ChemistrySelect
·
2024
·Vol. 9
·期 43
·e202403318
·
IF 1.9
Xinyue Zhang,Qiurong Chen,Yan Luo
Graphical In order to improve the stability and controlled release properties, NaClO 2 is microencapsulated based on emulsion crosslinking method adopting high biocompatibility sodium alginate (SA) and sodium carboxymethyl cellulose (CMC-Na) as shell material. The resulted sample is featured with selectivity and no secondary pollution, and brings about continuous degrading both liquid and gaseous formaldehyde. Sodium chlorite (NaClO 2 ) is a new type of air disinfectant, which can oxidize formaldehyde into carbon dioxide (CO 2 ) on account of releasing chlorine dioxide (ClO 2 ) gas under acidic condition. Unfortunately, NaClO 2 is prone to moisture absorption and decomposition when exposed to air. In this paper, NaClO 2 was microencapsulated based on emulsion crosslinking method for improving its stability and controlled release properties. Due to their high biocompatibility, sodium alginate (SA) and sodium carboxymethyl cellulose (CMC-Na) were selected as the wall material to prepare NaClO 2 -SA/CMC-Na composite microcapsules. The results showed that mean particle size of NaClO 2 -SA/CMC-Na composite microcapsules was about 225 nm, and their encapsulation ratio was up to 73.18%. In addition, the thermal stability and environmental tolerance of NaClO 2 are improved greatly through microencapsulating. It was proved by formaldehyde degradation testing that the efficiency of formaldehyde degradation using resulted samples can continue to increase after seven days in pH 6.5 environment, indicating their good controlled-release performance. Moreover, degradation efficiency on 30 µg/mL formaldehyde solution using the resulted microcapsules is up to 97.08%. Meanwhile, after 20 repetition degradation, NaClO 2 -SA/CMC-Na composite microcapsules can still continuously degrade formaldehyde gas. Therefore, NaClO 2 -SA/CMC-Na composite microcapsules reveal good stability and prolonged action on formaldehyde degradation.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL RESEARCH
·
2025
·
IF 7.7
Huasheng Wang,Shuang Deng,Hongyun Hu,Can Fang,Guangqian Luo,Ze Wang,Songgeng Li
Excessive ClO 2 tends to be produced and escape, causing secondary pollution when wet oxidation of NO with NaClO 2 is conducted under acidic conditions. NaClO 2 alkaline oxidation has accordingly received a wide attention. In this work, NaClO 2 alkaline oxidation of NO has been systematically studied in a self-built spray tower. Focus has been placed on the effects of acidic components contained in flue gas such as CO 2 , HCl and SO 2 . ClO 2 and HClO 2 are considered more effective for NO oxidation, which tend to be produced in an acidic environment. HCO 3 − has a relatively higher hydrolysis coefficient than ClO 2 − , leading to more HClO 2 formation. Similarity is found with HCl although the effect is not as significant as CO 2 due to its low concentration in flue gas. SO 2 exhibits a negative effect on NO removal since HClO 2 can be consumed by SO 2 . Nearly 100 % NO removal efficiency can be achieved although there is an initial time delay necessary for the neutralization of alkaline environment. A similar performance has been observed for HCl. On the contrary, SO 2 exhibits a negative effect on NO removal due to the competition with NO in the consumption of NaClO 2 . Additives such as NaClO and CTAC were also used to enhance NaClO 2 alkaline oxidation performance. Interesting to note that CTAC can nearly eliminate the time delay by intensifying the gas-liquid mass transfer.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Energies
·
2019
·Vol. 12
·期 15
·2966
·
IF 2.707
Pijian Gong,Xinxue Li
In this study, NaClO2was selected as a denitration oxidant. In order to clarify the mechanism of NaClO2as an oxidation agent for NO removal efficiency, the effects of H+and other factors (NaClO2concentration, temperature, and the other gas) on the NO removal efficiency were investigated. NaClO2showed a promotional ability on NO removal, whose efficiency increased with the increase of NaClO2concentration. One hundred percent removal efficiency of NO could be achieved when the NaClO2concentration was 0.014 mol/L. Furthermore, raising the reaction temperature benefited the removal of NO. The lower the pH, the better the NO removal efficiency. The promoting effect of H+on the NO removal was studied by the Nernst equation, ionic polarization, and the generation of ClO2. Under the optimal conditions, the best removal efficiency of NO was 100%. Based on the experimental results, the reaction mechanism was finally speculated.Keywords:sodium chlorite (NaClO2);wet scrubbing;removal efficiency;NO reaction mechanism
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2019
·
IF 3.021
Zhitao Han,Tian Lan,Zhiwei Han,Shaolong Yang,Jingming Dong,Deping Sun,Zhijun Yan,Xinxiang Pan,Liguo Song
Experiments were conducted to simultaneously remove NO and SO2 from simulated exhaust gas by cyclic scrubbing and online supplementing pH-buffered NaClO2 solutions in a bench-scale reactor. The effects of key operating parameters on pollutant removal performance had been investigated. The results suggested that an extremely high oxidant utilization rate could be obtained when the oxidant supplementing molar rate approached the oxidant consumption molar rate. Though co-existing SO2 in flue gas would consume a certain amount of the oxidant during the absorption process, the intermediate products of SO32– ions generated from SO2 hydrolysis might be in favor of NO2 absorption to some extent. The introduction of ethanol in scrubbing solution could enhance NOx removal performance largely, which was possibly because of its inhibition effect on SO32– oxidation. The reaction mechanism and reaction products in scrubbing solutions were also discussed roughly through theoretical calculations and ion chromatography analysis.
