Initial Ammonia Nitrogen Concentration Research Articles

Study on degradation of marine product processing waste water by Zeolite/Bi/ZnO catalyst

Nano-supported Zeolite/Bi/ZnO photocatalyst was successfully prepared and characterized by XRD, SEM testing means. Under the visible light, the effects of different factors such as Bi/Zn loading concentration, calcination time, calcination temperature, initial concentration of ammonia nitrogen /COD, illumination time and catalyst dosage on degradation of ammonia nitrogen/COD in deep processing of seafood wastewater were investigated. Furthermore, by carrying out orthogonal experiment, the study explored the optimal reaction conditions of self-made photocatalyst in practical application. It can be concluded that the self-made photocatalyst has a good degradation effect on the deep processing wastewater of marine products with lower concentration of pollutants, obvious effect has been obtained on the treatment of deep processing wastewater of marine product containing lower concentration of pollutants. The optimal experimental conditions for the degradation of ammonia nitrogen concluded as follows: when the calcination temperature of photocatalyst was 600 °C, the calcination time was 4 h, the catalyst dosage was 0.8 g/L, the initial concentration of ammonia nitrogen was 100 mg/L, illumination time was 2 h, the degradation rate can reach 80.9%. And the optimal experimental conditions of degradation of COD was concluded: when the calcination temperature of photocatalyst was 500 °C, the calcination time was 4 h, the catalyst dosage was 1.0 g/L, initial concentration of COD was 540 mg/L, illumination time was 3 h, the degradation rate can reach 94.1%. The results showed that compared with ZnO photocatalyst and Bi/ZnO photocatalyst, the Zeolite/Bi/ZnO photocatalyst has a significant effect on the degradation of COD and ammonia nitrogen.

Batch Kinetics of Nutrients Removal from Synthetic Meat Processing Wastewater by using Microalgae Botryococcus Sp.

Disposed meat processing wastewater contains high range of nutrients such as ammonia nitrogen and orthophosphate which will cause eutrophication and lead to destruction of ecosystem. Therefore, batch experiments were conducted to explore the influence of the range of initial concentration of ammonia nitrogen and orthophosphate found in meat processing wastewater in the removal of those nutrients during phycoremediation of synthetic wastewater by using microalgae Botryococcus sp. Michaelis-Menten rate expression was applied to generate biokinetic coefficients k, reaction rate constant, Km, half saturation constant and Y, yield coefficients. The experiment was conducted using synthetic wastewater with initial NH4-N concentration varying between 30-480 mg/l and PO43- concentrations varying between 14-239 mg/l. The results demonstrate removal efficiency of NH4-N between 42-100 % and PO43- between 63-96 %. Biokinetic coefficients were established as k = 1.72 mg NH4-N /mg chl a/day, Km = 52.29 mg/L and YN = 0.027 mg chl a/mg NH4-N for ammonia nitrogen and k = 1.13 mg PO43-/mg chl a/day, Km = 44.45 mg/L and YP = 0.038 mg chl a/mg PO43- for orthophosphate.

Preparation of non-sintered fly ash filter (NSFF) for ammonia nitrogen adsorption

ABSTRACTIn accordance with China’s goal of ‘treating wastes with wastes, turning wastes into treasure’, a non-sintered fly ash filter (NSFF) with sewage sludge as additive was prepared. It consists of 70.9% fly ash, 7% sewage sludge, 9% cement, 7.1% CaO, 1% NaHCO3 and 5% sodium silicate solution. After mixing, 34 g/(100 g dry material) water was added, and then was granulated and steam cured under 80°C for 16 h. NSFF’s main performance indexes include specific surface area (SSA) of 17.038 m2 g−1, filter media breaking rate (FMBR) of 2.2%, apparent density (AD) of 1140 kg m−3, and porosity of 41.67%, meeting the Chinese Standard CJ/T 299-2008. This NSFF has a larger SSA and a lower AD comparing with the other similar non-sintered fly ash ceramsite products. Moreover, leaching toxicity of the NSFF has met the Chinese Standards for Hazardous Wastes (GB5085.3-2007). Therefore, the NSFF is effective and safe to use as a water treatment filter media. The NSFF’s adsorption characteristics for ammonia nitrogen was investigated. Results showed that the optimized parameters for ammonia nitrogen adsorption are as follows, NSFF dosage at 5 g, initial ammonia nitrogen concentration of 225 mg L−1, pH at 7, contact time of 12 h and temperature at 30°C. Under the optimum conditions, the adsorption capacity of NSFF for ammonia nitrogen was 4.25 mg g−1. The adsorption process can be best described by Langmuir isotherm and pseudo-second-order kinetic model. The proposed adsorption mechanism include adsorption and cation exchange.

