基于清单分析的农业面源污染源强计算方法

为了计算农业面源污染的源强,基于清单分析的思想,建立了农业面源污染清单分析表、农业面源污染源强的计算公式及其影响参数值的确定方法,最终形成了农业面源污染源强计算的清单分析方法体系。采用士述方法,对江苏省常熟市农业面源污染源强的计算进行了实例研究,表明该方法是可行的。     

特长公路隧道全射流火灾通风网络解算研究*

为探究特长公路隧道全射流火灾在通风条件下隧道内风流分布及影响规律,基于斯考德-恒斯雷近似算法构建通风网络解算模型,并通过隧道现场风机效率测试和通风测试,验证通风网络解算模型的可靠性;引入火区阻力和火风压公式,建立全射流火灾通风网络计算模型。结果表明:铜锣山隧道射流风机正向运转效率为0.83~0.93,平均效率为0.882,风机反向运转效率为0.65~0.68,平均效率为0.665;现场通风测试结果与通风网络计算结果误差在15%以内;火灾通风阻力对隧道各支路的影响程度不同,其中,对事故隧道支路的影响最大,横通道支路次之,对非事故隧道支路的影响最小;隧道坡率对烟气分配的影响主要为火风压引起,上坡隧道时,火风压起动力作用,火灾支路风量与坡度成正相关,下坡隧道时,火风压起阻力作用,火灾支路风量与坡率成负相关。     

Modification of CeO2-ZrO2 catalyst by potassium for NOx-assisted soot oxidation

Potassium-modified ceria-zirconia catalyst was synthesized by wetness impregnation method.The ageing treatment was performed in static air at 800°C for 20 hr to evaluate the thermal stability of the catalyst.The catalysts were characterized by X-ray diffraction,BET surface area,oxygen storage capacity,NOx-temperature programmed desorption and soot-temperature programmed oxidation measurements.By introduction of potassium,the maximum soot oxidation rate temperature(Tm) of the ceria-zirconia based catalyst de...     

双道HG—AFS同时测定鲤鱼肝脏中痕量Hg和As

应用氢化物原子荧光法,测定鲤鱼肝脏中痕量Hg和As,该法具有原子吸收和原子发射光谱两种技术优势,同时它具有分析灵敏度高,干扰少,线性范围宽,可多元素同时测定等优点;在KBH4-酸还原体系中同时测定鱼肝中Hg和As,方法检出限分别为Hg：0．33ng／ml和As0．36ng／ml,线性范围分别为：0.1—2.0ng／ml和1．0—20．0ng／ml。加标回收率分别为Hg：96．0％和As：100．6％。分析结果可靠,方法令人满意,并适合大批量样品的分析.     

多水源化工园区综合废水的水体特征研究

为充分了解天津市滨海新区化工园区综合废水的水体特征,通过科学选取新区内某化工园区综合废水中的水质监测指标,借助GCMS和毒性分析技术,得以全面系统地分析出具有类似产业布局的多废水来源的化工园区废水水质特征,为完善同类型废水可生化性指标评价体系提供了参考,且便于后续废水处理工艺的达标化设计。     

Effects of tungsten oxide on the activity and thermal stability of a sulfate-derived titania supported platinum catalyst for propane oxidation

A Pt/WO₃/TiO₂ catalyst for propane oxidation was prepared by a stepwise wet impregnation method, and was aged at 800℃ for 5 hr. Compared to the sulfate-derived titania supported catalyst, the introduction of tungsten oxide as stable Bronsted acid sites led to the formation of more metallic platinum active sites at the Pt/WO₃ interface. The dissociation of surface intermediates for propane oxidation was promoted on the WO₃-modified catalyst. This, as well as the inhibition effects of tungsten oxide on the sintering of anatase and the phase transformation to rutile, resulting in a high activity and thermal stability for the Pt/WO₃/TiO₂ catalyst.     

