Photocatalytic degradation of Acid Blue 62 over CuO-SnO2 nanocomposite photocatalyst under simulated sunlight

The novel CuO-SnO2 nanocomposite oxide photocatalysts were prepared by simple co-precipitation method, and characterized by X- ray diffraction, transmission electron microscopy, N2 adsorption-desorption measurement and UV-Vis diffuse reflectance spectroscopy. The photocatalytic activities of CuO-SnO2, evaluated using the photodegradation of Acid Blue 62 as a probe reaction under the irradiation of Xenon light, were also found to be related to the calcination temperature and the molar ratio of Cu to Sn. The maximum photocatalytic activity of the CuO-SnO2 photocatalyst was observed to be calcined at 500~C for 3 h （the molar ratio of Cu to Sn was 1：1） due to the sample with good crystallization and high surface area. It also showed much higher photocatalytic activity in treatment dye wastewater under simulated sunlight irradiation compared to Degussa P25 TiO2.     

臭氧氧化四种偶氮染料废水的效果研究

以酸性大红、中性枣红、阳离子红、活性黑5四种模拟印染废水开展O3氧化偶氮染料的效果研究.实验中发现O3对染料具有非常好的脱色效果,30 min后除中性枣红外其他三种染料脱色率接近100％,但是单独O3的TOC去除率不高.光谱扫描表明,处理后染料的特征吸收峰很快消失,而紫外光区的吸收峰变化很小,推测O3氧化以直接氧化为主,打开了染料分子的发色基团,但并未将染料分子彻底氧化.还应加强O3氧化能力、彻底矿化去除污染物的研究.     

Decolorization of Orange II using an anaerobic sequencing batch reactor with and without co-substrates

We investigated the decolorization of Orange II with and without the addition of co-substrates and nutrients under an anaerobic sequencing batch reactor (ASBR). The increase in COD concentrations from 900 to 1750 to 3730 mg/L in the system treating 100 mg/L of Orange II-containing wastewater enhanced color removal from 27% to 81% to 89%, respectively. In the absence of co-substrates and nutrients, more than 95% of decolorization was achieved by the acclimatized anaerobic microbes in the bioreactor treating 600 mg/L of Orange II. The decrease in mixed liquor suspended solids concentration by endogenous lysis of biomass preserved a high reducing environment in the ASBR, which was important for the reduction of the Orange II azo bond that caused decolorization. The maximum decolorization rate in the ASBR was approximately 0.17 g/hr in the absence of co-substrates and nutrients.     

Heterogeneous Fenton degradation of azo dyes catalyzed by modified polyacrylonitrile fiber Fe complexes：QSPR (quantitative structure peorperty relationship) study

The amidoximated polyacrylonitrile (PAN) fiber Fe complexes were prepared and used as the heterogeneous Fenton catalysts for the degradation of 28 anionic water soluble azo dyes in water under visible irradiation. The multiple linear regression (MLR) method was employed to develop the quantitative structure property relationship (QSPR) model equations for the decoloration and mineralization of azo dyes. Moreover, the predictive ability of the QSPR model equations was assessed using Leave-one-out (LOO) and cross-validation (CV) methods. Additionally, the effect of Fe content of catalyst and the sodium chloride in water on QSPR model equations were also investigated. The results indicated that the heterogeneous photo-Fenton degradation of the azo dyes with different structures was conducted in the presence of the amidoximated PAN fiber Fe complex. The QSPR model equations for the dye decoloration and mineralization were successfully developed using MLR technique. MW/S (molecular weight divided by the number of sulphonate groups) and NN=N (the number of azo linkage) are considered as the most important determining factor for the dye degradation and mineralization, and there is a significant negative correlation betweenMW/S or NN=N and degradation percentage or total organic carbon (TOC) removal. Moreover, LOO and CV analysis suggested that the obtained QSPR model equations have the better prediction ability. The variation in Fe content of catalyst and the addition of sodium chloride did not alter the nature of the QSPR model equations.     

