| 1. |
- He, Yingnan, et al.
(author)
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Separable amino-functionalized biochar/alginate beads for efficient removal of Cr(VI) from original electroplating wastewater at room temperature
- 2022
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In: Journal of Cleaner Production. - : Elsevier. - 0959-6526 .- 1879-1786. ; 373
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Journal article (peer-reviewed)abstract
- An alginate gel bead composite adsorbent with polyethyleneimine (PEI) as a surface modifier and Eichhornia crassipes (EC) biochar, known as EC-alg/PEI-3, was added internally to the adsorb Cr(VI) from an aqueous environment. The functionalized gel beads were characterized using SEM, XPS, FTIR, and other techniques. The maximum adsorption capacities of EC-alg/PEI-3 were 714.3 mg g−1 at 10 °C and 769.2 mg g−1 at 25 °C. In the treatment of highly concentrated electroplating wastewater, EC-alg/PEI-3 can be dosed at 1.4 g L−1 to reduce the concentration of Cr(VI) to below 0.05 ppm. EC-alg/PEI-3 maintained a competitive adsorption capacity after six cycles. This spherical adsorbent material is easy to prepare, has a very high adsorption capacity, is environmentally friendly, and can be easily recycled. The EC-alg/PEI-3 gel beads are promising for the treatment of industrial wastewater.
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| 2. |
- He, Yingnan, et al.
(author)
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Separatable MoS2 loaded biochar/CaCO3/Alginate gel beads for selective and efficient removal of Pb(II) from aqueous solution
- 2022
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In: Separation and Purification Technology. - : Elsevier. - 1383-5866 .- 1873-3794. ; 303
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Journal article (peer-reviewed)abstract
- Centimeter-scale composite biochar-alginate gel beads (MoS2B/CaCO3/Alg) were designed for the adsorption of Pb(II) in water using MoS2 modified biochar as the filler, alginate as the matrix, and CaCO3 as the active additive component. The composite gel beads were characterized using scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR), X-ray diffraction (XRD), and other techniques. MoS2B/CaCO3/Alg showed excellent adsorption capacity over a wide range of pH 4–7. The maximum adsorption capacities obtained using the Langmuir model were 769.2, 833.3, and 909.1 mg g−1 at 10, 25 and 40 °C, respectively. At a dosing rate of 0.4 g L−1, MoS2B/CaCO3/Alg was able to reduce the Pb(II) concentration to below 0.05 ppm in complex simulated lead battery wastewater. After 10 repeated cycles, MoS2B/CaCO3/Alg maintained a high removal rate of 98.4 %. This spherical adsorbent is simple to prepare and easy to recover, has an ultra-high adsorption capacity, and is mechanically stable and resistant to interference, thus it is expected to be suitable for application in industrial wastewater treatment.
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| 3. |
- Huang, Yimin, et al.
(author)
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Facile synthesis of sodium lignosulfonate/polyethyleneimine/sodium alginate beads with ultra-high adsorption capacity for Cr(VI) removal from water
- 2022
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In: Journal of Hazardous Materials. - : Elsevier. - 0304-3894 .- 1873-3336. ; 436
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Journal article (peer-reviewed)abstract
- Chromium (VI) is a widely occurring toxic heavy metal ion in industrial wastewater that seriously impacts the environment. In this study, we used environmentally friendly sodium lignosulfonate (SL), polyethyleneimine (PEI), and sodium alginate (SA) to synthesize SL/PEI/SA beads by employing a simple crosslinking method with to develop a novel absorbent with excellent adsorption capacity and practical application in wastewater treatment. We studied the adsorption performance of SL/PEI/SA through batch adsorption and continuous dynamic adsorption experiments. SL/PEI/SA has ultra-high adsorption capacity (2500 mg·g-1) at 25 ℃, which is much higher than that of existing adsorbents. Humic acids and coexisting anions commonly found in wastewater have minimal effect on the adsorption performance of SL/PEI/SA. In the column system, 1 g SL/PEI/SA can treat 8.1 L secondary electroplating wastewater at a flow rate of 0.5 mLmin-1, thereby enabling the concentration of Cr(VI) in secondary electroplating wastewater to meet the discharge standard (< 0.2 mg·L-1). It is worth noting that the concentration of competitive ions in secondary electroplating wastewater is more than 500 times higher than that of Cr(VI). These results demonstrate that the novel SL/PEI/SA beads can be effectively applied in the removal of Cr(VI) in wastewater.
