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In this work, cathode materials of spent lithium-ion ternary batteries are recovered and used as metal precursor to prepare multi-metal oxides MnOx(SY) and GdMnO3(SY) via combustion method and sol–gel method, respectively. Furthermore, a series of MnOx(SY)-n and GdMnO3(SY)-n (n = 0.05, 0.10, 1.00, 4.00, n represents the dilute HNO3 concentration) catalysts are fabricated by acid treatment of MnOx(SY) and GdMnO3(SY) samples and catalytic activities of oxygenated VOCs oxidation over all the prepared catalysts are investigated. Catalytic evaluation results show that acid-treated MnOx(SY)-0.10 and GdMnO3(SY)-0.05 samples perform the optimum VOCs removal efficiency respectively, which may be attributed to their obvious enhancement of physicochemical properties. In detail, MnOx(SY)-0.10 and GdMnO3(SY)-0.05 samples exhibit the larger specific surface area, bigger amount of surface high-valence metal ions (Mn4+, Co3+, Ni3+), more abundant adsorbed oxygen species and better low-temperature reducibility, which can play a crucial role in the significant improvement of VOCs oxidation. In situ DRIFTS results imply that the possible main intermediates are -OCO, -COO and -C-O species produced during VOCs oxidation. Possible by-products are further determined via TD/GC–MS analysis.

The proper disposals of spent lithium-ion batteries (LIBs) and volatile organic compounds (VOCs) both have a significant impact on the environment and human health. In this work, different morphologies of α-MnO

Supported Pd-Cu NO3− reduction (NO3R) under H2 atmosphere is considered as a promising way to achieve NO3− removal directly in water through converting into N2, which is a harmless product in environment. However, desirable NO3R kinetics and N2 selectivity remain challenges. In this research, 2.5 wt% Cu and 10 wt% Pd are loaded on various oxides supports and combine with electrolytic in-situ H2 generation for NO3R. Pd10%Cu2.5%/TiO2 demonstrates a faster NO3R rate constant than Pd10%Cu2.5%/γ-Al2O3 and even greater than Pd10%Cu2.5%/CeO2. Pd10%Cu2.5%/γ-Al2O3 obtains better N2 selectivity than the other two. Crucially, the oxygen vacancies (VO) existing in TiO2 and CeO2 can reduce the nearby Cu2+ to Cu+, also Cu2+ can attract electrons from Pd0 to form Cu+ on the γ-Al2O3 surface. Verified by experiments and density functional (DFT) calculations, these Cu+ based active sites on the surface of substrates are vital for effective NO3− adsorption and high N2 selectivity.

For integral stereo imaging systems based on lens arrays, the cross-mixing of erroneous light rays between adjacent lenses seriously affects the quality of the reconstructed light field. In this paper, we proposed a light field reconstruction method based on the human eye viewing mechanism, which incorporates simplified human eye imaging into the integral imaging system. First, the light field model for specified viewpoint is established, and the distribution of the light source for each viewpoint is accurately calculated for the EIA generation algorithm of fixed viewpoint. Second, according to the ray tracing algorithm in this paper, non-overlapping EIA based on the human eye viewing mechanism is designed to suppress the amount of crosstalk rays fundamentally. The actual viewing clarity is improved with the same reconstructed resolution. Experimental results verify the effectiveness of the proposed method. The SSIM value is higher than 0.93, which verifies that the viewing angle range is increased to 62°.

In this work, solar drying technology was applied for the deep dewatering of coal slime to save thermal energy and reduce the dust produced during the hot drying process of coal slime. Solar drying technology is used to dry coal slime to realize its resource utilization. The influence of solar radiation intensity and slime thickness is investigated on the drying process. The greater the solar radiation intensity (SRI) is, the faster the drying indoor air and coal slime are heated, and the faster the drying efficiency is. As the slime becomes thinner, the internal water diffusion resistance becomes smaller and the drying efficiency correspondingly becomes faster. In addition, to facilitate the application of coal slime drying in the actual project, the Page model is fitted and found to have a good fit for solar drying coal slime. Meanwhile, the optimal drying conditions are determined by analyzing the energy utilization under different conditions. It is found that the target moisture content of 10% is optimal for coal slime drying with the highest energy utilization. The laying thickness (

