2种不同模块化填料组合的多级土壤渗滤系统的比较

以滇池入湖河流污水为对象,研究了2种不同模块化填料组合的多级土壤渗滤系统在不同运行条件下的处理效果差异.结果表明,各系统都具有较好的COD去除效果,平均去除率均在50％以上.沸石陶结系统无论曝气与否,均具有高NH⁺₄-N去除能力,出水浓度<1 mg/L.陶粒红壤MSL系统在8∶1的气水比下,具有良好的氨氮去除能力,平均去除率为84%;在非曝气条件下氨氮去除能力相对低一些,在40%以下.非曝气沸石陶结系统TN去除效果最好,平均去除率在68％以上,最高达到98％.其他3个系统在不同工况下TN去除效果差别较大.4个系统TP平均去除率在30％～90％之间,不同工况下去除效果不同.高污染负荷下,沸石陶结系统（M1、M2）的磷去除能力较强,稳定状态下平均去除率均在80％以上.通过分析系统沿程氮转化效率,探讨了各系统的氮去除机制.     

Evaluation of zeolites synthesized from fly ash as potential adsorbents for wastewater containing heavy metals

Both pure-form zeolites (zeolites A and X) were synthesized by applying a two-stage method during hydrothermal treatment of fly ash prepared initial gel. The difference of adsorption capacity of both fly ash-synthesized zeolits was assessed under the same adsorption conditions. Copper and zinc were chosen as target heavy metal ions. It was found that adsorption capacity of zeolite A showed much higher value than that of zeolite X. Thus, attention was focused on investigating the removal performance of heavy metal ions in aqueous solution on the synthetic pure-form zeolite A from fly ash, zeolite HS (hydroxyl-solidate) prepared from the residual fly ash (after synthesis of pure-form zeolite A from fly ash) and a commercial grade zeolite A. Batch method was employed to study the influential parameters such as initial pH value, adsorbents dosage and adsorption temperature on the adsorption process. The equilibrium data were well fitted by the Langmuir model and showed the affinity: Cu2+ > Zn2+ (adsorbent FA-ZA). The removal mechanism of metal ions followed adsorption and ion exchange processes. Attempts were also made to recover heavy metal ions and regenerate adsorbents (adsorbent FA-ZA).     

沸石在猪粪堆肥过程中保氮效果研究

通过设置未添加、添加5%、10%和15%沸石4个处理,试验研究了不同沸石添加量对猪粪、米糠堆肥的保氮效果.结果表明:添加沸石可以降低堆体的pH和水溶性NH4+-N含量,减少NH3的挥发损失;与对照处理相比,添加5%、10%、15%沸石处理可将N损失率分别降低12.33%、35.53%、47.32%;但沸石的添加量达到15%时,其堆体保持高温(≥55℃)的时间及平均堆温均较对照处理低,不利于堆肥的顺利进行,而添加5%、10%沸石处理的堆温较为合理.综合以上各项指标,研究认为沸石的适宜添加量为10%左右.     

活性炭和沸石组合吸附渗滤液中COD_(cr)和氨氮的试验研究

经过Fenton试剂氧化处理后的垃圾渗滤液用于吸附处理试验,试验分别得到活性炭和沸石的最佳反应pH值和反应时间后,将活性炭和沸石组合吸附渗滤液,4种吸附处理方式去除垃圾渗滤液中CODcr的能力为:活性炭-沸石沸石-活性炭活性炭活性炭/沸石;去除垃圾渗滤液中NH3-N的能力为:活性炭/沸石活性炭-沸石沸石沸石-活性炭。根据对比分析,确定了最佳吸附工艺应为活性炭-沸石组合工艺,该工艺对CODcr和NH3-N的去除率分别达到74.11%和80.86%。     

沸石处理电镀含铬废水的研究

沸石是一种天然矿物,价格低廉,在中国矿产丰富,又有一定的去除阳离子的能力。以临安美都电镀厂为实例,选用沸石为材料,设计了沸石对含铬废水的吸附实验,研究了pH、沸石用量、温度、接触时间四个因素对沸石吸附效果的影响,分析比较后得出最佳条件:在浓度为42.0 mg/L时,废水量与沸石的比例为30∶1;合理的处理时间为10分钟以上;合理的pH值环境为酸性环境;温度对处理的效率影响不明显。     

Performance tests of newly developed adsorption/plasma combined system for decomposition of volatile organic compounds under continuous flow condition