Anaerobic Digestion Effluents (ADEs) Treatment Coupling with Chlorella sp. Microalgae Production.

Nutrient removal effectiveness from anaerobic digestion effluents (ADEs) by Chlorella sp. cultivation and microalgae biomass productivity were evaluated in this study. The results showed that the highest Chlorella sp. biomass productivities of 386.5 ± 24.1 mg dry weight/L•d and 338.3 ± 11.0 mg dry weight/L•d were respectively obtained with the anaerobically digested effluent of municipal wastewater sludge and effluent from a fermentation tank treating dairy wastewater. Lower (p < 0.05) microalgal growth was achieved with anaerobically digested effluents of maize silage and swine slurry and cattle manure. The increase of the initial ammonia nitrogen concentration in ADEs to the level of 160 mg/L did not encourage Chlorella sp. productivity because of phosphorus limitation. The removal efficiencies of ammonia nitrogen, total nitrogen, total phosphorus, and chemical oxygen demand (COD) reached 99.7%, 98.6%, 88.2%, and 58.7%, respectively, depending on the source of ADE, but not on the initial ammonia nitrogen concentrations.

Ammonia-nitrogen and Phosphate Reduction by Bio-Filter using Factorial Design

Untreated landfill leachate is known to have endangered the environment. As such new treatment must be sought to ensure its cost-effective and sustainable treatment. Thus this paper reports the effectiveness of bio-filter to remove pollutants. In this research, the reduction of nutrients concentration was evaluated in two conditions: using bio-filter and without bio-filter. Synthetic wastewater was used in the batch culture. It was conducted within 21 days in the initial mediums of 100 mg/L ammonia-nitrogen. The nitrification medium consisted of 100 mg/L of ammonia-nitrogen while the nitrite assay had none. The petri dish experiment was also conducted to observe the existence of any colony. The results showed 22% of ammonia- nitrogen reduction and 33% phosphate in the nitrification medium with the bio-filter. The outcome showed that the bio-filter was capable to reduce the concentration of pollutants by retaining the slow growing bacteria (AOB and NOB) on the plastic carrier surface. The factorial design was applied to study the effect of the initial ammonia-nitrogen concentration and duration on nitrite-nitrogen removal. Finally, a regression equation was produced to predict the rate of nitrite-nitrogen removal without conducting extended experiments and to reduce the number of trials experiment.

Composite Photocatalysts of CNTS-TiO2: An Efficient Photocatalyst for the Degradation of Ammonia Nitrogen Pollutant in Mariculture Wastewater under UV Light Irradiation

In this study, composite photocatalyst of CNTS-TiO2 is employed to degrade ammonia nitrogen pollutant in mariculture wastewater under UV light irradiation. The photocatalyst was prepared by a sol-gel method and was characterized by SEM and XRD analysis.The photocatalytic degradation efficiency of ammonia nitrogen was analysed by various experimental parameters namely dosage, initial concentration of ammonia nitrogen, pH value, the concentration of H2O2, illumination timeand calcination time. The degradation of ammonia nitrogen pollution in mariculture wastewater was optimized by orthogonal experiment. According to the results, the best effect exists when the dose of catalysts was 60 mg, initial concentration of ammonia nitrogen was 10 mg/L, pH value was 9, concentration of H2O2 was 0.5 g/L, illumination time was 2.5 h, and calcination time was 1h. The removel rate of ammonia nitrogen can reach 75.78%.

