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To improve the removal capacity of rice straw biochar for heavy metals in acidic mine wastewater, magnesium-modified rice straw biochar (MBC) was prepared by impregnation-pyrolysis method. The effects of impregnation ratio, solution pH,adsorption time,and initial concentration on the removal of Cd(II) and Pb(II) from acid mine wastewater by MBC were investigated through batch adsorption experiments, and the features of MBC before and after adsorption were analyzed by characterisation techniques to explore the potential adsorption mechanisms. The results showed that the MBC prepared by impregnation-pyrolysis possessed a well-developed pore structure. The adsorption experiments showed that the removal efficiency for 10 mg/L of Pb(II) and Cd(II) by MBC reached the optimum values of 93. 58% and 97. 95% at impregnation ratio 2 : 1 and solution pH 5. 0 respectively. The removal process of Cd( II) and Pb(II) by MBC was consistent with the pseudo second order kinetic model and Langmuir adsorption isotherm model. According to the Langmuir model,the maximum adsorption capacities of MBC for Cd(II) and Pb(II) were 90. 45 mg/g and 138. 50 mg/g, respectively. FTIR and XRD analyses showed that the removal mechanism of Cd (II) and Pb (II) by MBC contained complexation, co-precipitation, ion exchange, and electrostatic interaction. After five regenerations, the removal efficiency of Cd(II) and Pb(II) by MBC was maintained at 85. 62% and 80. 16%, respectively. The above results indicated that MBC had great potential for treating acid mine wastewater containing Cd(II) and Pb(II). [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Nitrogen-doped mesoporous carbon（NMC） was synthesized using hard-template，and was characterized using specific surface area analyzer，transmission electron microscope，Fourier transform-infrared spectrometer and X-ray photoelectron spectroscopy. NMC was applied in the adsorption of Pb（Ⅱ） in two different tunnel construction wastewaters，and the effects of pH，reaction time on adsorption and its adsorption kinetics models and sorption isotherms were investigated. The results showed that the adsorption kinetics was best described by pseudo-second-order model，and its adsorption characteristics conformed to the Langmuir and Temkin model. According to the results of the experiments and characterization，Pb（Ⅱ） adsorption by NMC involved physisorption such as electrostatic interaction and pore diffusion and chemisorption like chelation with functional groups. The estimated maximum adsorption capacity based on Langmuir model was 493.5 mg/g and 603.9 mg/g，respectively for the two wastewaters. In addition，NMC could be regenerated and reused by treatment with HCl.

Chitosan-pectin gel beads (CPB) have high potential for removing heavy metals from food. This study aimed to improve their stability, recyclability, and adsorption capacity by modified CPB with gelatin (Gel) and carboxymethyl cellulose sodium (CMC). The structural characteristics of the modified CPBs were characterized using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG), Zeta potential, scanning electron microscopy (SEM), pore size distribution analysis (BET), X-ray photoelectron spectroscopy (XPS), specific surface area analysis. The adsorption-resolution conditions of modified CPB were optimized, and their actual removal efficiency for Pb(II) in C-phycocyanin was evaluated. Results showed that CMC-modified CPB (CMC-CPB) had higher thermal stability, rougher and more porous surface, larger specific surface area (20.28±1.35 m2/g), lower zeta potential, stronger metal ion adsorption capacity, and higher regeneration efficiency compared with CPB and Gel-CPB. FTIR showed the functional group of CPB had significant difference after modification, and the main group in CPB were carboxyl, hydroxyl, and amino groups. TG analysis presented the thermal stability of CMC-CPB was higher than that of CPB and Gel-CPB. XPS analysis showed CMC-CPB had the strongest absorption peak for Pb(II). The optimal pH and temperature for the three adsorbents (CPB, Gel-CPB, and CMC-CPB) to remove Pb(II) were 6.0 and 60 ℃, respectively. The Pb(II) adsorption process of all three adsorbents fit the Langmuir isotherm model (R2=0.9543~0.9811) and the pseudo-second-order kinetic model (R2=0.9963~0.9991), and the adsorption process belonged to the monolayer chemical adsorption, involving the complexation of -COO, -OH, -CO-NH, and Pb(II). Based on the Langmuir model curve, the maximum adsorption capacity (qmax) of CMC-CPB for Pb(II) was 69.37 mg/g, significantly higher than that of Gel-CPB and CPB (P

