PROGRESS IN ORGANIC COATINGS
·
2014
·
IF 2.302
Feigao Xu,Ning Xiang,Dan Li,Jiangang Yu,Daishe Wu,Qingjian Zhang
Deterioration of monuments constructed of limestone could be potentially arrested by applying a combination of coupling agents with consolidants, which can prevent acid attack and mechanical weakening. Two different coupling agents including N-(2-aminoethyl)-3-aminopropyl methyl dimethoxysilane (AE-APMDMS) and diethyl phosphatoethyl triethoxysilane(DEPETES) were used to link calcite . Calcite was impregnated with these coupling agents and studied by FTIR, TG-DSC and contact angle measurement. According to these techniques, new bands, a two stage decomposition pattern appeared and a slight increase in surface hydrophobicity for AE-APMDMS and DEPETES that indicated interactions between the coupling agents and calcite . The Scotch Tape test and compressive strength test showed that the cohesion between consolidant and limestone powder improved, while the ability of consolidation decreased, which were resulted by coupling agents. Resist acid test on limestone powder coated with the coupling agents resulted in a decreased deterioration rate. Limestone treated with combined consolidant plus AE-APMDMS or DEPETES showed a significant decrease in capillarity water absorption.
研究领域:
材料科学
·
文物保护
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2019
·
IF 5.108
Chao Song,Hua-Yu Liu,Shuang Guo,Shu-Guang Wang
As the most typical geological environment, limestone landforms are widespreading in the world and affect the waters that flow around them, which may also change the fate of organic contaminants in these waters. In this study, aquatic environment surrounding limestone was simulated with calcium carbonate , and the photolysis of tetracycline was evaluated under UV irradiation (30 μW/cm 2 ). More tetracycline (up to 98%) was removed in 4 h in the presence of calcium carbonate while only 50% of tetracycline was eliminated in control experiment. The removal of tetracycline was greatly enhanced due to the major roles of alkaline pH and minor roles of Ca 2+ and HCO 3 − /CO 3 2− . In alkaline pH, tetracycline existed as TCs − with higher electronic density in the ring structures, which was more easily attacked by OH. Besides, it could also change the bond orbital energy to facilitate tetracycline absorbing more photon. Moreover, alkaline pH was beneficial to generate more OH and thus promote the indirect photolysis. In addition, alkaline pH also changed the degradation path of tetracycline and rapidly convert tetracycline to the byproducts with m/z 457 via hydroxylation and hydrogen abstraction. This work provides not only better understanding about the fate of tetracycline in aquatic environments but also new insights into the treatment of antibiotic-contaminated water.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Cleaner Production
·
2017
·
IF 5.715
Lingjun Kong,Minhua Su,Yan Peng,Li'an Hou,Juan Liu,Haipeng Li,Zenghui Diao,Kaimin Shih,Ya Xiong,Diyun Chen
Because of the widespread application of activated carbon (AC) as adsorbents, reduced production costs are highly desirable, therefore, inexpensive alternatives for activated carbon precursors and eco-procedures are presently sought. In this work, AC was successfully prepared from sawdust through co-calcinations with limestone. The surface area and porosity of the resulting ACs were evaluated according to the N 2 adsorption at 77 K. Acid Orange II (AOII) was utilized as a negative dye to study the potential of the resulting AC as an adsorbent. Results revealed that the surface area and total pore volume were both increased greatly. When the activated carbon was prepared in mass ratios of 1:2 and 1:1 (calcium carbonate to sawdust), the surface area increased to 611.4 and 706.9 m 2 /g, respectively, and the adsorption capacities increased to 310.89 and 389 mg/g. These enhancements indicated efficient activation, resulting in energy-saving and environmentally friendly activated carbon production. Thus, this paper provides a cleaner process for producing activated carbon from waste sawdust through bioresource recycling.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Wei Wang,Yilong Hua,Shaolin Li,Weile Yan,Wei-xian Zhang
A common concern in the approval of nanotechnology for water treatment is whether there are advantages of these nanomaterials over conventional water treatment reagents. In this work, nanoscale zero-valent iron (nZVI) is compared with lime (Ca(OH) 2 ), the most widely used heavy metal precipitant, for Pb(II) and Zn(II) removal, in laboratory and field experiments. Water chemistry, treatment efficiencies and reaction products of the two reagents are compared and the study shows that the moderate solution pH of nZVI and its seed effect play vital roles in producing high-quality effluents. The results are then verified in a field continuous-flow experiment using tons of lime and kilos of nZVI. The results show that sub-ppm levels (∼0.1 mg/L) of Pb(II) and Zn(II) could not be achieved via lime precipitation alone, due to the solubility limits of metal hydroxides and their re-dissolution caused by the strong alkalinity of lime. In comparison, stable and lower levels of Pb(II) and Zn(II) were easily attained using nZVI, due to its multifunctional properties and good tolerance for influent fluctuation enabled by its inherent pH-stabilizing nature. SEM characterizations, particle size analyses and quiescent settling experiments show the ability of nZVI to generate large and consolidated solids that are amenable to gravitational separation. The study shows several key advantages of nZVI over lime technology in Pb(II) and Zn(II) removal. As lime is widely used for heavy metal removal, this work provides an effective advanced treatment process to supplement lime-based treatment methods.
