phosphorus removal by MBC. In addition, the larger the ratio of nitrogen to phosphorus and the higher the initial phosphorus concentration, the stronger the phosphorus removal capacity of MBC was. In the three treatments with MBC, BC+Mg2+, and Mg2+, the XRD analysis showed that NH4+ reacted with Mg2+ and PO43- in the solution to form MgNH4PO4·6H2O at N:P=5 or 10, promoting the removal of phosphorus. For recycling purposes, waste biomass from constructed wetlands could be used to produce MBC and treat polluted water rich in ammonium and phosphate. Moreover, the ammonium-nitrogen promotes the phosphate removal by MBC. The results from this study provide a new theoretical basis and data support for the treatment of water eutrophication.

Effects of different forms of nitrogen on chlorophyll-a and microcystin production of &lt;i&gt;Microcystis&lt;/i&gt; sp.

Adopting the method of batch culture,the effect of ammonia nitrogen and nitrate nitrogen at different concentrations on the production of chlorophyll-a and microcystin of Microcystis sp.isolated from Yanghe Reservoir was investigated.Results showed that,when Microcystis sp.was cultured with ammonia nitrogen,contents of chlorophyll-a increased with ammonia nitrogen concentration in the logarithmic growth phase.However,the high concentration inhibited the growth of algae cells.The productions of MCRR fluctuated with the increase of ammonia nitrogen concentration.There was a remarkable rise of microcystin productions,reaching to 6.345×10-8μg/cell,when the concentration of ammonia nitrogen was 10.0 mg/L.This was significantly different with other treatments.When Microcystis sp.was cultured with nitrate nitrogen condition,contents of chlorophyll-a increased undulately with the increasing of nitrate nitrogen concentration,and there was no difference among different groups.The productions of microcystin under high concentration increased with the concentration during the logarithmic growth phase.They increased to 1.223×10-8μg/cell when the concentration was 5.0 mg/L,and reached the maximum value which was far less than that of the ammonia nitrogen group.There was no significant difference on the growth of algae between the two nitrogen sources.Ammonia nitrogen was more beneficial to the synthesis of chlorophyll-a in algae cells with nitrogen concentration increasing under lower concentration(1.5-5.0 mg/L) during the logarithmic growth phase.The productions of microcystin under ammonia nitrogen condition were far larger than nitrate nitrogen group at the range of 1.0-10.0 mg/L,and there was significant difference among the groups.Overall,ammonia nitrogen was more easily to lead to the secretion of MCRR in algae cells.

Effect of Ammonia Nitrogen and Dissolved Organic Matter Fractions on the Genotoxicity of Wastewater Effluent during Chlorine Disinfection

Chlorine is a widely used disinfectant which prevents the spread of harmful pathogens when reusing wastewater, but harmful byproducts might be formed and cause adverse ecological and health effects. In this study, the potential effects of chlorination on the genotoxicity of different biologically treated wastewater samples were investigated using the umutest. For the firsttime, ammonia nitrogen (NH3-N) was found to significantly influence genotoxicity during wastewater chlorination. After chlorination, the genotoxicity decreased in wastewater with a low NH3-N concentration (<10-20 mg/L), but it increased notably in wastewater with a high NH3-N concentration (>10-20 mg/L). By fractionating the DOM (dissolved organic matter) in wastewater into different fractions, it was found that the hydrophilic substances (HIS) fraction of DOM was the key fraction involved in decreasing genotoxicity during the chlorination of wastewater with a low NH3-N concentration, while the hydrophobic acids (HOA) fraction of DOM was the key fraction involved in increasing genotoxicity during chlorination of wastewater with a high NH3-N concentration. Furthermore, fluorescence spectroscopy analysis on different fractions indicated that some free or combined aromatic amino acids might produce highly genotoxic byproducts during the chlorination of wastewater with a high NH3-N content, and this was then demonstrated through experiments on the chlorination of free aromatic amino acids.

EFFECT OF AMMONIA-NITROGEN ON GROWTH CHARACTERISTICS OF ACIDOGENIC BACTERIA IN ANAEROBIC DIGESTION

炭水化物とタンパク質を共に含む基質を用いた嫌気性消化における酸生成細菌の増殖特性に及ぼすアンモニア性窒素の影響を検討するため, デンプンとペプトンを用い, 反応槽内のアンモニア性窒素濃度を変化させた連続実験を行った. アンモニア負荷の増大に伴い, 炭水化物除去率が急激に減少し, 4.21g-TAN/g-VSSで20%以下になった. この炭水化物分解がアンモニアによる阻害を強く受けた条件では, 全菌体量は半減し, 炭水化物とタンパク質を共に分解可能な細菌群は主にタンパク質を分解することで増殖していたことが示された. また, 連続培養では, 炭水化物分解の大幅な減少の前段階として, エタノールが蓄積することが明らかとなった.

Effects of ammonia nitrogen on H 2 and CH 4 production during anaerobic digestion of dairy cattle manure

A number of researchers have verified the inhibitory effects of elevated H 2 concentrations on various anaerobic fermentation processes. The objective of this work was to investigate the potential for using hydrogen gas production to predict upsets in anaerobic digesters operating on dairy cattle manure. In an ammonia nitrogen overload experiment, urea was added to the experimental digesters to obtain increased ammonia concentrations (600, 1500, or 3000 mg N/l). An increase in urea concentration resulted in an initial cessation of H 2 production followed by an increase in H 2 formation. Additions of 600, 1500, or 3000 mg N/l initially resulted in the reduction of biogas H 2 concentrations. After 24 h, the H 2 concentration increased in the 600 and 1500 mg N/l digesters, but production remained inhibited in the 3000 mg N/l digesters. Both methane and total biogas production decreased following urea addition. Volatile solids reduction also decreased during these periods. The digester effluent pH and alkalinity increased due to the increased NH 4 + formed with added urea. Based on these results, changes in H 2 concentration could be a useful parameter for monitoring changes due to increased NH 3 in dairy cattle manure anaerobic digesters.