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Mineral processing wastewater (MPW) with large discharge and high toxicity affects environmental safety, and the realizing zero discharge of MPW is of great significance for reducing environmental pollution, saving water resources, and promoting the sustainable development of the mining industry. In this study, we reported natural marmatite (NM) as a low-cost and efficient photocatalyst for the treatment of MPW to help zero wastewater discharge. The photocatalytic activity of NM was evaluated by the removal of total organic carbon (TOC) from MPW under visible-light illumination, and the optimal degradation conditions were discussed. Results showed that superoxide free radicals (·O2-) were the dominant active species responsible for organic pollutants degradation, and 74.25% TOC removal was obtained after 120 min reaction under the optimum treatment conditions. Meanwhile, the wastewater treated by NM photocatalysis can be reused in the flotation system without adverse impact on the product index. Based on these findings, a model of zero wastewater discharge for flotation with the help of photocatalytic treatment was established, it indicated that the water of the whole system can be balanced without affecting the ore dressing index, which showed that visible light-driven photocatalyst has a promising application prospect in the treatment and recycling of industrial wastewater.
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Luz , Sulfetos , Águas Residuárias , Compostos de Zinco , Minerais , CatáliseRESUMO
Sodium oleate (NaOl) is widely used as collector for oxidised ore flotation, and residual NaOl in mineral processing wastewater is a serious threat to mine environment. In this work, the feasibility of electrocoagulation (EC) as an alternative for chemical oxygen demand (COD) removal from NaOl-containing wastewater was demonstrated. Major variables were evaluated to optimise EC, and related mechanisms were proposed to interpret the observations in EC experiments. The initial pH of the wastewater greatly affected the COD removal efficiency, which was likely to be related to the variation of predominant species. When the pH was below 8.93 (original pH), liquid HOl(l) was the predominant specie, which could be rapidly removed by EC thought charge neutralisation and adsorption. At original pH or higher, Ol- could react with dissolved Al3+ to form insoluble Al(Ol)3, which was subsequently removed through charge neutralisation and adsorption. The presence of fine mineral particles could reduce repulsion force of the suspended solids and promote flocculation, whereas the presence of water glass had an opposite effect. These results demonstrated that EC can be employed as an effective process to purify NaOl-containing wastewater. This study will contribute to deepening our understanding of EC technology for NaOl removal and provide useful information to researchers in mineral processing industry.
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Águas Residuárias , Poluentes Químicos da Água , Concentração de Íons de Hidrogênio , Eletrocoagulação/métodos , Minerais , Indústria Manufatureira , Eliminação de Resíduos Líquidos/métodos , Eletrodos , Resíduos Industriais/análiseRESUMO
In recent years, electrochemical oxidation (EO) shows the characteristics of green and high efficiency in removing chemical oxygen demand (COD) and ammonia nitrogen (NH3-N) from wastewater, which has been favored by researchers. However, at present, most of current studies on EO remain in laboratory stage, reports about pilot-scale or even industrial tests with large treatment capacity are few, which slowing down the use of the advanced technology to practical application. In this study, bench-scale tests, pilot-scale tests (treatment capacity 200-500 L/h), and industrial tests (treatment capacity 100 m3/h) were carried out by EO technology in view of the characteristics of tungsten smelting wastewater (TSW) with high salinity (NaCl), COD, and NH3-N. Results showed that the removal of COD and NH3-N was a competitive reaction in the EO process, and COD could be removed more preferentially than NH3-N. When NH3-N content was low, the influent pH had a minimal effect on its removal, and when NH3-N content was high, increasing the influent pH was beneficial to its removal. Industrial tests showed that the one-step removal of COD and NH3-N in TSW met the standard, and the power consumption per cubic meter of wastewater was only 4.2 kW h, and the treatment cost was much lower than the two-step process of "breaking point chlorination to remove NH3-N and adding oxidant to remove COD". This study has successfully realized industrial application of EO technology in TSW treatment for the first time and provided a successful case, which is helpful to accelerate the popularization and application of this technology in the field of high salinity organic ammonia nitrogen wastewater treatment.