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
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
·
2022
·
IF 3.752
Qian WEI,Liu-yang DONG,Cong-ren YANG,Xue-duan LIU,Fen JIAO,Wen-qing QIN
Lime (CaO) and sodium humate (NaHA) were used as the combined depressant for arsenopyrite pre-treated by CuSO 4 and butyl xanthate. Micro-flotation tests show that the combined depressant CaO and NaHA achieved the selective depression of arsenopyrite. Closed-circuit lab-scale test results indicate that the synergistic effect of CaO+NaHA achieved a satisfactory flotation separation of sphalerite and arsenopyrite, for which the Zn grade and recovery of Zn concentrate were 51.21% and 92.21%, respectively. Contact angle measurements, adsorption amount measurements and X-ray photoelectron spectroscopy analysis indicate that the dissolved calcium species (mainly as Ca 2+ ) were adsorbed on the mineral surfaces, thereby promoting NaHA adsorption. Moreover, the surface of the arsenopyrite absorbed more amount of calcium species and NaHA than that of the sphalerite, thereby accounting for the strong hydrophilic surface of arsenopyrite. The adsorption of NaHA on arsenopyrite was mainly chemical adsorption through its carboxyl groups and Ca atoms, whereas that on sphalerite surface was relatively weak.
研究领域:
矿物加工工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2021
·
IF 6.141
Jinmeng Zhu,Jinghan Ding,Peiyao Zhang,Wenqiang Dong,Xicheng Zhao,Mara Camaiti,Xuanhua Li
Due to the excellent compatibility and ageing-resistant performance, nanolime (NL) as a promising inorganic material is applied to consolidate aged sandstones and other arenaceous rocks based cultural heritage, such as wall paintings and stone relics. However, sometimes, NL does not assure a good consolidation strength for cultural relics. The existing researches on enhancing its consolidation strength are costly, time-consuming or still involving organic polymers. Here, utilizing inexpensive kaolin nanosheets as platform, we design and facilely synthesize a new nanolime/kaolin (N-K) nanocomposite by in-situ growth of Ca(OH) 2 nanoparticles on the surface of kaolin nanosheets. The kinetic stability of this nanocomposite is comparable to the NL. Application experiment shows that the consolidation strength of the N-K nanocomposite in the highly porous pterosaur fossil (65%, porosity) is stronger than that of NL. The reason is due to the incorporation of kaolin nanosheets into the CaCO 3 network after carbonation. For the first time, this work reports a new N-K inorganic nanocomposite and will facilitate the development of NL-based inorganic materials for the conservation of cultural heritage.
