A Further Investigation of NH4+ Removal Mechanisms by Using Natural and Synthetic Zeolites in Different Concentrations and Temperatures

We investigated the ammonium removal abilities of natural and synthetic zeolites with distinct Si/Al ratios and various surface areas to study how adsorption and ion exchange processes in zeolites perform under different ammonium concentrations and different temperatures. Five zeolites—natural mordenite, chabazite, erionite, clinoptilolite, and synthetic merlinoite—were immersed in 20, 50, and 100 mg/kg ammonium solutions. The results demonstrate that zeolites under high ammonium concentrations (100 mg/kg) possess higher physical adsorption capacity (0.398–0.468 meq/g), whereas those under lower ammonium concentrations (20 mg/kg) possess greater ion exchange properties (64–99%). The ion exchange ability of zeolites is extremely dependent on the cation content of the zeolites, and the cation content is affected by the Si/Al ratio. The surface area of zeolites also has a partial influence on its physical adsorption ability. When the surface area is less than 100 m2/g, the adsorption ability of zeolite increases obviously with surface area; however, adsorption ability is saturated as the surface area becomes larger than this critical value of 100 m2/g. When we placed the zeolites in 50 mg/kg ammonium concentration at different temperatures (5–50 °C), we found that the zeolites exhibited the highest ammonium removal ability at 30 °C and the potassium release was enhanced at 30–40 °C.

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Removing Ammonia From Wastewater Using Natural and Synthetic Zeolites: A Batch Experiment

10.26434/chemrxiv.9831542 ◽

2019 ◽

Author(s):

Judit Canellas ◽

Ana Soares ◽

Bruce Jefferson

Keyword(s):

Ion Exchange ◽

Research Direction ◽

Synthetic Zeolite ◽

Variable Load ◽

Natural Zeolites ◽

Component Solution ◽

Synthetic Zeolites ◽

Real Wastewater ◽

Regeneration Efficiency ◽

Natural And Synthetic

Ion exchange based processes for the removal of ammonium from wastewater using zeolites could be an attractive additional or potentially complementary treatment option for conditions that pose a challenge for biological processes, such as variable load or low temperatures. A range of natural and synthetic zeolites have been studied for removing ammonium from wastewater. However, the relatively low capacity of zeolites and challenges regarding regeneration have so far complicated efforts in this research direction. Here, we compare the most commonly used natural zeolites US-Clinoptilolite, UK-Clinoptilolite, Mordenite and Chabazite (using Na- and Ca- as main cation exchanger) as well as a thermally modified US-Clinoptilolite and a synthetic zeolite MesoLite in terms of their capacity and regeneration efficiency to determine whether a synthetic zeolite like MesoLite can address the aforementioned problems related to capacity and regeneration efficiency. This investigation was performed as a series of batch experiments on synthetic and real wastewater solutions. When zeolites were pre-saturated with sodium ions, we found the overall highest capacity of 4.6 meq/g for the synthetic zeolite MesoLite, relative to a range between 1.1 and 2.1 meq/g for the natural zeolites. Ammonium adsorption capacity of MesoLite with real wastewater ranged between 74 and 97% of what was observed for a synthetically generated mono component solution set at approximately the same ionic load. Our results indicate that MesoLite could be an appropriate media for ion-exchange based tertiary treatment of wastewater.

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Ammonium removal from anaerobic digester effluent by ion exchange

Water Science & Technology ◽

10.2166/wst.2009.317 ◽

2009 ◽

Vol 60 (1) ◽

pp. 201-210 ◽

Cited By ~ 20

Author(s):

T. Wirthensohn ◽

F. Waeger ◽

L. Jelinek ◽

W. Fuchs

Keyword(s):