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Amônia , Águas Residuárias , Amônia/análise , Tungstênio , Análise da Demanda Biológica de Oxigênio , Salinidade , Nitrogênio/análise , Eliminação de Resíduos Líquidos/métodosRESUMO
In this paper, we propose a method of intensity evaluation based on different pulse models using a femtosecond pulse laser, which enables long-range absolute distance measurement with nanometer precision and large non-ambiguity range. The pulse cross-correlation is analyzed based on different pulse models, including Gaussian, Sech(2), and Lorenz. The DC intensity and the amplitude of the cross-correlation patterns are also demonstrated theoretically. In the experiments, we develop a new combined system and perform the distance measurements on an underground granite rail system. The DC intensity and amplitude of the interference fringes are measured and show a good agreement with the theory, and the distance to be determined can be up to 25 m using intensity evaluation, within 64 nm deviation compared with a He-Ne incremental interferometer, and corresponds to a relative precision of 2.7×10(-9).
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ETHNOPHARMACOLOGICAL RELEVANCE: Realgar, a traditional mineral Chinese medicine, has been used in China for more than 2000 years. It has been recorded in many ancient and modern works that it has anti-cancer and anti-tumor effects. Of course, colon cancer is also within the scope of its treatment. Realgar needs to be processed into realgar decoction pieces by water grinding before being used for medicine. To ensure the consistency of efficacy and quality of realgar decoction pieces, modern methods need to be used for further quality control. AIM OF THE STUDY: The research of traditional mineral Chinese medicine is relatively difficult, and the related research is less. The purpose of this study is to control the quality of realgar decoction pieces by modern analytical technology and analyze its components. On this basis, its anti-colon cancer activity was discussed. MATERIALS AND METHODS: Several batches of realgar decoction pieces were analyzed by XRD, and the components of realgar decoction pieces were obtained. The quality control fingerprints of realgar decoction pieces were established by processing XRD spectra and similarity evaluation. Then, the effects of realgar decoction pieces on apoptosis of CT26 and HTC-116 cells were observed in vitro by Hoechst 33258 staining, flow cytometry, measurement of mitochondrial membrane potential and Western blot; In vivo, the mouse model of tumor-in-situ transplantation of colon cancer was established, and the related indexes were observed. RESULT: The explorations showed that the XRD Fourier fingerprints of realgar decoction pieces samples that had the same phase revealed 10 common peaks, respectively. The similarity evaluation of the established XRD Fourier fingerprint was greater than 0.900. We also demonstrated that realgar decoction pieces can promote apoptosis and inhibit tumor growth in colon cancer cells, its activating effect on p53 protein, and its safety when used within reasonable limits. CONCLUSION: The quality control of realgar decoction pieces by XRD is scientific and has the inhibitory effect on colon cancer, which has the development potential.
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Apoptose , Neoplasias do Colo , Animais , Apoptose/efeitos dos fármacos , Camundongos , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , Humanos , Sulfetos/farmacologia , Sulfetos/uso terapêutico , Arsenicais/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/uso terapêutico , Linhagem Celular Tumoral , Camundongos Endogâmicos BALB C , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Masculino , Controle de Qualidade , Antineoplásicos Fitogênicos/farmacologia , Antineoplásicos Fitogênicos/uso terapêuticoRESUMO
This paper presents an optimized preparation process for external ointment using the Definitive Screening Design (DSD) method. The ointment is a Traditional Chinese Medicine (TCM) formula developed by Professor WYH, a renowned TCM practitioner in Jiangsu Province, China, known for its proven clinical efficacy. In this study, a stepwise regression model was employed to analyze the relationship between key process factors (such as mixing speed and time) and rheological parameters. Machine learning techniques, including Monte Carlo simulation, decision tree analysis, and Gaussian process, were used for parameter optimization. Through rigorous experimentation and verification, we have successfully identified the optimal preparation process for WYH ointment. The optimized parameters included drug ratio of 24.5%, mixing time of 8 min, mixing speed of 1175 rpm, petroleum dosage of 79 g, liquid paraffin dosage of 6.7 g. The final ointment formulation was prepared using method B. This research not only contributes to the optimization of the WYH ointment preparation process but also provides valuable insights and practical guidance for designing the preparation processes of other TCM ointments. This advanced DSD method enhances the screening approach for identifying the best preparation process, thereby improving the scientific rigor and quality of TCM ointment preparation processes.
