SoilTrEC: a global initiative on critical zone research and integration

Soil is a complex natural resource that is considered non-renewable in policy frameworks, and it plays a key role in maintaining a variety of ecosystem services (ES) and life-sustaining material cycles within the Earth's Critical Zone (CZ). However, currently, the ability of soil to deliver these services is being drastically reduced in many locations, and global loss of soil ecosystem services is estimated to increase each year as a result of many different threats, such as erosion and soil carbon loss. The European Union Thematic Strategy for Soil Protection alerts policy makers of the need to protect soil and proposes measures to mitigate soil degradation. In this context, the European Commission-funded research project on Soil Transformations in European Catchments (SoilTrEC) aims to quantify the processes that deliver soil ecosystem services in the Earth's Critical Zone and to quantify the impacts of environmental change on key soil functions. This is achieved by integrating the research results into decision-support tools and applying methods of economic valuation to soil ecosystem services. In this paper, we provide an overview of the SoilTrEC project, its organization, partnerships and implementation.     

Study on turbulence characteristics and sensitivity of quadrant analysis to threshold level in Lake Taihu

Environmental Science and Pollution Research - The identification of coherent structures is very important in investigating the sediment transport mechanism and controlling the eutrophication in...     

The Investigation of the Toughening Mechanism of PHBV/PBAT with a Novel Hyperbranched Ethylenediamine Triazine Polymer Based Modifier: The Formation of the Transition Layer and the Microcrosslinking Structure

A new type of designed hyperbranched ethylenediamine trazine polymer (HBETP) is successfully synthesized and characterized based upon NMR and GPC. The prepared HBETP is used to modify the poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV)/poly(butylene adipate-co-terephthalate) (PBAT) blends. The effect of HBETP on the microstructure, mechanical properties and thermal properties of the blends is studied. The results indicate that upon addition of 1.0 wt% of HBETP, the impact strength of the PHBV/PBAT blends is increased by 47.1%; ?T_g of the blends decreases from 53.2 to 49.9 °C. These results, together with the morphology analysis of the fractured surface of the blends, conclude the formation of the transition layer between PHBV and PBAT. Also, the XRD result shows that the addition of HBETP can limit the growth of the PHBV crystals and causes the decrease of both the crystallinity and the grain crystalline size. The DSC result demonstrates that the addition of HBETP mainly affects the crystallization of the HB-HV binary eutectic region within PHBV. The mechanism of PHBV/PBAT toughening is due to the formation of the strong physical hydrogen bonding and the chemical micro-crosslinking between HBETP and PHBV/PBAT, which is proposed based on XPS characterization.     

Chemical deactivation of V2O5-WO3/TiO2 SCR catalyst by combined effect of potassium and chloride

V₂O₅-WO₃/TiO₂ catalyst was poisoned by impregnation with NH₄Cl, KOH and KCl solution, respectively. The catalysts were characterized by X-ray diffraction (XRD), inductively coupled plasma (ICP), N₂ physisorption, Raman, UV-vis, NH₃ adsorption, temperature-programmed reduction of hydrogen (H₂-TPR), temperature-programmed oxidation of ammonia (NH₃-TPO) and selective catalytic reduction of NO _x with ammonia (NH₃-SCR). The deactivation effects of poisoning agents follow the sequence of KCl>KOH?NH₄Cl. The addition of ammonia chloride enlarges the pore size of the titania support, and promotes the formation of highly dispersed V = O vanadyl which improves the oxidation of ammonia and the high-temperature SCR activity. K⁺ ions are suggested to interact with vanadium and tungsten species chemically, resulting in a poor redox property of catalyst. More importantly, potassium can reduce the Brønsted acidity of catalysts and decrease the stability of Brønsted acid sites significantly. The more severe deactivation of the KCl-treated catalyst can be mainly ascribed to the higher amount of potassium resided on catalyst.     

下垫面条件对流域极端事件影响及综合应对框架

在剖析下垫面条件变化对流域极端水文事件演变影响的基础上,构建了流域极端水文事件综合应对技术框架,并阐述其中的关键研究命题。结果表明,自然植被条件能够提高流域干旱之前土壤含水量并降低干旱过程中土壤蒸发速率,在一定程度上起到减缓干旱的强度和持续时间的作用;水利工程通过调节流域水资源的时空分布,增加可利用水资源量,能够缓解甚至规避流域干旱事件,但同时可能加剧坝址下游地区的干旱程度。自然植被条件将延长降水坡面产-汇流历时、降低洪峰流量,对极端降水洪涝事件具有一定的消减作用;此外,流域水土保持和修建水利工程等下垫面条件改变有利于河道行洪过程,能够起到缓解洪涝事件的作用。基于下垫面条件变化的流域极端水文事件综合应对技术框架包括旱涝事件监测、机理识别、影响评价和综合应对四个方面的内容,其中的关键研究命题主要为下垫面条件变化对流域极端水文事件影响的定量评估、面向流域极端水文事件合理的水土资源配置及其集成管理等。     