A selective separation-recovery process based on tuning organic acid was proposed to the resource recycling of spent lithium-ion batteries (LIBs) for the first time. The low-cost preparation of CoFe2O4, reuse of waste acid and recovery of Li can be realized in this process, simultaneously. Li and Co in spent LIBs can be leached efficiently using citric acid as a leaching agent, and separated effectively from leaching solution by tuning oxalic acid content. The results from the characterizations of the prepared CoFe2O4 (CoFe2O4-LIBs) show that it possesses higher ratio of Co(II)/Co(III) and Fe(II)/Fe(III), larger surface specific area and more number of acid sites in comparison with pure CoFe2O4. Besides, CoFe2O4-LIBs was used to activate peroxymonosulfate (PMS) for the degradation of bisphenol A (BPA). Interestingly, its degradation performance is superior to that of pure CoFe2O4 and the related Co-based catalysts. The excellent degradation performance can be maintained in presence of inorganic ions (e.g., C l − , HC O 3 − , H 2 P O 4 − and N O 3 − ) with high concentration or humic acid. Moreover, surface-bound S O 4 ∙ − is considered as the main reactive species for the degradation of BPA. More importantly, CoFe2O4-LIBs can be readily recycled by using an external magnet and own superior ability of regeneration.

In this work, manganese is selectively and efficiently recovered from spent lithium-ion batteries via advanced oxidation by using potassium permanganate and ozone, and the transition metal-doped α-MnO

The construction of composite crystal structure is an effective strategy for developing enhanced functionality and can generally be constructed via two steps. Herein, a series of α@δ-MnO2 catalysts with different α/δ phase ratios are one-pot synthesized using a hydrothermal method; their molar ratio of KMnO4 to MnSO4·H2O was accurately controlled from 2.9 to 3.7. The catalytic results show that all α@δ-MnO2 catalysts exhibit significantly better catalytic performance in oxidizing toluene than single α-MnO2 and δ-MnO2 due to a synergistic effect, in which α@δ-2 with the closest two-phase proportion has the highest activity (T90 = 238 °C under a WHSV of 60,000 mL·g−1·h−1). Various characterization results indicate that α@δ-2 has the largest specific surface area, highest defects, oxygen vacancies, and best low-temperature reducibility among α-MnO2, δ-MnO2, and α@δ-2. Also, the possible reaction pathway for oxidizing toluene over the prepared catalysts is speculated using both TD/GC–MS and in-situ DRIFTS experiments.

This paper proposes a simplified method to generate elemental images using the image pair of the scene for integral imaging stereo display. Firstly, the generalized superpixel matching algorithm is designed for integral imaging to obtain the depth map. We define the discrete boundary according to the characteristics of low-texture region. A kind of consistency check method by calculating the inclination degree of the discrete boundary is proposed. The remaining texture regions are handled by assisted growth matching method. The precise depth map is obtained through the above two steps. Secondly, the depth map and color image are used to generate multiple elemental images according to the reverse mapping principle. Therefore the reconstruction quality depends on the accuracy of depth map. The experiments verify that the depth map has small error range and prominent details which can improve the accuracy of reconstructed light field and is suitable for integral imaging.

In this work, manganese is selectively and efficiently recovered from spent lithium-ion batteries via advanced oxidation by using potassium permanganate and ozone, and the transition metal-doped α-MnO2 and β-MnO2 are one-step prepared for catalytic oxidation of VOCs. The recovery rate of manganese can be approximately 100% while the recovery efficiency of cobalt, nickel, and lithium is less than 15%, 2%, and 1%, respectively. Compared with pure α-MnO2 and β-MnO2, transition metal-doped α-MnO2 and β-MnO2 exhibit better catalytic performance in toluene and formaldehyde removal attributed to their lower crystallinity, more defects, larger specific surface area, more oxygen vacancies, and better low-temperature redox ability. Besides, the introduction of the appropriate proportion of cobalt or nickel into MnO2 can significantly improve its catalytic activity. Furthermore, the TD/GC-MS result indicates that toluene may be oxidized in the sequence of toluene - benzyl alcohol - benzaldehyde-benzoic acid - acetic acid, 2-cyclohexen-1-one, 4-hydroxy-, cyclopent-4-ene-1,3-dione - carbon dioxide. This method provides a route for the resource utilization of spent LIBs and the synthesis of MnO2.

