Polyvinylpyrrolidone K-30(PVP) was introduced into the preparation of nanozero-valent iron(n ZVI) and the traditional liquid-phase reduction was improved. The introduction of PVP simplified the traditional method.The ...Polyvinylpyrrolidone K-30(PVP) was introduced into the preparation of nanozero-valent iron(n ZVI) and the traditional liquid-phase reduction was improved. The introduction of PVP simplified the traditional method.The n ZVI prepared with this new approach showed excellent surface characters and high performance on the removal of cadmium. TEM results showed that the aggregates of n ZVI can reach to several micrometers in length but less than 100 nm in diameter. The iron particles that were enclosed by a layer of oxide film that is less than10 nm, demonstrated that the n ZVI possesses a core–shell structure. BET results indicate that the specific surface area of the n ZVI was 20.3159 m^2g^(-1). A three factor and three level orthogonal experiment was employed to find out the dominant factor that affects the removal rate of cadmium by n ZVI. Based on the range values, the prominence order of each factor was: initial p H of the solution N initial concentration of cadmium N dosage of n ZVI, the range was 96.453, 3.294 and 1.747, respectively. A simulation was performed under the same condition and a same conclusion was derived, this consistence confirmed the validity of the conclusion that p H is the most significant factor that affects the adsorption efficiency.展开更多
Nano-zero-valent irons(nZVI)have shown great potential to function as universal a nd low-cost magnetic adsorbents.Yet,the rapid agglomeration and easy surface corrosion of nZVI in solution greatly hinders their overal...Nano-zero-valent irons(nZVI)have shown great potential to function as universal a nd low-cost magnetic adsorbents.Yet,the rapid agglomeration and easy surface corrosion of nZVI in solution greatly hinders their overall applicability.Here,carboxylated cellulose nanocrystals(CCNC),widely available from renewable biomass resources,wer e prepared and applied for the immobilization of nZVI.In doing so,carboxylated cellulose nanocrystals supporting nano-zero-valent irons(CCNC-nZVI)were obtained via an in-situ growth method.The CCNC-nZVI were characterized and then evaluated for their performances in wastewater treatment.The results obtained show that nZVI nanoparticles could attach to the carboxyl and hydroxyl groups of CCNC,and well disperse on the CCNC surface with a size of〜10nm.With the CCNC acting as corrosion inhibitors improving the reaction activity of nZVI,CCNC-nZVI exhibited an improved dispersion stability and electron utilization efficacy.The Pb(II)adsorption capacity of CCNC-nZVI reached 509.3 mg·g^-1(298.15 K,pH=4.0),significantly higher than that of CCNC.The adsorption was a spontaneous exothermic process and could be perfectly fitted by the pseudo-second-order kinetics model.This study may provide a novel and green method for immobilizing magnetic nanomaterials by using biomassbased resources to develop effective bio-adsorbents for wastewater decontamination.展开更多
基金Supported by the National Natural Science Foundation of China(51278147)the Funds for Creative Research Groups of China(51121062)State Key Laboratory of Urban Water Resource and Environment(Harbin Institute of Technology)(2014TS02)
文摘Polyvinylpyrrolidone K-30(PVP) was introduced into the preparation of nanozero-valent iron(n ZVI) and the traditional liquid-phase reduction was improved. The introduction of PVP simplified the traditional method.The n ZVI prepared with this new approach showed excellent surface characters and high performance on the removal of cadmium. TEM results showed that the aggregates of n ZVI can reach to several micrometers in length but less than 100 nm in diameter. The iron particles that were enclosed by a layer of oxide film that is less than10 nm, demonstrated that the n ZVI possesses a core–shell structure. BET results indicate that the specific surface area of the n ZVI was 20.3159 m^2g^(-1). A three factor and three level orthogonal experiment was employed to find out the dominant factor that affects the removal rate of cadmium by n ZVI. Based on the range values, the prominence order of each factor was: initial p H of the solution N initial concentration of cadmium N dosage of n ZVI, the range was 96.453, 3.294 and 1.747, respectively. A simulation was performed under the same condition and a same conclusion was derived, this consistence confirmed the validity of the conclusion that p H is the most significant factor that affects the adsorption efficiency.
基金the Key Planning Project of Science and Technology of Fujian Province,China(Grant No.2018N0032).
文摘Nano-zero-valent irons(nZVI)have shown great potential to function as universal a nd low-cost magnetic adsorbents.Yet,the rapid agglomeration and easy surface corrosion of nZVI in solution greatly hinders their overall applicability.Here,carboxylated cellulose nanocrystals(CCNC),widely available from renewable biomass resources,wer e prepared and applied for the immobilization of nZVI.In doing so,carboxylated cellulose nanocrystals supporting nano-zero-valent irons(CCNC-nZVI)were obtained via an in-situ growth method.The CCNC-nZVI were characterized and then evaluated for their performances in wastewater treatment.The results obtained show that nZVI nanoparticles could attach to the carboxyl and hydroxyl groups of CCNC,and well disperse on the CCNC surface with a size of〜10nm.With the CCNC acting as corrosion inhibitors improving the reaction activity of nZVI,CCNC-nZVI exhibited an improved dispersion stability and electron utilization efficacy.The Pb(II)adsorption capacity of CCNC-nZVI reached 509.3 mg·g^-1(298.15 K,pH=4.0),significantly higher than that of CCNC.The adsorption was a spontaneous exothermic process and could be perfectly fitted by the pseudo-second-order kinetics model.This study may provide a novel and green method for immobilizing magnetic nanomaterials by using biomassbased resources to develop effective bio-adsorbents for wastewater decontamination.
