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Keywords = nitric acid modification 1

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16 pages, 9288 KiB  
Article
Synergistic Antioxidant Activity of Lycium barbarum Polysaccharide and Chlorogenic Acid and Its Effect on Inflammatory Response of NR8383 Cells
by Junye Yin, Dandan Zhao, Jian Song, Ran Gao, Xuan Wang, Huan Rao, Xiaoguang Gao and Jianxiong Hao
Foods 2024, 13(22), 3696; https://doi.org/10.3390/foods13223696 - 20 Nov 2024
Cited by 3 | Viewed by 1240
Abstract
It is inevitable for polyphenols and polysaccharides to interact during food preparation. Modifications in microstructure can lead to changes in the physical and chemical properties of food systems, which in turn may influence the nutritional characteristics and functional activities of the food. Recent [...] Read more.
It is inevitable for polyphenols and polysaccharides to interact during food preparation. Modifications in microstructure can lead to changes in the physical and chemical properties of food systems, which in turn may influence the nutritional characteristics and functional activities of the food. Recent studies have shown that, in addition to traditional Chinese medicine compounds, certain natural polysaccharides and polyphenols exhibit significant anti-inflammatory and antioxidant properties. These compounds are also associated with beneficial therapeutic effects for the prevention and treatment of acute lung injury. The objective of this study was to examine the synergistic antioxidant effects of chlorogenic acid (CA) and Lycium barbarum polysaccharide (LBP) in various ratios, along with their combined antioxidant and anti-inflammatory effects on LPS-induced inflammation in rat alveolar macrophages. Using the Combination Index (CI), which quantifies the synergistic or antagonistic effect of two substances, all four combinations showed synergistic antioxidant properties over a range of concentrations by in vitro antioxidant property experiments. However, based on comparing them, the four group ratios exhibited the highest antioxidant activity of the infusion at CA:LBP = 1:7, indicating synergistic interactions (CI < 1). In addition, the antioxidant and anti-inflammatory effects of the CA-LBP complex were observed to alleviate cellular inflammatory injury by reducing LPS-induced nitric oxide and reactive oxygen species production and inhibiting the release of inflammatory factors such as TNF-α and IL-6. Full article
(This article belongs to the Section Nutraceuticals, Functional Foods, and Novel Foods)
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20 pages, 3905 KiB  
Article
Activated Biochar Is an Effective Technique for Arsenic Removal from Contaminated Drinking Water in Pakistan
by Iftikhar Ahmad, Abdul Ghaffar, Ali Zakir, Zia Ul Haq Khan, Muhammad Farhan Saeed, Atta Rasool, Aftab Jamal, Adil Mihoub, Simone Marzeddu and Maria Rosaria Boni
Sustainability 2022, 14(21), 14523; https://doi.org/10.3390/su142114523 - 4 Nov 2022
Cited by 11 | Viewed by 3516
Abstract
Arsenic (As), the silent poison, is a widespread environmental pollutant which finds its way into drinking water supplies from natural or man-made sources and affects over 200 million people worldwide, including in Pakistan. It has been demonstrated that As causes serious health complications [...] Read more.
Arsenic (As), the silent poison, is a widespread environmental pollutant which finds its way into drinking water supplies from natural or man-made sources and affects over 200 million people worldwide, including in Pakistan. It has been demonstrated that As causes serious health complications as well as social and economic losses. A quick, cost-effective, and simple method for efficiently filtering As from drinking water is urgently needed. The present study evaluates the ability of chemical treatment solutions to activate the sorption capacity of biochar derived from cotton stalks. The surface characteristics of CSB (cotton stalk biochar), HN-CSB (treated with nitric acid: HNO3), and Na-CSB (treated with sodium hydroxide: NaOH) were investigated for their As sorption capacities and efficiency in removing As from contaminated drinking water. The chemical modification of biochar significantly increased the surface area and pore volume of CSB, with a maximum observed in HN-CSB (three times higher than CSB). Fourier-transform infrared spectroscopy (FTIR) analysis revealed several functional groups (OH, −COOH, C=O, N-H) on CSB, though the chemical modification of biochar creates new functional groups on its surface. Results showed that the maximum sorption capacity of CSB was (q = 90 µg g−1), of Na-CSB was (q = 124 µg g−1) and of HN-CSB was (q = 140 µg g−1) at an initial As concentration of 200 µg L−1, an adsorbent dose of 1 g L−1, with 4 h of contact time, a pH of 6 and a temperature of 25 ʰC. However, As removal was found to be 45–88% for CSB, 62–94% for Na-CSB and 67–95% for HN-CSB across all As concentrations. An isotherm model showed that As sorption results were best fitted to the Langmuir isotherm model in the case of CSB (Qmax = 103 µg g−1, R2 = 0.993), Na-CSB (Qmax = 151 µg g−1, R2 = 0.991), and HN-CSB (Qmax = 157 µg g−1, R2 = 0.949). The development of the largest surface area, a porous structure, and new functional groups on the surface of HN-CSB proved to be an effective treatment for As removal from contaminated drinking water. Both HN-CSB and Na-CSB are clearly cost-effective adsorbents under laboratory conditions, but HN-CSB is cheaper and more efficient in As removal than Na-CSB, allowing it to be used as a powerful and promising adsorbent for the removal of pollutants like Arsenic from aqueous solution. Full article
(This article belongs to the Special Issue Remediation of Contaminated Soil and Wastewater Treatment)
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17 pages, 3235 KiB  
Article
Modified Activated Carbon Fiber Felt for the Electrosorption of Norfloxacin in Aqueous Solution
by Xianzhen Li, Yue Hu, Diao She and Wei-Bo Shen
Sustainability 2020, 12(10), 3986; https://doi.org/10.3390/su12103986 - 13 May 2020
Cited by 19 | Viewed by 3297
Abstract
As an antibiotic, Norfloxacin (NOR) is widely found in the water environment and presents considerable harm to human beings. At present, the preparation of removal materials is complicated, and the removal efficiency is not high. The adsorption effect of modified activated carbon fiber [...] Read more.