Ion Exchange ◽

Cation Exchange ◽

Reverse Osmosis ◽

Exchange Capacity ◽

Ammonium Concentration ◽

Effluent Quality ◽

Ammonium Removal ◽

Anaerobic Digester Effluent ◽

Cation Exchange Resins ◽

Exchange Resins

The effluent of a 500 kW biogas plant is treated with a solid separation, a micro filtration and a reverse osmosis to achieve nutrient recovery and an effluent quality which should meet disposal quality into public water bodies. After the reverse osmosis, the ammonium concentration is still high (NH4-N = 467 mg/l), amongst other cations (K+=85 mg/l; Na+=67 mg/l; Mg2 + =0.74 mg/l; Ca2 + =1.79 mg/l). The aim of this study was to remove this ammonium by ion exchange. Acidic gel cation exchange resins and clinoptilolite were tested in column experiments to evaluate their capacity, flow rates and pH. Amberjet 1,500 H was the most efficient resin, 57 BV of the substrate could be treated, 1.97 mol NH4-N/l resin were removed. The ammonium removal was more than 99% and the quality of the effluent was very satisfactory (NH4-N < 2 mg/l). The breakthrough of the observed parameters happened suddenly, the order was sodium—pH—ammonium—potassium. The sharp increase of the pH facilitates the online control, while the change in conductivity is less significant. A regeneration with 3 bed volumes of 2 M HCl recovered 91.7% of the original cation exchange capacity.

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Enhanced ammonium removal efficiency by ion exchange process of synthetic zeolite after Na+ and heat pretreatment

Water Science & Technology ◽

10.2166/wst.2018.420 ◽

2018 ◽

Vol 78 (6) ◽

pp. 1417-1425 ◽

Cited By ~ 6

Author(s):

Kyujin Ham ◽

Beom Seok Kim ◽

Kwon-Young Choi

Keyword(s):

Heat Treatment ◽

Ion Exchange ◽

Removal Efficiency ◽

Freundlich Isotherm ◽

Synthetic Zeolite ◽

Isotherm Models ◽

Adsorptive Capacity ◽

Ammonium Concentration ◽

Zeolite A ◽

Ammonium Removal

Abstract In this study, the optimum ammonium removal by activation of synthetic zeolite in the aqueous phase was investigated by batch ion exchange adsorption assay, and its surface changes due to activation modification was elucidated accordingly. Among the adsorbents examined, modified synthetic zeolite A-4 was the most effective at ammonium removal. The best activation condition of zeolite A-4 was established by Na+ and 300 °C heat treatment at pH around 6 to 7. Besides, the removal efficiency was investigated under various reaction conditions of pH, adsorbent dosage, stirring speed, and initial ammonium concentration. Finally, the adsorptive capacity Qe of synthetic zeolite A-4 activated by Na+ and heat treatment was determined as 31.9 mg/g at 1,000 mg-N/L of ammonium, whereas that of natural zeolite was measured as 16.0 mg/g. The obtained adsorption data was fitted to both Langmuir and Freundlich isotherm models, and the Langmuir isotherm model provided a better correspondence than the Freundlich isotherm. Finally, regeneration cycles for synthetic zeolite A-4 was determined for further industrial applications and efficient ammonium removal.

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Evaluation and Comparison of Antimicrobial Properties of Natural and Synthetic Zeolites Exchanged with Silver, Zinc, Copper and Nickel Ions

Yafteh Lorestan University of Medical Sciences ◽

10.32592/yafteh.2021.23.2.10 ◽

2021 ◽

pp. 125-141

Keyword(s):

Antibacterial Activity ◽

Ion Exchange ◽

Antibacterial Properties ◽

Antimicrobial Properties ◽

Metal Cations ◽

Exchange Capacity ◽

Nickel Ions ◽

Antibacterial Materials ◽

Synthetic Zeolites ◽

Natural And Synthetic

Zeolites are high-porous active crystalline biomaterials. Recently many studies have been done on their antibacterial properties especially on zeolites exchanged with metallic cations. In this paper, we investigate the effective factors on the antimicrobial activity of natural and synthetic zeolites exchanged with silver, zinc, copper nickel, and bromide cations. This study reviews the published articles on the antibacterial properties of the natural and synthetic pure zeolites as well as the ion exchange ones. The results of our investigation show that ion exchange zeolites exhibit a very good antibacterial effects even in comparison with other conventional antibacterial materials. The strongest antibacterial activity was reported in silver exchanged zeolites against Bacillus cereus and Escherichia coli with MIC of 16 μg/ml. According to the results reported derived from different articles, it can be concluded that zeolites with biocompatibility and high ion exchange capacity can be used as efficient antibacterial materials. Pure zeolites have antibacterial activity at high concentrations, whereas all synthetic and natural zeolites exchanged with metal cations investigated in this paper exhibit good antibacterial activity at very low concentrations generally due to sustained and prolong release of metal cations.

