光催化三维蜂窝陶瓷网净化室内空气的研究

先制备钛酸溶胶和掺杂Fe3 的钛酸溶胶,用溶胶-凝胶法分别将其负载于具有一定厚度的矩形蜂窝陶瓷三维网载体上,再用程序升温法煅烧.得到复合纳米TiO2光催化三维蜂窝陶瓷网.经扫描电镜(SEM)测定,三维蜂窝陶瓷网体上负载膜的厚度为300～400 nm,TiO2的粒径为15～20 nm.将光催化三维蜂窝陶瓷网置于光处理箱体内,在紫外光强、循环风量一定的条件下,对容积为72.6 m3和81.4 m3房间进行空气净化.结果表明,无论掺Fe3 与否的TiO2光催化三维蜂窝陶瓷网都有净化效果,其中以掺Fe3 的效果最好:当甲醛起始浓度为0.404 mg/m3,18 h的去除率为99.5%;当起始细菌总数为924 cfu/m3,24 h后的灭菌率为99.5%.     

热加工车间热污染回收能力分析

针对热加工车间工业炉体积庞大、散热面分散的特点,采用导流罩的方式使近炉壁受热空气进入炉顶热交换器进行热量回收。使用导流罩可具有炉壁保温、环境美化和有效组织气流等3个方面的优点。根据传热原理着重对露墙及炉墙+导流罩2种方式的热污染排放量进行分析,并得出基本的热量计算公式。又以某轧钢加热炉进行计算引证,采用热泵回收技术后,热污染排放将会减少90%,并可回收热量404 kW,大大减少了向周围环境的热污染。     

回用炼油净化水结垢原因分析

针对炼油净化水回用过程中加入缓蚀剂结垢的问题,采用扫描电子显微镜、X射线荧光光谱仪等对净化水及垢样进行了详细的组成分析,并考察了净化水pH对净化水加缓蚀剂前后浊度的影响。实验结果表明,炼油净化水加缓蚀剂后的垢样主要成分为含硫物质,缓蚀剂在酸性环境下不稳定,会歧化分解成不溶于水的胶体状单质S,酸性越强,缓蚀剂分解越明显。净化水中的酸性物质是加入缓蚀剂后使净化水结垢的主要因素,而净化水中的酸性物质来源于NH4^＋的水解和水中的酚类物质。     

生活污水中蛋白质测试方法研究

分别用Folin-酚改进法、考马斯亮兰法和紫外分光光度法等3种测试方法测试了上海市某小区生活污水中的蛋白质含量,对这3种测试方法进行了比较,并采用氨基酸仪分析了生活污水中蛋白质水解后的氨基酸化学组成.试验结果表明,Folin-酚改进法测试蛋白质浓度的准确性与精确性优于考马斯亮兰法和紫外分光光度法,可用于测定生活污水中蛋白质的浓度;氨基酸仪法测得该生活污水中含有17种氨基酸,其中最多的为谷氨酸(3.6 mg/L),含量最低的是脯氨酸(0.8 mg/L);所测生活污水中蛋白质COD占总COD的18.9%.     

废水处理新技术中的超临界水氧化法

超临界水氧化法是一种有效处理有机废水的方法,本文在总结超临界水的特点和优点的基础上,着重介绍了超临界水氧化的基本原理,工艺流程及应用状况,探讨该项技术的前景与发展趋势。、     

Study on sulfur migration in activated carbon adsorption-desorption cycle: Effect of alkali/alkaline earth metals

Activated carbon (AC) has been widely used in the removal of SO₂ from flue gas owing to its well-developed pore structure and abundant functional groups. Herein, the effect of alkali/alkaline earth metals on sulfur migration was investigated based on the dynamic adsorption and temperature programmed desorption experiment. The adsorption and desorption properties of six types of AC (three commercial and three laboratory-made) were carried out on a fixed-bed experimental device, and the physical and chemical properties of samples were determined by X-ray fluorescence, X-ray diffraction, scanning electron microscopy/energy dispersive X-ray, and X-ray photoelectron spectroscopy analysis. The experimental results showed that the adsorbed SO₂ cannot be completely desorbed by increasing the regeneration temperature (350 – 850°C), while the SO₂ fixed in the AC combines with the Ca-based minerals in the ash to form a stable sulfate. For different samples, higher ash content, higher CaO content in the ash and a more developed pore structure lead to a higher SO₂ fixation rate. Moreover, the multiple adsorption-desorption cycles experiment showed that the effect of SO₂ fixation is mainly reflected in the first cycle, after which the adsorption and desorption amount are approximately the same. This study elucidates the effect of alkali/alkaline earth metals on the adsorption-desorption cycle of AC, which provides a deeper understanding of sulfur migration in the AC flue gas desulfurization process.     

好氧污泥对17β-雌二醇吸附性能的研究

研究了好氧活性污泥与失活好氧污泥对17β-雌二醇的吸附性能.17β-雌二醇初始质量浓度为500～10 000 ng/L,采用失活好氧污泥进行吸附,考察了吸附平衡时间、pH与温度对吸附的影响.研究结果表明,失活好氧污泥对17β-雌二醇的吸附在30 min内达到平衡;pH在6～9时对吸附没有影响,pH为9以上时,随着pH升高吸附量减少;温度升高吸附能力降低;其吸附符合Freundlich吸附,且呈线性吸附.在10、20、30 ℃时,Freundlich吸附常数KF分别为91.81、80.65、61.49 L/kg,分配系数Kd分别为561.80、 435.60、306.70 L/kg.另外研究了20 ℃时好氧活性污泥的KF与Kd,它们分别为91.72、514.90 L/kg,与同温下失活好氧污泥的KF和Kd差别均小于20%.     

Modeling and simulation study of the stoichiometric niche space and niche overlap based on the copula method

Environmental and Ecological Statistics - To qualify niche space and niche overlap, the current methods are based on a strict assumption of the normal distribution and restrict dependence to the...     

Physical,chemical and biological behaviour of fumigants on cottonseed

Fumigation is required to protect cottonseed in storage and pre-shipment from insect pests and/or microorganisms. Fumigation of cottonseed with carbon disulphide (CS₂), carbonyl sulphide (COS), ethanedinitrile (C₂N₂), ethyl formate (EF), methyl bromide (MB) and phosphine (PH₃) showed that >85% of the fumigants disappeared within 5?h of exposure. COS maintained >20?mg L^–1 for 24?h. After 1?day of aeration, 75%–85% of the absorbed COS and MB and 20%–40% of the absorbed CS₂, EF and PH₃ were released from treated cottonseed. The fumigant residues were reduced by 80% for COS, 50% for EF or MB and 25% for CS₂ after 1?day of aeration. After 13?days of aeration, fumigant residues were reduced by 95% for MB, 65% for EF, 55% for CS₂ and to natural levels in the COS residue. Carbon disulphide, COS, PH₃, EF and C₂N₂ had no effect on the germination of cottonseed, but germination was reduced to 50% by MB. COS has potential as a fumigant for control of insect pests in cottonseed because it dissipates quickly and does not negatively impact germination. On the other hand, MB appears to strongly absorb and requires an extended period for residues to dissipate, and it negatively impacts germination.     

Clay mineral adsorbents for heavy metal removal from wastewater: a review

Environmental Chemistry Letters - Heavy metal pollution such as water contamination by Pb, Hg, Cu, Cd and Cr ions is induced by rapid urbanization and industrialization and is a major threat to...