论现有环境质量综合指数的可能虚假性

通过各种例子,利用数学分析方法,得出如下结论:①现有的许多环境质量综合指数都存在着可能的虚假性,而这种虚假性是由数学模式本身的性质所决定的;②对于一个数学模式来说,当综合指数一定时,单项指数的值域也是一定的。      

陕南水镁石纤维的环境安全性评估

纤维水镁石在动物体内有一定的生物活性,但在人群流行性病学结果上显示的一系列信息如接尘工人只出现低的尘肺患病率,没有矽肺病和Ⅲ期尘肺患者。溶解性试验结果表明：水镁石纤维粉尘极易溶解在有机无机强弱酸、混合酸、有机无机铵盐、缓冲溶液中,也可部分溶于水中,导致其在体内滞留时间短且易于清除。说明水镁石纤维是安全的纤维材料且没有致瘤协同作用,由于矿物的表面/界面特征是除纤维特性以外控制纤维生物活性和危害性的关键因素之一,提出了矿物粉尘环境安全评价分类体系应突破矿物种的局限而深入到表面/界面的水平。     

便携式GC-MS在石油污染土壤应急监测中的应用

针对石油污染土壤中VOCs含量的应急监测,便携式气相色谱-质谱联用仪适用于土壤中甲苯、乙苯、二甲苯、三氯苯等13种苯系物的快速定量检测,通过对某废弃炼油厂土壤样品测定,该方法在快速定性的同时,定量测定5~20411μg/kg土壤样品具有很高的可靠性。     

甲烷水合物恒压分解动力学研究进展

相比气体水合物生成过程的研究,对分解过程的研究起步较晚且不深入,而研究水合物分解特征有助于水合物的开发、利用。为此,对甲烷水合物恒压分解动力学研究现状进行了分析和评价,主要评述了甲烷水合物恒压分解实验方法、恒压分解动力学参数的测定、恒压分解动力学模型构建等方面的内容,以期能够加深对甲烷水合物恒压分解动力学的理解及引起科研工作者的重视。最后,展望了未来气体水合物分解动力学的研究方向。     

蚀刻液水合肼还原除铜

将电路板厂废弃的蚀刻液,经氢氧化铜沉淀法回收大部分铜后,再采用水合肼还原,进一步除铜。反应温度为50℃,水合肼质量分数为3．0％,溶液pH为6．0,废液中铜的去除率可达98.5％,处理后废液中铜的质量浓度低于0．2g／L,可作为碱性蚀刻液重复利用。     

超声及N掺杂对TiO2光催化降解甲基橙活性的影响

在超声条件下采用溶胶-凝胶法制备了N掺杂纳米TiO2光催化剂,以甲基橙的光催化降解评价其光催化活性.运用XRD、透射电子显微镜、紫外-可见漫反射光谱等技术对试样的粒径、晶体结构及光学性能进行了表征.实验结果表明:超声能明显减小TiO2颗粒的粒径,提高颗粒分散度,提高TiO2在紫外光下的光催化剂活性;超声对N的掺杂产生了促进作用,使N掺杂纳米TiO2对可见光的吸收能力显著增强,在可见光下的光催化降解速率提高23％.     

Molecular docking analysis on antifungal properties of acid condensate produced from palm kernel shell

The rise in the number of fungi that resisted antifungal action is of serious concern nowadays. In this study, the potential of acid condensate (AC) produced from microwave-assisted pyrolysis of palm kernel shell (PKS) was investigated for its antifungal properties through molecular docking evaluation. The phenolic-rich AC was determined for its chemical compositions using the GC–MS analysis where compounds with the highest phenolics content were further evaluated (using the Autodock Tools 1.5.7) for its potential enzymes/protein binding properties. From the GC–MS analysis, catechol, guaiacol and syringol were present at highest percentages. This directly correlates with results obtained from the molecular docking works where all these ligands managed to bind (indicated by H-bond, π-stacking, hydrophobic interaction) with some of the amino acid at the active sites which indicate its potential to inhibit substrate binding of this enzyme. As a conclusion, this study demonstrated the potential use of AC from agricultural biomass such as PKS as a natural-based antifungal agent that can reduce environmental and health impacts.     

