Effective Elimination of Hazardous Chromium (VI) Using Periodic Elements and Contemporary Adsorption Methods by Using Magnesium Ferrite Nanoparticle: A Review

A well-known hazardous metal and top contaminant in wastewater is hexavalent chromium. The two forms of most commonly found chromium are chromate ( CrO 4 2− ) and dichromate ( Cr 2 O 7 2− ). Leather tanning, cooling tower blow-down, plating, electroplating, rinse water sources, anodizing baths etc. are the main sources of Cr (VI) contamination. The Cr (VI) is not only non-biodegradable in the environment but also carcinogenic to living population. It is still difficult to treat Cr contaminated waste water effectively, safely, eco-friendly, and economically. As a result, many techniques have been used to treat Cr (VI)-polluted wastewater, including adsorption, chemical precipitation, coagulation, ion-exchange, and filtration. Among these practices, the most practical method is adsorption for the removal of Cr (VI) from aqueous solutions, which has gained widespread acceptance due to the ease of use and affordability of the equipment and adsorbent. It has been revealed that Fe-based adsorbents’ oxides and hydroxides have high adsorptive potential to lower Cr (VI) content below the advised threshold. Fe-based adsorbents were also discovered to be relatively cheap and toxic-free in Cr (VI) treatment. Fe-based adsorbents are commonly utilized in industry. It has been discovered that nanoparticles of Fe-, Ti-, and Cu-based adsorbents have a better capacity to remove Cr (VI). Cr (VI) was effectively removed from contaminated water using mixed element-based adsorbents (Fe-Mn, Fe-Ti, Fe-Cu, Fe-Zr, Fe-Cu-Y, Fe-Mg, etc.). Initial findings suggest that Cr (VI) removal from wastewater may be accomplished by using magnesium ferrite nanomaterials as an efficient adsorbent.

Hexavalent Chromium Cr (VI) Removal from Water by Mango Kernel Powder

Metal trace elements (MTE) are among the most harmful micropollutants of natural waters. Eliminating them helps improve the quality and safety of drinking water and protect human health. In this work, we used mango kernel powder (MKP) as bioadsorbent material for removal of Cr (VI) from water. Uv-visible spectroscopy was used to monitor and quantify Cr (VI) during processing using the Beer-Lambert formula. Some parameters such as pH, mango powder, mass and contact time were optimized to determine adsorption capacity and chromium removal rate. Adsorption kinetics, equilibrium, isotherms and thermodynamic parameters such as ΔG˚, ΔH˚, and ΔS˚, as well as FTIR were studied to better understand the Cr (VI) removal process by MKP. The adsorption capacity reached 94.87 mg/g, for an optimal contact time of 30 min at 298 K. The obtained results are in accordance with a pseudo-second order Freundlich adsorption isotherm model. Finally FTIR was used to monitor the evolution of absorption bands, while Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) were used to evaluate surface properties and morphology of the adsorbent.

海藻酸钠基凝胶吸附材料对Cr(VI)吸附性能研究

海藻酸钠(SA)是一种天然生物质材料,其来源广、价格低,聚乙烯亚胺是一种含有氨基(-NH_(2))的水溶性高分子聚合物,螯合重金属离子能力强,众多研究者将二者结合其制备成吸附剂去除水溶液中的金属离子。本研究以海藻酸钠为基体,加入碳酸钙和聚乙烯亚胺,以戊二醛为交联剂,经冷冻干燥后形成吸附较好的海藻酸钠-聚乙烯亚胺吸附材料。采用吸附实验研究了材料对水中Cr(VI)的吸附性能,并研究初始浓度、溶液pH、吸附时间、吸附剂用量等对吸附效果的影响。实验结果表明:在Cr(VI)溶液初始浓度为15 mg/L、吸附剂用量0.4 g、吸附时间200 min,吸附温度为313 K时,Cr(VI)去除率达90%以上。

应用型背景下标志与VI设计课程实施课程思政的路径研究

全面推进课程思政建设是落实立德树人根本任务的战略举措。为适应新时代对课程思政高质量发展的要求,该文基于高校“三全育人”工作需求,在应用型背景下,探索课程思政元素有机融入艺术设计类专业课程的路径。针对标志与VI设计课程,首先根据神经语言程序学者罗伯特·迪尔茨关于人的认知的六个层次理论,设计课程思政元素体系,进而通过详细解读和挖掘六种层次描述课程思政元素体系的设计思路,最后提出从五个讲授部分和三个实践部分,在课程实施过程中融入课程思政元素的具体策略和路径,以期促进艺术设计类专业教学与课程思政有机融合,充分发挥课程思政在高校艺术设计类专业课程中的育人作用,为标志与VI设计课程的思政教学设计与教学改革提供参考。

