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Nickel sulfate solution fluoride separation with hydrous zirconium oxide

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Tungsten 2024年第2期6卷 367-381页

作者： Elbert M.Nigri Ummul K.Sultana André L.A.Santos James W.Vaughan Sonia D.F.Rocha Department of Mining Engineering Federal University of Minas GeraisBelo Horizonte 31270-901Brazil School of Chemical Engineering University of QueenslandSt Lucia 4072Australia

fluoride is an impurity in nickel sulfate production,which is required for electric vehicle batteries.Hydrous zirconium oxide(HZO)was evaluated for removing fl uoride from nickel sulfate solution.Maximum fluoride removal occurred at pH value 4 and optimal pH value is 4–5,considering Zr solubility.fluoride availability decreases with pH due to hydrogen fluoride and zirconium fluoride aqueous species.fluoride removal is initially rapid,with 50 wt.%removal in 7 min,followed by slow removal up to 68 wt.%after 72 h and follows second order rate kinetics.fluoride removal was dominated by an ion exchange mechanism and resulting Zr–F bonds were observed using Fourier-transform infrared spectroscopy.The presence of nickel sulfate decreased loading capacity compared to a salt-free solution.HZO maintained adsorption capacity through five cycles of loading and regeneration.

关键词： Hydrous zirconium oxide Nickel sulfate fluoride Adsorption Anion exchange

The function of doping nitrogen on removing fluoride with decomposing La-MOF-NH_2:Density functional theory calculation and experiments

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Journal of Environmental Sciences 2024年第1期135卷 118-129页

作者： Hongguo Zhang KuilinWan Jia Yan Qian Li Yufang Guo Lei Huang Samuel Raj Babu Arulmani Jian Luo School of Environmental Science and Engineering Guangzhou UniversityGuangzhou 510006China Guangzhou University-Linkoping University Research Center on Urban Sustainable Development Guangzhou UniversityGuangzhou 510006China School of Civil and Environmental Engineering Georgia Institute of TechnologyAtlantaGA 30332USA

fluoride is an important pollutant in wastewater,and adsorption is an effective way to remove fluoride.Because nitrogen plays an important role in adsorbent materials,computational models were developed to understand the changes in work function resulting from nitrogen doping.La-N-C-800℃,was prepared by pyrolyzing La-MOF-NH_(2)to verify the influence on the performance of removing fluoride by electrosorption.Material and electrochemical performance tests were performed to characterize La-N-C-800℃.Adsorption kinetics,adsorption thermodynamics,initial concentrations,pH,and ions competition were investigated using La-N-C-800℃for fluoride removal.In addition,density functional theory was applied to evaluate the function of nitrogen.When nitrogen atoms were added,the density of states,partial density of states,populations,and different orbits of charge were calculated to discover deep changes.Nitrogen strengthened the carbon structure and La_(2)O_(3)structure to remove fluoride.In addition,nitrogen can also act as an adsorption site in the carbon structure.These results provide design ideas for improving the performance of adsorbent materials by doping elements.

关键词： Capacitive deionization fluoride La-MOFs Doping nitrogen

Endogenous Trypsin Triggers Free fluoride Release from Antarctic Krill(Euphausia superba)Cuticle

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Journal of Ocean University of China 2024年第3期23卷 766-774页

作者： PENG Yuanhuai JI Wei JI Hongwu HAN Zhiping ZHANG Shiqi WEN Yaping College of Food Science and Engineering Lingnan Normal UniversityZhanjiang 524048China College of Biological and Food Engineering Guangdong University of EducationGuangzhou 510303China Guangdong Provincial Key Laboratory of Aquatic Products Processing and Safety Guangdong Ocean UniversityZhanjiang 524088China College of Food Science and Technology Guangdong Ocean UniversityZhanjiang 524088China College of Continuing Education Lingnan Normal UniversityZhanjiang 524048China

During postmortem storage,fluoride in Antarctic krill can be enriched in the muscle.Trypsin,as the most important digestive enzyme in Antarctic krill with a high activity in low temperature,plays a potential role in this process.In this study,endogenous trypsin was purified and its properties were investigated.The involvement of trypsin in the generation of free fluoride from Antarctic krill cuticle was explored.Cuticle microstructure before and after hydrolysis was compared with scanning electron microscopy,and the ash samples of the hydrolyzed Antarctic krill cuticle were analyzed with X-ray diffraction,Fourier transform infrared spectroscopy,and electron dispersive spectroscopy,respectively.Mass spectrometry analysis and inhibition tests confirmed that the purified enzyme was endogenous trypsin.Results of the present study indicated that trypsin digestion caused the increases of the concentrations of both fluoride ions and free amino N simultaneously,while the protein coated on the cuticle surface was dissolved too.However,no compositional change was detected in the cuticle inorganic salts.These findings suggest that trypsin triggered free fluoride release from Antarctic krill cuticle.In addition,the kinetics of free fluoride release could be described by the equation C_(W)=(1-0.97^(-0.006t)-0.03e^(0.0558t))x337.53+10.50.The present study improved the understanding of the role of trypsin in free fluoride release from Antarctic krill cuticle,facilitating future studies aimed at reducing the fluoride content in krill protein during Antarctic krill processing.

