scholarly journals Evaluation and mechanism of ammonia nitrogen removal using sediments from a malodorous river

2018 ◽  
Vol 5 (3) ◽  
pp. 172257 ◽  
Author(s):  
Xing Chen ◽  
Xia Jiang ◽  
Wei Huang

Malodorous rivers are among the major environmental problems of cities in developing countries. In addition to the unpleasant smell, the sediments of such rivers can act as a sink for pollutants. The excessive amount of ammonia nitrogen (NH 3 −N) in rivers is the main factor that causes the malodour. Therefore, a suitable method is necessary for sediment disposition and NH 3 −N removal in malodorous rivers. The sediment in a malodorous river (PS) in Beijing, China was selected and modified via calcination (PS-D), Na + doping (PS-Na) and calcination–Na + doping (PS-DNa). The NH 3 −N removal efficiency using the four sediment materials was evaluated, and results indicated that the NH 3 −N removal efficiency using the modified sediment materials could reach over 60%. PS-DNa achieved the highest NH 3 −N removal efficiency (90.04%). The kinetics study showed that the pseudo-second-order model could effectively describe the sorption kinetics and that the exterior activated site had the main function of P sorption. The results of the sorption isotherms indicated that the maximum sorption capacities of PS-Na, PS-D and PS-DNa were 0.343, 0.831 and 1.113 mg g −1 , respectively, and a high temperature was favourable to sorption. The calculated thermodynamic parameters suggested that sorption was a feasible or spontaneous (Δ G  < 0), entropy-driven (Δ S  > 0), and endothermic (Δ H  > 0) reaction.

2015 ◽  
Vol 16 (1) ◽  
pp. 115-127 ◽  
Author(s):  
P. Dhanasekaran ◽  
P. M. Satya Sai ◽  
C. Anand Babu ◽  
R. Krishna Prabhu ◽  
K. K. Rajan

Arsenic is a toxic element found naturally in groundwater. Due to its carcinogenicity, risk for heart diseases and diabetes, arsenic needs to be removed from groundwater for potable application. ‘Anjili’ tree sawdust was chemically modified with ferric hydroxide and activated alumina (SFAA) and used as an adsorbent for the removal of arsenic from groundwater. The adsorbent was characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) to study the pore structure and surface functional groups. Effect of contact time, initial concentration, pH, particle size and temperature was studied. Arsenic adsorbed by SFAA followed Freundlich adsorption isotherm. Maximum sorption of arsenic by SFAA adsorbent occurred at pH 6.5. Arsenic sorption kinetics followed a pseudo-second-order model. The maximum sorption capacity at 303 K was found to be 54.32 mg/g for As(III) and 77.60 mg/g for As(V). Interference of other ions on the adsorption was in the order of PO43− &gt; SO42− &gt; HCO3− &gt; NO3−.


2004 ◽  
Vol 49 (5-6) ◽  
pp. 207-214 ◽  
Author(s):  
J.J. Lee ◽  
C.U. Choi ◽  
M.J. Lee ◽  
I.H. Chung ◽  
D.S. Kim

This research is concerned with the removal of ammonia nitrogen and phosphorus in foodwaste by crystallization. Reductions have been achieved by struvite formation after the addition of magnesium ions (Mg2+). Magnesium ions used in this study were from magnesium salts of MgCl2. The results of our analysis using scanning electron microscopy and energy dispersive X-ray analysis showed that the amount of struvite in precipitated sludge grew enough to be seen with the naked eye (600-700μm). EDX analysis also showed that the main components of the struvite were magnesium and phosphorus. NH3-N removal efficiency using MgCl2 was 67% while PO4-P removal efficiency was 73%. It was confirmed that nitrogen and phosphorus could be stabilized and removal simultaneously through anaerobic digestion by Mg, NH3 and PO4-P, which were necessary for struvite formation.


2013 ◽  
Vol 361-363 ◽  
pp. 764-767
Author(s):  
Hai Tang ◽  
Long Ouyang ◽  
Xiang Zhao

The ammonia nitrogen (NH4-N) removal enhanced by biological aerobic filter (BAF) packed with novel micro-mesoporous lightweight zeolite particles (LZP) as carrier. The results showed that the biofilm can quickly grow up using LZP as media in the BAF. HLR of 1.2 was chosen as the optimal value under the average influent NH4+-N concentration of 24.6 mg/L, percent NH4-N removal of 87% and NLR of 0.24 kgN/m3.d was achieved. The kinetic performance of the LZP-BAF indicated that the relationship of NH4-N removal efficiency with the L could be described by an exponential equation (Ce/Ci=exp (-1.24/L0.344)).