Characteristics of the stabilized/solidified municipal solid wastes incineration fly ash and the leaching behavior of Cr and Pb

Fly ash is a hazardous byproduct of municipal solid wastes incineration (MSWI). An alkali activated blast furnace slag-based cementitious material was used to stabilize/solidify the fly ash at experimental level. The characteristics of the stabilized/solidified fly ash, including metal leachability, mineralogical characteristics and the distributions of metals in matrices, were tested by toxic characteristic leaching procedure (TCLP), X-ray diffraction (XRD) and scanning electron microscopy-energy dispersive spectrometer (SEM-EDS) respectively. Continuous acid extraction was utilized to extract metal ions and characterize their leaching behavior. The stabilization/solidification procedure for MSWI fly ash demonstrates a strong fixing capacity for the metals by the formation of C-S-H phase, hydrated calcium aluminosilicate and ettringite. The stabilized/solidified fly ash shows a dense and homogeneous microstructure. Cr is mainly solidified in hydrated calcium aluminosilicate, C-S-H and ettringite phase through physical encapsulation, precipitation, adsorption or substitution mechanisms, and Pb is mainly solidified in C-S-H phase and absorbed in the Si-O structure.     

无锡冬季和春季大气中细粒子化学组分及其特性分析

本研究对无锡冬(2011年1月)春(2011年5月)两季PM2.5、PM10颗粒物浓度进行了传统的膜采样及离线检测分析,并运用大气气体/气溶胶水溶性离子在线收集及分析(GAC-IC)系统对PM2.5颗粒物中水溶性无机离子(WSII)进行了在线检测,时间分辨率为30 min.无锡冬、春两季PM2.5的浓度分别为108.15±41.76μg·m-3和84.40±26.74μg·m-3,其PM2.5/PM10比值分别为0.81±0.07和0.78±0.07,有较强的二次气溶胶生成过程.铵可用性指数(J冬季=101.2%±22.3%,J春季=79.5%±20.2%)分析表明冬季无锡大气颗粒物中铵(NH+4)相对比较富余,而春季则出现铵(NH+4)亏损现象,春季光化学反应更为活跃,硫氧化率(SOR)由冬季的0.15±0.05增至春季的0.35±0.13,硫酸盐(SO2-4)浓度增加明显,导致铵(NH+4)相对不足.硫氧化率(SOR)没有明显的季节变化,冬、春两季均为0.15.细粒子中的WSII与气态污染物、气象因子、硫氧化率(SOR)和氮氧化率(NOR)等的主成分分析表明无锡大气光化学反应与污染物的其他来源,例如工业源、交通移动源、生物质燃烧源等,有很好的协同作用,共同推高了大气中颗粒物的浓度.观测期间同时测得冬季PM2.5颗粒中有机碳(OC)与元素碳(EC)浓度之间有较好的相关性(R2=0.839),两者有一个共同的主导源,而春季来源则比较复杂,两者相关性较差;二次有机碳(SOC)的半定量分析表明春季大气中有机气溶胶的形成有较强的二次转化过程.     

Influences of charcoal and bamboo charcoal amendment on soil-fluoride fractions and bioaccumulation of fluoride in tea plants

High levels of fluoride in tea plants pose a potential health risk to humans who drink tea. It has been demonstrated that tea plant fluoride is closely related to the available fluoride in soil. But approaches that could be used to regulate the availability of fluoride in soil have been rarely seen. This study aims to investigate how the addition of charcoal and bamboo charcoal affected soil fluoride availability and bioaccumulation of fluoride in tea plants. In a microcosm experiment, tea plants were grown in the tea garden soil mixed with different amounts of charcoal and bamboo charcoal [that is, 0.5, 1.0, 2.5, and 5.0?% (w/w)]. Soil-fluoride fractions and fluoride accumulated in tea plants were determined using the sequential extraction and ion selective electrode method. Obtained results showed that both charcoal and bamboo charcoal additions significantly enhanced the concentrations of Fe/Mn oxide-bound fluoride, but significantly reduced the concentrations of water-soluble and exchangeable fluoride (p?相似文献