电纺丝制备磁性单晶BiFeO_(3)纳米纤维并用于Cr(VI)的可见光催化还原

本工作提出一种将溶胶凝胶与静电纺丝结合的分步快速烧结技术,成功制备了单晶BiFeO_(3)纳米纤维。通过热重差热分析(TG-DTG)、XRD、SEM、TEM、EDS、紫外可见漫反射光谱和氮气吸附脱附曲线等测试对所制备材料的结构和形貌进行表征。同时,考察了BiFeO_(3)纳米纤维在可见光下对水中Cr(VI)的光催化还原性能。结果显示,相比于传统方式制备的纳米颗粒,该材料因更大的比表面积而具有更高的光催化活性。空穴消耗剂酒石酸的加入能够促进该材料对Cr(VI)的光催化还原反应,使还原效率提高87%。总之,本文制备的BiFeO_(3)材料能在可见光下响应,并在常温下具有弱磁性,能通过磁场力回收,在环境净化领域具有广阔的应用前景。

基于CO_(2)活化的竹基多孔炭催化还原Cr(VI)的性能研究

以竹粉为原料、CO_(2)为活化剂制备竹基多孔炭(ZH-100),并用于催化还原Cr(VI)。分析了反应温度、催化剂用量、还原剂甲酸用量、Cr(VI)初始质量浓度对竹基多孔炭催化活性的影响,采用XPS、XRD和交流阻抗测试技术对反应前后的多孔炭进行表征,以揭示其催化还原Cr(VI)的作用机制。结果表明:竹基多孔炭催化还原Cr(VI)的最佳实验条件为Cr(VI)初始质量浓度120 mg/L、温度60℃、ZH-100炭催化剂添加量0.1 g,还原剂甲酸添加量1.5 mL,在该条件下反应10 min,Cr(VI)还原率高达99.44%;重复使用3次后,ZH-100的催化还原能力略有下降,但仍能在30 min内达到99.22%的Cr(VI)还原率。分析发现,Cr(VI)的去除过程包括物理吸附和化学还原,其中以化学还原占主导;催化剂重复使用性能下降原因包括表面官能团消耗、碳微晶排列无序化及阻抗增大,ZH-100对Cr(VI)的催化还原机制为官能团介导和类石墨微晶介导。

基于VI视觉识别系统的饲料品牌策划

VI视觉识别系统是具有统一性、系统性的视觉符号系统,在饲料品牌策划中能起到树立品牌形象,扩大品牌知名度和影响力,增强品牌信任感等显著效果,所以能为饲料品牌发展提供有力支撑。而在应用VI视觉识别系统的过程中,要注意把握好饲料品牌策划的原则,力求通过标志设计、标准色设计、包装设计以及信息推广等途径不断优化饲料品牌策划方案,确保饲料品牌能在激烈的市场竞争中脱颖而出,以良好的品牌为饲料企业带来溢价效应和增值效应。

Efficient removal of Cr(VI) by polydopamine-modified lignin from aqueous solution: Batch and XAFS studies

Lignocellulose has the potential to become a bio-based adsorbent due to its biodegradability and renewability.In this study,a novel polydopamine functionalized-lignin(lignin@PDA),prepared via self-polymerization of dopamine(PDA)on lignin,was used as a bio-based adsorbent for rapid scavenging of hexavalent chromium(Cr(VI)).The morphology,functional groups,crystalline structure,and chemical composition of lignin@PDA were characterized with a scanning electron microscope-energy dispersive spectrometer,Fourier transform infrared spectroscopy,X-ray diffraction,and X-ray photoelectron spectroscopy.The Cr(VI)adsorption process of lignin@PDA was studied using batch experiments as a function of pH,ionic strength,adsorbent dose,and contact time at room temperature.The adsorption rate of lignin@PDA was five times greater than that of the unmodified lignin,with a maximum adsorption capacity of 102.6 mg/g in an acidic medium.The adsorption of Cr(VI)on lignin@PDA fit the pseudo-secondorder equation and the Freundlich model,indicating that the adsorption process was mainly dominated by chemisorption and surface complexation.The thermodynamic parameters showed that adsorption of Cr(VI)on lignin@PDA was an endothermic and spontaneous process.The X-ray absorption fine structure results showed that sorption and reduction of Cr(VI)into Cr(II)occurred simultaneously on lignin.Moreover,PDA coating not only improved the reactivity of lignin but also promoted the complete reduction of Cr(VI)by lignin.According to these results,polydopamine functionalized-lignin is a promising bio-based adsorbent for immobilization of Cr(VI)from wastewater.