Effective removal of ammonia nitrogen from waste seawater using crystal seed enhanced struvite precipitation technology with response surface methodology for process optimization.

Traditional biological treatment was not effective for removing nitrogen from saline wastewater due to the inhibition of high salinity on biomass activity. In this context, a method of removing ammonia nitrogen from waste seawater was proposed by struvite precipitation which was enhanced by seeding technique. The abundant magnesium contained in waste seawater was used as the key component of struvite crystallization without additional magnesium. The effects of pH and P:N molar ratio on ammonia nitrogen removal efficiency were studied. The results showed that optimum pH value was in range of 8.5-10 and the P:N molar ratio should be controlled within 2:1-3:1. XRD and SEM-EDS analyses of the precipitates proved that Ca2+ and excess Mg2+ contained in waste seawater inhibited the struvite crystallization by competing PO43- to form by-products. Then, seeding technique for enhancing the struvite crystallization was investigated, and the results indicated that using preformed struvite as crystal seed significantly improved the ammonia nitrogen removal efficiency, especially when initial ammonia nitrogen concentration was relatively low. Moreover, response surface optimization experiment following a Box-Behnken design was conducted. A response surface model was established, based on which optimum process conditions were determined and interactions between various factors were clarified. At last, economic evaluation demonstrated this proposed method was economic feasible.

Ammonia nitrogen removal from aqueous solution by local agricultural wastes

Excess ammonia nitrogen in the waterways causes serious distortion to environment such as eutrophication and toxicity to aquatic organisms. Ammonia nitrogen removal from synthetic solution was investigated by using 40 local agricultural wastes as potential low cost adsorbent. Some of the adsorbent were able to remove ammonia nitrogen with adsorption capacity ranging from 0.58 mg/g to 3.58 mg/g. The highest adsorption capacity was recorded by Langsat peels with 3.58 mg/g followed by Jackfruit seeds and Moringa peels with 3.37 mg/g and 2.64 mg/g respectively. This experimental results show that the agricultural wastes can be utilized as biosorbent for ammonia nitrogen removal. The effect of initial ammonia nitrogen concentration, pH and stirring rate on the adsorption process were studied in batch experiment. The adsorption capacity reached maximum value at pH 7 with initial concentration of 500 mg/L and the removal rate decreased as stirring rate was applied.

Characteristics of two novel cold- and salt-tolerant ammonia-oxidizing bacteria from Liaohe Estuarine Wetland

To achieve a better contaminant removal efficiency in a low-temperature and high-salt environment, two novel strains of cold- and salt-tolerant ammonia-oxidizing bacteria (AOB), i.e., Ochrobactrum sp. (HXN-1) and Aquamicrobium sp. (HXN-2), were isolated from the surface sediment of Liaohe Estuarine Wetland (LEW), China. The optimization of initial ammonia nitrogen concentration, pH, carbon–nitrogen ratio, and petroleum hydrocarbons (PHCs) to improve the ammonia-oxidation capacity of the two bacterial strains was studied. Both bacterial strains showed a high ammonia nitrogen removal rate of over 80% under a high salinity of 10‰. Even at a temperature as low as 15°C, HXN-1 and HXN-2 could achieve an ammonia nitrogen removal rate of 53% and 62%, respectively. The cold- and salt-tolerant AOB in this study demonstrated a high potential for ammonia nitrogen removal from LEW.

Adsorption of ammonia nitrogen in aqueous solution by the acid activated water treatment sludge

The ammonia nitrogen in aqueous solution can contribute to the eutrophication of water bodies, depletion of dissolved oxygen and toxicity to fish and other aquatic organisms. The removal of ammonia nitrogen in aqueous solution was carried out with many kinds of methods. In this research, the potential and effectiveness of the water treatment sludge was studied as the alternative adsorbents for the removal of ammonia nitrogen in aqueous solution. The water treatment sludge was activated by acid solution. Then, the effects of temperature, contact time and initial ammonia nitrogen concentration on ammonia nitrogen adsorption by the acid activated water treatment sludge were investigated. The results showed that the acid activated water treatment sludge contains porous structures and high surface area. The equilibrium data fitted with the Langmuir isotherm. The adsorption data fitted the pseudo-second-order model much better with R2 greater than the pseudo-first-order model. The values of ΔH° and ΔS° were -34.28 kJ/mol and -113.09 J/mol, respectively. The value ΔG° of was 0.41 kJ/mol at 308 K.