The adsorption/plasma decomposition with the combination of adsorption honeycomb-sheets and a plasma element is a new technology for small-sized apparatuses to decompose volatile organic compounds (VOCs) at concentrations lower than about 100 ppm. The feasibility of the prototype adsorption/plasma decomposition apparatus was evaluated with the simulated exhausts containing one VOC component and with real exhausts from a painting booth and an adhesion factory. The apparatus decomposed VOCs e ectively at the painting booth exhaust but not always satisfactorily at the adhesion factory exhaust. The performance test results with real exhausts were discussed with respect to the concentration and discharge pattern of the exhausts and the basic properties of the system such as cooperation of adsorption and plasma reaction and the concentration dependence of the performance.     

Effect of ultrasound irradiation and Ni-loading on properties and performance of CeO2-doped Ni/clinoptilolite nanocatalyst used in polluted air treatment

In this research nanocatalysts containing 5, 10 and 15 wt.% of Ni, dispersed by sonication over CeO₂–clinoptilolite composite support were compared toward total oxidation of toluene. Their catalytic performance at different temperatures between 150 and 350 °C was studied based on the oxidative destruction of toluene. The results indicated that the activity of Ni/CeO₂–clinoptilolite nanocatalyst for toluene oxidation increased from 33 to 44% at 250 °C by employing sonochemical method in synthesis of catalyst. Meanwhile, the catalytic activity was also improved when Ni content was increased from 5 to 10 and 15 wt.%. With the aid of several characterization techniques like XRD, FESEM, PSD, EDX, BET and FTIR, the correlation between nanocatalyst structure and its activity was addressed. It is indicated that sonochemical method can lift the catalytic activity due to the better dispersion of catalyst active components and also higher surface area. Among sonicated samples, 15 wt.% Ni nanocatalyst showed the highest toluene oxidation due to the better dispersion of catalyst active components and hence to more effective catalytic sites.     

分子筛在气体分离与净化中的应用

主要展示了多种分子筛在对空气中的主要成分O2、N2、CO2、H2O等气体进行分离时表现出的不同性能,以及对有害气体NOx和SO2消除作用;展望了分子筛作为空气分离吸附剂的进一步发展,以及作为消除有害气体的催化剂的研究重点。     

Tailor-made FAU zeolite composite membrane for wastewater treatment

In this work, a novel multipurpose Faujasite (FAU) zeolite composite membrane was fabricated by in-situ hydrothermal method to separate different solute molecules such as vanillic acid, phenol, and brilliant green from the aqueous solution. The coal fly ash based ceramic substrate was synthesized and used as substrate for preparing the zeolite composite membrane. The X-ray diffraction (XRD) pattern confirmed the crystalline nature of membranes and the presence of Quartz and hematite in the composite membrane. The presence of Si-O and Al-O in zeolite coated composite membrane was confirmed by Fourier Transform infrared spectroscopy (FTIR) analysis. Scanning electron microscope (SEM) analysis showed the porous structure and 8.34 μm thickness of zeolite coating on membrane. The isoelectric point of composite membrane was observed at pH 2.07 through zeta potential analysis. Brunauer-Emmett-Teller (BET) surface area, average pore volume and pore diameter of zeolite composite membrane were estimated as 6.406 m²/gm, 0.0070 cm³/gm, and 4.371 nm, respectively. The hydraulic pore radius and porosity of composite membranes were 27.7 nm and 20.1%. The maximum separation efficiency of FAU zeolite composite membrane towards vanillic acid, phenol and brilliant green was estimated as 78.67%, 89.13%, and 94.28%, respectively, for 200 mg/L feed concentration at 276 kPa applied pressure. The results obtained in this study reveals that the multipurpose FAU zeolite composite membrane fabricated in this study can be effectively used for separation of various solutes molecules present in the wastewater.     

天然沸石负载TiO2光催化降解敌敌畏和对硫磷

以钛酸丁酯为原料,以天然沸石作载体负载TiO2制备光催化剂;并采用高压汞灯为光源,用负载型TiO2光催化降解敌敌畏和对硫磷.结果表明,浓度为1.2×10-4mol/L的农药光照2 h左右可完全被光催化氧化为PO3-4.同时,还研究了合成光催化剂的处理温度、溶液的初始pH值、过氧化氢浓度等对负载TiO2光催化降解的影响.