Solidification/Stabilization of Chromium in Red Mud-based Geopolymer

Up to 1.5wt%of Cr(Ⅲ)salts(CrCl_(3),and Cr_(2)O_(3))and Cr(Ⅵ)salts(Na_(2)CrO_(4),and CaCr_(2)O_(7))were incorporated into red mud-based geopolymers,respectively.The solidification/stabilization,compressive strength,and durability of the Cr-containing geopolymers were investigated.The experimental results indicate that the red mud-based geopolymer could effectively solidify/stabilize different types of Cr salts with solidification/stabilization rates of above 99.61%.Geopolymers are environmentally safe when the dosage of CaCr_(2)O_(7)is≤1.0wt%,or the dosage of CrCl_(3),Cr_(2)O_(3),and Na_(2)CrO_(4)is≤1.5wt%,respectively.The effects of Cr salts on the compressive strength varies with the type and content of Cr salts.The freeze-thaw cycle is more destructive to geopolymer properties than sulfate attack or acid rain erosion.The solidification/stabilization of Cr is mainly attributed to the following reasons:a)The chemical binding of Cr is related to the formation of Cr-containing hydrates(eg,magnesiochromite((Mg,Fe)(Cr,Al)_(2)O_(4)))and doping into N-A-S-H gel and C-A-S-H gel framework;b)The physical effect is related to the encapsulation by the hydration products(e g,N-A-S-H gel and C-A-S-H gel).This study provides a reference for the treatment of hazardous Cr-containing wastes by solid waste-based geopolymers.

Investigation of Hexavalent Chromium Reduction in Strong Saline and Acidic Nitro-Phosphate Solutions

Phosphorus fertilizers from less pure sedimentary sources become increasingly important, due to depletion of phosphorus from igneous rock of high quality. Consequently, robust methods with potential to remove various types of hazardous elements are required. Among such impurities, hexavalent chromium (Cr(VI)) is very likely to become a future challenge. Different industrial ways to treat phosphate rock are currently being practised, and we have here studied how chromium behaves when using the nitro-phosphate process. The reduction mechanism of Cr (VI) in nitric acid and phosphoric acid solutions was investigated by measuring redox potential and UV-VIS spectra. The results show that Cr (VI) is not stable in strong nitric acid solutions. Reduction of Cr (VI) species decreased with decreasing temperature, NO2 concentration, ionic strength and absence of light. These findings support the proposed reduction reaction:The reduction rate was observed proportional to the nitric acid decomposition: .

Effects of iron oxide on crystallization behavior and spatial distribution of spinel in stainless steel slag

Chromium plays a vital role in stainless steel due to its ability to improve the corrosion resistance of the latter.However,the re-lease of chromium from stainless steel slag(SSS)during SSS stockpiling causes detrimental environmental issues.To prevent chromium pollution,the effects of iron oxide on crystallization behavior and spatial distribution of spinel were investigated in this work.The results revealed that FeO was more conducive to the growth of spinels compared with Fe2O3 and Fe3O4.Spinels were found to be mainly distrib-uted at the top and bottom of slag.The amount of spinel phase at the bottom decreased with the increasing FeO content,while that at the top increased.The average particle size of spinel in the slag with 18wt%FeO content was 12.8μm.Meanwhile,no notable structural changes were observed with a further increase in FeO content.In other words,the spatial distribution of spinel changed when the content of iron oxide varied in the range of 8wt%to 18wt%.Finally,less spinel was found at the bottom of slag with a FeO content of 23wt%.