Faced with a large amount of spent lithium-ions batteries from new energy vehicles and portable electronic devices such as personal computers and mobile phones. If they are not treated properly, they would not only result in serious environmental pollution but also lead to the loss of valuable resources like Co and Li. At present, most of researchers mainly focused on the metal recovery via hydrometallurgical and pyrometallurgical method. In this work, manganese-based metal oxides (MnOx(SY), MnOx(MS)) and cobalt-based oxides (CoOx(GS)) are synthesized using manganese and cobalt-based metals recovered from spent ternary, manganate and cobaltate lithium-ion batteries as a precursor, respectively. A series of supported multi-metal oxides were prepared by supporting 10% (wt) of MnOx(SY), MnOx(MS) and CoOx(GS) on CeO2 with different morphologies via impregnation method. The catalytic activities of the metal oxides during the oxidation of 2-ethoxyethyl acetate are investigated. The results obtained show that MnOx(MS)/CeO2-C, MnOx(SY)/CeO2-C and CoOx(GS)/CeO2-P have better catalytic performances due to their excellent physicochemical properties compared to the MnOx(SY), MnOx(MS), CoOx(GS), CeO2-R, CeO2-P, CeO2-C, MnOx(MS)/CeO2-R, MnOx(MS)/CeO2-P, MnOx(SY)/CeO2-R, MnOx(SY)/CeO2-P, CoOx(GS)/CeO2-R, CoOx(GS)/CeO2-C. In-situ diffuse reflectance infrared fourier transform spectroscopy results prove that gaseous O2 plays a vital role in facilitating the complete oxidation of intermediates such as ‒C˭O, ‒COO, ‒C‒O‒C, ‒C‒O into CO2 during 2-ethoxyethyl acetate oxidation. Furthermore, thermal desorption/gas chromatography-mass spectrometer results show that the main by-products obtained during 2-ethoxyethyl acetate oxidation are ethanol,2-methoxy-; ethanol, 2-methoxy-, acetate and acetic acid.

In order to avoid the discharge of deplating wastewater with high concentration of NO3−, an environmental friendly process, consisting of precipitation, electrodeposition and oxidation, is developed in this research for the treatment of real high acidic deplating wastewater containing Ag+, Cu2+, NO3− and chemical oxygen demand (COD). The wastewater is treated by precipitation to remove Ag+, electrodeposition to remove Cu2+, oxidation to reduce COD successively and then reused for deplating plastic plated parts. In precipitation process, 99.9% Ag+ in wastewater is precipitated by HCl and silver metal is then recovered through the replacement of AgCl by iron powder. Because of the high conductivity, Cu2+ in wastewater is then separated and recovered as copper metal on cathode through electrodeposition. The effect of electrodeposition parameters including cathode material, current density, electrode distance, reaction temperature and Cu2+ initial concentration is investigated. Up to 89.3% Cu2+ can be recovered in 80 min at the optimal condition. Finally, the COD is removed from 1360 mg L−1 to 378 mg L−1 in subsequent H2O2 oxidation process to ensure the reuse of water. Because the valuable Ag and Cu metals are recovered and the COD is removed, the wastewater can be reused as deplating solution. The estimated profit of this precipitation-electrodeposition-oxidation process reveals its practical feasibility. Furthermore, the process realizes the cleaner production of the deplating technology because it avoids the discharge of unmanageable wastewater with high NO3− concentration. More importantly, the process can also be improved to treat similar wastewater.

Li et al. [Pattern Recognition 41 (2008) 3287 -- 329 proposed the constrained maximum variance mapping method. The CMVM is globally maximizing the distances between different manifolds. We find out that globally minimizing the distances between the same manifolds can have better recognition than CMVM method on the Yale face database, ORL face database and UMIST face database. Hence we propose to use an inverse constrained maximum variance mapping method (ICMVM) which can be seen as the inverse Laplacian Fisher discriminate criteria. Experiment results suggest that this new approach performs well.