Prediction of future disposal of end-of-life refrigerators containing CFC-11

The objective of this study was to predict the number of refrigerators containing CFC-11 blown isolation foam and the amount of CFC-11 banked in these refrigerators. By using a Weibull-based survival function, the number of CFC-11 containing and still-functioning refrigerators was estimated to be approximately 1.6 million in 2013 in Turkey. In order to determine the amount of CFC-11 in the isolation foam of these refrigerators, polyurethane (PU) foam samples were taken from a refrigerator manufactured in 1993 and the quantity of CFC-11 was analyzed by a GC-MS. It was determined that 113–195 mg CFC-11/g PU remains in the PU foam depending on the location such as door, sides, top and bottom. Knowing that a mid-sized refrigerator contains 4 kg PU on average, the total amount of PU foam to be disposed of is 6344 tons when the CFC-11 containing refrigerators in Turkey become obsolete in the near future. Furthermore, 717–1237 tons of CFC-11 are expected to be banked in the PU foam of these refrigerators which will exert an equivalent amount of ozone depleting potential (ODP). In addition, the global warming potential will vary between 3.4 and 5.9 million tons of CO₂.     

Types of Ectomycorrhiza as Pollution Stress Indicators: Case Studies in Slovenia

Mycorrhiza is the main spatial and temporal linkage between different constituents in a forest ecosystem. The functional compatibility and stress tolerance of ectomycorrhizal types is species specific, and therefore the information on the ectomycorrhizal community structure can add to the understanding of processes in forest ecosystems and can also be applied as tools for bioindication of pollution stress in forest soils. We have studied the effects of pollution (N and S) on trees and forest soils by: (1) quantification of ECM types diversity as in situ indicators in forest stands, (2) determination and quantification of pollution-sensitive or -insensitive ECM types as passive monitors, (3) root growth and development of ECM on nonmycorrhizal spruce seedlings, planted at the studied sites (active monitors), and (4) ECM infection (a bioassay based on mycorrhizal inoculum potential) of seedlings in an experimental set-up as ex situ testers. ECM species richness for Norway spruce trees (Picea abies) showed higher values in unpolluted sites than in polluted ones, while the differences were not significant for European beech trees (Fagus sylvatica). As pollution-sensitive or -insensitive ECM species in spruce forests, we suggest Hydnum rufescens (sensitive) and Paxillus involutus (unsensitive). Mycorrhizal potential in Norway spruce seedlings as a bioassay for soil N and S pollution was effective, and is suggested as an additional, standardized and widely comparable system in bioindication of soil pollution.     

Climate impact on social systems: the risk assessment approach

A novel approach to the problem of estimating climate impact on social systems is suggested. This approach is based on a risk concept, where the notion of critical events is introduced and the probability of such events is estimated. The estimation considers both the inherent stochasticity of climatic processes and the artificial stochasticity of climate predictions due to scientific uncertainties. The method is worked out in some detail for the regional problem of crop production and the risks associated with global climate change, and illustrated by a case study (Kursk region of the FSU). In order to get local climatic characteristics (weather), a so-called statistical weather generator is used. One interesting finding is that the 3% risk level remains constant up to 1.0–1.1°C rise of mean seasonal temperature, if the variance does not change. On the other hand, the risk grows rapidly with increasing variance (even if the mean temperature rises very slowly). The risk approach is able to separate two problems: (i) assessment of global change impact, and (ii) decision making. The main task for the scientific community is to provide the politicians with different options; the choice of admissible (from the social point of view) critical events and the corresponding risk levels is the business of decision makers.     