油田采出液乳化程度的影响因素试验研究

通过模拟油田采出液,考察了油水比、聚合物、表面活性剂及天然固体颗粒物对油田采出液乳化程度的影响。试验表明:随着油水比下降,模拟水样含油量降低,油珠Zeta电位升高,平均粒径变大,水样乳化稳定性减弱;HPAM会吸附于油珠表面从而增强其负电性,降低油珠间的有效碰撞,使油珠的平均粒径较小,导致油水分离较困难;表面活性剂会直接降低水样的表面张力,增强油水亲和性,导致水样含油量增大,同时增强了油珠的负电性,不利于油珠的集结聚并;天然固体颗粒物本身有一定的电负性,降低了油珠的Zeta电位,增加油珠的静电排斥,妨碍油珠的聚并,同时使水样的含油量升高,最终导致乳状液稳定。     

国内外石油公司甲烷排放差异性分析及启示

甲烷排放管控是国际石油公司推动低碳能源转型的一项重要举措,也是达成净零碳排放愿景的一个重要手段。研究发现,国内外石油公司的油气生产活动水平、甲烷排放控制水平、甲烷排放核算方法等3个方面均存在较大差异性。我国油井单井产量低,地面工程量大、工艺复杂,流程工艺中甲烷排放突出,油气系统甲烷排放水平较高,油气生产甲烷排放控制水平与国外石油公司相比尚有较大差距,与国外甲烷排放核算方法也存在较大差异性。着眼于甲烷排放管控,我国石油公司应充分衡量甲烷排放现状、生产活动水平、甲烷排放控制措施经济性和适用性等多重因素,严格控制潜在甲烷排放节点,并进一步做好甲烷排放检测、监测和数据统计工作,持续完善甲烷排放报告和核查体系。     

富水区隧道渗漏病害虹吸排水处置方法模型试验研究

针对隧道渗漏水病害问题,提出了一种新型隧道虹吸排水处置方法。通过室内物理模型试验,分析了虹吸排水作用对隧道围岩地下水的影响。结果表明:虹吸排水系统对地下水位的分布影响较大,虹吸管处地下水位变化尤为明显。降雨强度是影响虹吸排水流量的重要因素,降雨强度增大,虹吸排水流量先增大后维持最大流量不变,降雨所需疏干时间增长。围岩渗透系数与虹吸管径是影响地下水位分布与虹吸排水效果的重要因素,围岩渗透系数与虹吸管径越大,地下水位整体降深越大,虹吸排水流量维持在最大流量的稳定时间越短,地下水疏干时间越短,虹吸排水效果越好。     

Managing the adverse thermal effects of urban development in a densely populated Chinese city

Guangzhou city in South China has experienced an accelerated urban development since the 1980s. This paper examines the impact of the urban development on urban heat islands through a historical analysis of urban-rural air temperature differences. Remote sensing techniques were applied to derive information on land use/cover and land surface temperatures and to assess the thermal response patterns of land cover types. The results revealed an overriding importance of urban land cover expansion in the changes in heat island intensity and surface temperature patterns. Urban development was also related to a continual air temperature increase in the 1980s and 1990s. The combined use of satellite-derived vegetation and land cover distributions with land surface temperature maps provides a potential useful tool for many planning applications. The city's greening campaigns and landscaping designs should consider the different cooling effects of forest, shrubs and grassy lawns for temperature control and should plant more tall trees.     

动态臭氧/紫外线法处理磺基水杨酸废水

研究了在有或无紫外线 (UV)照射的条件下臭氧 (O3 )对磺基水杨酸废水的处理效果。用O3 与UV协同处理磺基水杨酸废水比仅用O3 和仅用UV的处理效果好得多 ,其COD去除率大于后二者的COD去除率之和。试验选用的动态O3 /UV法处理磺基水杨酸废水的工艺条件为 :O3 发生器放电功率 90 %× 180W ,UV功率 14W ,废水循环流速 10 0mL/min ,处理时间 90min。在此条件下 ,废水COD去除率可达 80 %左右。在上述的O3 发生器放电功率、UV功率、废水循环流速条件下 ,处理 1min时废水变澄清