As an antibiotic, Norfloxacin (NOR) is widely found in the water environment and presents considerable harm to human beings. At present, the preparation of removal materials is complicated, and the removal efficiency is not high. The adsorption effect of modified activated carbon fiber felt (MACFF) electrosorption and its influencing factors on NOR were studied. Activated carbon fiber felt (ACFF) was modified with 20% nitric acid, and the ACFFs were characterized by SEM, TEM, and FTIR both before and after modification. The optimal working conditions for electrosorption with an MACFF electrode were as follows: the voltage was 1.0 V, the pH was 6, and the plate spacing was 10 mm. The maximum adsorption capacity of the MACFF for NOR was 128.55 mg/g. Model fitting showed that pseudo-second-order kinetic model and Langmuir model were more suitable for explaining this adsorption process. In addition, this study found that, with 20% nitric acid as the regeneration liquid and under the reverse charging method, the regeneration rate of the MACFF electrode was maintained at approximately 96% and the regeneration was good, therefore, this technology can not only save operation costs but also has good development prospects in sewage treatment. Full article
(This article belongs to the Section Resources and Sustainable Utilization)
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20 pages, 4107 KiB  
Article
Natural and Chemically Modified Post-Mining Clays—Structural and Surface Properties and Preliminary Tests on Copper Sorption
by Beata Jabłońska, Mark Busch, Andriy V. Kityk and Patrick Huber
Minerals 2019, 9(11), 704; https://doi.org/10.3390/min9110704 - 14 Nov 2019
Cited by 12 | Viewed by 3652
Abstract
The structural and surface properties of natural and modified Pliocene clays from lignite mining are investigated in the paper. Chemical modifications are made using hydrofluoric acid (HF), sulfuric acid (H2SO4), hydrochloric acid (HCl), nitric acid (HNO3), sodium [...] Read more.
The structural and surface properties of natural and modified Pliocene clays from lignite mining are investigated in the paper. Chemical modifications are made using hydrofluoric acid (HF), sulfuric acid (H2SO4), hydrochloric acid (HCl), nitric acid (HNO3), sodium hydroxide (NaOH), and hydrogen peroxide (H2O2), at a concentration of 1 mol/dm3. Scanning electron microscopy is used to detect the morphology of the samples. Nitrogen adsorption isotherms were recorded to determine the specific surface area (SSA), mesoporosity, microporosity, and fractal dimensions. The raw clay has an SSA of 66 m2/g. The most promising changes in the structural properties are caused by modifications with HF or H2SO4 (e.g., the SSA increased by about 60%). In addition, the raw and modified clays are used in preliminary tests with Cu(II) sorption, which were performed in batch static method at initial Cu(II) concentrations of 25, 50, 80, 100, 200, 300, and 500 mg/dm3 in 1% aqueous suspensions of the clayey material. The maximum sorption of Cu(II) on the raw material was 15 mg/g. The structural changes after the modifications roughly reflect the capabilities of the adsorbents for Cu(II) adsorption. The modifications with HF and H2SO4 bring a similar improvement in Cu(II) adsorption, which is around 20–25% greater than for the raw material. The structural properties of investigated clays and their adsorptive capabilities indicate they could be used as low-cost adsorbents (e.g., for industrial water pretreatment). Full article
(This article belongs to the Special Issue Mineral Sorbents)
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