Applied Mechanics and Materials Vols. 361-363

Abstract: By monitoring the water quality (Dec., 2009-2011) of the three sections of the moat in Xuchang, the data show that three-year average turbidity of the water at North, East, South sections is 18.6,16.7 and 12.4 respectively, and with average COD at 43 mg / L, 37.5 mg / L and 29.5 mg / L in accordance, as well as with BOD₅ content at 16.1mg / L, 15.0mg / L and 8.7 mg / L. The integrated pollution index of the three mentioned sections was 2.54,1.94 and 1.06 in December 2011, increasing by 29.6%, 22% and 34.2% in comparison with the same period in 2009. The fluorescence spectrometer tests display that the main components of organic pollutants at the northern and eastern sections are organic detergent, cooking oil and a variety of plant and animal protein in complex traits.

Abstract: In this paper, an IC reactor whose effective volume was 6m³ was used in the experiment to determine the best condition when decontaminating the straw-washing water produced in the straw-based pulping and papermaking industry. The best condition of IC reactor to treat straw-washing wastewater through experiment was: the pH should be controlled in the neutral range, not less than 6.6; the temperature should be maintained at about 31°C, not more than 35°C; the fluctuation range of volume loading should better not be over 15%; To meet the alkalinity of the reactor over 1000mg/L, the dosage of sodium bicarbonate was 12kg / d. In the processing of reactor treating straw-washing wastewater, COD removal rate was lower, and effluent VFA stayed at a high level continuously. So the hydrolysis-acidification process was more appropriate than anaerobic treatment when decontaminating the straw-washing water.

Abstract: Electrochemical oxidation process was adopted to treat the tannery wastewater effluent from a biological processing unit. The experiments were carried out in an electrochemical reactor using RuO₂\SnO₂ coated on titanium as anode and stainless steel as cathode. The changes of Chemical Oxygen Demand (COD) reduction, Total Organic Carbon (TOC) removal and other relative parameters have been determined as a function of treatment time, applied current density and chloride concentration. Results indicate that electrochemical oxidation can treat tannery wastewater effectively. The results obtained at 7.5mA/cm² demonstrated that 48.7% of TOC and 58.9% of COD were degraded in 150min of processing. In addition, the addition of chloride showed no significant to the removal of COD and TOC.

Abstract: The characteristics of combined ultrafiltration technologies such as powdered activated carbon/UF, coagulation/UF, submerged ultrafiltration and the treatment effects of micro-polluted water resources are introduced. And the influence of the addition of PAC or coagulant on membrane flux is also summarized and analyzed. At last, the development of combined ultrafiltration technologies is prospected, and the research points and directions are indicated.

Abstract: Coal washing wastewater is the end of the wet coal mine coal washing process industrial water , which contains a lot of slime and silt , causing serious pollution to the environment of the mine near this study, coagulation treatment of coal washing wastewater to determine the best flocculants and optimum operating parameters : agitation intensity 90r/min, polyaluminum chloride (30mg / l) dosage of 10ml the polyacrylamide dosage 3ml , pH = 7-11 . The treated effluent can be reused , either to protect the environment , but also save water resources .

Abstract: The adsorption of Cr(VI) by modified Bamboo shell has been investigated using chemical methods and IR spectrometry. The optimal condition for the adsorption of Cr(VI) by modified Bamboo shell is at 298 K and pH = 1.0, which gives a static saturated adsorption capacity of 12.68 mg·g-1, an apparent adsorption rate constant of k298 = 9.56 × 10-4 s-1, and an apparent adsorption activation energy of 7.38 kJ·mol-1. The adsorption follows the Langmuir and Freundlich isotherms and the liquid film diffusion is the controlling process of the adsorption. The adsorption thermodynamic parameters are ΔH = 66.04 kJ·mol-1, ΔS = 0.2974 kJ·mol-1·K-1, ΔG = −22.58~−28.52 kJ·mol-1. The anions HPO42-, H2PO4- and SO42- have negligible influence on the adsorption capacity. Small amount of desorption is observed only at pH > 11. The adsorption of Cr(VI) by modified bamboo shell is mainly a chemical process.

Abstract: The performance of sulfonamide and macrolide antibiotics in a spiked water removed by O₃ and O₃/H₂O₂ was evaluated uder different conditions such as ozone dosage, pH and H₂O₂/O₃ mole ratio. The results showed that O₃ and O₃/H₂O₂ were proved to be effective to oxdize sulfamethoxazole of sulfonamides containing the aromatic ring and erythromycin of macrolides, which were built of mostly saturated hydrocarbon structure, and O₃ was preferentially to oxidize sulfamethoxazole. With the reaction time of 30 min, when the ozone cocentrations were 2mg/L and 3mg/L, sulfamethoxazole and erythromycin removal efficiency was 93% and 91%, respectively. The sulfamethoxazole and erythromycin were removed completely within 30 min with ozone 6 mg/L. Degradation of sulfamethoxazole containing unsaturated C-C bonds occured easier at low pH only by O₃. Degradation of erythromycin with fully saturated structure was difficult, but the improved removal efficiency could be obtained at higher pH. The high concentratins of H₂O₂ to ozonation was favor to remove those antibiotics. At the 0.5 mole ratio of H₂O₂/O₃ ,the highest removal efficiency could be reached for all the antibiotics .

Abstract: In this paper, ZnO photocatalyst was prepared by sol-gel method with the assistance of ionic liquid (IL). The structure, morphology and the photoinduced charge separation rate of the photocatalyst prepared (IL-ZnO) were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and surface photovoltage spectroscopy (SPS), respectively. The results reveal that ionic liquid enhances the photoinduced charge separation rate. The activity of ZnO for photocatalytic decolorization of methyl orange (MO) solution was evaluated. The results show that the photocatalytic activity of IL-ZnO is higher than that of ZnO.

Abstract: Flocculation process with P(AM-AA-AMPS) as flocculants was used for the DEP removal from water. The structure and morphologies of the flocculants was characterized by scanning electron microscope (SEM). To maximize the DEP removal efficiency, single factor technique and an orthogonal array L₉ (3⁴) were employed to optimize the factors of dosage, initial pH value and stirring time. The results show that the optimal conditions are dosage of 10mg·L^-1, initial pH value of 9 and stirring time of 6min. Moreover, flocculants dosage is the best significant factors in DEP removal.

Abstract: According to the characteristic of high ammonia nitrogen concentration of Huaihe River in winter, a pilot-scale test was studied in this paper. This paper compared the start-up and operation performance of zeolite biofilter, quartz sand + activated carbon biofilter and zeolite + activated carbon composite biofilter in lower temperature. The results show that three kinds of biofilters for NH₄⁺-N have high remove effects. Average removal rate of zeolite biofilter, quartz sand + activated carbon biofilter, zeolite + activated carbon composite biofilter for NH₄⁺-N were 73%,64% and 78% and effluent NH₄⁺-N concentration were 0.31mg/L,0.24mg/L,0.21mg/L. Average COD_Mn removal rate of three kinds of biofilters were 5%,13% and 28%. Zeolite + activated carbon composite biofilter does not exist to NO₂-N accumulation phenomenon and showed good ability to start-up and running.