Magnetic flocculation technology was investigated for the removal of copper and zinc ions from simulated tin smelting wastewater, and the effects of magnetic powder dosage, flocculant dosage, and pH on the removal of copper and zinc ions were estimated. The results show that the effluent quality is poor with magnetic powder, PAC and PAM separately dosed, but when magnetic powder is combined with PAC or PAM, the excellent effluent quality is obtained with the removal rate of the copper and zinc ions of more than 90% and 70% respectively. In addition, under the condition of magnetic powder dosage of 30g/L and PAC dosage of 60mg/L, pH show more significant effect on zinc ions than copper ions with pH increased from 5 to 10, and the removal rate of zinc ions increase by about 24%, while the removal rate of copper ions only increase by about 2.5%. Compared with the system with single metal ion, the coexistent ion system has excellent heavy metal removal efficiency, namely the copper ions removal rate increase by 3.42%, and the zinc ions removal rate increase by 0.46%. Moreover, magnetic flocculation technology presents the characteristics of shorter time of flocculation and sedimentation, smaller volume of the flocs and faster separation velocity.

N, Fe co-doped TiO2 photocatalyst was synthesized by sol-gel method. The catalyst prepared was characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Ultraviolet and visible spectroscopy (UV-vis). The results showed that the N, Fe co-doped TiO2 prepared had the anatase structure. The absorption edge of the photocatalyst shifted to longer wavelength and photocatalytic activity for degradation of Methylene blue (MB) under Xe-lamp (350 W) was much more active than un-doped TiO2, N-TiO2 Fe-TiO2 and P-25.

In this paper, the producing process of using V2O3 as raw material to obtain vanadium nitride was analyzed through the predominance area diagrams. The analysis shows that VN-phase can be accessed in the conversion process of V2O3 by controlling gas phase composition and temperature of the reaction system and the one-step method preparing for vanadium nitride is feasible. Effect of technical parameters on nitrogen content of products is investigated. The temperature of the reaction system has prominent influence on the nitrogen content of products, and the reaction is very sensitive to temperature. The quantities of nitrogen increase first and decrease later with increasing the reactive temperature, and the result researches the optimum at 1673K. The nitrogen content of the products tended to be constant after soaking over 2 hours at 1673K.Experimental observations shows that additives can increase the nitrogen content of VN. However, the effect of various additives on the nitrogen content is different. Among the additives referred in this paper, the effect of the iron powder, compounds of alkaline earths and NH4Cl are superior.

The azeotropic mixture ethyl acetate-ethanol (EA-EtOH) enables effective separation by extractive distillation. The effectiveness of an extractive distillation process depends on the solvent selection, so the single and mixed solvent for separating ethyl acetate-ethanol by extractive distillation were examined. The results showed that the volatility of the ethyl acetate relative to ethanol increased with an increase of the ratio of any given solvent. The selectivity of the mixed solvent is superior to the single solvent. The measured data were correlated well using modified UNIFAC model. Simultaneously, the influence of temperature on solvent selectivity was proposed by using the Clausius-Mosotti equation.

Distillation-crystallization coupling process is a new kind of separation technology based on vapor-liquid equilibrium and solid-liquid equilibrium. The separation of azeotropic systems composed with Acetic acid and N-neptane by distillation-crystallization process (DCC) was studied in this paper. We apply the orthogonal experiment to search for the optimal technique process. The final results demonstrate that the DCC process can purify the heavy and light components over 90 wt% respectively, verifying the advantage of the DCC for the azeotropic systems separation.