Publications by authors named "Xiao-min Dou"

In this research, a new method for sewage sludge (SS) disposal was introduced, by which heavy metals were implanted into sewage sludge before pyrolysis. Cu was adopted as the representative of heavy metals to test this process and was implanted in the form of CuCl2. Effects of Cu implanting concentration and reaction temperature on the residual ratio and immobilization of heavy metals in pyrolysis char were studied.

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The method co-precipitation was applied to preparation the zirconium hydroxide as a type drinking-water defluoridation adsorbent. The effect of the preparation conditions on the adsorptive capacity was studied. The optimization of preparation condition for zirconium hydroxide concludes that co-precipitation time is 10 h, pH value is 7.

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The Langmuir two-site equation, X-ray photoelectron spectroscopy, and extended X-ray absorption fine structure spectroscopy have been employed to study the competitive behaviors of fluoride (F) and phosphate (P) in relation to arsenate adsorption on an Fe-Ce adsorbent as well as the mechanisms involved. The two-site isotherm revealed the presence of two kinds of adsorption sites with different binding affinities for arsenate. Both the total and low-binding-energy maximum adsorption capacities (Q and Q(1)) of arsenate decreased significantly even at a molar ratio of As/P=1:0.

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An Fe-Ce bimetal adsorbent was investigated with X-ray powder diffraction (XRD), transmission electron micrograph (TEM), Fourier transform infrared spectra (FTIR), and X-ray photoelectron spectroscopy (XPS) methods for a better understanding of the effect of surface properties on arsenate (As(V)) adsorption. In the adsorption test, the bimetal oxide adsorbent showed a significantly higher As(V) adsorption capacity than the referenced Ce and Fe oxides (CeO2 and Fe3O4) prepared by the same procedure and some other arsenate adsorbents reported recently. XRD measurement of the adsorbent demonstrated that the phase of magnetite (Fe3O4) disappears gradually with the increasing dosage of Ce4+ ions until reaching a molar ratio of Ce4+ to Fe3+ and Fe2+ of 0.

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