研究领域:
文物保护
·
材料科学
·
古生物学
✓ 已验证
产品关联
DOI
高影响因子
TRANSACTIONS OF THE INDIAN INSTITUTE OF METALS
·
2025
·Vol. 78
·期 4
·1-10
·
IF 1.6
Pan Qi,Zhu Zhen,Lin Xiaocheng,Guo Bao,Jiang Kaixi
It is a waste of gallium resource to discard the high aluminum-containing gallium electrolyte. The Ga/Al separation is difficult by only using lime precipitation because of high gallium loss rate. The present study employs an adsorption resin LSC-600P to recover gallium in the simulated gallium electrolyte and then uses lime to remove aluminum, leaving only alkali solution recycled. The results showed that the aluminum removal rate in the gallium electrolyte was 93.12% under the conditions of reaction temperature of 85 °C, addition of lime 2 times to the theoretical molar ratio of calcium to aluminum, reaction time of 3 h and stirring speed of 600 r/min. In the experiments of gallium adsorption, after six adsorption–desorption cycles, the adsorption rate of gallium by LSC-600P resin still reached 98.6%, and the adsorption rate of aluminum was lower than 4.5%. In the desorption process, the desorption rate of gallium was more than 98%, and the aluminum content in the stripping solution after desorption was almost negligible. The resin exhibits high adsorption affinity for gallium while demonstrating minimal adsorption for aluminum.
研究领域:
冶金学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
CEMENT & CONCRETE COMPOSITES
·
2024
·
IF 10.8
Aidarus Yonis,Yanchen Oinam,Prabhat Vashistha,Aron Berhanu Degefa,Geta Bekalu Belayneh,Solmoi Park,Sukhoon Pyo
This study investigates the environmental and mechanical implications of incorporating silica fume into lime-activated thermo-mechanically treated waste concrete powder (TMWCP) to develop a sustainable clinker-free binder. The novel activation method involves thermo-mechanical treatment of WCP, followed by lime and calcium formate chemical activation. The results demonstrated that incorporating silica fume enhanced the pozzolanic reactivity , which led to the formation of C–S–H, pore refinement, and a dramatic increase in compressive strength . For instance, the incorporation of 20 % and 25 % silica fume exhibited compressive strength of 46 MPa and 43 MPa after 28 days of curing. The developed clinker-free binder with the addition of 20 % silica fume demonstrated a reduction in mineral resource consumption of 99.3 % and CO 2 emissions of 13 % and 69.3 % compared to the sample without silica fume and ordinary Portland cement , respectively. This study offers a promising avenue for the widespread utilization of WCP as an environmentally friendly clinker-free binder.
研究领域:
建筑材料学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2019
·
IF 4.561
Sultan Ahmed Khoso,Zhiyong Gao,Mengjie Tian,Yuehua Hu,Wei Sun
The depression of pyrite (FeS 2 ) through an organic depressant is not only ineffective but also nonselective which causes poor selectivity . In this research, the depression effect of an organic polymer ‘poly-γ-glutamic acid (γ-PGA, a widely available class of polysaccharides)’ on pyrite flotation was improved by the addition of lime (CaO). The most encouraging flotation results were received at relatively lower concentrations of CaO and γ-PGA. The addition of CaO and γ-PGA had a synergistic inhibitory effect on pyrite flotation with a minor compromise in terms of the chalcopyrite grade at low alkaline conditions (pH 9). Adsorption studies and zeta potential measurements revealed that both CaO and γ-PGA were greatly adsorbed onto the pyrite surface than chalcopyrite. The addition of CaO and γ-PGA underwent a two-step depression effect on pyrite surface: (1) calcium species dissolved from CaO prefrentially adsorbed onto the pyrite surface and decreasing its negative charges; (2) pre-adsorbed calcium hydroxyl species promoted the adsorption of γ-PGA onto the pyrite surface. The XPS and FT-IR measurements revealed that γ-PGA formed the chemical coordination bonds with Ca-species on pyrite surface. Based on these measurement analyses, a two-step depression mechanism of CaO and γ-PGA on pyrite was also proposed. The envisaged scheme has its own benefits of environmental friendliness and cost-effective characteristics in Cu S flotation systems.