Photocatalytic parameters and kinetic study for degradation of dichlorophenol-indophenol (DCPIP) dye using highly active mesoporous TiO2 nanoparticles

Highly active mesoporous TiO_2 of about 6 nm crystal size and 280.7 m~2/g specific surface areas has been successfully synthesized via controlled hydrolysis of titanium butoxide at acidic medium. It was characterized by means of XRD(X-ray diffraction), SEM(scanning electron microscopy), TEM(transmission electron microscopy), FT-IR(Fourier transform infrared spectroscopy), TGA(thermogravimetric analysis), DSC(differential scanning calorimetry) and BET(Brunauer–Emmett–Teller) surface area. The degradation of dichlorophenol-indophenol(DCPIP) under ultraviolet(UV) light was studied to evaluate the photocatalytic activity of samples. The effects of different parameters and kinetics were investigated. Accordingly, a complete degradation of DCPIP dye was achieved by applying the optimal operational conditions of 1 g/L of catalyst, 10 mg/L of DCPIP, pH of 3 and the temperature at 25 ± 3°C after 3 min under UV irradiation. Meanwhile, the Langmuir–Hinshelwood kinetic model described the variations in pure photocatalytic branch in consistent with a first order power law model.The results proved that the prepared TiO_2 nanoparticle has a photocatalytic activity significantly better than Degussa P-25.     

厌氧生物法处理果胶废水的研究

采用经果胶废水驯化的厌氧污泥处理果胶废水,考察了果胶浓度、温度对厌氧去除果胶和COD的影响,并对降解产物进行了分析.结果表明,与未驯化厌氧污泥处理果胶废水相比,驯化后的污泥对果胶去除率提高了59.2%.果胶浓度分别为100、2 500和4 500 mg·L-1时,果胶降解速率分别为4.5、49.8和74.0 mg·(L·h)-1,说明果胶浓度越高,降解速率越快.果胶浓度低于500 mg·L-1,COD去除率较低,仅为41.6%~82.0%,果胶浓度高于1 000 mg·L-1,COD去除率稳定在91%以上.温度越高,降解果胶所需的时间越短.随着温度在5~35℃范围内变化,厌氧污泥对果胶废水中COD的去除率从38.6%逐渐增加到91.5%,当温度高于35℃时,厌氧污泥对果胶废水中COD的去除率逐渐降低.果胶降解的中间产物主要是乙酸、丙酸、低级酯、烷基醇(C12~C40).     

铁屑法处理含染料废水中铁屑表面化学研究

采用扫描电镜和X射线光电子能谱技术对铁屑法处理含染料废水中铁屑反应前后的表面进行了研究,结果表明：铁屑表面主要由Fe,C,O,S,Si以及其它构成铸铁的微量元素等组成．铁屑表面快速氧化是染料脱色的关键和前提步骤,铁屑表面铁的羟基氧化物增多是铁屑失活的重要原因．超声方法是铁屑再生方法之一,铸铁中的硫有助于染料脱色．     

利用废啤酒酵母泥对活性黑31的吸附特性研究

利用粉末状废啤酒酵母泥对水中活性黑31进行吸附去除实验,研究了不同溶液初始pH值、不同温度对活性黑31的吸附性能,继而探讨了其吸附热力学和解吸性能。结果表明：在强酸条件下（pH 3）,废啤酒酵母泥对活性黑31的吸附量最大;温度对废啤酒酵母泥吸附活性黑31的性能影响不大,温度从25℃升至50℃,吸附量只减少了9.9 mg...     

铁屑过滤+H2O2预处理难降解染料废水的研究

介绍了铁屑过滤+H2O2预处理难降解染料废水实验研究结果.采用铁屑过滤微电解法预处理难降解染料废水,当进水pH为4,停留时间为8 min时,出水BOD5/COD较原水提高0.2-0.3;若在铁屑过滤进水中加入H2O2(30%)8‰投加量,可使废水可生化性得到显著改善,有利于后续采用生化法处理.