研究领域:
环境工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2021
·
IF 9.381
Shuang Xu,Dan Huo,Kaiqing Wang,Qiulin Yang,Qingxi Hou,Fengshan Zhang
An efficient and low-cost approach to preparing CNFs with succinic acid hydrolysis and NaClO 2 oxidation is explored. High-temperature-short-time hydrolysis can depolymerize the cellulose, whereas the dispersibility of the CNFs is hugely enhanced by NaClO 2 oxidation under alkaline condition. The degradation of cellulose in succinic acid hydrolysis follows first-order reaction kinetics and is severely influenced by the hydrolysis temperature, moreover, the molecular chains of the cellulose are seriously cracked under the optimized condition. The NaClO 2 oxidation greatly improves the zeta potential (−36.2 mV) and the dispersibility of the CNFs. The obtained CNFs have an ultimate yield of 94.6%, and the diameter distribution is mainly within 20–40 nm. In addition, some amount of carboxyl groups in the cellulose will be instead of the hydroxyl groups , and the crystallinity of the CNFs is significantly increased.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Chemistry
·
2019
·
IF 1.727
Han Zhitao,Gao Yu,Yang Shaolong,Dong Jingming,Pan Xinxiang,Lan Tian,Song Liguo,Yan Zhijun,Sun Deping,Ning Kaixuan
Experiments were conducted to remove NO from simulated flue gas in a rotating packed bed (RPB) reactor with NaClO2 as wet scrubbing oxidant and diesel exhaust gas as carrier gas. The effects of various operating parameters (rotational speed, solution pH, NaClO2 concentration, liquid-gas ratio, and NO and SO2 concentrations) on NO removal performance were investigated preliminarily. The results showed that with the increase of rotational speed, oxidant concentration, and liquid-gas ratio, NO removal efficiency increased obviously. NO removal efficiency increased largely with the decrease of solution pH, and a complete removal of NO could be attained at pH 4. NO concentration imposed little effect on NO removal efficiency while coexisting SO2 in exhaust gas could enhance NOx removal greatly.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2020
·
IF 5.162
Jie Hao,Fangxia Wu,Rong Tang,Yuanyuan Sun,Dehua Liu,Zhenqing Zhang
Oxidized starch (oxStarch) is a major derivative of starch. In present study, 4-acetamide-TEMPO system was firstly applied to prepare specifically oxidized starch, homogeneous 1,4-linked α-D-glucuronan. The impact of oxidant amount, 4-acetamide-TEMPO amount and reaction temperature on the properties of products were investigated. The product structures were characterized with 1 H NMR for degree of oxidation (DO), SEC-MALS for MW, MS for analysis of oxidized oligosaccharides , and in-source fragmented MS for analysis of oxidized polysaccharides . The results showed that the DO of oxStarches increased, but their MWs decreased with the raise of oxidant amount; higher 4-acetamide-TEMPO amount provided higher efficiency of specific oxidation of starch, in which the product has higher DO and MW; no significant difference have been observed between the oxStarches oxidized at 4 and 25 °C, but significant degradation was observed at 50 °C. In each product, having a MW distribution, the portion with smaller size has higher DO. While some unspecific oxidation was still observed observed on the second hydroxyl groups of sugar ring in the following order of priority, position 3 > 2 > 1 > 0.