2007 ◽  
Vol 20-21 ◽  
pp. 635-638 ◽  
Author(s):  
Karol Campos ◽  
Eric Guibal ◽  
Francisco Peirano ◽  
M. Ly ◽  
Holger Maldonado

Mercury sorption on chitosan was investigated in batch and continuous systems. Chitosan sorption properties were determined through sorption isotherms. Langmuir and Freundlich equations were used for the modeling of isotherms at pH 5. In batch systems, maximum sorption capacities reached 550 mg Hg/g. Sorption kinetics have been studied as a function of sorbent particle size and stirring rate. Dynamic removal of mercury was tested in a fixed bed reactor investigating the following parameters: particle size, column size, flow velocity and metal ion concentration. Clark and Adams-Bohart models were evaluated for the simulation of breakthrough curves. This study shows that chitosan is an effective sorbent for the treatment and recovery of mercury from dilute effluents at near neutral pH.


1991 ◽  
Vol 18 (6) ◽  
pp. 940-944 ◽  
Author(s):  
J. B. Sérodes ◽  
E. Walsh ◽  
O. Goulet ◽  
J. de la Noue ◽  
C. Lescelleur

Design criteria of a pilot plant for treating secondary municipal effluents using filamentous, bioflocculating micro-algae were evaluated. Using a sequential batch reactor, the best removal rate of ammonia nitrogen was reached for 25% draw volume; at 20–22 °C, up to four cycles per day could be achieved giving a removal efficiency of approximately 2 g of N per day and per square meter of basin (200 mm deep) with negligible nitrogen residual; increasing the water level by increments of 200 mm (from 200 to 600 mm) increased the N removal efficiency in a way similar to an increase in the number of renewals per day on a 200 mm deep basin. The dominant micro-algae (Chlorhormidium) was heavily influenced by the water temperature. Key words: micro-algae, municipal wastewater, water treatment, ammonia nitrogen, removal rate, removal efficiency.


2019 ◽  
Vol 79 (1) ◽  
pp. 126-136 ◽  
Author(s):  
Yan Chen ◽  
Wei Chen ◽  
Quanzhou Chen ◽  
Changhong Peng ◽  
Dewen He ◽  
...  

Abstract In this study, a novel poly ligand exchanger-Zn(II)-loaded resin was designed to effectively remove ammonia-nitrogen (NH3-N) from wastewater. The surface morphology and structure of the Zn-loaded resin were characterized using scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and Fourier transform infrared spectroscopy (FTIR), respectively. SEM shows the surfaces of the Zn(II)-loaded resin were rough and nonporous and EDS demonstrated that Zn2+ was loaded onto the resin successfully. In addition, the combination form of Zn(II) with NH3-N adsorption reagent was revealed by FTIR spectra; the complex could be R-N-R-O-Zn-O-R-N-R and R-N-R-(O-Zn)2. The kinetics and equilibrium of the NH3-N adsorption onto the Zn(II)-loaded resin has been investigated. The effects of pH, reaction time, and temperature on NH3-N removal from wastewater by Zn(II)-loaded resin were investigated, and the results showed that the maximum adsorption capacity reached 38.55 mg/g at pH 9.54 at 298 K in 240 min. The adsorption ability of the modified resin decreased with an increase in temperature. Moreover, the NH3-N adsorption followed a pseudo-second-order kinetic process. The kinetic data demonstrated that the adsorption process might be limited by a variety of mechanisms. The study can provide the scientific foundation for the extensive application of a novel poly ligand exchanger-Zn(II)-loaded resin to remove NH3-N from wastewater.


2018 ◽  
Vol 10 (7) ◽  
pp. 2491 ◽  
Author(s):  
Jianxin Fan ◽  
Guoliang Zhao

Sorption properties play a key role in the mobility of selenium (Se) and fraction distribution changes, leading to the bioavailability of Se in the soil environment. Thus, the effect of soil physicochemical properties on the sorption of exogenous selenite was investigated to predict the rate and capacity of sorption. Correlation analysis and multiple linear regression were used to observe the relationship between sorption characteristics and soil properties. Sequential extraction was used to observe the fractions of Se at different ages in soil. Results indicated that sorption isotherms followed the Langmuir equation, and the sorption capacity ranged from 50.7 to 567 mg·kg−1 with pseudo-second-order sorption kinetics. The correlation and multiple linear regression analyses showed that sorption parameters were significantly positively correlated with dithionite–citrate–bicarbonate-extracted Fe (FeDCB), dithionite–citrate–bicarbonate-extracted Al (AlDCB), amorphous Fe (FeOX), and soil organic matter (SOM), whereas pH was negatively correlated. Sequential extraction analyses revealed that the fraction distribution of Se in soil varied with the age, and the content of elemental Se increased with prolonged aging. FeDCB, AlDCB, FeOX, pH, and SOM play important roles in selenite sorption onto soils. Selenite sorption onto soil can be reduced to a lower-state Se, such as elemental Se and selenides, during the aging process. This information on the environmental behavior of Se is used to develop agronomic strategies for increasing Se levels in food crops and improving human health.


