Directions for combustion engine aerosol measurement in the 21st century

The Coordinating Research Council convened two Real-Time PM Measurement Workshops in December 2008 and March 2009 to take an intensive look at the current status and future directions of combustion aerosol measurement. The purpose was to examine the implications of parallel rapid developments over the past decade in ambient aerosol science, engine aftertreatment technology, and aerosol measurement methodology, which provide benefits and challenges to the stakeholders in air quality management. The workshops were organized into sessions targeting key issues in ambient and source combustion particulate matter (PM). These include (1) metrics to characterize and quantify PM, (2) the need to reconcile ambient and source measurements, (3) the role of atmospheric transformations on modeling emissions and exposures, (4) the impact of sampling conditions on PM measurement, and (5) the potential benefits of novel PM instrumentation. This paper distills the material presented by subject experts and the insights derived from the in-depth discussions that formed the core of each session. The paper's objectives are to identify areas of consensus that allow wider practical application of the past decade's advances in combustion aerosol measurement to improve emissions and air quality modeling, develop emissions reduction strategies, and to recommend directions for progress on issues in which uncertainties remain.     

Coupled solar photo-Fenton and biological treatment for the degradation of diuron and linuron herbicides at pilot scale

A coupled solar photo-Fenton (chemical) and biological treatment has been used to remove biorecalcitrant diuron (42 mg l(-1)) and linuron (75 mg l(-1)) herbicides from water at pilot plant scale. The chemical process has been carried out in a 82 l solar pilot plant made up by four compound parabolic collector units, and it was followed by a biological treatment performed in a 40 l sequencing batch reactor. Two Fe(II) doses (2 and 5 mg l(-1)) and sequential additions of H2O2 (20 mg l(-1)) have been used to chemically degrade the initially polluted effluent. Next, biodegradability at different oxidation states has been assessed by means of BOD/COD ratio. A reagent dose of Fe=5 mg l(-1) and H2O2=100 mg l(-1) has been required to obtain a biodegradable effluent after 100 min of irradiation time. Finally, the organic content of the photo-treated solution has been completely assimilated by a biomass consortium in the sequencing batch reactor using a total suspended solids concentration of 0.2 g l(-1) and a hydraulic retention time of 24h. Comparison between the data obtained at pilot plant scale (specially the one corresponding to the chemical step) and previously published data from a similar system performing at laboratory scale, has been carried out.     

Photocatalytic treatment of dimethoate by solar photocatalysis at pilot plant scale

Titanium dioxide photocatalysis, using 200 mgl⁻¹ of TiO₂, and photo-Fenton, using 20 mg l⁻¹ of iron, were applied to the treatment of dimethoate dissolved in water at 50 mg l⁻¹. A heterogeneous photocatalysis test was performed in a 35-l solar pilot plant with Compound Parabolic Collectors (CPCs) under natural illumination. A homogeneous photocatalysis test was performed in a different solar pilot plant with four CPC units and a total volume of 75 l. In this work total disappearance of dimethoate and 90% of mineralization were attained in both solar treatments. Treatment time, hydrogen peroxide consumption and ferric phosphate precipitation during photo-Fenton treatment were discussed. An erratum to this article can be found at     

玉米自交系氮效率基因型差异的比较研究

采用溶液培养的方法。选用经田间，土壤试验对N反应有典型差异的玉米自交系478，H21，Wu312,Zong31,Baici，在4个供氮水平下（0.04,0.4,2和4nmol/L)，研究了不同基因型玉米苗期氮素吸收，利用的差异及其原因，结果表明：极低N胁迫条件下（０.04mmol/L),总干重的基因型差异是由根系，地上部的共同作用的结果，高N下，总干重是由地上部的差异所决定的（表1），极低供N条件下，4578的总干重最大，且有较高的氮效率，Wu312,Zong31相对较低，478相对较高的氮效率主要来源于吸收效率的差异。该基因型在低N下总吸氮量最高，H21居中，Baici,Zong31相对较低，478相对较高的氮效率主要来源于吸收效率的差异。该基因型在低N下总吸氮量最高，H21居中，Baici,Zong31,Wu312相对较低（图1），吸收效率的差异主要是由于根系全N量的不同所致（图3），而根系全N量的差异主要是由于根系大小不同（表1），在极低氮水平下，不同基因型玉米根系全氮量的变幅比地上部高出28.1%，高N下（4mmol/L)，全N量的变幅比地上部高出15.4%(图2，图3），在0.04mmol/L下，478与Wu312,Zong31的利用效率不存在显著差异（表2）。     

喀斯特地区丛枝菌根真菌多样性研究进展

丛枝菌根真菌（Arbuscular Mycorrhizal Fungi,AM真菌）在喀斯特地区生态修复中具有潜在的可利用性,关于喀斯特地区AM真菌多样性以及生态功能的研究已成为近年来的热点问题。本文归纳了喀斯特地区分离出的AM真菌名录,旨在为喀斯特高效生态修复菌种筛选提供支撑材料。综述了喀斯特地区土壤石灰性、营养物质匮乏、空间异质性强,植被逆向演替、植物种类多样等特点对喀斯特地区AM真菌多样性的影响规律,总结了AM真菌对于喀斯特地区土壤结构、营养元素循环、植物抗旱性、植物个体养分吸收、植被演替方面的生理生态功能及作用机理,以期为喀斯特地区AM真菌适生性研究、AM真菌潜在生态功能有效利用、AM真菌-植物共生体系筛选与培育等环节做出指引,为菌根技术在喀斯特生态修复中的应用提供理论基础。未来的研究应进一步深入探究AM真菌多样性影响机制,探讨AM真菌与植物适生性之间的关系,以及加强AM真菌-植物共生体系筛选与培育。     

