催化臭氧化降解有机废水及影响因素

主要论述了自制的V-O型催化荆催化臭氧化降解有机废水的研究。试验表明，以TiO2，SiO2，ZrO2作栽体，在氮气或氧气中焙烧，而制得的6种催化荆中，V-O／SiO2／N2显示了较好的催化性能和活性；通过催化荆吸附试验和在反应体系中加入一定量的自由基猝灭荆，初步探讨了其催化机理，即催化荆和臭氧反应，生成了氧化性极强的羟基自由基；催化臭氧化时间、催化荆用量、进气臭氧浓度、体系pH值等因素均对降解产生一定的影响。     

中国高放废物地质处置:现状和展望

本文阐述了中国的高放废物处置政策,回顾了中国高放废物地质处置在选址和场址评价、缓冲回填材料等方面的进展,提出了中国高放废物地质处置的初步规划,指出我国计划在2015年确定地下实验室场址.还展望了国际合作前景.     

Efficient use of resources: urban waste ash and soil fertility on the Jos Plateau, Nigeria

Waste disposal constitutes an acute problem in numerous African cities. One solution could lie in the recycling of the nutrient-rich waste into agriculture taking place in and around cities. Farmers involved in vegetable production around Jos, Nigeria, have developed a sophisticated soil fertility management strategy combining inorganic fertilizers, manure and urban waste ash. This paper: (1) investigates the socio-economic constraints linked to obtaining scarce organic inputs, particularly urban waste ash and the health hazards (particularly heavy metal contamination of soil and crops) caused by using this ash and (2) suggests ways to improve use of this important resource.     

Preservation of coal-waste geochemical markers in vegetation and soil on self-heating coal-waste dumps in Silesia,Poland

Occurrence and distributions of geochemical markers on vegetation and in soils covering two self-heating coal waste dumps were investigated with gas chromatography-mass spectrometry (GC–MS) and compared with those of bitumen expelled on the coal waste dump surface. Presence of biomarkers, alkyl aromatic hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), and such polar compounds as phenols indicate that components of self-heating coal wastes indeed migrate to soils and plants surface and their characteristic fingerprints can be applied in passive monitoring to investigate migration of contaminants from self-heating coal wastes. Moreover, results allow to discriminate between the Upper- and Lower Silesian coal basins, notwithstanding value shifts caused by heating. Mechanisms enabling the migration of geochemical compounds into soils include mixing with weathered coal-waste material, transport in gases emitted due to self-heating and, indirectly, by deposition of biomass containing geochemical substances. Transport in gases involves mostly lighter compounds such as phenols, methylnaphthalenes, methylbiphenyls, etc. Distributions and values of geochemical ratios are related to differences in their boiling temperatures in the case of lighter compounds but preserve geochemical features in the case of heavier compounds such as pentacyclic trierpanes.     

Evidence of technetium and iodine release from a sodalite-bearing ceramic waste form

Sodalites have been proposed as a possible host of certain radioactive species, specifically ⁹⁹Tc and ¹²⁹I, which may be encapsulated into the cage structure of the mineral. To demonstrate the ability of this framework silicate mineral to encapsulate and immobilize ⁹⁹Tc and ¹²⁹I, single-pass flow-through (SPFT) tests were conducted on a sodalite-bearing multi-phase ceramic waste form produced through a steam reforming process. Two samples made using a steam reformer samples were produced using non-radioactive I and Re (as a surrogate for Tc), while a third sample was produced using actual radioactive tank waste containing Tc and added Re. One of the non-radioactive samples was produced with an engineering-scale steam reformer while the other non-radioactive sample and the radioactive sample were produced using a bench-scale steam reformer. For all three steam reformer products, the similar steady-state dilute-solution release rates for Re, I, and Tc at pH (25 °C) = 9 and 40 °C were measured. However, it was found that the Re, I, and Tc releases were equal or up to 4.5x higher compared to the release rates of the network-forming elements, Na, Al, and Si. The similar releases of Re and Tc in the SPFT test, and the similar time-dependent shapes of the release curves for samples containing I, suggest that Re, Tc, and I partition to the sodalite minerals during the steam reforming process.     

