Enhanced Fenton-like removal of nitrobenzene via internal microelectrolysis in nano zerovalent iron/activated carbon composite

2015 ◽  
Vol 73 (1) ◽  
pp. 153-160 ◽  
Author(s):  
Sihai Hu ◽  
Yaoguo Wu ◽  
Hairui Yao ◽  
Cong Lu ◽  
Chengjun Zhang

The efficiency of Fenton-like catalysis using nano zerovalent iron (nZVI) is limited by nZVI aggregation and activity loss due to inactive ferric oxide forming on the nZVI surface, which hinders electron transfer. A novel iron–carbon composite catalyst consisting of nZVI and granular activated carbon (GAC), which can undergo internal iron–carbon microelectrolysis spontaneously, was successfully fabricated by the adsorption–reduction method. The catalyst efficiency was evaluated in nitrobenzene (NB) removal via the Fenton-like process (H2O2-nZVI/GAC). The results showed that nZVI/GAC composite was good for dispersing nZVI on the surface of GAC, which permitted much better removal efficiency (93.0%) than nZVI (31.0%) or GAC (20.0%) alone. Moreover, iron leaching decreased from 1.28 to 0.58 mg/L after reaction of 240 min and the oxidation kinetic of the Fenton-like reaction can be described well by the second-order reaction kinetic model (R2 = 0.988). The composite catalyst showed sustainable catalytic ability and GAC performed as a medium for electron transfer in internal iron–carbon microelectrolysis to promote Fe2+ regeneration and Fe3+/Fe2+ cycles. Therefore, this study represents an important method to design a low cost and high efficiency Fenton-like catalyst in practical application.

2015 ◽  
Vol 659 ◽  
pp. 304-309
Author(s):  
Khemmakorn Gomonsirisuk ◽  
Thanakorn Wasanapiarnpong

Organic contaminated wastes water from petrochemical industries can be removed by adsorbent and photocatalyst. In this work, the degradation rate of phenol have been studied at different ratios of activated carbon/NaA zeolite composite materials coated with TiO2 photocatalyst which are easily to be fabricated into tubular shape by extrusion method. In addition, the foam-inserted composite can be floated on the surface of waste water for the higher phocatalyst activity. While the composite is the low cost adsorbent with high absorption and high ion exchange properties. In order to optimize the efficiency of material, the various ratios of activated carbon/NaA zeolite (3:1, 1:1 and 1:3) and amount of coated TiO2 on the specimen’s surface was studied by UV/Vis spectrophotometer which related to phenol concentration. Moreover the various amount of phenolic resins (10, 20, 30, 40 and 50 wt%) at different reduction firing temperatures (600 and 650 °C) with soaking time of 1, 2 and 3 hours affected to the compressive strength of samples. For the characterization, XRD is used to characterize the phase and SEM is used to provide the morphology of the prepared composite materials.


2016 ◽  
Vol 4 (41) ◽  
pp. 15913-15919 ◽  
Author(s):  
Yang Yang ◽  
Tianyu Liu ◽  
Qiang Liao ◽  
Dingding Ye ◽  
Xun Zhu ◽  
...  

Low-cost electrodes were used in miniature microbial fuel cells to generate a remarkably high volumetric power density.


2019 ◽  
Vol 137 (22) ◽  
pp. 48746 ◽  
Author(s):  
Preethi Ramadoss ◽  
Thankam Regi ◽  
Mohammed Isfahur Rahman ◽  
D. Arivuoli

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Xiaotao Zhang ◽  
Yinan Hao ◽  
Ximing Wang ◽  
Zhangjing Chen ◽  
Chun Li

This paper presents low-cost and recyclable activated carbon (XLAC) derived from Xanthoceras sorbifolia Bunge hull for high-efficiency adsorption of Cd(II) and Hg(II) ions in industrial wastewater. XLAC was prepared through H3PO4 activation and was characterized using N2 adsorption-desorption, scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDX), and Fourier transform infrared (FTIR) spectroscopy. In single-metal-system adsorption experiments, the maximum adsorption capacities for Cd(II) and Hg(II) obtained under different experimental conditions were 388.7 and 235.6 mg·g−1, respectively. All adsorption equilibrium data fit perfectly with the Langmuir isotherm model. In a binary metal system, competitive studies demonstrated that the presence of Cd(II) significantly decreased the adsorption of Hg(II), but the adsorption of Cd(II) showed a little change in the presence of Hg(II). In addition, XLAC can be regenerated with a 0.01 mol·L−1 HNO3 solution and reused at least four times. The FTIR spectra revealed that a chemical interaction occurs between functional groups containing lone electron pairs in XLAC and metal ions. Overall, these results suggest that XLAC may be suitable as an adsorbent for heavy metal removal from wastewater streams.


Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 23
Author(s):  
Stanley Onyinye Okonji ◽  
Linlong Yu ◽  
John Albino Dominic ◽  
David Pernitsky ◽  
Gopal Achari

Selenomethionine (SeMet) and selenocysteine (SeCys) are the most common forms of organic selenium, which is often found in the effluent of industrial wastewater. These organic selenium compounds are toxic, bioavailable and most likely to bioaccumulate in aquatic organisms. This study investigated the use of two adsorbent candidates (granular activated carbon (GAC) and nano zerovalent iron (nZVI)) as treatment technologies for SeMet and SeCys removal. Batch experiments were performed and inductively coupled plasma optical emission spectrometer (ICP-OES) was used for sample analysis. Experimental data showed GAC demonstrated a higher affinity towards the removal of SeMet and SeCys compared to nZVI. The removal efficiency of SeCys and SeMet by GAC was 96.1% and 86.7%, respectively. NZVI adsorption capacity for SeCys was 39.4% and SeMet < 1.1%. Irrespective of the adsorbent, SeMet is more refractory to be adsorbed compared to SeCys. Kinetics data of GAC and nZVI agreed well with the pseudo-second-order model (R2 > 0.990). The experimental data of SeCys was characterized by Langmuir model, indicating monolayer adsorption. The adsorption capacity of nZVI for SeCys increased significantly by about 35%, with a decrease in pH from 9.0 to 4.0, indicating that SeCy removal by nZVI is pH dependent. While electrostatic attraction is considered the driving mechanism for nZVI adsorption, GAC uptake capacity is controlled by weak van der Waal forces. The adsorption of binary adsorbates (SeMet and SeCys) exhibited an inhibitory effect due to the competitive interaction between contaminant molecules.


2014 ◽  
Vol 627 ◽  
pp. 3-6 ◽  
Author(s):  
M.Y. Ho ◽  
Poi Sim Khiew ◽  
D. Isa ◽  
T.K. Tan ◽  
W.S. Chiu ◽  
...  

In this study, a symmetric electrochemical capacitor has been fabricated by adopting the lithiated compound (LiFePO4)-activated carbon (AC) composite as the core electrode materials. The electrochemical performances of the prepared supercapacitor were studied using cyclic voltammetry (CV) in 1.0 M Na2SO3 solution. Experimental results reveal that the maximum specific capacitance of 112.41 F/g is obtained in 40 wt % LiFePO4 loading on AC electrode in comparison to that of pure AC electrode (76.24 F/g) in 1 M Na2SO3. The enhanced capacitive performance of the 40 wt % LiFeO4 –AC composite electrode is believed attributed to the contribution of synergistic effect of electric double layer capacitance (EDLC) on the surface of AC as well as pseudocapacitance via intercalation/extraction of Na+, SO32-and Li+ ions in LiFePO4 lattices. The composite electrodes can sustain a stable capacitive performance at least 1000 cycles with only ~5 % specific capacitance loss after 1000 cycles. Based on the findings above, 40 wt % LiFeO4 –AC composite electrodes which utilise low cost materials and environmental friendly electrolyte is worth being investigated in more details.


RSC Advances ◽  
2020 ◽  
Vol 10 (24) ◽  
pp. 14262-14273 ◽  
Author(s):  
Hongyan Li ◽  
Lianxin Liu ◽  
Jianguo Cui ◽  
Jiali Cui ◽  
Fang Wang ◽  
...  

Edible fungus residue as an efficient and low-cost precursor was used to produce Edible Fungus residue Activated Carbon (EFAC) using the zinc chloride activation method at a 1 : 2 impregnation ratio and 600 °C activation for 3 hours.


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