VI创意设计提升奢侈品皮具品牌影响力探析

随着社会经济的发展,VI的创意设计对于品牌影响力的作用越来越受到品牌方和消费者的重视。如何通过VI创意设计来提升奢侈品皮具品牌的影响力也是一个值得探讨的过程。本文从VI的概念、VI创意设计在奢侈品皮具中的表现形式和如何提升奢侈品皮具品牌的影响力等方面进行分析,以达到抛砖引玉的作用。

Efficient and rapid capture of uranium(Ⅵ) in wastewater via multiamine modified β-cyclodextrin porous polymer

It is quite important to ensure the safety and sustainable development of nuclear energy for the treatment of radioactive wastewater. To treat radioactive wastewater efficiently and rapidly, two multi-amine β-cyclodextrin polymers(diethylenetriamine β-cyclodextrin polymer(DETA-TFCDP) and triethylenetetramine β-cyclodextrin polymer(TETA-TFCDP)) were prepared and applied to capture uranium. Results exhibited that DETA-TFCDP and TETA-TFCDP displayed the advantages of high adsorption amounts(612.2and 628.2 mg·g-1, respectively) and rapid adsorption rates, which can reach(88 ± 1)% of their equilibrium adsorption amounts in 10 min. Moreover, the adsorbent processes of DETA-TFCDP and TETATFCDP on uranium(Ⅵ) followed the Langmuir model and pseudo-second-order model, stating they were mainly chemisorption and self-endothermic. Besides, TETA-TFCDP also showed excellent selectivity in the presence of seven competing cations and could be effectively reused five times via Na2CO3as the desorption reagent. Meanwhile, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy illustrated that the enriched multi-amine groups and oxygen-containing functional groups on the surface of TETA-TFCDP were the main active sites for capturing uranium(Ⅵ). Hence, multi-amine β-cyclodextrin polymers are a highly efficient, rapid, and promising adsorbent for capturing uranium(Ⅵ)from radioactive wastewater.

乡村振兴战略背景下“VI设计与制作”课程思政教学探索与实践——以农产品包装设计项目为例

2023年中央一号文件《中共中央国务院关于做好2023年全面推进乡村振兴重点工作的意见》中提到实施文化产业赋能乡村振兴计划,如何引领乡村产业发展,推动乡村振兴战略,提升农产品消费引力,成为业界关注的热点。产品包装设计是品牌形象的直接展示,对于农产品的品牌打造、提档升级、促进销售有着重要作用。本文以农产品包装设计项目为例,探究如何将思政元素融入到“VI设计与制作”课程中,以创意设计赋能新农村建设为切入,让设计助力乡村振兴,提升学生服务国家乡村振兴的意识,实现培养“重民生、强素质、懂设计、会创新”的人才目标。

多媒体时代“VI设计”课程教学创新研究

“VI设计”课程是视觉传达设计专业的专业核心课程。传统VI设计以企业或品牌的基础系统和应用系统设计为主,随着多媒体技术时代的涌入,VI设计着重以品牌形象塑造为设计理念,通过品牌元素与IP形象等应用延展,树立品牌意识和观念。分析了“VI设计”课程教学存在的问题,阐述了“VI设计”课程教学创新策略。

Mark VIe控制系统在燃驱压缩机组控制系统升级改造中的应用

针对当前集成了不同厂家几套子系统的一些燃驱压缩机组控制系统结构复杂、维护成本高等问题,应用基于Mark VIe控制平台来升级改造该系统。以某改造项目为例,应用双冗余Mark VIe控制系统架构,Mark VIe SIL3模件作为紧急停机和火气保护系统的硬件,同时采用Mark VIe ControlST统一软件平台。结果表明:新控制系统采用了一体化硬件、软件设计,提高了机组控制系统的安全可靠性,有利于日常运行维护,而且新系统具有在线监测功能,有助于系统故障排查。

本科教育VI设计教学中传统图形融入探索

本科教育VI设计教学中融入传统图形,有助于培养学生创新思维和设计思维,还能培养学生文化意识,传承我国传统文化。基于此,本文分析本科教育VI设计教学中传统图形的艺术表现,探讨本科教育传统图形融入VI设计教学实践流程,并从案例教学、教学方法多样化、学生文化意识培育、小组讨论学习、传统图形的基本信息介绍等方面出发,探索本科教育VI设计教学中传统图形融入策略和方法,旨在提供一些有益参考,提高VI设计教学效率。

沉浸式教学模式的探索实践——以《VI设计》为例

文章首先对沉浸式教学模式的概念进行了阐述,分析了视觉传达专业《VI设计》的教学现状,并论述了沉浸式教学模式在高校教学活动中的探索与实践。具体来说,文章以《VI设计》课程为例,从教师授课内容、学生研究方法、作业成绩评定等方面对沉浸式教学模式展开论述,通过教学模式与沉浸式的结合,探讨了全球数字化背景下高校教学模式的新思路。