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| 4. |
- Zhao, Xue, et al.
(author)
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Simultaneous anchoring of Ni nanoparticles and single-atom Ni on BCN matrix promotes efficient conversion of nitrate in water into high-value-added ammonia
- 2022
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In: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 433:Part 2
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Journal article (peer-reviewed)abstract
- Electrochemical synthesis of ammonia driven by clean energy is expected to realize the supply of ammonia for distributed production of industry and agriculture. Here, nickel nanoparticles and nickel in the form of single atoms were simultaneously anchored on the electrochemically active carrier BCN matrix through a structured domain strategy, which realized a high-efficiency, high-value-added, conversion of nitrate in sewage. Specifically, the electrochemical nitrate reduction reaction (NIRR) driven by BCN@Ni in alkaline media achieves an ammonia yield rate as high as 2320.2 μg h−1 cm−2 (at −0.5 V vs RHE), and Faraday efficiency as high as 91.15% (at −0.3 V vs RHE). Even in neutral and acidic media, the ammonia yield rates of NIRR driven by BCN@Ni are as high as 1904.2 μg h−1 cm−2 and 2057.4 μg h−1 cm−2, respectively (at −0.4 V vs RHE). The 15NO3- isotope labeling experiment verified that the recorded ammonia all came from the electrochemical reduction of NO3– on BCN@Ni. Density functional theory (DFT) calculations show that both nano-Ni and single-atom Ni in BCN@Ni have the ability to electrochemically convert NO3– into NH3, and that the addition of BCN can further promote the NIRR on Ni.
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| 5. |
- Zhao, Xue, et al.
(author)
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Two-dimensional BCN matrix inlaid with single-atom-Cu driven electrochemical nitrate reduction reaction to achieve sustainable industrial-grade production of ammonia
- 2021
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In: APPLIED MATERIALS TODAY. - : Elsevier. - 2352-9407. ; 25
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Journal article (peer-reviewed)abstract
- Electrochemical methods have been proven to effectively eliminate nitrates in sewage and convert them into high value-added ammonia products. Here, after annealing treatment of metal boron cluster organic polymers formed by the combination of 1,10-phenanthroline, Cu2+ and closo-[B12H12](2)(-), a Cu single-atom doped BCN (B-doped CN) with a diamond-shaped nanosheet structure was obtained. In the electrochem-ical reduction reaction of nitrate, BCN-Cu exhibits excellent catalytic activity, specifically: 1) the ammonia yield rate reached as high as 498.85 mu g h(-1) cm(-2), 1047.14 mu g h(-1) cm(-2), 1900.07 mu g h(-1) cm(-2) and 3358.74 mu g h(-1) cm(-2) at -0.3 V, -0.4 V, -0.5 V and -0.6 V vs reversible hydrogen electrode, respectively, and Faradaic efficiency is 95.90%, 97.28%, 98.23% and 97.37%; 2) after repeated use of BCN-Cu 10 times or continuous operation for 16 h, the activity against electrochemical reduction reaction of nitrate anions is almost unchanged. The (NO3-)-N-15 isotopic labeling experiment proved that the detected NH3 comes from the reduction of NO3- on BCN-Cu. Control experiments show that the presence of Cu determines whether BCN-Cu has the possibility of catalyzing electrochemical reduction reactions of nitrate, and the presence of the B element enhances the catalytic activity of BCN-Cu. Density functional calculations indicate that in the water phase the process of reducing NO3- to NH3 on Cu-0 is an exothermic reaction, and that the adsorption process of NO3- on Cu-0 is the rate-determining step.
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