Virgin microplastics were aged by oxidative-UV ageing in a laboratory simulation to investigate the sorption characteristics of virgin and aged polyethylene(PE), polypropylene(PP), polystyrene(PS), polyvinyl chloride (PVC) and poly lac tic acid(PLA) microplastics to Cr(VI) and Pb(II) in aqueous solution. SEM, BET, XRD, XPS and FTIR results show that oxidative-UV ageing increases the surface roughness, pore volume and oxygen-containing functional groups of microplastics. The kinetic and isotherm adsorption experimental results show that the adsorption of Cr(VI) and Pb(II) by primitive microplastics and aging microplastics is dominated by physical adsorption of monolayers and chemical adsorption of multiple layers, respectively・ The adsorption capacity and adsorption characteristics of microplastics against heavy metals Cr(VI) and Pb(II) are related to the types of microplastics. The biodegradable microplastic PLA showed strong adsorption capacity for both Cr(VI) and Pb(11). [ABSTRACT FROM AUTHOR]

This study aimed to extract pectin from local Majiayou pomelo (Citrus grandis (L.) Osbeck) peel in Jiangxi province with distilled water, hydrochloric acid and citric acid, respectively, and analyze the physicochemical components of pectin and its adsorption properties on Pb(II), and explicit the effect of adsorption parameters (initial pH value, initial ion concentration, adsorption time) on Pb (II) and its adsorption mechanism by adsorption isotherms and adsorption kinetics. The results showed that the yield of pectin by citric acid extraction (CEP) was highest (28.62%), followed by hydrochloric acid extraction (HEP) and distilled water extraction (WEP). In addition, the esterification degree (58.20%) and molecular weight (598.40 ku) of CEP were significantly lower than those of WEP and HEP (P<0.05), indicating that CEP had more carboxyl and higher solubility. The three pectins showed optimal adsorption of Pb (II) at initial pH 5.0, and reached equilibrium after 120 min adsorption. In addition, the adsorption capacity of CEP on Pb (II) was significantly higher than that by WEP and HEP. The adsorption isotherms of the three pectins were in accordance with Langmuir monolayer adsorption model, and the adsorption kinetics of the three pectins was consistent with pseudo first-order kinetics model. The adsorptions of three pectins on Pb (II) were the result of physical and chemical adsorption. Conclusion: The physicochemical properties of pectin and its adsorption capacity on Pb (II) were closely related to the extraction method, and CEP has a high adsorption capacity on Pb (II), which could be used as a low-cost, efficient, natural and environmental friendly adsorbent for removal of Pb (II). [ABSTRACT FROM AUTHOR]

Copyright of Journal of Guangxi Normal University - Natural Science Edition is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Among the natural clay minerals, sepiolite has been widely used in environmental remediation fields due to its fibrous chain structure of interlayer between silicon oxygen tetrahedron and magnesium oxygen octahedron, which has large specific surface area and pore volume. In this study, SiO2-Mg(OH)2 composite material was first prepared derived from sepiolite via acid-alkaline treatment, and magnetite was then loaded on the composite, forming magnetic nanocomposite (SiO2-Mg(OH)2-Fe3O4) with high specific surface area. Mean-while, the removal performance of this new nanocomposite material to Pb(II) was studied, systematically. The results demonstrate that the removal capacity of the magnesia-containing nanocomposite (SiO2-Mg(OH)2-Fe3O4,) for Pb(II) is 257.6 mg/g, which has higher specific surface area and good magnetism compared with raw sepiolite. The adsorption data fit well with the pseudo-first-order adsorption kinetic model and Freundich isotherm model. Due to the simplicity of the synthetic procedure, the high removal efficiency for Pb(II), as well as the easy separation of the adsorbent from water, the sepiolite nanocomposites have notewor thy application potential in the environmental field. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Nanchang University (Engineering & Technology) is the property of Nanchang University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Hydrometallurgy of China is the property of Hydrometallurgy of China Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, W-MoS2/CS beads were produced by W-MoS2 na no-flower and chitosan (CS), the effect of MoS2 inserting on the morphology and pore structure of composite beads was analyzed,and the adsorption capacity of Pb(II) onto W-MoS2/CS beads were examined by se veral variable s like the pH of the solution, adsorption time, the initial concentration of Pb(II) and coexistence of metal ions during the adsorption process. The results show that: W-MoS2 nanoflowers inserted into the CS gel played a role in fixing and bonding the gel structure, which making the inner structure of beads more solid and the surface of the beads more rough. The W-MoS2/CS beads maintain good pore structure. As the pH value increases in the range of 4 ~ 7, the adsorption capacity of composite beads for Pb ( II ) increased first and then decreased, reaching a maxim urn at pH of 7. The adsorption rate of W-MoS2/CS beads increased sharply before 30 rninutes, and finally reached adsorption equilibrium abo ut 120 minutes. The adsorption of Pb( II) by W-MoS2/CS was well described by the Langmuir isotherm model, which is a typical rnonolayer adsorption, and the theoretical maximum adsorption capacity of W-MoS2/ CS-2 (50 mg MoS2) reached up to 663. 7rng/g,which is much higher than most carbon-based and sulfur-functionalized nanornaterials. At the same tirne, it is found that the W-MoS2/ CS exhibited super selectivity to Pb(II) under the conditions of the coexistence of metal ions. And after 5 regeneration cycles, the adsorption performance of the W-MoS2/CS remained stable, reflecting the excellent reusability of. The design of WMoS2/CS expands the application range of chitosan-based materials in the field of water treatment. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to investigate the properties of graphene oxide supported cobalt ferrate (CoFe2 O4/GO) nanocomposites and their removal effects on Pb (n) in aqueous solution，the synthesized CoFe2O4/GO nanocomposites were characterized by XRD，FTIR，SEM，XPS，SQUID，Raman and N2 adsorption. The permeable reaction barrier was used to investigate the practicability of these materials and the effect of different acidity and temperature on the removal of Pb (H)in the reaction process. The mechanism of removing Pb (K) from aqueous solution by CoFe2 O4/GO nanocomposites was studied by means of kinetics and adsorption isotherm. The results show that the crystal plane of GO and the cubic spinel structure of CoFe204 are found by XRD characterization, FTIR spectra showed that Co--0 and Fe--O vibrate?and the surface of CoFe2()4/GO contains a large number of unsaturated groups such as -- OH，一C = O?and --COO--. SEM spectra showed that CoFe2O4/GO partially agglomerated and some void structures were observed，the average particle size of CoFe2O4 is 48. 93 nm. XPS characterization showed that the surface of CoFe2O4/GO contained C，0，Fe，Co，especially Co2p. The saturation magnetization of CoFe204/G0 is approximately 27. 01 A • m2/kg. The ratio of D peak to G peak of these materials is higher，which indicates that CoFe2O4/GO has better oxidation?and it contains a large number of oxygen containing groups. The BET specific surface area of CoFe2O4/GO is 148,672 3 m2/g，and the pore size is concentrated at approximately 3. 93 nm. The simulated wastewater can be treated by permeable reaction barrier and saturated gradually after 100 minutes. It is desirable to reuse the material within 4 times. The optimum acidity of the reaction system is pH = 8. With the increase of temperature?the removal rate of Pb(n)increases ?and the increase of temperature is beneficial to adsorption. Freundlich isotherm sorption and quasi second order kinetics are more suitable for describing the process of CoFe2 O4/GO adsorbing Pb (J[) * Permeable reaction barrier combined with CoFe2O4/GO nanocomposites has a good effect on removal Pb(H)from simulated wastewater. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Research of Environmental Sciences is the property of Research of Environmental Sciences Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Layered double hydroxides, which can be synthesized from metal ions and their analogs, have abundant interlayer ions, surface functional groups, and adsorption characteristics that have been extensively studied. But the adsorption-desorption process may cause secondary pollution of the environment. In this study, the layered double hydroxides that adsorbed Congo red were converted into mixed metal oxide/carbon composites by a calcining carbonization method, and its adsorption performance for heavy metal ions Pb(Ⅱ) in aqueous solution was studied in detail. The results show that the prepared mixed metal oxide/carbon composites have a faster adsorption rate and higher adsorption capacity for Pb(Ⅱ). The adsorption capacity reached more than 150 mg·g -1 in 30 min, and increased with the content of Mg 2+ introduced into the layered double metal hydroxide, reaching a maximum of 368 mg·g -1 . The removal mechanism of Pb(Ⅱ) by mixed metal oxide/carbon composites was caused by the formation of insoluble Pb 3 (CO 3 ) 2 (OH) 2 on the surface. This research lays the foundation for the application of mixed metal oxide/carbon composites in the remediation of lead-containing soils.

Eucalyptus biochar(BC) was prepared and potassium permanganate was used to modify the biochar(KBC). Static adsorption experiments on Pb(Ⅱ) in aqueous solution were carried out to investigate the effects of pH, adsorbent dosing, adsorption time, temperature, and initial concentration on the adsorption of Pb(Ⅱ). The results showed that the optimum pH was 5 while the adsorption reached saturation after 6 h. When the temperature was 25℃, the initial concentration of Pb(Ⅱ) was 100 mg·L -1 with an adsorbent dosage of 0.06 g; the maximum adsorption of Pb(Ⅱ) by KBC was 83.059 mg·g -1 , with a removal rate of 99.67%. The adsorption of Pb(Ⅱ) by KBC followed the pseudo-second-order kinetic model and the Langmuir isothermal adsorption model, which is a monolayer adsorption occurring on a homogeneous surface. The adsorbents were characterized using the BET method, scanning electron microscopy and energy dispersive spectroscopy(SEM-EDS), X-ray diffraction(XRD), Fourier transformed infrared(FT-IR) and X-ray photoelectron spectroscopy(XPS). The adsorption mechanism of Pb(Ⅱ) by KBC oxygen-containing and manganese-containing groups was through complexation and precipitation, and the formation of -O-Pb-O- bidentate complexes on the surface of the biochar. Therefore, potassium permanganate-modified BC can be used as a good Pb(Ⅱ) adsorbent.

The specific characteristics and mechanism of passivation of Pb in soil were studied using HAP/C composite (PBGC-HAP/C) as passivation, and using proportion of PBGC-HAP/C, particle size and type of passivator, soil moisture content, soil pH value of Pb, and particle size of the material as influencing factors. The results showed that with an increase in dosage of the passivator and passivation time, the passivation effect increases gradually. Reducing the particle size of the passivator is beneficial to improving the passivation effect. pH has a greater impact on passivation, with the passivation effect obviously rising with increased pH, and the passivation rate in an alkaline environment can reach above 99%. An increase in water content is beneficial to the improvement of the passivation effect, but the contribution is not significant. Through comparative analysis of the XPS, XRD, and FT-IR of materials before and after passivation, the results indicated that the passivation of PBGC-HAP/C to Pb is mainly through direct and indirect effects. Direct effects include physical adsorption, chemical complexation, electrostatic interaction, ion exchange, and precipitation; the indirect effect is mainly enhanced by increasing the pH value of the organic matter.