Adsorption of ammonia nitrogen in aqueous solution by the acid activated water treatment sludge

The ammonia nitrogen in aqueous solution can contribute to the eutrophication of water bodies, depletion of dissolved oxygen and toxicity to fish and other aquatic organisms. The removal of ammonia nitrogen in aqueous solution was carried out with many kinds of methods. In this research, the potential and effectiveness of the water treatment sludge was studied as the alternative adsorbents for the removal of ammonia nitrogen in aqueous solution. The water treatment sludge was activated by acid solution. Then, the effects of temperature, contact time and initial ammonia nitrogen concentration on ammonia nitrogen adsorption by the acid activated water treatment sludge were investigated. The results showed that the acid activated water treatment sludge contains porous structures and high surface area. The equilibrium data fitted with the Langmuir isotherm. The adsorption data fitted the pseudo-second-order model much better with R2 greater than the pseudo-first-order model. The values of ΔH° and ΔS° were -34.28 kJ/mol and -113.09 J/mol, respectively. The value ΔG° of was 0.41 kJ/mol at 308 K.

Evaluation of ammonia–nitrogen removal efficiency from aqueous solutions by ultrasonic irradiation in short sonication periods

In this study, mechanisms and efficiency of ammonia–nitrogen removal from aqueous solutions by ultrasonic irradiation were investigated. Depending on the factors affecting the sonication (initial concentration, initial pH, ultrasonic power density and sonication period), sonication tests were carried out and ammonium–nitrogen removal efficiency by ultrasonic irradiation was determined. In these experiments, ammonia–nitrogen removal efficiency was achieved in the range of 8–64%. In short sonication periods, the best ammonia–nitrogen removal efficiency was achieved at pH 8.2–11. Lower ammonia–nitrogen removal efficiency was observed in high initial ammonia–nitrogen concentration of solutions. It was observed that high initial ammonia–nitrogen concentrations may led to decreased ammonia–nitrogen removal efficiency however quantity of ammonia–nitrogen removal was higher. Because high initial concentration had a negative impact on the sonochemical reactions the heat of cavitation bubbles was reduced. Ammonia–nitrogen removal efficiency was increased with ultrasonic density and sonication period. This study showed that effective ammonia–nitrogen removal could be achieved by the ultrasonic irradiation in short sonication periods (as 60–600s). Specific cost of ammonia–nitrogen removal by the ultrasonic irradiation from simulated ground water, surface water, wastewater and landfill leachate was also calculated. The specific removal cost was varied between 0.01 and 0.25$/g ammonia–nitrogen.

Influence of outside environmental variations on ammonia nitrogen adsorption characteristics of HVMT/PC/EPDM composite

A new kind of ammonia nitrogen (AN) sewage water treatment composite was prepared by melt blending, with synthetic rubber ethylene propylene diene monomer (EPDM) and polycarbonate (PC) as the matrix, the natural vermiculite (VMT) powder modified by hydrochloric acid solution (HVMT) as the filler. By Fourier transform infrared (FTIR) measurement and XRD measurement, it was confirmed that the HVMT was more suitable as filler than VMT. By considering the influence of pH, temperature, adsorption composite content and initial mass concentration on removal rate and adsorption capacity, it can be concluded that the removal rate increased first and then decreased with the increasing pH. “Room temperature” was the optimum temperature for the composite. The removal rate of AN increased with the increasing adsorption composite content. When the adsorption reached equilibrium, the removal rate remained unchanged; the adsorption capacity of AN increased with increasing initial concentration. The removal rate increased gradually with lower initial concentration of AN. When the initial concentration increased to a certain level, the removal rate started to decline. When the initial concentration and composite content showed adsorption equilibrium, the adsorption capacity remained unchanged. The composite can be recycled to be reused after regeneration for nine cycles; the AN adsorption capacity of composite was decreased by only 4.5 %. If the composite can be prepared in large-scale production lines, the costs of HVMT/PC/EPDM porous composite can be controlled at less than USD 16/kg.

