| 1. |
- Zhang, Yunqiu, et al.
(författare)
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Nanomanganese cobaltate-decorated halloysite nanotubes for the complete degradation of ornidazole via peroxymonosulfate activation
- 2023
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier. - 0021-9797 .- 1095-7103. ; 630, s. 855-866
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Tidskriftsartikel (refereegranskat)abstract
- Peroxymonosulfate (PMS) driven by halloysite nanotubes (HNTs) modified with nanomanganese cobaltate (MnCo2O4) generates reactive oxygen species (ROS) that offer high degradation efficiency and mineralization rates for many typical antibiotic pollutants, such as ornidazole (ONZ). The experimental results show that halloysite nanotubes (HNTs) modified with nanomanganese cobaltate (MnCo2O4@HNTs denoted as MCO@HNTs) can degrade ONZ completely over a wide pH range (6.08–11.00) with little influence of the pH value. MCO@HNTs + PMS exhibited higher catalytic activity and lower Co- and Mn-ion leaching rates. It also showed a strong anti-interference effect on natural lake water and anions. Additionally, PMS can be quickly activated and consumed in natural lakes to avoid secondary pollution. The roasting of MCO@HNTs showed good catalytic activity and stability after degrading ONZ. The combination of ion quenching and electron paramagnetic resonance (EPR) analysis illustrated that the MCO@HNTs + PMS system had a strong oxidation capacity, and the produced singlet oxygen (1O2) was the main ROS for ONZ degradation. The degradation pathway of ONZ via the MCO@HNTs + PMS system was proposed based on the types of intermediates determined via liquid chromatography-mass spectrometry (LC-MS). This comprehensive study shows the preparation of a simple, environmentally friendly, and cheap PMS activation catalyst that has practical application value in the treatment of antibiotic wastewater and provides a focus on actual water testing with residual amount of PMS.
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| 2. |
- Zhao, Xue, et al.
(författare)
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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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Ingår i: APPLIED MATERIALS TODAY. - : Elsevier. - 2352-9407. ; 25
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Tidskriftsartikel (refereegranskat)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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| 3. |
- Jia, Xiuxiu, et al.
(författare)
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Mesopore-rich badam-shell biochar for efficient adsorption of Cr(VI) from aqueous solution
- 2021
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Ingår i: Journal of Environmental Chemical Engineering. - : Elsevier. - 2213-3437. ; 9:4
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Tidskriftsartikel (refereegranskat)abstract
- Cr(VI) is a common pollutant in wastewater and many previous studies using biochar-based materials as adsorbents for their well adsorption performance. However, the preparations of some biochars are complex, uneconomical, and with a poor reusability, which set limit on their practical application. Here, a mesoporous-rich biochar-based Cr(VI) adsorbent was easily prepared by pyrolyzing the badam-shell that in situ activated by concentrated phosphoric acid (H3PO4), with the aim of improving the removal effect of Cr(VI) in an aqueous solution. The partition coefficient (PC) was used to compare the performance of adsorbents more comprehensively, and the maximal PC value of the activated badam-shell biochar (ABSB) was 978.8 L g-1. In addition, its maximum adsorption capacity was 276.6 mg g-1. ABSB has a superior removal effect on the relatively low concentration of Cr(VI) (= 50 mg L-1), and residual Cr(VI) can meet the maximum emission standard (< 0.5 mg L-1) of industrial wastewater. The specific surface area of ABSB (1359.5 m2 g-1) was approximately four times that of pristine badam-shell biochar (BSB) (371.87 m2 g-1). The adsorption mechanisms involved were redox, complexation, electrostatic attraction and hydrogen bonding. The removal rate of Cr(VI) on ABSB remained at 81.6% after six cycles of adsorption-desorption. In a word, our study provides a simple, economic, and environmental method in fabricating the new adsorbent, which is highly promising and will not cause secondary pollution.
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| 4. |
- Zeng, Yanbo, et al.
(författare)
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A simple polypropylene fiber membrane embedded with clean La(OH)3 nanoparticles for highly efficient phosphate anions removal
- 2022
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Ingår i: Journal of Environmental Chemical Engineering. - : Elsevier. - 2213-3437. ; 10:5
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Tidskriftsartikel (refereegranskat)abstract
- Lanthanide materials are attracting increasing attention owing to their ability to strongly bind with phosphorus (P). In this paper, a novel method of producing clean lanthanum nano-aerosols by spark ablation is proposed, the particles are uniformly deposited on a cheap and readily available Polypropylene(PP) fiber membrane in a special gas environment, and combined with water (solvent) for hydrothermal synthesis of the new material, PP-La. Material characterization confirmed that the formation of La(OH)3 nanoparticles and ligand exchange plays an important role in the phosphorus adsorption process, extended X-ray absorption spectroscopy demonstrated that phosphate was bound to the lanthanum site. The adsorption capacity of PP-La for phosphate is 188.6 mg P/g La, and the cost index (capacity/synthesis cost) is 132.54 mg P/USD. In addition, unlike most sorbents, PP-La has the advantage of being easily separated from water. This synthesis method is green and simple, the lanthanum is not toxic, the Polypropylene fiber membrane is cheap and has better mechanical strength, and the application prospect is very broad. Our results provide a new strategy for the development of efficient adsorbents and the treatment of eutrophication by selective adsorption of phosphate in lakes, reservoirs, rivers, and other water bodies.
