Effect Of Ammonia Concentration Research Articles

The effect of ammonia concentration on the treatment of bio electrochemical leachate using MFCs technology.

Microbial fuel cells (MFCs) have garnered attention in bio-electrochemical leachate treatment systems. The most common forms of inorganic ammonia nitrogen are ammonium ([Formula: see text]) and free ammonia. Anaerobic digestion can be inhibited in both direct (changes in environmental conditions, such as fluctuations in temperature or pH, can indirectly hinder microbial activity and the efficiency of the digestion process) and indirect (inadequate nutrient levels, or other conditions that indirectly compromise the microbial community's ability to carry out anaerobic digestion effectively) ways by both kinds. The performance of a double-chamber MFC system-composed of an anodic chamber, a cathode chamber with fixed biofilm carriers (carbon felt material), and a Nafion 117 exchange membrane is examined in this work to determine the impact of ammonium nitrogen ([Formula: see text]) inhibition. MFCs may hold up to 100mL of fluid. Therefore, the bacteria involved were analysed using 16S rRNA. At room temperature, with a concentration of 800mg L-1 of ammonium nitrogen and 13,225mg L-1 of chemical oxygen demand (COD), the study produced a considerable power density of 234 mWm-3. It was found that [Formula: see text] concentrations above 800mg L-1 have an inhibitory influence on power output and treatment effectiveness. Multiple routes removed the most nitrogen ([Formula: see text]-N: 87.11 ± 0.7%, NO2 -N: 93.17 ± 0.2% and TN: 75.24 ± 0.3%). Results from sequencing indicate that the anode is home to a rich microbial community, with anammox (6%), denitrifying (6.4%), and electrogenic bacteria (18.2%) making up the bulk of the population. Microbial fuel cells can efficiently and cost-effectively execute anammox, a green nitrogen removal process, in landfill leachate.

Design of trigeneration plant for electricity freshwater production, and district heating: A case study Periwinkle Lifestyle Estate, Lagos Nigeria

This study proposes a design of a trigeneration plant for the usage of Periwinkle Lifestyle Estate in Lagos State Nigeria. The proposed system would provide electricity, heating and freshwater requirements for residential buildings from a renewable energy source. Concentrated photovoltaic solar thermal (CPV/T) collector is used to generate the electricity and provides the required amount of thermal energy to the multistage flash desalination plant and Kalina cycle due to its high electrical and thermal effectiveness. The EES is used to model the tri-generation system by solving the governing equations with an interconnected structure, while TRNSYS and HOMER software was also used to collect the solar data for the case study area. The combined trigeneration structure can produce 0.6412 kg/s of freshwater, 1520.25 kW of electricity generation, and 91.57 kW of heat required for the district heating application, for the usage of Periwinkle lifestyle estate Lagos State Nigeria. The designed system can serve as an alternative to producing high-quality freshwater for drinking and irrigation, reliable and steady electricity and heating services during the winter season, without pollution. • A trigeneration system using CPVT is presented. • The effect of ammonia concentration on the system is analyzed. • The combined trigeneration structure can produce 0.6412 kg/s of freshwater, 1520.25 kW of electricity generation. • The proposed system can meet the electricity, heating and fresh water demands of case study city.

Synthesis of PbTiO3 nanoplates by two-step hydrothermal method with pH-adjusting agent of ammonia solution

ABSTRACT PbTiO3 nanoplates were synthesized by a two-step hydrothermal method, and ammonia solution was chosen as a pH-adjusting agent. The effect of ammonia concentration in the second-step precursors, Pb-Ti feedstock concentration, reaction temperature, and time on crystallization and morphologies of PbTiO3 nanocrystals was investigated. The typical single-crystal PbTiO3 nanoplates with stair-like edge were formed, as the nominal ammonia concentration in the first-step precursors was 8.8 mol/L, the nominal ammonia concentration in the second-step precursors was 4.4 mol/L, the nominal Pb-Ti feedstock concentration was 0.05 mol/L, and they were synthesized at 200°C for 20 h. The thickness of the PbTiO3 nanoplates was about 45 nm, and the lateral size was about 400 nm. The ammonia solution played an important role in the formation of PbTiO3 nanoplates, and the growth mechanism of PbTiO3 nanoplates synthesized by the two-step hydrothermal method in ammonia solution was discussed.

Correction to: High-solids thermophilic anaerobic digestion of sewage sludge: effect of ammonia concentration

In the original publication of the article, the Eq. 4 has been wrongly published.