2012 ◽  
Vol 209-211 ◽  
pp. 2053-2057
Author(s):  
Jin Xiang Liu ◽  
Shui Bo Xie ◽  
Chun Ning Cheng ◽  
Jin Sheng Lou ◽  
Shi You Li

The effect of bed material heights on treatment performance of pollutants from micro-polluted raw Water was studied in zeolite - Ceramics biological aerated filter(ZCBAF) technology. The test results showed the removal rate of CODMn, NH4+-N and UV254 will improve with the increase of media height, most of CODMn and UV254 were removed within the first 440mm , when the media height over 440mm, the effect of increase height is inconspicuous removal, and ammonia-nitrogen removal has evident improvement during 220-440mm. At the media height of 20mm, 40mm and 60mm in ZCBAF respectively, the removal efficiency of CODMn is 18.05%,31.6% and 38.62% respectively, NH4+-N removal efficiency is 29.78%,81.28% and 93.02% respectively , and UV254 removal efficiency is 7.81%,10.11% and 11.26% respectively under the air/water ratio of 1:1 and the hydraulic loading of 1.2m3/(m2.h). Removal rate of CODMn was decreased with the increase of hydraulic loading, and removal effect of NH4+-N and UV254 had not big influence.


2016 ◽  
Vol 104 (9) ◽  
pp. 635-647 ◽  
Author(s):  
Sabriye Yusan ◽  
Anastasia Bampaiti ◽  
Sema Erenturk ◽  
Fotini Noli ◽  
Mahmut A. A. Aslani ◽  
...  

Abstract In this study, for the first time ZnO nanoparticles and diatomite-supported ZnO nanocomposite have been utilized as adsorbent for the removal of Th(IV) ions from aqueous solutions under different experimental conditions. The Langmuir, Freundlich, Temkin and Dubinin– Radushkevich (D–R) isotherms were used to analyze the equilibrium data. The sorption equilibrium data were fitted well to the Langmuir isotherm with maximum sorption capacities values was found to be 1.105 mmol/g and 0.320 mmol/g for ZnO nanoparticles and diatomite supported ZnO nanocomposite, respectively. Pseudo-first and pseudo-second order equations, Intraparticle diffusion and Bangham’s models were considered to evaluate the rate parameters and sorption mechanism. Sorption kinetics were better reproduced by the pseudo-second order model (R2 > 0.999), with an activation energy (Ea) of +99.74 kJ/mol and +62.95 kJ/mol for ZnO nanoparticles and diatomite-supported ZnO nanocomposite, respectively. In order to specify the type of sorption reaction, thermodynamic parameters were also determined. The evaluated ΔG* and ΔH* indicate the non-spontaneous and endothermic nature of the reactions. The results of this work suggest that both of the used materials are fast and effective adsorbents for removing Th(IV) from aqueous solutions and chemical sorption plays a role in controlling the sorption rate.


2021 ◽  
Vol 109 (2) ◽  
pp. 85-97
Author(s):  
Abeer E. Kasem ◽  
Ezzat A. Abdel-Galil ◽  
Nabil Belacy ◽  
Nagwa A. Badawy

Abstract The sorption kinetics and equilibrium isotherms of zirconium, uranium, and molybdenum ions onto synthetic polyaniline/SiO2 composite (PAn/SiO2) have been studied using batch-sorption techniques. This study was carried out to examine the sorption behavior of the PAn/SiO2 for the removal of Zr(IV), U(VI), and Mo(VI) ions from an aqueous solution. The influence of some parameters on the sorption process was also studied. The maximum sorption for Zr(IV), U(VI), and Mo(VI) ions was achieved at 60 min shaking time. Langmuir isotherm model is the most representative for discussing the sorption process with a maximum sorption capacity of 24.26, 21.82, and 13.01 mg/g for Zr(IV), U(VI), and Mo(VI) ions, respectively. Kinetic modeling revealed that the sorption of all ions follows the pseudo-second-order kinetic model. The results demonstrated that both the external and intra-particular diffusion are taken into account in determining the sorption rate. Thermodynamic parameters like ΔG°, ΔH°, and ΔS° for the sorption process were evaluated. The synthetic composite has been successfully applied for the removal and recovery of U(VI) ions from real solution (monazite leachate) using a chromatographic column packed with PAn/SiO2 composite with a breakthrough capacity equal to 239.70 mg/g.


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