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Huang L.,Shandong University | Huang L.,Shandong Dalong Industrial Ltd Liability Company | Sun Y.,Shandong University | Yue Q.,Zhejiang University | And 3 more authors.
Desalination and Water Treatment | Year: 2012

This paper reports a study of adsorption of Cd(II) from aqueous solutions using activated carbon made from lotus stalks (LSAC). The properties of LSAC were characterized by scanning electron microscopy and BET surface area. Zeta potential was also determined. The batch Cd(II) adsorption on LSAC was performed to study the different sorption parameters (time, pH, temperature and ionic strength) that influence the adsorption of Cd(II) onto LSAC and to explore the adsorption mechanisms. Bench-scale column tests were also carried out to determine breakthrough curves with varying flow rates and fixed-bed heights. In general, the theoretical qe calculated using the pseudo-second-order kinetic model agreed better with the experimental data than the first-order one. Among the three widely-used isotherms (Langmuir, Freundlich, and Temkin models), the Langmuir model appeared to describe the experimental results best. The Adam-Bohart equation was appropriate for relative concentration ranging from 0.01 up to 0.5 in this study. The pH of the initial solution affected the sorption of Cd(II) on LSAC to the greatest extent, and presence of Mg2+ resulted in a larger competition to the active sites than Na+, implying ion exchange and electrostatic attraction adsorption mechanisms. © 2012 Desalination Publications. All rights reserved.


Huang L.,Shandong University | Huang L.,Shandong Dalong Industrial Ltd Liability Company | Yang T.,Shandong University | Wang W.,Shandong Normal University | And 2 more authors.
Applied Microbiology and Biotechnology | Year: 2012

Two sequencing batch reactors were synchronously operated to investigate the effect of manganese (II) (Mn2+) augmentation on aerobic granulation. Reactor 1 (R1) was added with 10 mg/L Mn2+, while there was no Mn2+ augmentation in reactor 2 (R2). Results showed that R1 had a faster granulation process than R2 and R1 performed better in chemical oxygen demand (COD) and ammonium nitrogen (NH4 +-N) removal efficiencies. Moreover, the mature granules augmented with Mn 2+ behaved better on their physical characteristics and size distributions, and they also had higher production of extracellular polymeric substances (EPS) content. The result of threedimensional excitation and emission matrix fluorescence showed that Mn2+ had the function of causing organic material diversity (especially proteins diversity) in EPS fraction from granules. Polymerase chain reaction and denaturing gradient gel electrophoresis techniques were employed to analyze the microbial and genetic characteristics in mature granules. The results exhibited that Mn2+ augmentation was mainly responsible for the higher microbial diversity of granules from R1 compared with that from R2. Uncultured sludge bacterium A16 (AF234726) and Rhodococcus sp. WTZ-R2 (HM004214) were the major species in R1, while only uncultured sludge bacterium A16 (AF234726) in R2. Moreover, there were eight species of organisms found in both two aerobic granules, and three species were found only in aerobic granules from R1. It could be concluded that Mn 2+ could enhance the sludge granulation process and have a key effect role on the biological properties during the sludge granulation. © Springer-Verlag 2011.


Huang L.,Shandong University | Huang L.,Shandong Dalong Industrial Ltd Liability Company | Sun Y.,Shandong University | Wang W.,Shandong Normal University | And 2 more authors.
Chemical Engineering Journal | Year: 2011

The paper presents advantages and limitations of microwave heating in preparation of lotus stalk-based activated carbon by comparing the characteristic and adsorption properties of carbons with microwave (Mic-LSAC) and conventional (LSAC) heating methods employing H3PO4 as chemical agent. Mic-LSAC was produced with radiation power of 700W and radiation time of 15min. LSAC was allowed by single step to get carbonized at 450°C in a muffle furnace for 1h. Both produced carbons showed typical Type IV nitrogen adsorption isotherms. Mic-LSAC had large surface area of 1434m2/g and micropore volume of 1.337cm3/g, while LSAC had surface area of 1220m2/g and micropore volume of 1.191cm3/g. Moreover, Mic-LSAC had higher portion of mesopores than LSAC. Boehm's titration results and Fourier transform infrared spectra indicated that Mic-LSAC possessed smaller acidic oxygen functionalities. Mic-LSAC had higher pHpzc, more ordered stacking of layer compared to LSAC. For both adsorbents, the adsorption kinetics followed the pseudo-second-order model and the adsorption equilibrium data were very well represented by the Langmuir isotherm. The maximum adsorption capacities obtained at pH 2.80 were 564.97mg/g and 537.63mg/g for Mic-LSAC and LSAC, respectively. The differences of textual and chemical characteristics caused by heating method were related to adsorption capacity. © 2011 Elsevier B.V.


Huang L.,Shandong University | Kong J.,Shandong University | Wang W.,Shandong Normal University | Zhang C.,Shandong University | And 2 more authors.
Desalination | Year: 2012

Zizania latifolia was prepared for activated carbons with the method of H 3PO 4 activation. On the basis of Zizania latifolia activated carbons (ZLAC), adsorption of basic fuchsin (BF) on Fe(III) and Mn(II) modified ZLAC and ZLAC was investigated respectively. Surface morphology and function groups of ZLAC were measured by scanning electron microscopy (SEM), BET surface area and Fourier transform infrared spectroscopy (FTIR). Both of the results from the Fourier transform infrared spectroscopy and Boehm's titration indicated that the ZLAC owned more acid oxygen functional groups than the alkaline functional groups. The discussions of contact time, dosage and pH were in favor for explaining the adsorption mechanism. The adsorption process agreed well with the pseudo-second-order kinetics (R 2>0.99) and the Langmuir isotherm equation (R 2>0.99), and the maximum adsorption capacity acquired can reach 238.10mg/g. The negative free energy (δG) and positive enthalpy (δH) indicated a spontaneous and endothermic adsorption process. Results also showed that the adsorption effect of Fe(III) and Mn(II) modified ZLAC was much better than ZLAC. © 2011 Elsevier B.V.


Huang L.,Shandong University | Shi C.,Shandong University | Zhang B.,Shandong University | Niu S.,Shandong Dalong Industrial Ltd Liability Company | Gao B.,Shandong University
Separation Science and Technology (Philadelphia) | Year: 2013

In this research, activated carbon fiber heated by microwave (WACF) under nitrogen (N2) atmosphere adsorption of tetracycline antibiotics (TCs) was analyzed. WACF was obtained under the microwave radiation temperature of 600°C and the radiation time of 15 min. The properties of WACF were characterized by a scanning electron microscope (SEM), N2 adsorption/desorption isotherms, and X-ray diffraction (XRD) compared with activated carbon fibers (ACF) without any treatment. WACF had lower surface area (1008 m2/g) but higher external surface area (429 m2/g) than ACF (surface area: 1153 m2/g; external surface area: 308 m2/g). Meanwhile, the adsorption efficiencies of TCs (including tetracycline hydrochloride (TC) and oxytetracycline hydrochloride (OTC)) on WACF were both increased by about 4 times. These results indicated that mesoporosity amplification of WACF played a crucial role in the adsorption capacity of the two TCs. The kinetics and equilibrium data were agreed well with the pseudo-second-order kinetics model (R 2 > 0.99) and Langmuir isotherm model (R 2 > 0.98), respectively. It suggested that the adsorption process was dominated by chemisorption. Batch experiments showed the maximum adsorption capacities for both adsorbates were 339 and 331 mg/g respectively at pH 2. © 2013 Copyright Taylor and Francis Group, LLC.

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