Tetracycline adsorption mechanisms by NaOH-modified biochar derived from waste Auricularia auricula dregs

2021 ◽  
Author(s):  
Jiawei Zhao ◽  
Yingjie Dai
Keyword(s):  
Adsorption Mechanisms ◽  
Auricularia Auricula ◽  
Modified Biochar

scholarly journals Sustainable Chromium (VI) Removal from Contaminated Groundwater Using Nano-Magnetite-Modified Biochar via Rapid Microwave Synthesis

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 103
Author(s):  
Xiaoming Song ◽  
Yuewen Zhang ◽  
Nan Cao ◽  
Dong Sun ◽  
Zhipeng Zhang ◽  
...  
Keyword(s):  
Synthesis Method ◽  
Microwave Treatment ◽  
Contaminated Groundwater ◽  
Maximum Adsorption Capacity ◽  
Intraparticle Diffusion Model ◽  
Adsorption Mechanisms ◽  
Chromium Vi ◽  
Modified Biochar ◽  
Pseudo Second Order ◽  
Nano Fe3o4

This study developed a nano-magnetite-modified biochar material (m-biochar) using a simple and rapid in situ synthesis method via microwave treatment, and systematically investigated the removal capability and mechanism of chromium (VI) by this m-biochar from contaminated groundwater. The m-biochar was fabricated from reed residues and magnetically modified by nano-Fe3O4. The results from scanning electron microscopy (SEM) and X-ray diffraction (XRD) characterisations confirmed the successful doping of nano-Fe3O4 on the biochar with an improved porous structure. The synthesised m-biochar exhibited significantly higher maximum adsorption capacity of 9.92 mg/g compared with that (8.03 mg/g) of the pristine biochar. The adsorption kinetics followed the pseudo-second-order model and the intraparticle diffusion model, which indicated that the overall adsorption rate of Cr(VI) was governed by the processes of chemical adsorption, liquid film diffusion and intramolecular diffusion. The increasing of the pH from 3 to 11 significantly affected the Cr(VI) adsorption, where the capabilities decreased from 9.92 mg/g to 0.435 mg/g and 8.03 mg/g to 0.095 mg/g for the m-biochar and pristine biochar, respectively. Moreover, the adsorption mechanisms of Cr(VI) by m-biochar were evaluated and confirmed to include the pathways of electrostatic adsorption, reduction and complexation. This study highlighted an effective synthesis method to prepare a superior Cr(VI) adsorbent, which could contribute to the effective remediation of heavy metal contaminations in the groundwater.

scholarly journals Enhanced adsorption of ciprofloxacin by KOH modified biochar derived from potato stems and leaves

2017 ◽  
Vol 77 (4) ◽  
pp. 1127-1136 ◽  
Author(s):  
Ruining Li ◽  
Zhaowei Wang ◽  
Jialei Guo ◽  
Yan Li ◽  
Hanyu Zhang ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Nitrogen Adsorption ◽  
Adsorption Mechanisms ◽  
Modified Biochar ◽  
Bonding Interaction ◽  
Before And After ◽  
Stems And Leaves ◽  
Enhanced Adsorption ◽  
Adsorption Desorption ◽  
Kinetics And Isotherms

Abstract Potato stems and leaves biochar (PB) was prepared by pyrolysis at a temperature of 500°C under anoxic conditions. In order to strengthen the adsorption capacity, biochar was modified with alkaline solution (alkali modified biochar, APB). Two kinds of biochars were adopted as adsorbents to remove ciprofloxacin (CIP) from aqueous solution. The adsorption behavior of CIP onto biochar before and after alkali modified including adsorption kinetics and isotherms were investigated. The effects of different factors (equilibrium time, pH, temperature and initial concentration) during the adsorption process were also investigated. Biochar samples were characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and nitrogen adsorption–desorption isotherm. The results showed that the alkali treated biochar possessed more mesopores than raw biochar, and accordingly exhibited a more excellent adsorption performance (23.36 mg·g−1) than raw biochar. Hydrophobic interaction, hydrogen-bonding interaction, electrostatic interaction, and π − π interaction were the adsorption mechanisms for CIP uptake onto the two adsorbents.

