Beijing Changping Water Authority

Beijing, China

Beijing Changping Water Authority

Beijing, China
SEARCH FILTERS
Time filter
Source Type

Jiao C.,Beijing University of Chemical Technology | Xu C.,Beijing University of Chemical Technology | Li S.,Beijing University of Chemical Technology | Yang W.,Chinese Research Academy of Environmental Sciences | And 4 more authors.
Gaodeng Xuexiao Huaxue Xuebao/Chemical Journal of Chinese Universities | Year: 2017

Iron oxyhydroxide/expanded graphite composites were prepared via surface grafting under the environment of acid and ultrasonic oscillations, with expanded graphite as carrier material and iron oxyhydroxide(FeOOH) prepared as the modifier. Scanning electronic microscopy(SEM), X-ray diffraction(XRD) X-ray photoelectron spectroscopy(XPS) and Fourier transform infrared spectroscopy(FTIR) techniques were employed to characterize the composite. Then the removal performance of arsenic by the composite was determined. The results show that the iron oxyhydroxide loaded on the surface of expanded graphite evenly as the sub-micron spherical by hydrogen bond and chemical bonds. The removal rate of arsenic can reach 99% using 0.5 g composite to treat 50 mL simulated waste water containing 0.5 mg/L arsenic after 90 min, and the treated waste water can reach the drinking standard. The removal rate of arsenic by the composite improves with the increase of iron content in the composite, and when the iron content in the composite reaches 55%, the removal rate of arsenic can reach 72.6% using 0.5 g composite to treat 50 mL simulated waste water containing 2.0 mg/L arsenic within 60 min, three times as high as that of ordinary expanded graphite. In addition, the dissociated iron oxyhydroxide reacts with arsenic in the vicinity of the composite material and the removal process of arsenic confirms to the secondary dynamics equation and Temkin isotherm adsorption model. © 2017, Higher Education Press. All right reserved.


Xu C.,Beijing University of Chemical Technology | Xu C.,CAS Research Center for Eco Environmental Sciences | Zhang L.,Beijing University of Chemical Technology | Yang W.,Chinese Research Academy of Environmental Sciences | And 5 more authors.
Gaodeng Xuexiao Huaxue Xuebao/Chemical Journal of Chinese Universities | Year: 2017

Zero-valent iron(ZVI) loaded onto expanded graphite(EG) as a composite material(EG-ZVI) was prepared through chemical deposition method to remove nitrate. The EG/ZVI was characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM) and X-ray photoelectron spectroscopy(XPS). It is observed that the EG was successfully loaded with sub-micron scale zero-valent iron. Batch experiments with variable theoretical ZVI mass loading, pH values and temperature were conducted to evaluate the removal performance of EG-ZVI. The results showed that the removal rate of nitrate was 2.3 times higher than that for EG. Furthermore, the removal of nitrate by EG-ZVI shows little dependence on solution pH. Even at pH=9, the nitrate removal efficiency could attain 65% after reaction for 90 min. Galvanic cell effect and high specific surface area are the main reasons for the enhanced removal of nitrate by EG-ZVI with chemical reduction and physical adsorption. And third-order kinetic model is well fitted. XPS were used to analyze the mechanisms of nitrate removal, which indicated that ZVI loaded on the surface was oxidized, and the removed nitrate was reduced to NH4 +-N and NO2 --N. In addition, EG-ZVI could overcome the shortcomings of ZVI which formed undesirable precipitation of ferrous hydroxide on the surface during reaction frequently. High removal capability, excellent stability and broad applicability make EG-ZVI ideal candidates for nitrate removal in practical application. © 2017, Higher Education Press. All right reserved.


Qi J.,Beijing University of Chemical Technology | Jiao W.,CAS Research Center for Eco Environmental Sciences | Jiao Z.,Beijing Changping Water Authority | Lin A.,Beijing University of Chemical Technology
Beijing Huagong Daxue Xuebao (Ziran Kexueban)/Journal of Beijing University of Chemical Technology (Natural Science Edition) | Year: 2017

ATP was prepared by treating natural attapulgite with acid, and then modified by the cationic surfactants octade cyltrimethyl ammonium chloride and dimethyldistearylammonium chloride to prepare 1831-ATP and D1821-ATP, respectively. The effects of varying pH, time and ion concentration on the sorption efficiency of lead (II) on attapulgite were investigated in batch experiments and the thermodynamic and dynamic laws of the sorption were studied. The results showed that the sorption was strongly pH-dependent and ion concentration had little impact on sorption. The sorption process can be described by a pseudo-second-order rate model. The Freundlich model fitted the sorption data better than the Langmiur model. Since the adsorption process is not described primarily by monolayer and chemical adsorption, the adsorption of lead (II) on 1831-ATP is better than that on ATP from the view point of both capacity and rate. © 2017, Editorial Board of Journal of Beijing University of Chemical Technology (Natural Science Edition). All right reserved.

Loading Beijing Changping Water Authority collaborators
Loading Beijing Changping Water Authority collaborators