Relationships of nitrous oxide fluxes with water quality parameters in free water surface constructed wetlands

The effects of chemical oxygen demand (COD) concentration in the influent on nitrous oxide (N₂O) emissions, together with the relationships between N₂O and water quality parameters in free water surface constructed wetlands, were investigated with laboratoryscale systems. N₂O emission and purification performance of wastewater were very strongly dependent on COD concentration in the influent, and the total N₂O emission in the system with middle COD influent concentration was the least. The relationships between N₂O and the chemical and physical water quality variables were studied by using principal component scores in multiple linear regression analysis to predict N₂O flux. The multiple linear regression model against principal components indicated that different water parameters affected N₂O flux with different COD concentrations in the influent, but nitrate nitrogen affected N₂O flux in all systems.     

我国“十二五”期间推进清洁生产工作的思考

在末端治理日臻完善的时代,清洁生产是人类污染治理方式和生产力发展方式上的一次革命。我国推行清洁生产已有10余年,但进展较缓慢。本文在阐释清洁生产内涵的基础上分析了我国在推行清洁生产过程中存在的部分问题及其原因,提出了相应的对策和建议。     

关于推进三明市节能减排的对策建议

我国上世纪五、六十年代新兴的工业城市,工业结构大多以重化工业为主,节能减排任务十分艰巨。本文选择福建省三明市这一极具有代表性的地方工业城市进行调研剖析,阐述了三明市当前节能减排的形势与任务,分析了在推进节能减排工作中存在的主要问题,并提出了应对措施和建议。     

关于排污权的一级市场和二级市场问题

在分析建立和完善排污权市场机制必要性的基础上,提出了排污权一级市场和二级市场的概念,阐述了参与主体不同、实施手段不同、风险大小不同和作用效果不同是一级市场与二级市场的主要区别;指出排污权一级市场需要解决的核心是公平问题,二级市场需要解决的核心是效率问题,并提出了保证排污权一级市场的公平性和提高二级市场效率的若干重要措施.这对于当前我国实施排污权有偿取得与排污交易,建立排污权市场机制具有重要借鉴意义.     

我国排污权交易落实的现实要求及有效性分析

从排污权基本概念出发，在分析我国进行排污权交易必要性的基础上，提出进行交易还存在的问题，并给出相应的建议。     

汽车尾气排放与大气污染

随着汽车工业的迅猛发展,汽车在带给人们生活方便和快捷的同时,也给人类生存环境造成了污染。文章阐述了当前国内外汽车尾气排放污染现状,并详细介绍了汽车尾气中一氧化碳、氮氧化物、二氧化硫、碳氢化合物等有害物质以及所产生的臭气、噪声、二氧化碳等对环境及人体健康的危害。     

Emission of volatile organic compounds (VOC) from tropical plant species in India

Foliar emission of volatile organic compounds (VOC) from common Indian plant species was measured. Dynamic flow enclosure technique was used and the gas samples were collected onto Tenax-GC/Carboseive cartridges. The Tenax-GC/Carboseive cartridges were attached to the thermal disorber sample injection system and the gas sample was analysed using gas chromatography (GC) with flame ionisation detection (FID). Fifty-one local plant species were screened, out of which 36 species were found to emit VOC (4 high emitter; 28 moderate emitter; and 4 low-emitter), while in the remaining 15 species no VOC emission was detected or the levels of emission were below detection limit (BDL). VOC emission was found to vary from one species to another. There was a marked seasonal and diurnal variation in VOC emission. The minimum and maximum VOC emission values were < 0.1 and 87 microgg(-1) dry leaf h(-1) in Ficus infectoria and Lantana camara respectively. Out of the 51 plant species studied, 13 species are reported here for the first time. Among the nine tree species (which were selected for detailed study), the highest average hourly emission (9.69+/-8.39 microgg(-1) dry leaf) was observed in Eucalyptus species and the minimum in Syzygium jambolanum (1.89+/-2.48 microgg(-1) dry leaf). An attempt has been made to compare VOC emission from different plant species between present study and the literature (tropical and other regions).     

基于小波神经网络的瓦斯涌出量预测研究

准确地预测瓦斯涌出量对于指导矿井设计和安全生产有重要意义,而瓦斯涌出量是一个与自然因素及开采技术等多因素有关的非线性建模问题。鉴于传统神经网络方法解决非线性问题收敛速度慢,易陷入局部最优解的缺陷,笔者提出一种既充分利用小波变换的时频局部化性质,又能结合神经网络的自学习能力的小波神经网络预测瓦斯涌出量的方法,并建立了预测模型。在此基础上,采用Delphi语言,设计了小波/BP神经网络仿真器。通过实例分析表明该方法较传统神经网络收敛迅速,预测精度高。     

采场低压通风控制有害气体涌出量新技术的研究与应用

基于空气动力学观点,将回采工作面与其后相随的采空区分成两大组成部分:一部分称为通风空间,其风流是有组织的,另一部分称为漏风空间,其风流是非组织性的。两空间相互敞开,又紧紧相邻、存在着密切的风流联系。当开采工作面上、下两端存在着风压差,就可以带动相邻的采空区陷落岩石的孔隙与裂隙中的气体流动,构成采空区中、深部区域的漏风源、汇。笔者提出的采场低压通风系统,采用砌隔漏风墙的方法,切断两空间联系。经现场井下多年应用实践研究后表明,其对于开采瓦斯含量大、煤与瓦斯突出严重的复杂煤层的矿井,尤其是对采空区瓦斯及有害气体涌出量大、且无条件进行瓦斯抽放的回采工作面,能有效地抑制和减少采场瓦斯和有害气体涌出量,且措施费用很低,很值得推广应用。     

重庆市基于排放绩效的火电行业二氧化硫总量控制研究

本文介绍了排放绩效及排放绩效方法在火电行业二氧化硫总量控制方面的应用，并对重庆市火电机组及其二氧化硫排放状况进行了全面调查，根据重庆市二氧化硫污染防治的需要制定了各时段机组“十一五”期间的排放绩效控制标准，利用排放绩效方法测算了重庆市火电行业二氧化硫总量控制目标，提出了总量配额分配方法。