关键词： Antarctic krill cuticle fluoride trypsin

Effect of fluoride on the Ion-association of Calcium Phosphate and Crystallization of Hydroxyapatite

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Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 831-838页

作者：宋昊月 CAI Meng 袁萍邹朝勇 School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China

Using a titration setup to accurately control the reaction conditions and in situ monitor the reaction,we showed that fluoride exhibited negligible effects on the ion association process of calcium and phosphate and the formation of ACP nanospheres in a buffer solution with constant ionic strength.However,the stability of ACP increased with increasing fluoride concentration,which was ascribed to the inhibitory effect of fluoride on the aggregation of ACP nanospheres and the nucleation of nanocrystals on the surface of ACP nanospheres.Furthermore,fluoride could inhibit the lateral growth of HAP nanosheets and promote the formation of rod-like crystals.These results further improve our understanding of the crystallization pathway of HAP crystals and the regulatory effects of fluoride.

关键词： crystallization amorphous calcium phosphate hydroxyapatite fluoride

fluoride contamination in groundwater:A global review of the status,processes,challenges,and remedial measures

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Geoscience Frontiers 2024年第2期15卷 1-29页

作者： E.Shaji K.V.Sarath M.Santosh P.K.Krishnaprasad B.K.Arya Manisha S.Babu Department of Geology University of KeralaKariavattom CampusThiruvananthapuramKerala 695581India School of Earth Sciences and Resources China University of Geosciences(Beijing)29 Xueyuan RoadBeijing 100083China Department of Earth Science University of AdelaideAdelaideSA 5005Australia Department of Geology Central University of KeralaTejaswini HillsPeriyeKasaragodKerala 671316India

Groundwater pollution by fluoride is one of the prime concerns of the world population due to its toxicity,which results in adverse health impacts.In this paper,we review the current scenario of the fluoride contamination of groundwater in various countries across the globe and its impact on human health.During the last decade,several newly affected regions have been reported all over the world,with more than 100 countries affected by fluoride contamination in groundwater(concentration exceeding the acceptable limit of 1.5 mg/L defined by the World Health Organization).fluoride poisoning is mainly due to the unsupervised ingestion of products for dental and oral hygiene and over-fluoridated drinking water.It is estimated that more than 200 million people from different countries are affected by fluoriderelated groundwater issues and health problems.The highest among these are from the countries in Africa(38),Asia(28),and Europe(24),followed by countries like South America(5),North America(3),and Australia(2).The source of fluoride in drinking water is primarily geogenic,together with forage,grasses and grains,tea,and anthropogenic sources.These countries affected were correlated with climatic zones and geological factors to gain insights into geospatial relations.Our analyses show that most of the fluoride pollution-prone zones are located in high-grade metamorphic terranes with granitoid or alkaline intrusions,geothermal hot springs,and volcanic regions with arid or semi-arid climatic conditions.This study also finds that children across the globe are more vulnerable than adults to fluoride contamination.The review finds that,although there are efficient fluoride removal techniques,including filters with next-generation nanomaterials,to date,there has not been a single technique developed that can claim to be a practically robust solution for fluoride removal from drinking water.Therefore,we suggest developing next-generation filters that can retain essential minerals in water and remove only harmful ones and se

关键词： fluoride Groundwater Water contamination WHO standards Climate zones Remediation Sustainable Development Goals

An efficient approach for the treatment of radioactive waste perfluoropolyether lubricants via a synergistic effect of thermal catalysis and immobilization

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Journal of Environmental Sciences 2024年第2期136卷 512-522页

作者： Xinhang Du Wenhua Tong Xinyu Zhou Jia Luo Yuqiu Liu Yabo Wang Panyu Li Yongkui Zhang Department of Pharmaceutical&Biological Engineering School of Chemical EngineeringSichuan UniversityChengdu 610065China