High-solids thermophilic anaerobic digestion of sewage sludge: effect of ammonia concentration

High-solids thermophilic anaerobic digestion fed with sewage sludge of 7–8% and 9–10% total solids was investigated at the hydraulic retention time of 20 days in this lab-scale study. The anaerobic digester fed with 7–8% sewage sludge was successfully operated, resulting in volatile solids (VS) destruction of 57.8% and methane production of 0.327 L/gVS (at standard temperature and pressure). When fed with 9–10% sewage sludge, the control digester was upset after about 80 days of operation. Total ammonia nitrogen (TAN) of 2500 mgN/L or more caused inhibition to anaerobic microorganisms. Another digester combined with weekly batch ammonia stripping of digested sludge in a side-stream configuration (80 °C, 2 h, initial pH of 9 with NaOH and return ratio of 70%), was maintained at the average TAN of 1720 mgN/L, and was able to continue without ammonia inhibition. TAN was a better indicator on inhibition of ammonia than free ammonia nitrogen (FAN). Microbial analysis revealed poor microbial diversity of digested sludge, that is, Class Clostridia for Bacteria and Geneus Methanothermobacter and Methanosarcina for Archaea were predominated. In conclusion, high-solids thermophilic anaerobic digestion can accommodate the influent sewage sludge up to 10%, as far as TAN is properly controlled in digester.

The effect of ammonia concentration on the microstructure and electrochemical properties of NiO nanoflakes array prepared by chemical bath deposition

This paper presents the electrochromic (EC) characteristics of nickel oxide (NiO) nanoflakes array prepared by chemical bath deposition (CBD) method with different ammonia concentration. Prepared NiO films have porous structure with 2-dimensionally networked nanoflake arrays. The addition of aqueous ammonia significantly affects the growth of NiO film. Moreover, appropriate amount addition of aqueous ammonia is important in obtaining a balanced EC performance of NiO films between transmittance modulation and cycling durability. Excess concentration of ammonia cause not only a decrease in the thickness of NiO films but also change the growth direction of flakes. XPS results present that high concentration of ammonia could induce the peak shifting toward the low binding energy, which attributed from initial state effect between nickel and oxygen, which is substituted by nitrogen. The best electrochemical durability at 550 nm was achieved for NiO-25 film with high transmittance modulation (Tbleaching: 86.8% and Tcoloring: 23.4%) and noticeable cycling stability (only 25% decrease after 5000 cycles).

Evaluating the level of ammonia and sulfide in the liquid phase during anaerobic digestion of slaughterhouse waste operating at mesophilic scale digester—the impact of inhibition and process performance

The performance of experimental batch-reactor loaded with slaughterhouse waste at mesophilic temperature was investigated as well as the inhibition of both ammonia and sulfide concentration in the aqueous phase. The digester was operated for 68 days by evaluating the process stability basing on controlling parameters such as pH, volatile fatty acids and alkalinity in relation to the methane produced. The maximum CH4 content of 69.6% was achieved at 0.37 VFA/Alkalinity ratio and pH of 7.51 during day 37 of anaerobic digestion. However, a sudden increase of ammonia nitrogen in the digester from day 44 to day 68 decreased the methane content about 62.15% from 65% to 24.6%. Similarly, as the amount of sulfide content decreased in the liquid phase, gaseous H2S was elevated up to 132 ppm in the 68th day. During this time, it was observed that the ratio of VFA/Alkalinity decreased to 0.16, with a very low concentration of VFA, which was 150.92 mg/L. This phenomenon indicated that all the acids produced were consumed by methanogens and ammonia inhibition was at the highest rate due to the increase of ammonia nitrogen concentration in the last days of digestion. Furthermore, among of peculiar characteristic shown by slaughterhouse waste is the ability to maintain the pH above 7 without the addition of any buffering agent throughout the AD process. Meanwhile, the evaluation of the level of both ammonia and sulfide in the aqueous phase revealed that the inhibitory effect of ammonia concentration was higher than sulfide concentration.