18650型锂离子电池燃烧特性及火灾危险性评估

为评估18650型锂离子电池的火灾危险性,以3种不同品牌的商品三元18650型锂离子电池为研究对象,采用锥形量热仪在不同辐射热和荷电状态下对3种电池进行了燃烧试验,分析了电池的热释放参数、烟参数、毒性参数和质量损失参数。并在试验的基础上构建了锂离子电池火灾危险性综合评估指标体系,计算了这3种电池在辐射热35kW/m^2及品牌1的18650型锂离子电池在25 kW/m^2条件下的火灾危险指数。结果表明:电池的热参数和毒性参数随电池荷电状态(SOC)和辐射热增大而增大,满电状态下的品牌1电池在辐射热为50 kW/m^2、35 kW/m^2和25 kW/m^2时的热释放速率峰值分别为9.23 kW、8.64 kW和6.26 kW;生烟量随电池SOC和辐射热增大而减小;综合评估得出了3种电池的火灾危险性。     

海水对含水层沉积物中镭解吸的模拟实验

本研究采用莱州湾沿岸含水层中的沉积物,通过渗滤实验模拟镭的解吸过程。结果表明,在典型的地下水流速范围内(0.02~0.30 cm/min),镭同位素(223Ra、224Ra、226Ra)的解吸没有显著变化。在海水与淡水的混合过程中,解吸的镭比活度与水的盐度呈显著的线性正相关关系。当盐度超过海水盐度时(如S=80的卤水中),解吸的镭比活度则趋于最值平台。对比模拟估算的地下水中镭的比活度与莱州湾沿岸实测间隙水中镭的比活度,223Ra和224Ra的结果基本一致,而226Ra的实测结果较模拟估算结果偏小。可能由于含水层中226Ra经反复解吸后得不到母体核素及时补充所致。本研究将为更好地理解镭同位素在含水层中的地球化学行为提供科学依据,为合理地选择量化海底地下水排放(submarine groundwater discharge,SGD)模型的镭端元值提供新的参考视角。     

Environmental impact assessment of non-wood based pulp production by soda-anthraquinone pulping process

Paper pulp manufacturing is the main non-food industrial utilization of plant biomass. Non-wood and agricultural residues are potential raw materials in the production of specialty papers. This chapter aims to quantify the environmental impacts associated with non-wood high quality paper pulp manufacture via soda-anthraquinone (AQ) cooking process by means of the application of LCA methodology in a cradle-to-gate analysis. Hemp (Cannabis sativa) and Flax (Linum usitatissimum) were evaluated as raw materials for the production of high quality non-porous pulp. A specialty paper pulp mill was analysed in detail and process chain was divided in six subsystems: agricultural activities, chemicals production, electricity production, transport, pulp production and waste treatment. Inventory data came from interviews and surveys (on-site measurements). When necessary, the data were completed with bibliographic resources.Abiotic resources depletion (AD), global warming (GW), ozone layer depletion (OLD), human toxicity (HT), ecotoxicity, photochemical oxidant formation (POF), acidification (A) and eutrophication (E) were the impact categories analysed in this study. According to the results, the environmental impact is mainly caused by the production of chemicals, electricity and fibres (agricultural activities) due to greenhouse gases emissions, phosphorous and nitrogen compounds emissions. The activities inside the pulp mill present minor contribution to almost all impact categories, excluding GW (15%) and E (6%) as well as OLD (25%). This study provides useful information for non-wood based industries related not only to pulp manufacture but also to panels or biorefineries with the aim of increasing their sustainability.     

MS SQL SERVER复制技术在地震前兆数据集成中的应用

基于WINDOWS NT 网络操作系统的MS SQL SERVER复制环境，分析并探讨了SQL SERVER复制技术、 复制模块的参数设置及其在地震前兆数据集成中的应用。 通过实例说明了SQL SERVER复制技术在地震前兆数据集成中应用的可行性。 同时，对复制过程中常出现的事务日志空间问题进行了剖析，并提出了解决办法。 分析结果表明，应用SQL SERVER复制技术进行数据交换、 共享及应用是较为有效的，而且也是可行的。     

梦清园芦苇湿地根际微生物特性研究

本文通过对上海市梦清园芦苇湿地净化苏州河污染水体的示范工程采样分析，结果表明芦苇根际的微生物数量、酶的活性高于非根际的土壤。根际细菌、真菌和放线菌的数量均比非根际多，R／S平均值分别为70．3、9．5、2．9。相对于硝酸细菌而言亚硝酸细菌的根际效应较为明显，无论根际还是非根际的亚硝酸细菌数量均高于硝酸细菌的数量。根际细菌和硝化细菌数量随着水力停留时间增加而增加，而根际反硝化细菌数量则减少。菌剂和酶制剂的加入使得非根际泥样异养细菌、真菌、放线菌和亚硝酸细菌比对照组稍高，硝酸细菌和反硝化细菌则较少；而根际泥样中加菌剂和酶制剂组微生物数量比空白组高出1—2个数量级，在投加菌和酶制剂后酶活性无论在根际还是非根际都得到提高，高于对照组约5—6个酶活单位。