Catalytic oxidation effect of MnSO4 on As(III) by air in alkaline solution

The catalytic oxidation effect of MnSO₄ on As(III) by air in an alkaline solution was investigated. According to the X-ray diffraction (XRD), scanning electron microscope-energy dispersive spectrometer (SEM-EDS) and X-ray photoelectron spectroscopy (XPS) analysis results of the product, it was shown that the introduction of MnSO₄ in the form of solution would generate Na_0.55Mn₂O₄·1.5H₂O with strong catalytic oxidation ability in the aerobic alkaline solution, whereas the catalytic effect of the other product MnOOH is not satisfactory. Under the optimal reaction conditions of temperature 90°C, As/Mn molar ratio 12.74:1, air flow rate 1.0 L/min, and stirring speed 300 r/min, As(III) can be completely oxidized after 2 hr reaction. The excellent catalytic oxidation ability of MnSO₄ on As(III) was mainly attributed to the indirect oxidation of As(III) by the product Na_0.55Mn₂O₄·1.5H₂O. This study shows a convenient and efficient process for the oxidation of As(III) in alkali solutions, which has potential application value for the pre-oxidation of arsenic-containing solution or the detoxification of As(III).     

皮革和毛皮加工废水处理技术

采用混凝沉淀-酸化水解-悬挂链曝气-生物接触氧化组合工艺处理皮革和毛皮加工生产废水。实验结果表明;进水COD为2400mg/L,处理后出水COD≤100mg/L,去除率≥95.8%。各项水质指标均稳定地达到了GB8978-96污水综合排放一级标准。     

Promotional effect of cobalt doping on catalytic performance of cryptomelane-type manganese oxide in toluene oxidation

The cryptomelane-type manganese oxide (OMS-2)-supported Co (xCo/OMS-2; x = 5, 10, and 15 wt.%) catalysts were prepared via a pre-incorporation route. The as-prepared materials were used as catalysts for catalytic oxidation of toluene (2000 ppmV). Physical and chemical properties of the catalysts were measured using the X-ray diffraction (XRD), Fourier transform infrared spectroscopic (FT-IR), scanning electron microscopic (SEM), X-ray photoelectron spectroscopy (XPS), and hydrogen temperature-programmed reduction (H₂-TPR) techniques. Among all of the catalysts, 10Co/OMS-2 performed the best, with the T_90%, specific reaction rate at 245°C, and turnover frequency at 245°C (TOF_Co) being 245°C, 1.23 × 10⁻³ mol_toluene/(g_cat·sec), and 11.58 × 10⁻³ sec⁻¹ for toluene oxidation at a space velocity of 60,000 mL/(g·hr), respectively. The excellent catalytic performance of 10Co/OMS-2 were due to more oxygen vacancies, enhanced redox ability and oxygen mobility, and strong synergistic effect between Co species and OMS-2 support. Moreover, in the presence of poisoning gases CO₂, SO₂ or NH₃, the activity of 10Co/OMS-2 decreased for the carbonate, sulfate and ammonia species covered the active sites and oxygen vacancies, respectively. After the activation treatment, the catalytic activity was partly recovered. The good low-temperature reducibility of 10Co/OMS-2 could also facilitate the redox process accompanied by the consecutive electron transfer between the adsorbed O₂ and the cobalt or manganese ions. In the oxidation process of toluene, the benzoic and aldehydic intermediates were first generated, which were further oxidized to the benzoate intermediate that were eventually converted into H₂O and CO₂.     

接触氧化-电解工艺处理印染废水

主要介绍了采用生物接触氧化 电解工艺处理印染废水的设计及运行情况。处理系统运行结果表明 :当进水CODCr、BOD5和色度分别为 764 5mg L、2 63 7mg L和 42 0倍时 ,系统出水CODCr、BOD5和色度分别为 160 5mg L、48 9mg L和 12倍 ,去除率分别为 79%、81 5 %和 97 1%。该工艺运行稳定 ,操作控制方便     

全程自养脱氮工艺的研究

以悬浮填料床作为全程自养脱氮反应器，用不含有机碳的合成氨氮废水进行反应器的启动。系统的氨氮和总氮去除率分别达80％和60％左右。通过批式实验对全程自脱氮做进一步的研究。结果表明，通过控制反应器中DO的浓度，可以控制氨氧化和反硝化的比率；当DO为0.8mg/L时，氨氮几乎完全转化为氮气，氨氧化和反硝化在此时达到了动态平衡；在低DO情况下，氨氮和亚硝氮同时存在，氨氮和总氮的转化率都大幅度的提高，说明氨氮可以亚硝氮为电子受体，在无外加有机碳源的情况下进行反硝化。     

氧化塘处理高速公路服务区污水技术初探

提出并试验研究了氧化塘处理高速公路服务区污水的方法，所得结果可用于高等级公路服务区及管理区污水处理。     

长炼第二污水处理场氧化沟工艺运行小结

臭伯尔氧化沟池容大，停留时间长，运行稳定，对氧化沟污泥培养及开工运行进行了小结，并结合运行过程中的几个问题进行了分析和探讨。     

Cu／A1-Ce-PILC在丙烯选择性催化还原NO反应中的失活研究

采用聚合羟基复合阳离子合成交联黏土A1-Ce-PILC，经SO4^2-改性后，以浸渍法制备了铜基交联黏土催化剂Cu／A1-Ce-PILC，并将其应用于C3H6选择性催化还原NO的反应，350℃时NO转化率达到最大值56％，700℃时下降至22％．为探究催化剂高温失活的原因，采用XPS、TPR、TGA、Py-IR和DSC对反应前后催化剂的物化性能进行了表征．结果表明，经过H2预处理活化后活性组分Cu物种以Cu^＋形式存在，而高温反应后Cu物种除以Cu^＋和Cu^2＋ 2种形式存在外，还出现了少量CuO物种；高温反应过程中A1-Ce-PILC上结构羟基和SO4^2-流失导致催化剂表面酸性减弱；此外，还存在表面积炭覆盖了部分活性中心并堵塞了催化剂孔道的现象．这三者的共同影响促进了C3H6深度氧化，抑制了NO还原，从而导致催化剂的失活．     

用硫酸渣制备铁基颜料铁黄

以硫酸渣为原料，用黄铁矿粉作还原剂，采用湿式空气氧化法制备铁基颜料铁黄。试验得出的适宜工艺条件为：Fe^2 浓度0．25—0．40mol/L，氧化温度70℃，用氢氧化钠或氨水调节反应液的pH，氧化过程溶液的pH控制在3—4。依照该工艺制得的铁基颜料铁黄，其各项指标符合HG／T2249—91标准。     

气浮--厌氧--生物接触氧化工艺处理屠宰废水

介绍了采用气浮-厌氧-生物接触氧化工艺处理屠宰废水的工程实例。当进水CODcr≤4500mg／L时，出水可达到国家《肉类加工工业污染物排放标准》(GB13457—1992)一级标准。