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Removing Ammonia From Wastewater Using Natural and Synthetic Zeolites: A Batch Experiment

10.26434/chemrxiv.9831542.v1 ◽

2019 ◽

Author(s):

Judit Canellas ◽

Ana Soares ◽

Bruce Jefferson

Keyword(s):

Ion Exchange ◽

Research Direction ◽

Synthetic Zeolite ◽

Variable Load ◽

Natural Zeolites ◽

Component Solution ◽

Synthetic Zeolites ◽

Real Wastewater ◽

Regeneration Efficiency ◽

Natural And Synthetic

Ion exchange based processes for the removal of ammonium from wastewater using zeolites could be an attractive additional or potentially complementary treatment option for conditions that pose a challenge for biological processes, such as variable load or low temperatures. A range of natural and synthetic zeolites have been studied for removing ammonium from wastewater. However, the relatively low capacity of zeolites and challenges regarding regeneration have so far complicated efforts in this research direction. Here, we compare the most commonly used natural zeolites US-Clinoptilolite, UK-Clinoptilolite, Mordenite and Chabazite (using Na- and Ca- as main cation exchanger) as well as a thermally modified US-Clinoptilolite and a synthetic zeolite MesoLite in terms of their capacity and regeneration efficiency to determine whether a synthetic zeolite like MesoLite can address the aforementioned problems related to capacity and regeneration efficiency. This investigation was performed as a series of batch experiments on synthetic and real wastewater solutions. When zeolites were pre-saturated with sodium ions, we found the overall highest capacity of 4.6 meq/g for the synthetic zeolite MesoLite, relative to a range between 1.1 and 2.1 meq/g for the natural zeolites. Ammonium adsorption capacity of MesoLite with real wastewater ranged between 74 and 97% of what was observed for a synthetically generated mono component solution set at approximately the same ionic load. Our results indicate that MesoLite could be an appropriate media for ion-exchange based tertiary treatment of wastewater.

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Production of gaseous nitrogen compounds in a novel process for ammonium removal

Water Science & Technology ◽

10.2166/wst.2002.0480 ◽

2002 ◽

Vol 46 (1-2) ◽

pp. 215-222 ◽

Cited By ~ 2

Author(s):

M. Green ◽

N. Denekamp ◽

O. Lahav ◽

S. Tarre

Keyword(s):

Ion Exchange ◽

Nitrogen Losses ◽

Nitrifying Bacteria ◽

Ammonium Concentration ◽

Nitrogen Compounds ◽

Secondary Effluent ◽

Batch Experiments ◽

Gaseous Nitrogen ◽

Nitrogen Gas ◽

Ammonium Removal

The production of gaseous nitrogen compounds, particularly the greenhouse gas nitrous oxide, was investigated in a novel process for ammonium removal from wastewater. The process is based on the adsorption of ammonium on zeolite followed by bioregeneration. The zeolite serves the dual purpose of an ion exchanger and a physical carrier for nitrifying bacteria which bio-regenerate the ammonium saturated mineral. An analysis of the nitrifying population composition in the reactor fed with simulated secondary effluent (NH4+ = 50 mg/l) revealed that about half of the bacteria in the biofilm were common ammonium oxidizers Nitrosococcus mobilis and Nitrosomonas, while the other half were nitrite oxidizers. The amount of nitrogen losses, under different conditions, and the identification of the emitted gases (N2 or N2O) were investigated in two sets of experiments: (I) batch experiments using biomass originating from the ion exchange reactor with and without the addition of nitrite, and (II) continuous experiments using the ion exchange reactor with zeolite as the biomass carrier. In the batch experiments, nitrite and oxygen concentrations were determined as the major parameters responsible for the formation of gaseous nitrogen gas during ammonia oxidation by autotrophic bacteria. Continuous experiments showed that the major parameter significantly affecting nitrogen losses was the amount of ammonium adsorbed by the zeolite during the ion exchange phase. The amount of ammonium adsorbed determines the ammonium concentration during the initial period of bioregeneration, which in turn directly influences oxygen demand and the resulting concentrations of oxygen and nitrite. It was concluded that the formation of nitrogen gas compounds in the ion exchange/bioregeneration process can be eliminated by adjusting the operational regime to have a shorter adsorption phase resulting in smaller amounts of ammonium adsorbed per cycle.