中国排污许可证制度执行现状调查

本研究以广州、石家庄、兰州、哈尔滨和大同5个城市为调研对象,收集各城市20年来许可证相关的法规制度,并与各城市环境保护监管部门负责人及典型企业环保专职人员进行了访谈。研究表明,中国排污许可证制度在提高企业环保守法意识和推动总量减排上起到了明显作用,但也面临着法律体系不完善,行政资源不足、排放量核算方法不明确、处罚力度弱以及公众参与不充分等问题。在此基础上,本研究提出中国排污许可证制度的改进建议,为决策部门制定相应的政策提供科学和技术的支撑。     

Implications of Upstream Flow Availability for Watershed Surface Water Supply across the Conterminous United States

Although it is well established that the availability of upstream flow (AUF) affects downstream water supply, its significance has not been rigorously categorized and quantified at fine resolutions. This study aims to fill this gap by providing a nationwide inventory of AUF and local water resource, and assessing their roles in securing water supply across the 2,099 8‐digit hydrologic unit code watersheds in the conterminous United States (CONUS). We investigated the effects of river hydraulic connectivity, climate variability, and water withdrawal, and consumption on water availability and water stress (ratio of demand to supply) in the past three decades (i.e., 1981–2010). The results show that 12% of the CONUS land relied on AUF for adequate freshwater supply, while local water alone was sufficient to meet the demand in another 74% of the area. The remaining 14% highly stressed area was mostly found in headwater areas or watersheds that were isolated from other basins, where stress levels were more sensitive to climate variability. Although the constantly changing water demand was the primary cause of escalating/diminishing stress, AUF variation could be an important driver in the arid south and southwest. This research contributes to better understanding of the significance of upstream–downstream water nexus in regional water availability, and this becomes more crucial under a changing climate and with intensified human activities.     

燃煤电厂PM_(2.5)减排技术与装备探讨

燃煤电厂在我国电力工业中占有很大的比重,其烟尘排放污染问题也尤其突出。大量燃煤烟尘的排放造成了严重的环境污染,特别是其中的细颗粒物PM2.5,能长期悬浮于大气中,对人类的健康造成了长期持续的危害,因此燃煤电厂PM2.5减排技术对于环境保护事业具有重要的意义和深远的影响,大力发展PM2.5减排技术与装备是电力行业大势所趋。     

壬基酚对多刺裸腹溞连续世代的毒性效应

为探讨典型环境激素壬基酚(nonylphenol,NP)对枝角类浮游动物多刺裸腹溞连续世代的毒性效应,在实验室条件下,暴露连续3个世代(F0、F1、F2)多刺裸腹溞于0.02~0.10 mg·L-1的NP。15 d后测定成体死亡率、首胎繁殖时间、后代数目、成体蜕皮次数以及终点体长。研究结果表明,NP对F0代多刺裸腹溞具有很高的致死率;随着世代的增加,在相同NP质量浓度暴露下,与母代成体的死亡率相比,子代多刺裸腹溞成体的死亡率增高,致死毒性放大;NP对多刺裸腹溞连续3个世代的繁殖力都有显著抑制作用(P0.05),并随着世代递增,NP对子代繁殖力的抑制增强;在NP暴露下,多刺裸腹溞F0首胎繁殖时间明显推迟,NP暴露浓度与延迟程度呈正相关,呈现出剂量-效应关系,首胎繁殖时间延迟的趋势也存在于F1、F2世代中且存在放大效应;但是连续3个世代多刺裸腹溞成体的蜕皮次数都不受NP暴露影响;F0和F1世代多刺裸腹溞终点体长降低,并呈现明显的剂量-效应关系,但与F1相比,F2低浓度处理组受试个体终点体长呈增加趋势。对结果进行分析,认为多刺裸腹溞在NP暴露后的母代DNA或DNA完整性遭到破坏导致子代在相同NP质量浓度暴露下更容易受到NP致死性的影响;NP化合物具有的苯酚结构抑制枝角类体内葡萄糖、硫酸盐与类固醇的结合,从而引起体内荷尔蒙水平异常,最终对诸如生殖等生理行为造成不利影响;多刺裸腹溞成体的蜕皮次数都不受NP暴露影响表明蜕皮激素系统未受到干扰,且NP对生长的影响显然存在蜕皮外的其他作用机制。