5种植物材料的水解释碳性能及反硝化效率

碳源在硝酸盐去除过程中起电子供体的作用,是生物反硝化反应的关键物质之一。为解决污水处理脱氮时碳源不足抑制反硝化反应造成脱氮效率低的问题,本研究选取风车草、甘蔗渣、芦竹、美人蕉和稻草秆5种植物材料作为反硝化碳源,探讨不同植物材料的水解释碳能力和释放规律;并进一步以其水解液作为外加碳源,探讨其对反硝化脱氮效率的影响。研究结果表明,植物材料水解释碳过程符合二级动力学反应规律,不同植物材料的释碳能力具有显著性差异,以甘蔗渣在固液比1∶80时COD释放当量最大,为45.45 mg/L;添加植物水解液可显著提高反硝化脱氮效率,以芦竹水解液脱氮效果最好,达到71.9%。此外,碳氮比是影响脱氮效率的重要因素之一,以碳氮比为9时反硝化脱氮效果最佳。     

重庆主城区秋冬季逆温对空气质量影响的观测分析

2013年9—11月利用RPG-HATPRO地基多通道微波辐射计对重庆主城区大气进行连续探测,统计了大气逆温情况,并对典型重污染天气下大气逆温与空气质量状况进行综合分析。结果表明,逆温出现的频率为63.3%,基本为接地逆温类型,逆温层厚度为953 m,逆温强度为0.3℃/hm;逆温的存在为气溶胶的积聚和凝聚创造了有利条件。     

Determination of Fungicide Kresoxim-Methyl Residues in Cucumber and Soil by Capillary Gas Chromatography with Nitrogen-Phosphorus Detection

The method of residue analysis of kresoxim-methyl and its dissipation rate in cucumber and soil in a greenhouse were studied. Residues of kresoxim-methyl were extracted from cucumber and soil matrices with acetone, purified by liquid-liquid extraction and Florisil cartridges, and then determined by GC with NP-detector. The limit of detection was estimated to be 9× 10^?12 g, and the minimum determination concentration of kresoxim-methyl in the samples was 0.005 mg kg^?1. The average recoveries ranged from 89.4 to 100.2% with a coefficient variation between 2.4 and 8.9%. Dissipation study showed that the half-lives of kresoxim-methyl in cucumber were approximately 6.5 days at both the recommended and double the recommended dosage. Half-lives for both the treatments were approximately 8 days in soil. The present study revealed that the residues in cucumber were below the MRL (0.05 mg kg^?1, fixed by EU) after 7 days for both treatments.     

Development of IC-ELISA for detection of organophosphorus pesticides in water

Diethyl (carboxymethyl) phosphonate (DECP) was used as the hapten to develop an indirect competitive enzyme-linked immunosorbent assay (IC-ELISA) for detecting organophosphorus pesticides (OPs). Conjugator of DECP with bovin serum albumin (BSA) was used as the immunogen for producing the polyclonal antibodies (PcAbs). Three antisera were obtained after the immune procedure. Characterization studies of the PcAbs indicated that the titer of antiserum-1 was highest in 3 antisera, and antiserum-1 had high affinity and specificity to the parathion, dichlorvos and pirimiphos. The IC-ELISA showed an IC₅₀ of 0.428 μ g/mL with a detection limit of 0.0125 μ g/mL to parathion. The assay also indicated that the IC₅₀ values of pirimiphos and dichlorvos were 0.331 μ g/mL and 1.25 μ g/mL respectively, and the detection limits of pirimiphos and dichlorvos were 0.0116 μ g/mL and 0.048 μ g/mL respectively. Recoveries of parathion, pirimiphos and dichlorvos spiked into water samples ranged from 90% to 160%. The results indicated that the ELISA could be a convenient and supplemental analytical tool for monitoring OPs residues in environmental water samples.     

Degradation of rizazole in water–sediment systems

This study investigated the degradation of rizazole in water-sediment systems (West Lake system, WL; Beijing–Hangzhou Grand Canal system, BG) with two different types of sediments under aerobic and anaerobic conditions. The half-lives of rizazole in the WL water phase (14.59–15.13 d) were similar to those in the BG water phase (15.90–16.46 d). Within 3–7 d, the rizazole concentration in the sediments reached the maximum values, i.e., equilibrium. Rizazole dissipation was faster in the WL sediment phase with higher organic matter content (T_1/2 = 18.99–19.09 d) compared with the BG sediment phase (T_1/2 = 31.08–33.32 d). Rizazole degradation was slightly faster in the West Lake water-sediment system (WL system) (T_1/2 = 17.11–18.05 d) than in the Beijing–Hangzhou Grand Canal water—sediment system (BG system) (T_1/2 = 20.51–25.02 d). The aerobic degradation of rizazole was similar to its anaerobic degradation in the water-sediment system. The findings are useful to understand the behavior of pesticide in environment.     

高压实新疆阿尔泰膨润土微观结构随吸力变化特征

采用压汞法(MIP)和扫描电镜(SEM)法,在自由和侧限状态下,试验研究了高压实新疆阿尔泰膨润土在不同吸力条件下的微观结构变化特征。吸力的控制采用了气相法和渗析(液相)法。研究结果表明:(1)低吸力范围内,自由膨胀和侧限条件下的高压实膨润土土水特征存在明显差异;(2)膨润土在自由和侧限状态下的水化过程中呈现出了截然不同的微结构变化特征。自由膨胀条件下,土的吸水膨胀量主要来自土中大孔隙的逐渐膨胀。侧限状态下,随着控制吸力的降低,膨润土的大孔隙逐渐被压缩,较小孔隙的数量不断增加,土中孔隙分布变得更加均匀。     

香根草人工湿地处理生活污水的试验研究

通过建立香根草人工湿地系统,研究该系统对生活污水的COD、TP、TN的处理效果以及系统的耐污性。在水力停留时间(HRT)为6h的条件下,COD、TP、TN的去除率分别为63.5%、88.3%、72.4%。研究表明,香根草人工湿地系统对城镇生活污水具有较好的净化效果,且系统在该试验条件下耐污性良好。     

上海市青浦区PM10污染状况及其与气象要素的关系

利用2006-2010年上海市青浦区PM10和同期地面气象要素的监测资料,定量分析PM10的季节变化规律以及PM10与降雨量、大气湿度和风速之间的关系。分析结果表明:PM10浓度在夏季处于低值,冬季处于高值;5mm/d以上的降雨对PM10有显著的清除作用,且春夏季降雨的清除作用大于秋冬季节。PM10浓度与大气湿度基本呈负相关关系。风速在一定范围内有利于PM10的扩散但不至造成扬尘,春夏季节的适宜风速是1.5～3.5m/s,冬季的适宜风速是1.5～2.5m/s。     

电能表电磁兼容辐射干扰问题探讨

本文首先概述了我国的电能表市场,进而引出电磁兼容(EMC)的问题;通过针对两个典型电磁兼容辐射骚扰问题提出了详细的分析和解决方案。     

电器防雷滤波技术探讨

我国是雷电多发地区,在我们日常生活中电器经常会被雷电击坏或不能正常工作。本文就产品设计中我们常采用的一种既防雷又解决滤波的防雷滤波技术讨论,并加以验证。