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Development and Characterization of Amine-Clay Hybrid Adsorbents for CO2 Capture

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1133.547 ◽

2016 ◽

Vol 1133 ◽

pp. 547-551 ◽

Cited By ~ 2

Author(s):

Ali E.I. Elkhalifah ◽

Mohammad Azmi Bustam ◽

Azmi Mohd Shariff ◽

Sami Ullah ◽

Nadia Riaz ◽

...

Keyword(s):

Adsorption Capacity ◽

Surface Area ◽

Surface Properties ◽

Molar Mass ◽

Adsorption Ability ◽

Stepwise Increase ◽

Inverse Effect ◽

Bet Method ◽

Sodium Form

The present work aims at a better understanding of the influences of the intercalated mono-, di- and triethanolamines on the characteristics and CO2 adsorption ability of sodium form of bentonite (Na-bentonite). The results revealed that the molar mass of intercalated amines significantly influenced the structural and surface properties as well as the CO2 adsorption capacity of Na-bentonite. In this respect, a stepwise increase in the d-spacing of Na-bentonite with the molar mass of amine was recorded by XRD technique. However, an inverse effect of the molar mass of amine on the surface area was confirmed by BET method. CO2 adsorption experiments on amine-bentonite hybrid adsorbents showed that the CO2 adsorption capacity inversly related to the molar mass of amine at 25 ͦC and 101 kPa. Accordingly, Na-bentonite modified by monoethanolammonium cations adsorbed as high as 0.475 mmol CO2/g compared to 0.148 and 0.087 mmol CO2/g for that one treated with di- and triethanolammonium cations, respectively.

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Contemporary applications of natural and synthetic zeolites from fly ash in agriculture and environmental protection

Journal of Cleaner Production ◽

10.1016/j.jclepro.2021.127461 ◽

2021 ◽

pp. 127461

Author(s):

Justyna Szerement ◽

Alicja Szatanik-Kloc ◽

Renata Jarosz ◽

Tomasz Bajda ◽

Monika Mierzwa-Hersztek

Keyword(s):

Fly Ash ◽

Environmental Protection ◽

Synthetic Zeolites ◽

Natural And Synthetic

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Band Engineering and Morphology Control of Oxygen-Incorporated Graphitic Carbon Nitride Porous Nanosheets for Highly Efficient Photocatalytic Hydrogen Evolution

Nano-Micro Letters ◽

10.1007/s40820-020-00571-6 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Yunyan Wu ◽

Pan Xiong ◽

Jianchun Wu ◽

Zengliang Huang ◽

Jingwen Sun ◽

...

Keyword(s):

Surface Area ◽

Hydrogen Evolution ◽

Carbon Nitride ◽

Separation Efficiency ◽

Physical Adsorption ◽

Graphitic Carbon ◽

Graphitic Carbon Nitride ◽

Photocatalytic Hydrogen Evolution ◽

Band Engineering ◽

Highly Efficient

AbstractGraphitic carbon nitride (g-C3N4)-based photocatalysts have shown great potential in the splitting of water. However, the intrinsic drawbacks of g-C3N4, such as low surface area, poor diffusion, and charge separation efficiency, remain as the bottleneck to achieve highly efficient hydrogen evolution. Here, a hollow oxygen-incorporated g-C3N4 nanosheet (OCN) with an improved surface area of 148.5 m2 g−1 is fabricated by the multiple thermal treatments under the N2/O2 atmosphere, wherein the C–O bonds are formed through two ways of physical adsorption and doping. The physical characterization and theoretical calculation indicate that the O-adsorption can promote the generation of defects, leading to the formation of hollow morphology, while the O-doping results in reduced band gap of g-C3N4. The optimized OCN shows an excellent photocatalytic hydrogen evolution activity of 3519.6 μmol g−1 h−1 for ~ 20 h, which is over four times higher than that of g-C3N4 (850.1 μmol g−1 h−1) and outperforms most of the reported g-C3N4 catalysts.

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