高放废物处置库新疆阿奇山预选地段区域水文地质特征

新疆阿奇山地区是我国高放废物处置库预选地段之一。在野外调查、样品采集和测试的基础上,讨论了该地段区域水文地质特征,结果表明,阿奇山地段地下水可划分为松散岩类孔隙水、碎屑岩类裂隙孔隙水和基岩裂隙水3种类型,其单井涌水量一般10m~3/d,属于典型的低含水介质;区域地下水流向为自南东流向北西;位于吐鲁番盆地的艾丁湖一带为阿奇山地段地下水的最终排泄区。     

Profit,reputation and ‘doing the right thing’: Convention theory and the problem of food waste in the UK retail sector

In 2014, Tesco – one of the world’s largest food retailers – revealed that it had generated almost 57,000 tonnes of food waste in its UK operations over the previous twelve-month period. This shocking statistic added to existing evidence of a significant environmental and social problem in the UK and across the world. This paper utilises convention theory to examine the role of major retailers in the context of this global problem and assesses their motivations for acting on food waste. Drawing on interviews with key stakeholders (including major retailers), the analysis investigates their main justifications for action on food waste. It finds that retailers mostly appealed to three conventions or ‘orders of worth’ (civic, market and opinion) and used these as a basis for their commitment to food waste reduction. We argue that the combination of these different justifications is feasible and necessary in the context of the retail sector but that they may also lead to some unintended consequences (in the retail sector and beyond). Crucially, we demonstrate how the dilution of civic justifications (by their financial and reputational counterparts) might produce negative outcomes and inaction as retailers attempt to adhere to the so-called ‘food waste hierarchy’. The paper highlights the continuing significance of convention theory as a framework for analysing possible responses to the social and environmental challenges confronting global agro-food systems.     

处置单元核素135Cs迁移数值模拟研究

根据高放废物地质处置库概念设计,以北山花岗岩为参考岩性,内蒙古高庙子膨润土为参考缓冲材料,使用数值模拟软件tough2对放射性核素¹³⁵Cs在处置单元及其围岩中的迁移行为进行了数值模拟研究,考虑放射性核素衰变释热对核素迁移的影响。研究表明:膨润土对核素具有较强的滞留作用,模拟200000年后核素在花岗岩中迁移了1 m左右,且峰值为10-6个数量级;前10 a模型的温度变化最剧烈且温差最大,10 a后模型整体温度开始降低,2 000 a后整体温度接近于初始温度;温度的变化会引起核素迁移速率的改变,但总体温度对核素迁移的影响不大。     

花岗岩风化料弃土快速堆填过程中不排水抗剪强度评估

沿海沿江城市地下开挖产生的工程渣土含泥量大、含水率高且较松散,主要运往渣土场进行堆填处置。由于产量巨大而处置场地有限,许多渣土场在运营过程中存在堆填速度快、缺乏排水设施、超高超库容堆填等问题,容易引发堆填体失稳事故。目前对于非饱和工程渣土堆体在快速堆填过程中的失稳机制认识尚不清晰,尤其是对这一过程中的高饱和度工程渣土强度增长规律缺乏足够的认识。以深圳红坳渣土场填料——花岗岩风化料(CDG)填土为研究对象,对不同初始饱和度土样进行三轴不排水不排气等向压缩和剪切试验,结果表明:非饱和CDG填土不排水抗剪强度随围压增大呈非线性增长,增长速率与试样初始饱和度密切相关;当土样压缩后的饱和度超过0.7,不排水强度随围压的增长速率显著降低。基于有效固结应力法的原理,结合Hilf孔压公式和修正剑桥模型,提出了一种工程渣土不排水抗剪强度估算方法,并通过与试验结果对比验证了该方法对初始饱和度高于0.6的CDG填土的适用性。利用该方法确定的不排水强度cu与正应力σn的关系可应用于高饱和度工程渣土快速堆填中的稳定性分析。     

Transforming agricultural land use through marginal gains in the food system

There is an increasing need for transformational changes in the global food system to deliver healthy nutritional outcomes for a growing population while simultaneously ensuring environmental sustainability. However, such changes are subject to political and public constraints that usually allow only gradual, incremental changes to occur. Drawing inspiration from the British cycling team’s concept of marginal gains, we show how transformation might be reconciled with incremental changes. We demonstrate that a set of marginal food system changes acting to increase production efficiency, to reduce losses or to adjust diets could collectively reduce the agricultural land required globally for food production by 21%, or over a third given higher adoption rates. The results show that while all categories of action are important, changes in consumer choices in Europe, North America and Oceania and in the supply-chain in Africa and West and Central Asia have the greatest potential to reduce the land footprint of the food system.