研究领域:
矿物加工工程
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
·
2022
·
IF 3.752
Guo-tao ZHOU,Yi-lin WANG,Tian-gui QI,Qiu-sheng ZHOU,Gui-hua LIU,Zhi-hong PENG,Xiao-bin LI
The conversion mechanism of Al-goethite under the action of different additives (lime or reductant for typical or reductive Bayer digestion) was investigated by thermodynamic calculation, XRD, and SEM−EDS. The results show that the formation of Fe-substituted hydrocalumite is crucial to converting Al-goethite to hematite during Bayer digestion by adding lime. However, the conversion proceeds more easily under the action of reductant due to the rapid formation of magnetite. Additionally, Bayer liquor composition significantly affects the product composition and also the conversion rate of Al-goethite. Compared to typical Bayer digestion with Al-goethite containing gibbsitic bauxite as raw material, the red mud yield of reductive Bayer digestion decreases from 39.02% to 31.19%, and the grade of TFe in red mud increases from 41.66% to 53.80%.
研究领域:
矿物加工工程
·
材料科学与工程
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2023
·
IF 3.9
Jinmeng Zhu,Jinghan Ding,Yuke Li,Qi Wang,Fan Yang,Cong Jia,Yaxu Zhang,Xichen Zhao,Wenqiang Dong,Jia Wang,Zhiyong Lu,Xuanhua Li
After decades of research in the conservation of cultural heritage, nanolime (NL) has emerged as a potential alternative inorganic material to the frequently used organic materials. However, its poor kinetic stability in water has been a major challenge that restricted its penetration depth through cultural relics and resulted in unsatisfactory conservation outcomes. Here, for the first time, we realize NL water dispersion by modification of ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate) via a sample aqueous solution deposit method. Our findings indicate that the cation of the ionic liquid (IL) binds strongly to the surface of NL particles (IL-NL) by forming hydrogen bonds with Ca(OH)2 facets. The absorption of IL causes an unexpected significant alteration in the morphology of NL particles and results in a drastic reduction in NL’s size. More importantly, this absorption endows NL excellent kinetic stability dispersed into water and implements NL water dispersion, which makes a breakthrough in terms of extreme poor kinetic stability of as-synthesized NL and commercial NL in water. The mechanism driving IL-NL water dispersion is explained by Stern theory. In the context of consolidating weathered stone, the presence of IL may delay carbonation of NL but the penetration depth of IL-NL through stone samples is three times deeper than that of as-synthesized and commercial NLs. Additionally, the consolidation strength of IL-NL is similar to that of as-synthesized NL and commercial NL. Moreover, IL-NL has no significant impact on the permeability, pore size, and microstructure of consolidated stone relics. Our research contributes to the field of NL-related materials and will enhance the dissemination and utilization of NL-based materials in the preservation of water-insensitive cultural heritage.
研究领域:
文物保护
·
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POLYMERS AND THE ENVIRONMENT
·
2021
·Vol. 29
·期 6
·1727-1741
·
IF 3.667
Peng Xilong,Li Yue,Liu Shuang,Jiang Tian,Chen Wenjin,Li Dan,Yuan Jiren,Xu Feigao
In this experiment, chitosan (CS), waste limestone and diammonium hydrogen phosphate were used as raw materials to synthesize HAp-coated-stone composites/CS by one-step blending method. Then, the prepared HAp-coated-stone composites/CS composite material was used to remove Cu (II) in the solution. The structure and microstructure of the composite were characterized by Fourier transform infrared spectroscopy, X-ray diffraction analysis, Scanning Electron Microscopy, Brunauer–Emmett–Teller and Thermogravimetric Analysis. The results showed that with the addition of CS, the overall thermal stability of the composite improved, while its specific surface area decreased. Moreover, the composite was a mesoporous material. HAp-coated-stone/CS composites with small amounts of CS (0.5%) can remarkably increase Cu (II) removal. The HAp-coated-limestone/CS-0.5% had better resistance to pH changes compared with HAp-coated-limestone. Under the initial concentration of 20 mg/L, the maximum adsorption capacity for Cu (II) adsorption by HAp-coated-limestone/CS-0.5% was about 130.75 mg/g at 40 °C. The equilibrium data and kinetic were well described by Freundlich models and pseudo-second-order, respectively. The possible mechanisms for Cu (II) adsorption onto HAp-coated-stone/CS composites surface have been proposed.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）