Effect of ammonia concentration on hythane (H2 and CH4) production in two-phase anaerobic digestion

Co-production of hydrogen and methane by two-phase anaerobic digestion (AD) may offer a sustainable solution for the centralized treatment of food waste (FW), while ammonia accumulation is potentially encountered. A mesophilic two-phase AD was investigated for hydrogen and methane production from FW at varying ammonia concentrations. The process achieved a hydrogen yield of 47.7 mL/g VS and a methane yield of 335 mL/g VS by optimizing the organic loading rate (OLR) and recirculation ratio. Total ammonia nitrogen (TAN) concentration of 4044 mg/L corresponded to a threshold in the hydrogen reactor, above which ammonia would initiate inhibition of hydrogenogenesis and acidogenesis. Methane yield was recovered in the methane reactor after acute inhibiting effects of TAN below 5800 mg/L, while TAN above 6200 mg/L caused chronic inhibition of methanogens. Adjusting hydraulic retention time (HRT) and recirculation ratio in hydrogen and methane reactors reduced TAN to 960 and 2105 mg/L respectively, resulting in successful recovery was achieved in the hydrogen reactor but not in the methane reactor. The two-phase AD for methane and hydrogen production can be a promising solution for ammonia accumulation in AD from FW.

One-Step Synthesis of Nonspherical Organosilica Particles with Tunable Morphology

A one-step sol-gel method was developed to synthesize nonspherical organosilica particles with tunable morphology. The morphology of organosilica particles can be tuned from spherical to golf ball-like or bowl-like through varying the molar ratio of tetraethoxysilane (TEOS) to vinyltrimethoxysilane (VTMS) in the precursors. The morphology and interior structure of the organosilica particles were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. The effect of ammonia concentration on the morphology of organosilica particles was investigated. The growth process of golf ball-like and bowl-like particles was tracked by SEM in detail, and the formation mechanism of nonspherical organosilica particles was also proposed.

Hydrothermal Synthesis of PbTiO3 Nanocrystals with a pH-Adjusting Agent of Ammonia Solution

The PbTiO3 nanocrystals were synthesized by a hydrothermal method, and ammonia solution was firstly used as a pH-adjusting agent. The effect of ammonia concentration on formation and morphologies of PbTiO3 nanocrystals was investigated. At low ammonia concentration (0–2.2 mol/L), no perovskite PbTiO3 phase was formed. When the ammonia concentration was 4.4 mol/L, the rod-like PbTiO3 nanocrystals with highly crystalline were successfully synthesized. As the ammonia concentration further increased to 13.2 mol/L, the flake-like PbTiO3 nanocrystals were formed. The PbTiO3 nanocrystals were firstly synthesized by the hydrothermal method with the pH-adjusting agent of ammonia solution. When the ammonia concentration was 4.4 mol/L, the single-phase PbTiO3 nanorods were successfully synthesized.

Simulation of Stimuli-Responsive and Stoichiometrically Controlled Release Rate of Doxorubicin from Liposomes in Tumor Interstitial Fluid.

To simulate the stimuli-responsive and stoichiometrically controlled doxorubicin (DOX) release from liposomes in in vivo tumor interstitial fluid (TIF), the effect of ammonia concentration and pH on the DOX release from liposomes in human plasma at 37°C was quantitatively evaluated in vitro and the release rate was calculated as a function of ammonia concentration and pH. Human plasma samples spiked with DOX-loaded PEGylated liposomes (PLD) or Doxil®, containing ammonia (0.3-50mM) at different pH values, were incubated at 37°C for 24h. After incubation, the concentration of encapsulated DOX in the samples was determined by validated solid-phase extraction (SPE)-SPE-high performance liquid chromatography. Accelerated DOX release (%) from liposomes was observed as the increase of ammonia concentration and pH of the matrix, and the decrease of encapsulated DOX concentration. The release rate was expressed as a function of the ammonia concentration and pH by using Henderson-Hasselbalch equation. The DOX release from PLD in TIF was expressed as a function ammonia concentration and pH at various DOX concentrations. Further, it was found that the DOX release from liposomes in a simulated TIF was more than 15 times higher than in normal plasma.

Silver nanoparticle formation by femtosecond laser induced reduction of ammonia-containing AgNO3 solution

This paper reports the synthesis of silver colloids by femtosecond laser ablation of ammonia-containing AgNO3 solution. Effect of ammonia concentration in solution on the production of Ag nanoparticles was discussed. It is found that ammonia rules out significantly to the formation of Ag nanoparticles at which no Ag nanoparticle were formed in the solution without ammonia. Using the solution with the optimum ratio of ammonia to Ag+ ions, we further investigate the growth process of Ag nanoparticle by monitoring the evolution of its absorption spectra at 402 nm as a function of irradiation time. The result showed that the growth process was fit to the simple exponential function, and confirmed that the addition of ammonia alone to the metal ion system can boost the particle production by femtosecond laser.