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Aprendizado de Máquina , Pomadas , Reologia , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/administração & dosagem , Medicina Tradicional Chinesa , Composição de Medicamentos/métodos , Dodecilsulfato de Sódio/química , Método de Monte CarloRESUMO
Under the severe situation of global warming, low-carbon development is gaining more and more attention. Due to the different research methods, research samples, and the selection of performance indicators, there is greater disagreement on the relationship between carbon performance and financial performance. The study covers the dataset starting from 2013 to 2020 regarding 352 Chinese-listed companies with high energy consumption industries. The study uses the System GMM to explore the association between carbon performance and financial performance. The results we provided show that (1) carbon performance can significantly improve financial performance, but this effect is intertemporal. (2) Financial performance enhances carbon performance, and this effect is not lagged. (3) In terms of ownership structure heterogeneity, non-state-owned firms have a more significant effect of carbon performance on their financial performance, while the positive impact of financial performance on carbon performance is more pronounced in state-owned firms. The above findings provide a theoretical basis to motivate enterprises to improve their carbon performance and help China achieve the carbon neutrality goal as soon as possible.
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Carbono , Propriedade , Indústrias , China , Aquecimento GlobalRESUMO
It is still controversial whether environmental information disclosure (EID) can alleviate firms' financing constraints. Existing studies have not addressed the issue of whether internal control can address the financing constraint in the context of institutional weaknesses and managerial opportunism of environmental information disclosure quality (EIDQ). Therefore, through constructing multiple linear regression analysis, we empirically studied the impact of EIDQ on the financing constraint of Chinese firms and the moderating effect of internal controls on the above relationship. The findings showed that (1) improving EIDQ could significantly alleviate the financing constraint problem of enterprises, and the mitigation effect is more significant among non-state enterprises; (2) the quality of internal control helps to strengthen the mitigation effect of EIDQ on the financing constraint; and (3) further research found that the mitigation effect of EIDQ on financing constraints was more significant in a sample with a high degree of marketization, stricter government regulation, and non-political affiliation among non-state-owned enterprises. This study provides new ideas for promoting institutional optimization of EID and the development of green finance.
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Comércio , Revelação , China , Regulamentação Governamental , OrganizaçõesRESUMO
In this paper, element distribution patterns of red mud particles with different grading temperatures were explored based on TIMA and EDS, and alkali removal performance of different particle sizes under high temperature grading was compared. The results show that non-clay phases in the particles coagulate with the clay phases of different sodium contents during stacking process, thus forming a mixture phase containing clay phase and other impurities. The potential of grading utilization of red mud is displayed by process mineralogy studies. The elements and phases of different particle sizes of red mud cannot be effectively separated by grading at room temperature. Due to high-temperature grading, red mud is divided into three particle sizes, namely, a (above 100 µm), b (38-100 µm), and c (below 38 µm), with Na2O contents of 3.25%, 2.31%, and 8.13%, respectively, decreasing to 1.00%, 0.27%, and 2.99% after alkali removal. The different elements and phases of red mud can be effectively separated by high-temperature grading, which promotes the classification of different particle sizes and the comprehensive utilization of red mud.
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Temperatura Alta , Temperatura , ArgilaRESUMO
This study investigates an environmentally friendly technology that utilizes waste by-products (waste acid and waste alkali liquids) to treat mineral processing wastewater. Chemical precipitation is used to remove silicate from scheelite (CaWO4) cleaning flotation wastewater and the waste by-products are used as a substitute for calcium chloride (CaCl2). A series of laboratory experiments is conducted to explain the removal of silicate and the characterization and formation mechanism of calcium silicate. The results show that silicate removal reaches 90% when the Ca:Si molar ratio exceeds 1.0. The X-ray diffraction (XRD) results confirm the characterization and formation of calcium silicate. The pH is the key factor for silicate removal, and the formation of polysilicic acid with a reduction of pH can effectively improve the silicate removal and reduce the usage of calcium. The economic analysis shows that the treatment costs with waste acid (0.63 $/m3) and waste alkali (1.54 $/m3) are lower than that of calcium chloride (2.38 $/m3). The efficient removal of silicate is confirmed by industrial testing at a plant. The results show that silicate removal reaches 85% in the recycled water from tailings dam.