Enhanced removal of NO3-N from water using Fe-Al modified biochar: behavior and mechanism

2019 ◽  
Vol 80 (10) ◽  
pp. 2003-2012 ◽  
Author(s):  
Hanyang You ◽  
Wenying Li ◽  
Yi Zhang ◽  
Zilin Meng ◽  
Zhenxiao Shang ◽  
...  
Keyword(s):  
Ligand Exchange ◽  
Adsorption Process ◽  
Maximum Adsorption Capacity ◽  
Batch Experiments ◽  
Order Model ◽  
Freundlich Model ◽  
Adsorption Mechanisms ◽  
Adsorption Performance ◽  
Modified Biochar ◽  
N Removal

Abstract To remove NO3-N from water, coconut shell biochar (CSB) was modified by a solution of FeCl3, a solution of AlCl3 and a mixture solution of FeCl3 and AlCl3 respectively. The obtained modified biochar with the best effect of NO3-N adsorption was screened out to explore the adsorption behavior and mechanism of NO3-N removal by batch experiments and kinetics and thermodynamics and correlated characterization. The results indicated that the mixture solution of FeCl3- and AlCl3- modified CSB (Fe-Al/CSB) showed the best adsorption performance for NO3-N removal. Iron and aluminum elements existed on the surface of Fe-Al/CSB in the form of FeOOH, Fe2O3, Fe2+, and Al2O3 respectively. The adsorption process could reach equilibrium in 20 min. An acidic condition was favorable for NO3-N adsorption. The presence of coexisting anions was not conducive for NO3-N adsorption. The quasi-second-order model and Freundlich model could be well fitted in the adsorption process. The maximum adsorption capacity of Fe-Al/CSB fitted by the Langmuir model could reach 34.20 mg/g. The adsorption of NO3-N by Fe-Al/CSB was an endothermic and spontaneous process. Ligand exchange and chemical redox reaction were the NO3-N adsorption mechanisms which led to NO3-N adsorption by Fe-Al/CSB.

Comparison of the fixation of several metal ions onto a low-cost biopolymer

2002 ◽  
Vol 2 (5-6) ◽  
pp. 217-224 ◽  
Author(s):  
Z. Reddad ◽  
C. Gérente ◽  
Y. Andrès ◽  
P. Le Cloirec
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Low Cost ◽  
Operating Conditions ◽  
Order Kinetic ◽  
Adsorption Mechanisms ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Beet Pulp ◽  
Removal Of Metal Ions

In the present work, sugar beet pulp, a common waste from the sugar refining industry, was studied in the removal of metal ions from aqueous solutions. The ability of this cheap biopolymer to sorb several metals namely Pb2+, Cu2+, Zn2+, Cd2+ and Ni2+ in aqueous solutions was investigated. The metal fixation capacities of the sorbent were determined according to operating conditions and the fixation mechanisms were identified. The biopolymer has shown high elimination rates and interesting metal fixation capacities. A pseudo-second-order kinetic model was tested to investigate the adsorption mechanisms. The kinetic parameters of the model were calculated and discussed. For 8 × 10-4 M initial metal concentration, the initial sorption rates (v0) ranged from 0.063 mmol.g-1.min-1 for Pb2+ to 0.275 mmol.g-1.min-1 for Ni2+ ions, with the order: Ni2+ > Cd2+ > Zn2+ > Cu2+ > Pb2+. The equilibrium data fitted well with the Langmuir model and showed the following affinity order of the material: Pb2+ > Cu2+ > Zn2+ > Cd2+ > Ni2+. Then, the kinetic and equilibrium parameters calculated qm and v0 were tentatively correlated to the properties of the metals. Finally, equilibrium experiments in multimetallic systems were performed to study the competition of the fixation of Pb2+, Zn2+ and Ni2+ cations. In all cases, the metal fixation onto the biopolymer was found to be favourable in multicomponent systems. Based on these results, it is demonstrated that this biosorbent represents a low-cost solution for the treatment of metal-polluted wastewaters.

Arsenic volatilization in flooded paddy soil by the addition of Fe-Mn-modified biochar composites

2019 ◽  
Vol 674 ◽  
pp. 327-335 ◽  
Author(s):  
Lina Lin ◽  
Zhengguo Song ◽  
Xuewei Liu ◽  
Zulqarnain Haider Khan ◽  
Weiwen Qiu
Keyword(s):  
Paddy Soil ◽  
Modified Biochar ◽  
Flooded Paddy Soil
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