Isolation and Identification of Ammonia Nitrogen Degradation Strains from Industrial Wastewater

Nine strains of ammonia nitrogen degradation strains from C1 to C9 were isolated from industrial wastewater to study their degradation and conversion of ammonia nitrogen. The results showed that C2 strain with a high degradation activiity of ammonia nitrogen, and the ammonia nitrogen degradation rate of the activated C2 strain was 93% within 24 h when the initial concentration of ammonia nitrogen was 200 mg/L under the conditions of inoculation 10%, temperature 35?C, pH 7.0, rotation 200 r/min. And C2 was identified as Bacillus amyloliquefaciens.

Performance of Nitrogen Removal by Pseudomonas sp. WSH 1001

The influence factors of ammonia-and nitrate-nitrogen removal capability by Pseudomonas sp.WSH 1001,its application in actual wastewater and the comparison in nitrogen removal capability between Pseudomonas sp.WSH 1001 and other commercially available microbial preparations were studied in this research.The results indicated that ammonia-and nitrate-nitrogen removal capability was higher when glucose or sodium citrate was used as carbon sources in the pre-cultured process of Pseudomonas sp.WSH 1001.The temperature between 20 ℃ and 35 ℃ had no effect on ammonia-and nitratenitrogen removal efficiency.The dissolved oxygen level in shaking flask greatly influenced ammonia-and nitrate-nitrogen removal efficiency.Metal ions such as Cu2+,Co2+and Zn2+greatly inhibited the capability of the strain to remove ammonia-and nitrate-nitrogen.When initial ammonia nitrogen concentration was 70 mg L-1 in synthetic waste water,ammonia nitrogen and total nitrogen removal efficiency were 99.64% and 94.94% in 6 h,respectively.When nitrate nitrogen was used as sole nitrogen source(50 mg L-1),nitrogen removal efficiency was 87.69% in 8 h.When Pseudomonas sp.WSH 1001 was used as microbial preparation in the treatment of actual wastewater(the initial concentration of ammonia nitrogen and COD was 44 and 113 mg L-1,respectively) supplemented with 3 g L-1 sodium succinate as external carbon source,ammonia nitrogen removal efficiency was 99.23%,which was higher than those of other commercially available microbial preparations.It is demonstrated that Pseudomonas sp.WSH 1001 was favorable to practical application.

Study on the Treatment of Ammona-Nitrogen Wastewater by Magnesium Ammonium Phosphate

Large quantities of ammonia-nitrogen (-N) in wastewater is one of the main causes of eutrophication that endanger both natural water bodies and fresh water seriously. Thus, it is necessary to find an economic and feasible method to remove the ammonium-nitrogen in wastewater before they are returned to the environment. Magnesium ammonium phosphate precipitation method is one of the effective technology of wastewater treatment. In this paper, the influence of initial ammonia-nitrogen concentration, pH, temperature and mole ratio of :NH+4 :Mg2+were studied, What is more, the optimum condition of this process was determined. The results indicated that ammonia-nitrogen concentration is decreased from 1434 mg/L to 95.65 mg/L, and the removal rate reached 93.33% at the optimum conditions, which laying a foundation for the following biochemical treatment.

Nitrogen-removal efficiency in an upflow partially packed biological aerated filter (BAF) without backwashing process