柴窝堡湖表层底泥重金属污染评价

研究了乌鲁木齐市柴窝堡湖表层底泥的重金属含量,并采用Hakanson潜在生态危害指数法对底泥中的重金属潜在生态风险进行评价。结果表明:底泥中Cu、Zn、Pb、Cd含量均超出乌鲁木齐市土壤背景值。除湖心区外,Cd在5个监测区域中的潜在生态危害均为中等;其它重金属在5个采样点的潜在生态危害均为轻微。各重金属间的相关性分析表明,Zn与Cu,Pb与Cd、Cu呈显著正相关,说明这4种元素污染源可能相同。柴窝堡湖表层底泥受到Cu、Zn、Pb、Cd污染,需采取相应措施防止重金属由底泥进入水相。     

Re-use of remediated soils for the bioremediation of waste oil sludge

We investigated the possibility of re-using remediated soils for new bioremediation projects by spiking these soils with waste oil sludge in laboratory based microcosms. The level of Total Petroleum Hydrocarbon (TPH) reduction was high (>80%) in naturally attenuated microcosms and was not significantly improved by biostimulation, bioaugmentation and the combined treatment of bioaugmentation and biostimulation by week 12. This indicated that the observed TPH reduction might have been related to the soil's inherent hydrocarbon-degrading potential. Microbial community analysis (16S rDNA and ITS-based Denaturing Gradient Gel Electrophoresis fingerprints) confirmed the dominance of hydrocarbon degrading genera such as Alcanivorax and Scedosporium. Cluster and Shannon diversity analysis revealed similar but stable bacterial and fungal communities in naturally attenuated and amended microcosms indicating that rapid reduction in TPH may not always be accompanied by changes in soil microbial communities. This study has therefore shown that soils previously used for bioremediation can have an improved hydrocarbon degrading potential which was successfully re-harnessed for new projects. This ability to re-harness this potential is attractive because it substantially reduces operational costs as no additional bioremediation treatments are needed. It can also extend a landfill's lifespan as soils can be re-used again before landfill disposal.     

Human Impacts to River Temperature and Their Effects on Biological Processes: A Quantitative Synthesis1

Hester, Erich T. and Martin W. Doyle, 2011. Human Impacts to River Temperature and Their Effects on Biological Processes: A Quantitative Synthesis. Journal of the American Water Resources Association (JAWRA) 47(3):571‐587. DOI: 10.1111/j.1752‐1688.2011.00525.x Abstract: Land‐use change and water resources management increasingly impact stream and river temperatures and therefore aquatic organisms. Efforts at thermal mitigation are expected to grow in future decades. Yet the biological consequences of both human thermal impacts and proposed mitigation options are poorly quantified. This study provides such context for river thermal management in two ways. First, we summarize the full spectrum of human thermal impacts to help thermal managers consider the relative magnitudes of all impacts and mitigation options. Second, we synthesize biological sensitivity to river temperature shifts using thermal performance curves, which relate organism‐level biological processes to temperature. This approach supplements the popular use of thermal thresholds by directly estimating the impact of temperature shifts on the rates of key biological processes (e.g., growth). Our results quantify a diverse array of human thermal impacts, revealing that human actions tend to increase more than decrease river temperatures. Our results also provide a practical framework in which to quantify the sensitivity of river organisms to such impacts and related mitigation options. Finally, among the data and studies we synthesized, river organisms appear to be more sensitive to temperature above than below their thermal maxima, and fish are more sensitive to temperature change than invertebrates.     

基于不确定性分析的垃圾焚烧烟气中重金属的土壤沉积及生态风险评估

采用CALPUFF模式模拟某城市垃圾焚烧烟气中重金属Pb和Cd的地面大气浓度,并借助土壤浓度模型以Monte Carlo模拟不确定性处理方法估算重金属经沉降在土壤中的累积,最后利用潜在生态危害指数法对重金属在土壤中的长期累积量进行生态风险评估.结果表明,Pb和Cd的大气浓度最大值分别为5.59×10-3μg·m-3和5.57×10-4μg·m-3,土壤浓度增量中值最大分别为2.26 mg·kg-1和0.21 mg·kg-1;高生态风险区集中在焚烧炉附近的下风向地区,生态风险主要由Cd贡献,Pb基本无污染风险;城市最大污染点达较高生态危害水平概率为55.30%,农村最大污染点达中等生态危害水平概率达72.92%.此外,对土壤浓度模型的参数进行敏感性分析表明,城、乡区域模拟结果分别对土壤混合厚度和干沉降速率敏感性最强.     

