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.     

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.     

大尺度料斗卸料扬尘控制技术的研究与探讨

针对大尺度料斗在抓料斗、重载汽车等卸料过程中产生的扬尘问题,分别对单侧抽风式扬尘控制技术、多侧抽风式扬尘控制技术、单侧吹吸式扬尘控制技术和多侧吹吸式扬尘控制技术等扬尘控制技术的扬尘控制效果进行了探讨。另外,针对两边同时具有卸料点的大尺度料斗,在重载汽车卸料过程中产生的扬尘问题,提出了移动式扬尘控制技术对其扬尘进行控制;并结合具体实例对移动式扬尘控制技术的应用进行了介绍,同时指出了其使用过程中存在的问题。     

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。     

全氟辛烷羧酸(PFOA)与全氟辛烷磺酸(PFOS)的细胞毒性效应

新型污染物全氟辛烷羧酸(PFOA)与全氟辛烷磺酸(PFOS)在全球范围内的各种环境介质中被广泛检出,对生态安全和人体健康造成威胁。利用MTT(噻唑蓝)法研究了PFOA/PFOS对人体细胞的毒性效应。结果表明,低剂量PFOA和PFOS对人体正常肝细胞增殖具有显著毒性,其3 d半数抑制浓度(IC50值)分别约为5和0.5μg·L-1。此外,PFOA和PFOS均对MCF-7细胞增殖表现出显著的非单调剂量-毒性效应,并且在环境浓度范围(0.6μg·L-1)内均可促进MCF-7细胞增殖,表现出潜在的类雌激素作用风险。     

双酚A对斑马鱼成鱼肝脏功能基因转录调控的影响

运用实时定量即时聚合链式反应RT-PCR方法,研究了双酚A对斑马鱼成鱼肝脏的功能基因转录水平的影响。结果显示,28 d半静水暴露以后,FGF8A和STAU 2 表现出传统的正剂量—效应关系,CLDN 1和CALCA的表达为倒剂量—抑制效应关系,SP 4基因在15 μg·L^-1 双酚A时表现为显著抑制效应,但是在150 和1 500 μg·L^-1却表现为显著的诱导效应。 试验进一步探讨了这些表达异常的基因在双酚A干扰去除后能否自我调节和修复。结果显示,CLDN 1能恢复到正常表达水平,而其他4个基因在低剂量组却维持原来的高毒性作用水平甚至表现出更高的毒性作用。研究证明双酚A对斑马鱼成鱼肝脏的基因转录调控具有一定的非单调剂量—效应作用。     

Modeling changes in the coastal ecosystem of the Pearl River Estuary from 1981 to 1998

The coastal ecosystem of the Pearl River Estuary (PRE) has been overfished and received a high level of combined pollution since the 1980s. Ecopath with Ecosim was used to construct two ecosystem models (for 1981 and 1998) to characterize the food web structure and functioning of the ecosystem. Pedigree work and simple sensitivity analysis were carried out to evaluate the quality of data and the uncertainty of the models. The two models seem reliable with regards to input data of good quality. Comparing the variations of outputs of these two models aimed to facilitate assessment of changes of the ecosystem during the past two decades.The trophic structure of the ecosystem has changed with an increase in the biomass proportion of lower trophic level (TL) organisms and a decrease in top predator biomass proportion. All the indices of ecosystem maturity examined show that the system was in a more mature condition in 1981 than in 1998, although the system has been in a condition of stress due to anthropogenic disturbances, such as environmental pollution and habitat destruction since 1981. The ecosystem was aggregated into six and seven integral TLs in 1981 and 1998, respectively, using the trophic aggregation routine of Ecopath. Most of the total system biomass and catch took place at TL II and III in both years. But the distribution of the total system biomass and catch at different TLs changed with decreasing proportions in higher TLs in 1998. The mean transfer efficiency was 9.1% and 10.2% in 1981 and 1998, respectively.Comparative network analysis allowed quantification of the importance of direct and indirect trophic interactions among functional groups. Moreover, a method derived from the mixed trophic impact (MTI) analysis allowed estimating importance of groups in terms of “keystoneness” and identifying the keystone species in the two models over the past two decades. The results indicate that there were no clear keystone species in 1998 but two keystone species at medium trophic levels were identified in 1981. Moreover, organisms located at low trophic levels such as phytoplankton, zooplankton and benthic invertebrates were identified to have relatively high keystoneness in the ecosystem.     

化学需氧量和总有机碳在水质在线监测中的比较

化学需氧量（COD）和总有机碳（TOC）是定量表示水体受有机物污染的2个重要代表性指标。传统的COD在线监测方法在监测有机污染物方面存在一定的挑战,系统比较了COD和TOC在线监测方法在特殊水质中的应用。结果显示：TOC对难氧化有机物的氧化效率高达98%,高氯离子和无机还原性离子对TOC测量误差影响分别约为10%和7%。TOC可更直接、更准确地反映出水体受有机物污染的情况,最后对TOC指标在水质在线监测中的推广应用提出建议。