Filtering Brackish Water by Photovoltaic-Powered Membrane

Photovoltaic-powered membrane was taken to filter brackish water. Effect of ammonia concentration, pressure and salinity on ammonia and total dissolved solids (TDS) removal, water recovery and energy consumption had been investigated. Results show that ammonia concentration did not influence ammonia and TDS removal, water recovery, and energy consumption obviously. Results of ammonia concentration of 10, 20 and 35 mg/l were similar to that of 5 mg/l. For salinity, the better filtration was achieved when the concentration of salinity was lower. With increment of pressure, ammonia and TDS removal increased simultaneously. The ammonia and TDS removal of more than 98% attained with the water recovery of 40.6% at the energy consumption of 2.0 kWh/m3. It illustrates that salinity and pressure were definitely crucial to brackish water filtration with photovoltaic-powered membrane.

Effect of ammonia on the agglomeration of zirconia nanoparticles during synthesis, and sintering by spark plasma sintering

Synthesis conditions have important impacts on the properties of ultrafine nanoparticles; understanding the interdependences of such properties on specific synthetic parameters can lead to controlled and optimized products. Here we discuss the effect of coprecipitation conditions during the synthesis of ultrafine yttria stabilized zirconia (YSZ) nanoparticles and gadolinium doped YSZ. We focused on the effect of ammonia concentration as precipitating agent. Although based on the nucleation theory one expects smaller particle sizes for higher concentrations of NH4OH, the usage of 1M or 5M of NH4OH lead to similar grain sizes (<6nm). However, the more concentrated condition led to highly agglomerated powders. This was attributed to an increase in the ionic force in the precipitating environment that caused particle coagulation. The resultant powders thus showed significantly different densification behaviors during sintering using spark plasma sintering, with the agglomerated powders achieving lower relative densities.

Ammonia Decomposition at Titanium Oxide Nanotube Photosensitive Anode

Kinetic behavior of ammonia decomposition at titanium dioxide nanotube photosensitive anode was studied. Ammonia was dissolved into water to form solutions with difference concentrations. The ammonia concentration ranges from 0.025 wt% to 10 wt%. Time-dependent open-circuit potential was measured to examine the photochemical response of the cell. The ammonia decomposition behavior was confirmed by measuring the decrease in pH values of the solutions. In addition, the kinetic behavior of ammonia decomposition was characterized under the actions of both ultra violet light irradiation and polarization. The current density values at the titanium dioxide nanotube anode during anodic polarization and UV light irradiation tests were used to compare the ammonia decomposition rates associated with photon excitation and polarization. The double–layer capacitance was estimated as high as 35 F/m indicating the excellent charge storing capability of Original Research Article Gan et al.; ACRI, 3(4): 1-12, 2016; Article no. ACRI.25848 2 the nanotube photosensitive anode. The effect of ammonia concentration on the open-circuit potential was also observed. In the lower ammonia concentration range, the change in the open circuit potential increase with the increasing in the ammonia concentration. Interestingly, in the higher concentration range from 2.5 wt% to 10 wt%, the change in the open circuit potential reveals a reversed trend.

Alkaline Ammonia Electrolysis on Electrodeposited Platinum for Controllable Hydrogen Production.

Ammonia is beginning to attract a great deal of attention as an alternative energy source carrier, because clean hydrogen can be produced through electrolytic processes without the emission of COx . In this study, we deposited various shapes of Pt catalysts under potentiostatic mode; the electrocatalytic oxidation behavior of ammonia using these catalysts was studied in alkaline media. The electrodeposited Pt was characterized by both qualitative and quantitative analysis. To discover the optimal structure and the effect of ammonia concentration, the bulk pH value, reaction temperature, and applied current of ammonia oxidation were investigated using potential sweep and galvanostatic methods. Finally, ammonia electrolysis was conducted using a zero-gap cell, producing highly pure hydrogen with an energy efficiency over 80 %.