陕西省ODS使用量分布特征的分析

通过调查陕西省消耗臭氧层物质(ODS)的销售和使用量,分析了陕西省消耗臭氧层物质的行业和地区分布特征。根据各受控物质的特点,计算了这些物质的实际使用量的臭氧消耗潜能(ODP)值。结果表明,2008年陕西省使用的ODS总量约为679.95 t,按照ODP值折算,相当于约132.76 t当量CFC-11。ODS的使用主要集中在清洗行业和制冷行业,区域重点在西安市。     

疏松型纳滤膜对饮用水中无机阳离子的截留特性及分离选择性

选用典型疏松型纳滤膜NF270对离子强度为1.5~24 mmol·L^-1的3种无机盐（MgCl₂、CaCl₂、NaCl）的单一盐溶液、混合盐溶液（MgCl₂/CaCl₂+NaCl）及某地下水进行纳滤实验,解析该膜在不同离子环境中的阳离子截留特性,并考察Ca²⁺/Mg²⁺在膜表面的吸附及对膜表面电荷的屏蔽作用对静电效应和盐离子截留率的影响.结果表明,NF270膜表面负电荷密度较高,对Ca²⁺和Mg²⁺都具有较强的吸附效应.NF270过滤相同离子强度的3种单一盐溶液时（特别是离子强度为1.5~6 mmol·L^-1）,道南效应较为显著,限定性离子Cl^-发挥了重要作用,截留率关系为NaCl >MgCl₂≈CaCl₂.混合盐溶液中,Ca²⁺/Mg²⁺显著降低了膜表面电势的绝对值,在道南效应、空间位阻效应和介电效应的综合作用下,Ca²⁺/Mg²⁺在反离子竞争中占据优势,截留率关系为Ca²⁺/Mg²⁺>Na⁺.地下水中同样存在反离子竞争效应,且由于SO₄^2-的存在,提高了各反离子的截留率.     

微孔曝气与覆盖对城市重污染河道底泥磷形态分布及释放过程的影响

采用自行研发的泥-水界面微孔曝气系统,开展了底泥表面曝气和覆盖对城市重污染河道底泥磷释放及形态分布规律的影响研究.结果表明,微孔曝气能够有效提高上覆水的溶解氧(DO)和沉积物的氧化还原电位(Eh),能够将泥-水界面Eh维持在-100 m V左右,DO提高到6 mg·L-1以上.与对照比较,原位覆盖处理的上覆水DO和Eh有一定提高,但仍明显低于微孔曝气处理.与对照相比较,微孔曝气处理均有效降低上覆水中总磷(TP)和溶解性正磷酸盐(PO3-4)的含量.试验结束时,微孔曝气(A)和微孔曝气+原位覆盖处理(A+C)上覆水中TP含量由初始的0.201 mg·L-1分别降至0.062 mg·L-1和0.050 mg·L-1;上覆水中PO3-4含量由0.086 mg·L-1和0.078 mg·L-1分别降至0.026 mg·L-1和0.023 mg·L-1.与对照相比,微孔曝气处理明显降低了底泥间隙水中TP的浓度,在整个培养期间,其TP含量平均下降38.8%(A)和47.9%(A+C).底泥原位覆盖处理对抑制泥-水界面磷释放能力要弱于微孔曝气处理,而且在试验后期(50 d),上覆水中TP和PO3-4的含量均有所反弹.不管有无覆盖,泥-水界面微孔曝气处理均显著改变了表层底泥磷形态分布特征,显著降低了底泥中铁铝结合态磷(Fe/Al-P)组分比例,而钙结合态磷(Ca-P)含量比例却出现明显增加.单一的表面覆盖处理对底泥磷形态分布特征没有显著影响(P0.05).研究表明,与单一的处理效果相比较,泥-水界面纳米微孔曝气处理,并结合底泥原位覆盖,更有利于抑制城市重污染河道泥-水界面中磷的释放风险.