Perfluoropolyether(PFPE)lubricants are a kind of high-molecular polymer with many excellent properties.However,the use of PFPEs in the nuclear industry can lead to partial decomposition and carrying radionuclides,resulting in a large amount of radioactive waste PFPE lubricants annually.Moreover,radioactive waste PFPE lubricants are difficult to be effectively treated due to their high stability,the risk of possible leakage of radionuclides,and hypertoxic fluorine-containing by-products.In this study,without any precedent,a strategy of Mn O_(2)-catalyzed decomposition and Na_(2)CO_(3)-immobilized conversion was proposed for PFPE lubricant decomposition and fluorine immobilization simultaneously based on the Lewis acid-base and oxygen vacancies concept.A high fluorine conversion efficiency of 95.4%was achieved.Meanwhile,the mechanism of decomposition suggested that Mn O_(2)mainly provided Lewis acid sites and attacked the(basic)fluorine or oxygen atoms in PFPE molecules.The decomposition of PFPE chains was proceed down and volatile fluorine-containing gas was released by partial electron transfer,intramolecular disproportionation reaction,and unzipping fashion.Subsequently,gas by-products could be further oxidized and then immobilized into fluoride salts by carbonate solid absorbents.Overall,this study provides a simple,safe,and potentially practical strategy for the harmless conversion of refractory fluorinated organic wastes,especially perfluoropolymers.

关键词： Perfluoropolyether lubricants Catalyzed decomposition Fluorine-containing gas Immobilized conversion fluoride

Spatial-Temporal Analysis of Drinking Water Type of Endemic Fluorosis—China,2009–2022

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China CDC weekly 2024年第2期6卷 25-29页

作者： Lijun Zhao Zhe Li Mang Li Hongna Sun Wei Wei Lin Gao Qiaoshi Zhao Yang Liu Xiaohong Ji Cheng Li Jian Wang Yanhui Gao Junrui Pei Center for Endemic Disease Control Chinese Center for Disease Control and PreventionHarbin Medical UniversityHarbin CityHeilongjiang ProvinceChina Key Lab of Etiology and Epidemiology Education Bureau of Heilongjiang Province(23618504)Ministry of Health of PRHarbin Medical UniversityHarbin CityHeilongjiang ProvinceChina

What is already known about this topic?Endemic fluorosis,caused by high fluoride levels in drinking water,has been a significant health issue in rural areas of China for many decades.What is added by this report?There has been a notable decline in the detection rate of dental fluorosis in children aged 8–12 years in drinking water fluorosis areas across the country from 2009 to 2022.While 14 provincial-level administrative divisions are classified as low-probability clusters,Tianjin remains classified as a high-probability cluster.What are the implications for public health practice?The current policy for preventing and controlling endemic fluorosis in China needs adjustment.Rather than focusing solely on regions with high incidence,there should be a shift towards monitoring and early warning of fluoride exposure.Additionally,local containment measures should be intensified.

关键词： intensified Spatial fluoride

Effects of chronic fluoride exposure on spatial learning and memory and hippocampal P13K/Akt/mTOR signaling pathway in second offspring rats

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China Medical Abstracts(Internal Medicine) 2024年第1期41卷 20-21页

作者：赵辰飞 Key Lab Edu Ministr Environ Pollution Monitor&Dis ContrSch Public HealthGuizhou Med UnivGuiyang 550025

Objective To study the effects of chronic fluoride exposure on spatial learning and memory and the expression of phosphatidylinositol 3-kinase (PI3K),protein kinase B (Akt),and mammalian target of rapamycin (mTOR) in ... 详细信息

关键词： PI3K fluoride rats

Predicting geogenic groundwater fluoride contamination throughout China

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Journal of Environmental Sciences 2022年第5期34卷 140-148页

作者： Hailong Cao Xianjun Xie Yanxin Wang Hongxing Liu School of Environmental Studies&State Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesWuhan 430074China

Endemic fluorosis exists in almost all provinces of China.The long-term ingestion of groundwater containing high concentrations of fluoride is one of the main causes of fluoro-sis.We used artificial neural network to model the relationship between groundwater fluo-ride concentrations from throughout China and environmental variables such as climatic,geological.and soil parameters as proxy predictors.The results show that the accuracy and area under the receiver operating characteristic curve of the model in the test dataset are 80.5%and 0.86%,respectively,and climatic variables are the most effective predictors.Based on the artificial neural network model,a nationwide prediction risk map of fluoride concen-trations exceeding 1.5 mg/L with a 0.5×0.5 arc minutes resolution was generated.The high risk areas are mainly located in western provinces of Xinjiang,Tibet,Qinghai,and Sichuan,and the northern provinces of Inner Mongolia,Hebei and Shandong.The total number of people estimated to be potentially at risk of fluorosis due to the use of untreated high flu-oride groundwater as drinking water is about 89 million,or 6%of the population.The high fluoride groundwater risk map helps the authorities to prioritize areas requiring mitigation measures and thus facilitates the implementation of water improvement and defluorida-tion projects.

关键词： fluoride Groundwater Prediction Artificial neural network China