Removal of Trace Mercury in Water by Iron Manganese Oxide Modified Biochar

2021 ◽  
Vol 15 (5) ◽  
pp. 629-638
Author(s):  
Sheng Liu ◽  
Xujie Li ◽  
Zilin Su ◽  
Linya Yi ◽  
Zhanli Chen ◽  
...  

Mercury wastewater is a kind of heavy metal wastewater discharged from many industrial processes. The treatment of a large amount of mercury-containing wastewater increasingly requires high-efficiency, low-cost, and low-cost treatment materials, treatment processes and technologies to ensure compliance with mercury standards. This paper mainly studies the effect of iron-manganese oxide modified biochar on the removal of trace mercury in water. The prepared activated carbon is added to a mercury solution with a proper concentration, and a single factor adsorption experiment of pH, initial concentration, amount of activated carbon, particle size, temperature, and time is performed. In this paper, iron manganese oxide modified biochar is listed as the research object. The activated carbon is studied through the adsorption characteristics, adsorption mechanism and influencing factors of mercury in the solution, and the process technology and optimization parameters of the modified activated carbon to treat mercury-containing wastewater are explored. The maximum adsorption capacity of modified activated carbon calculated by Lagergren quasi-first-order kinetic model is 16.62 mg/g. This indicates that the adsorption kinetics of Hg by iron-manganese oxide modified biochar is more consistent with the Lagergren quasi-secondary kinetic model and is also more efficient.

2019 ◽  
Vol 72 (9) ◽  
pp. 717
Author(s):  
Junying Song ◽  
Zhanbin Huang ◽  
Fengzhi Yang

Excess pentavalent vanadium(v) has severely degraded water quality and posed a huge threat to human health over the past several decades. Hence, it’s urgent and significant to explore a novel adsorbent which is low cost and efficient to treat vanadium pollution. In this work, a novel iron-manganese oxide@diatomite (MnFe2O4@DE) adsorbent with superior removal performance for simulated vanadium(v) wastewater was synthesised via a facile hydrothermal method. The as-prepared MnFe2O4@DE composite was characterised through different characterisation techniques. The results indicated that the MnFe2O4 nanoparticles were uniformly deposited on the surface of diatomite, resulting in a larger specific surface area and pore volume of the composite. In addition, the MnFe2O4@DE adsorbent exhibited the highest adsorption capacity for vanadium(v) (18.37mgg−1±0.5%), which was up to around 13.24 and 1.33 times as much as that of pure diatomite and MnFe2O4, respectively. This is mainly attributed to the enhanced specific surface area and pore volume. Furthermore, X-ray photoelectron spectroscopy (XPS) analysis demonstrated vanadium(v) could be reduced to low valence vanadium with low toxicity by the MnFe2O4@DE composite which could exist as VO2+ and VO+ cations in solution. The adsorption process was better fitted with a pseudo-second-order kinetic model and Langmuir model, which is spontaneous and endothermic. Overall, the novel MnFe2O4@DE composite could be applied as a promising adsorbent in addressing vanadium pollution issues due to its properties of low cost, effectiveness, and environmental friendliness.


2021 ◽  
Vol 11 (5) ◽  
pp. 13214-13231

An activated carbon was developed from Moringa oleifera seed and modified with iron nanoparticles (AC-Fe) for application in the oils and greases (O&G) adsorption of the produced water. Activated carbon was prepared by pyrolysis and chemical activation using NaOH. Surface modification was performed by the wet impregnation method. AC-Fe was characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller surface area analyzer (BET), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Boehm titration, and point of zero charge (pHPZC). The amount of O&G adsorbed on AC-Fe was sensitive to pH, initial concentration and temperature, but independent of ionic strength. Freundlich isotherm adjusted well, confirming the heterogeneous distribution of active sites and multilayer. The pseudo-second-order kinetic model accurately represents the O&G adsorption process by AC-Fe. Under different temperatures, the maximum amount of O&G adsorption in AC-Fe calculated by the pseudo-second-order kinetic model was 121.95 mg g-1 (298 K), 111.11 mg g-1 (303 K), and 106.38 mg g-1 (308 K). This high adsorption capacity demonstrates the new material potential as a low-cost adsorbent for O&G removal.


Author(s):  
Ali Ahmadfazeli ◽  
Yousef Poureshgh ◽  
Yousef Rashtbari ◽  
Hamed Akbari ◽  
Peyman Pourali ◽  
...  