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| 5. |
- He, Yingnan, et al.
(författare)
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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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Ingår i: Journal of Cleaner Production. - : Elsevier. - 0959-6526 .- 1879-1786. ; 373
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Tidskriftsartikel (refereegranskat)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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| 6. |
- Huang, Yimin, et al.
(författare)
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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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Ingår i: Journal of Hazardous Materials. - : Elsevier. - 0304-3894 .- 1873-3336. ; 436
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Tidskriftsartikel (refereegranskat)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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| 7. |
- Jia, Xiuxiu, et al.
(författare)
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Rod-shaped lanthanum oxychloride-decorated porous carbon material for efficient and ultra-fast removal of phosphorus from eutrophic water
- 2023
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Ingår i: Separation and Purification Technology. - : Elsevier. - 1383-5866 .- 1873-3794. ; 306
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Tidskriftsartikel (refereegranskat)abstract
- Removal of excess phosphorus (P) from water systems can effectively prevent eutrophication and maintain the ecological balance. In this study, we used a novel freeze-drying thermal oxidation process to prepare a rod-shaped lanthanum oxychloride decorated porous carbon material, polyvinylpyrrolidone /LaOCl (PL). PL showed excellent performance in removing P from water; the preparation method had not been reported previously. Specifically, the adsorption capacity of PL for P was as high as 90.9 mg P/g, and the removal rate was greater than 92.0 % over a wide pH range (2.5–11). Fast adsorption kinetics is an important feature for P removal. The high removal rate of PL for P could be achieved in a short time; that is, more than 97.8 % of the P species could be removed in only 25 min (initial concentration: 20 mg P/L). For water samples from the natural Laoyu River (24 μg P/L), 0.01 g of PL could reduce approximately 53 L of water to below the eutrophication threshold value (20 μg P/L). Furthermore, after five repetitions of the adsorption–desorption process, no significant decrease in the P removal efficiency was observed. The high adsorption capacity, fast adsorption kinetics, and persistent cyclic stability of PL for P in water were attributed to the advanced preparation process, in which freeze-drying ensured the porosity of the adsorbent and the uniformity of LaCl3 distribution; and the subsequent heat treatment created conditions for the generation of LaOCl species with stable adsorption activity. The adsorption mechanism mainly involved ion exchange, electrostatic attraction, and hydrogen bonding. This study provides a theoretical basis for preparing new adsorbing materials of P and technical support for preventing water eutrophication.
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| 8. |
- Li, Xue, et al.
(författare)
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Self-supported porous copper oxide nanosheet arrays for efficient and selective electrochemical conversion of nitrate ions to nitrogen gas
- 2023
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Ingår i: Journal of Materials Science & Technology. - : Elsevier. - 1005-0302. ; 137, s. 104-111
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Tidskriftsartikel (refereegranskat)abstract
- Electrochemical techniques have shown advantages for the removal of low-concentration nitrate. Here, copper oxide nanosheets were grown on self-supporting nickel foam (NF) to prepare electrodes (CuO/NF), which realized the rapid and highly selective conversion of nitrate pollutants in sewage into nontoxic and harmless N2. The CuO/NF afforded 100% NO3– removal within 100 min and 99.53% selectivity for N2 at –50 mA without producing a lot of by-products (NO2–, NH4+, and N2H4). Furthermore, 81.8% of NO3– was removed under the given conditions after six experimental repetitions. These results suggest that the catalyst has excellent electrochemical stability. The performance of CuO/NF for the electrocatalytic removal of NO3– in simulated wastewater (which contained Cl– and SO42–) was almost unaffected. Because of the high efficiency, high stability, and low cost of CuO/NF, this catalyst is practical for the removal of nitrate for wastewater purification.
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| 9. |
- YanWu, Lue, et al.
(författare)
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Be-10 in quartz gravel from the Gobi Desert and evolutionary history of alluvial sedimentation in the Ejina Basin, Inner Mongolia, China
- 2010
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Ingår i: Chinese Science Bulletin. - : Springer Science and Business Media LLC. - 1001-6538 .- 1861-9541. ; 55:33, s. 3802-3809
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Tidskriftsartikel (refereegranskat)abstract
- Reconstructing the evolutionary history of the Gobi deserts developed from alluvial sediments in arid regions has great significance in unraveling changes in both tectonic activity and climate. However, such work is limited by a lack of suitable dating material preserved in the Gobi Desert, but cosmogenic Be-10 has great potential to date the Gobi deserts. In the present study, Be-10 in quartz gravel from the Gobi deserts of the Ejina Basin in Inner Mongolia of China has been measured to assess exposure ages. Results show that the Gobi Desert in the northern margin of the basin developed 420 ka ago, whereas the Gobi Desert that developed from alluvial plains in the Heihe River drainage basin came about during the last 190 ka. The latter developed gradually northward and eastward to modern terminal lakes of the river. These temporal and spatial variations in the Gobi deserts are a consequence of alluvial processes influenced by Tibetan Plateau uplift and tectonic activities within the Ejina Basin. Possible episodes of Gobi Desert development within the last 420 ka indicate that the advance/retreat of alpine glaciers during glacial/interglacial cycles might have been the dominant factor to influencing the alluvial intensity and water volume in the basin. Intense floods and large water volumes would mainly occur during the short deglacial periods.
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