研究领域:
化学
·
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Environmental Technology & Innovation
·
2018
·
IF 0
Jiaorong Yan,Feixiang Zhou,Ying Zhou,Xianghao Wu,Qiulian Zhu,Huayan Liu,Hanfeng Lu
The removal of NO x with low oxidation degree, low temperature, and high vapor content from small coal-fired boiler emission through selective catalytic reduction is difficult. This study investigated liquid oxidation and absorption to remove NO x systematically. Thermodynamic calculation showed that the equilibrium constants of the NO oxidation and NO x absorption reaction are high; thus, NO x treatment by liquid oxidation and absorption is feasible. Four oxidants (NaClO 2 , NaClO, H 2 O 2 , and KMnO 4 ) and four absorbents (Ca(OH) 2 , CaCO 3 , NaOH, and Na 2 CO 3 ) were used to study the reaction mechanism of the oxidation and absorption processes. Results show that NaClO 2 solution is the best oxidant, and the optimum pH value of the oxidation reaction is 5–6. The oxidation degree reaches 100% when the concentration of the NaClO 2 solution is 1.0%, and the oxidation degree can still reach approximately 50% when the concentration is 0.1%. Ca(OH) 2 slurry has the best absorption performance among the four kinds of absorbents. The NO x removal efficiency of Ca(OH) 2 slurry can reach approximately 70% when the oxidation degree is 50%. The removal efficiency is up to 80% when the oxidation degree is 100%.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
ENERGY & FUELS
·
2021
·
IF 3.605
Wenbo Jia,Chuanmin Chen,Songtao Liu,Yue Cao
In this study, the Hg0 removal characteristics of NaClO2 in limestone slurry were investigated in a bubbling reactor. The effects of slurry conditions (pH, temperature, and Cl– concentration) and flue gas components (NO, SO2, HCl, etc.) on Hg0 removal activity and efficient Hg0 removal duration were explored. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to characterize the solid products prepared under different conditions. It was found that NaClO2 exhibited superior Hg0 removal activity when both SO2 and NO were present in the flue gas, while the Hg0 removal efficiency reduced significantly in the absence of SO2 and/or NO. The Hg0 removal activity of NaClO2 decreased significantly with the increase of pH value. The slurry temperature had no obvious effect on Hg0 removal activity, while higher temperature could enhance the Hg0 re-emission at a later stage. However, the presence of Cl– in limestone slurry could notably inhibit the Hg0 re-emission. The characterization results showed that the presence of SO2 and NO promoted the formation of HgCl2, Hg(NO3)2, and HgSO4, thus significantly enhancing the Hg0 removal activity of NaClO2 in limestone slurry.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Energies
·
2018
·Vol. 11
·期 5
·
IF 2.676
Zhitao Han,Dongsheng Zhao,Dekang Zheng,Xinxiang Pan,Bojun Liu,Zhiwei Han,Yu Gao,Junming Wang,Zhijun Yan
In order to enhance the mass transfer efficiency between gas–liquid interfaces, NaClO2mist generated by an ultrasonic humidifier was used to remove NO from simulated flue gas. The effects of some key parameters (the gas flow rate, the NaClO2concentration in the solution, the inlet NO concentration, the NaClO2solution pH) on NO removal efficiency were investigated preliminarily. The results showed that NaClO2mist could oxidize NO with a much higher efficiency compared with other mists containing either NaClO or H2O2as oxidants. With an increase in the gas flow rate from 1.5 to 3.0 L·min−1, the atomizing rate of the NaClO2solution increased almost linearly from 0.38 to 0.85 mL·min−1. When the gas flow rate was 2.0 L·min−1, a complete removal of NO had been reached. NO removal efficiency increased obviously with an increase in the NaClO2concentration in the solution. With an increase in the inlet NO concentration, the ratio of NO in the flue gas and NaClO2in the mist increased almost linearly. Furthermore, the NaClO2mist exhibited a relatively stable and high NOxremoval efficiency in a wide pH range (4–11) of NaClO2solutions. The reason for the high NO removal efficiency was mainly ascribed to both the strong oxidative ability of NaClO2and the improved mass transfer at the gas-liquid interface.
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2020
·Vol. 27
·期 14
·16963-16971
·
IF 3.056
Gong Pijian,Li Chunyu,Li Xinxue
Marine diesel engines produce a lot of exhaust gas (NO, SO 2 ). Based on the situation that wet scrubbing methods have been already applied to ship desulfurization and seawater is easily accessible around the ships, this paper proposed a novel AOP (advanced oxidation process) of NaClO 2 (sodium chlorite) with Cl − (abundant Cl − exist in seawater) to remove NO from the flue gases of marine engines. The buffer capacity of NaAC (sodium acetate), the effect of Cl − concentration, and Cl − promotion mechanism on NO removal were investigated. The result showed that the existence of NaAC in solution could inhibit the rapid decline of the solution pH. The addition of Cl − achieved a remarkable promotion to NO removal at lower NaClO 2 concentration, which was due to the fast generation of ClO 2 from the promotion decomposition of NaClO 2 by Cl − in acidic condition. Then, the thermodynamic and dynamic mechanism of the generation of ClO 2 was intensively analyzed. And the mechanism of NO removal was discussed finally.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Dan Peng,Jie Zhao,Xujun Liang,Xuetao Guo,Huosheng Li
Bio-based aerogel has become an attractive sorbent for spilled oil and organic pollutants because of its light weight, high porosity and strong sorption capacity. However, the current fabrication process is mainly "bottom-up" technology , which is cost-expensive, time-consuming, and energy-intensive. Herein, we report a top-down, green, efficient and selective sorbent prepared from corn stalk pith (CSP) using the deep eutectic solvent (DES) treatment, followed by TEMPO/NaClO/NaClO 2 oxidization and microfibrillation, and then hexamethyldisilazane coating. Such chemical treatments selectively removed lignin and hemicellulose, broke the thin cell walls of natural CSP, forming an aligned porous structure with capillary channels. The resultant aerogels had a density of 29.3 mg/g, a porosity of 98.13%, and a water contact angle of 130.5 ◦ , exhibiting excellent oil/organic solvents sorption performance, with a high sorption capacity in the range of 25.4–36.5 g/g, approximately 5–16-fold higher than CSP, and with fast absorption speed and good reusability.
研究领域:
材料科学
·
环境工程
·
化学工程
·
可持续化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）