Effect of ammonia concentration on the catalytic activity of Pd-Cu supported on attapulgite clay prepared by ammonia evaporation in CO oxidation at room temperature

AbstractWith attapulgite clay (APT) as support, the Pd-Cu/APT catalysts were prepared by an ammonia evaporation method and characterized by N2-physisorption, XRD, FT-IR, TEM and H2-TPR. The effect of ammonia concentration on the catalytic performance of Pd-Cu/APT in CO oxidation at room temperature was investigated in a fixed-bed continuous flow microreactor. The results showed that CuO appears as the main Cu species in the Pd-Cu/APT catalysts prepared with over low or over high ammonia concentration, whereas the quantity of Cu2(OH)3Cl phase is much less. However, a proper concentration of ammonia is of benefits to forming stable Cu2(OH)3Cl species in Pd-Cu/APT; owing to its high dispersion, nano-platelet morphology and strong interaction with Pd species, the presence of stable Cu2(OH)3Cl can significantly promote the catalytic performance of Pd-Cu/APT in CO oxidation. Under a gas hourly space velocity (GHSV) of 6000 h−1 for a feed stream containing 1.5% CO and 3.3% water, the Pd-Cu/APT catalyst exhibits excellent activity and stability in CO oxidation even at room temperature.

Effect of Ammonia Concentration on Silica Spheres Morphology and Solution Hydroxyl Concentration in Stober Process.

Ammonia was used as catalyst to synthesize spherical silica particles by Stober process. More details about the effect of ammonia concentration on the silica powders were investigated. With increase of ammonia concentration from 0.05 to 1.75 mol/L, it was found that particle size increased from 0.068 to 0.91 μm and number density of silica particles decreased rapidly from 9242.40 x 10(10) to 4.62 x 10(10)/mL. Besides, the ratio of standard deviation and the particle size decreased with the increase of ammonia concentration. These results were well consistent with prediction of aggregation model. It was proved that ammonia resulted in persistently high pH values of solutions, which were vital to form large silica spheres. In the formation process of silica spheres, solution hydroxyl concentration was reduced, which might be attributed to transfer of negative charge in hydroxyl groups to silica spheres.

Peanut shaped ZnO microstructures: controlled synthesis and nucleation growth toward low-cost dye sensitized solar cells

This paper describes a simple, low-temperature and cost effective chemical precipitation method in aqueous media to synthesis uniformly distributed zinc oxide (ZnO) microstructures for the fabrication of dye-sensitized solar cells (DSSCs). The size and morphology of the ZnO microstructures are systematically controlled by adjusting the concentration of the precursors, zinc acetate dihydrate and ammonium hydroxide. X-ray diffraction (XRD) and scanning electron microscopy are used for the structural characterizations and photoluminescence and Fourier transform infrared spectroscopy are used to characterize the optical properties of the ZnO, respectively. The results reveal that ZnO crystallites exhibit hexagonal wurtzite structure with preferential orientation along c-axis. The effect of ammonia concentration on the crystallinity, morphology and optical properties of ZnO microstructures and the concomitant effect on the efficiency of DSSCs is also quantified. The peanut-shaped ZnO microstructure, which was found to increase DSSCs performance over other microstructure, is studied in detail in order to develop a formation mechanism. A sandwich type eosin yellow sensitized solar cell is prepared using peanut-shaped ZnO microstructures, which showed an efficiency of 0.37%. Ammonia was found to play a crucial role in the evolution of ZnO morphologies. These results are promising and provide a path towards low-cost high-performance DSSCs based on peanut-shaped ZnO microstructures and produced with only relatively simple wet chemistry synthesis.

Properties of CdS Chemically Deposited thin films on the Effect of Ammonia Concentration

The effect of ammonia concentration on electrical properties, optical properties and structural properties of chemical bath deposited (CBD) Cadmium sulphide (CdS) thin films has been revealed. The films were prepared by using cadmium acetate as cadmium ion (Cd 2+ ) source, thiourea as sulphur ion (S 2- ) source and ammonia as the complexing agent. Ammonia concentration was changed from 0.1 M - 3.0 M. Ammonia concentration at 2.0 M uniform, dense and continuously coated films were obtained. Not only typical cadmium- pure but also unusual sulphur deficiency phenomena were observed for CBD CdS thin films. In the present investigation, the carrier concentration varied form 1.831X10 6 cm -3 to 1.026X10 6 cm -3 when ammonia concentration is changed from 0.5M to 2.5 M. The direct band gap energy at 0.5M is 1.92eV while at 2.5M is 2.65eV. The surface morphology of as deposited thin films is almost smooth and no grains were observed clearly at low molar concentration and predominant grains at the concentration of ammonia is 2.0M. By estimated Cd:S ratio value is found to be 1.04 by using EDAX. The thin film deposited at 2.0M concentration shows the highest degree crystallinity. The formation mechanism of the films with various ammonia concentrations is discussed. Keywords: Ammonia effect, CBD-CdS thin films, Optical studies, SEM, XRD