An upflow, partially packed biological aerated filter (BAF) reactor was used to remove nitrogen in the form of ammonia ions by a nitrification process that involves physical, chemical and biological phenomena governed by a variety of parameters such as dissolved oxygen concentration, pH and alkalinity. Dissolved oxygen (DO) and pH were shown to have effects on the nitrification process in this study. Three C:N ratios i.e., 10, 4 and 1 were compared during this study by varying the nitrogen loading while the carbon loading was kept constant at 0.405 ± 0.015 kg chemical oxygen demand m−3 d−1. The removal efficiencies of ammonia linearly increase with a rise of the initial concentration of ammonia-nitrogen. The results of the 115 days' operation of the BAF system showed that its overall NH3-N performance was good, where a removal efficiency of 87.0 ± 2.9%, 89.2 ± 1.38% and 91.1 ± 0.7% and COD removal of 87.6 ± 2.9%, 86.4 ± 2.1% and 89.5 ± 2.6% were achieved for the C:N ratios of 10, 4 and 1, respectively on average, over 6 h hydraulic retention time (HRT). No clogging occurred throughout the period although backwashing was eliminated. It was concluded that the BAF system proposed in this study removed nitrogen by the nitrification process extremely well.

Nitrification in natural waters with high suspended-solid content––A study for the Yellow River

In this research, the mechanism regarding the effects of suspended solids on nitrification in freshwater systems with high solid contents was examined. Experimental studies were conducted for natural water of the Yellow River under laboratory conditions. Nitrification kinetics was investigated in water systems with various levels of suspended-solid contents. The associated mechanisms were analyzed through investigation of the adsorption–desorption of ammonium nitrogen, the process of bacteria growth, and the feature of nitrification kinetics. The results indicated that the presence of suspended solids could accelerate the nitrification process. The nitrification rate would increase non-linearly with the increase of suspended-solid content. When the initial concentration of ammonia nitrogen was 12.70 mg/l in the water system, the ratios of half-time duration for nitrification would be 1.88:1.23:1 under suspended-solid contents of 0, 1.84 and 5.00 g/l, respectively. When the initial concentration of ammonia nitrogen was around 1.0 mg/l in the water system, the nitrification rates in systems with suspended-solid contents of 1.81 and 3.42 g/l would then be approximately 9 and 12 times that without suspended solids, respectively. The populations of nitrifying bacteria would rise with increasing suspended-solid content. The existence of suspended solids would increase the contact chances between bacteria and nitrogen, resulting in accelerated nitrification processes; this was manifested by the increased K 4 ( μ max/ K S) along with the raised suspended-solid contents while fitting nitrification kinetics with the growth-based logistic model. Since the amount of ammonium nitrogen adsorbed on suspended-solid surface was non-linearly proportional to the suspended-solid content, the nitrification rate was also non-linearly proportional to the suspended-solid content.

General model for the steady-state response properties of fiber-optic ammonia gas sensors

A mathematical model is derived to describe the steady-state response properties of the fiber-optic ammonia sensor. Unlike our previous model, the present model permits any concentration of total ammonia nitrogen initially present in the internal solution of the sensor. A cubic equation is solved to give the magnitude of the nonprotonated form of the indicator dye under equilibrium conditions. For the first time, the effect of the initial ammonia nitrogen concentration in the internal solution is evaluated. In addition, the response equation is differentiated with respect to the sample ammonia concentration to give an expression that can be used to evaluate the effects of critical experimental parameters on the measurement sensitivity. This model is verified by comparing predicted and actual responses for several different fiber-optic sensor configurations. The model is used to generate surface maps that allow evaluation of the interrelationships between key experimental parameters such as the indicator concentration, sample ammonia concentration, internal ammonium chloride concentration and indicator acid dissociation constant. Results of this analysis indicate that optimal responses and maximal sensitivity require careful selection of values for these parameters.

Nitrification Rate in Biological Processes

At least four reaction rate equations have been proposed to describe the process of nitrification. A more precise understanding of this reaction rate is needed to optimize the design of the process. The proposed equations which include the Monod, zero-order, first-order, and autocatalytic growth are reviewed. An experimental study is described which was designed to better understand the process reaction rate. The study involved a thin film biological reactor fed with a synthetic medium developed for the study of nitrification. This simple model was used to provide flexibility and control over such parameters as hydraulics, slime layer thickness, contact time, and wall growth problems. The rate determination was developed by varying both initial concentration and contact time. Results indicate that the reaction rate is zero-order between an initial ammonia nitrogen concentration of 2.5 mg/l - 673 mg/l.