Abstract This article was aimed at investigating the removal of metronidazole (MNZ) from aquatic solutions by modified activated carbon (MAC) with amine groups. The effect of various parameters on the adsorption rate such as the initial pH, adsorbent dose and initial concentration of MNZ and contact time were scrutinized. MAC was characterized by Fourier transform infrared spectroscopy and Brunauer–Emmett–Teller techniques. The obtained results illustrated that under the optimum conditions (pH = 3, contact time = 50 min, initial MNZ concentration = 5 mg/L and MAC dose = 0.5 g/L), the maximum adsorption efficiency was 95%. Furthermore, the kinetic studies indicated the applicability of the pseudo-second-order kinetic model, whereas the adsorption isotherm fitted well with the Freundlich model (0.996), and the maximum adsorption capacity was 66.22 mg/g. The SBET and the total pure volume of MAC were 706.92 m2/g and 0.532 cm3/g, respectively. Also, the regeneration tests demonstrated that MAC had good stability after five cycles (73%). It can be concluded that MAC, as an effective adsorbent, has a high ability to remove MNZ from aqueous solutions.


Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2682
Author(s):  
Gyuhyeon Kim ◽  
Young-Mo Kim ◽  
Su-Min Kim ◽  
Hyun-Uk Cho ◽  
Jong-Moon Park

In this study, magnetic steel slag biochar (MSSB) was synthesized from low-cost steel slag waste to investigate the effectiveness of steel slag biochar composite for NH4-N removal and magnetic properties in aqueous solution. The maximum adsorption capacity of NH4-N by MSSB was 4.366 mg/g according to the Langmuir model. The magnetic properties of MSSB indicated paramagnetic behavior and a saturation magnetic moment of 2.30 emu/g at 2 Tesla. The NH4-N adsorption process was well characterized by the pseudo-second order kinetic model and Temkin isotherm model. This study demonstrated the potential of magnetic biochar synthesized from steel slag waste for NH4-N removal in aqueous solution.


2014 ◽  
Vol 9 (1) ◽  
pp. 166-174 ◽  
Author(s):  
Rajeshwar M. Shrestha ◽  
Margit Varga ◽  
Imre Varga ◽  
Amar P. Yadav ◽  
Bhadra P. Pokharel ◽  
...  

Activated carbons were prepared from Lapsi seed stone by the treatment with H2SO4 and HNO3 for the removal of Ni (II) ions from aqueous solution. Two activated carbon have been prepared from Lapsi seed stones by treating with conc.H2SO4 and a mixture of H2SO4 and HNO3 in the ratio of 1:1 by weight for removal of Ni(II) ions. Chemical characterization of the resultant activated carbons was studied by Fourier Transform Infrared Spectroscopy and Boehm titration which revealed the presence of oxygen containing surface functional groups like carboxyl, lactones and phenols in the carbons. The optimum pH for nickel adsorption is found to be 5. The adsorption data were better fitted with the Langmuir equations than Freundlich adsorption equation to describe the equilibrium isotherms. The maximum adsorption capacity of Ni (II) on the resultant activated carbons was 28.25.8 mg g-1 with H2SO4 and 69.49 mg g-1 with a mixture of H2SO4 and HNO3. The waste material used in the preparation of the activated carbons is inexpensive and readily available. Hence the carbons prepared from Lapsi seed stones can act as potential low cost adsorbents for the removal of Ni (II) from water. DOI: http://dx.doi.org/10.3126/jie.v9i1.10680Journal of the Institute of Engineering, Vol. 9, No. 1, pp. 166–174


2019 ◽  
Vol 6 (9) ◽  
pp. 190523 ◽  
Author(s):  
Lu Luo ◽  
Xi Wu ◽  
Zeliang Li ◽  
Yalan Zhou ◽  
Tingting Chen ◽  
...  

Activated carbon (AC) was successfully prepared from low-cost forestry fir bark (FB) waste using KOH activation method. Morphology and texture properties of ACFB were studied by scanning and high-resolution transmission electron microscopies (SEM and HRTEM), respectively. The resulting fir bark-based activated carbon (ACFB) demonstrated high surface area (1552 m 2 g −1 ) and pore volume (0.84 cm 3 g −1 ), both of which reflect excellent potential adsorption properties of ACFB towards methylene blue (MB). The effect of various factors, such as pH, initial concentration, adsorbent content as well as adsorption duration, was studied individually. Adsorption isotherms of MB were fitted using all three nonlinear models (Freundlich, Langmuir and Tempkin). The best fitting of MB adsorption results was obtained using Freundlich and Temkin. Experimental results showed that kinetics of MB adsorption by our ACFB adsorbent followed pseudo-second-order model. The maximum adsorption capacity obtained was 330 mg g −1 , which indicated that FB is an excellent raw material for low-cost production of AC suitable for cationic dye removal.


Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2498 ◽  
Author(s):  
Marwa Elkady ◽  
Hassan Shokry ◽  
Hesham Hamad

Nano-activated carbon (NAC) prepared from El-Maghara mine coal were modified with nitric acid solution. Their physico-chemical properties were investigated in terms of methylene blue (MB) adsorption, FTIR, and metal adsorption. Upon oxidation of the ACS with nitric acid, surface oxide groups were observed in the FTIR spectra by absorption peaks at 1750–1250 cm−1. The optimum processes parameters include HNO3/AC ratio (wt./wt.) of 20, oxidation time of 2 h, and the concentration of HNO3 of 10% reaching the maximum adsorption capacity of MB dye. Also, the prepared NAC was characterized by SEM, EDX, TEM, Raman Spectroscopy, and BET analyses. The batch adsorption of MB dye from solution was used for monitoring the behavior of the most proper produced NAC. Equilibrium isotherms of MB dye adsorption on NAC materials were acquired and the results discussed in relation to their surface chemistry. Langmuir model recorded the best interpretation of the dye adsorption data. Also, NAC was evaluated for simultaneous adsorption of six different metal ions (Fe2+, Ni2+, Mn2+, Pb2+, Cu2+, and Zn2+) that represented contaminates in petrochemical industrial wastewater. The results indicated that the extracted NAC from El-Maghara mine coal is considered as an efficient low-cost adsorbent material for remediation in both basic dyes and metal ions from the polluted solutions.


2017 ◽  
Vol 75 (10) ◽  
pp. 2390-2402 ◽  
Author(s):  
Bellington Mudyawabikwa ◽  
Henry H. Mungondori ◽  
Lilian Tichagwa ◽  
David M. Katwire

The aim of this study was to prepare activated carbon from tobacco stalks using microwave heating. The prepared activated carbon was applied as an adsorbent in methylene blue (MB) removal from water. The optimum conditions for activated carbon preparation were a radiation power of 280 W for a period of 6 minutes after the impregnation of the precursor material with 30% ZnCl2 for 24 hours. The activated carbon yield and iodine number were 49.43% and 1,264.51 mg/g respectively. The activated carbon also had a point of zero charge of 5.81 with an adsorption capacity of 123.45 mg/g for MB. The optimum conditions for MB adsorption were a pH of 6.5 with an adsorbent dosage of 0.2 g/50 mL at 25 °C. The MB adsorption kinetics followed the pseudo second order kinetic model with the intra-particle diffusion model suggesting a two-step adsorption mechanism. The adsorption data also fitted well within the Langmuir adsorption isotherm model. Tobacco stalks can successfully be turned into an economically important product.


2014 ◽  
Vol 1043 ◽  
pp. 219-223 ◽  
Author(s):  
Noor Shawal Nasri ◽  
Jibril Mohammed ◽  
Muhammad Abbas Ahmad Zaini ◽  
Usman Dadum Hamza ◽  
Husna Mohd. Zain ◽  
...  

Concern about environmental protection has increased over the years and the presence of volatile organic compounds (VOCs) in water poses a threat to the environment. In this study, coconut shell activated carbon (PHAC) was produced by potassium hydroxide activation via microwave for benzene and toluene removal. Equilibrium data were fitted to Langmuir, Freundlich and Tempkin isotherms with all the models having R2 > 0.94. The equilibrium data were best fitted by Langmuir isotherm, with maximum adsorption capacity of 212 and 238mg/g for benzene and toluene, respectively. The equilibrium parameter (RL) falls between 0 and 1 confirming the favourability of the Langmuir model. Pseudo-second-order kinetic model best fitted the kinetic data. The PHAC produced can be used to remediate water polluted by VOCs.


2010 ◽  
Vol 8 (6) ◽  
pp. 1273-1280 ◽  
Author(s):  
Sayed Mohammadi ◽  
Mohammad Karimi ◽  
Daryoush Afzali ◽  
Fatemeh Mansouri

AbstractTwo series of activated carbon have been prepared by chemical activation of Amygdalus Scoparia shell with phosphoric acid or zinc chloride for the removal of Pb(II) ions from aqueous solutions. Several methods were employed to characterize the active carbon produced. The surface area was calculated using the standard Brunauer-Emmet-Teller method. The microstructures of the resultant activated carbon were observed by scanning electron microscopy. The chemical composition of the surface resultant activated carbon was determined by Fourier transform infrared spectroscopy. In the batch tests, the effect of pH, initial concentration, and contact time on the adsorption were studied. The data were fitted with Langmuir and Freundlich equations to describe the equilibrium isotherms. The maximum adsorption capacity of Pb(II) on the resultant activated carbon was 36.63 mg g−1 with H3PO4 and 28.74 mg g−1 with ZnCl2. To regenerate the spent adsorbents, desorption experiments were performed using 0.25 mol L−1 HCl. Here we propose that the activated carbon produced from Amygdalus Scoparia shell is an alternative low-cost adsorbent for Pb(II) adsorption.


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