垃圾焚烧中氯化物对重金属Cd迁移转化特性的影响

采用管式炉和模拟垃圾对垃圾焚烧中氯化物对重金属Cd迁移转化特性的影响进行了研究,使用ICP-AES(美国EPA消解方法)、SEM、EDS和XRD分析技术对重金属浓度、灰渣表面形貌、成分和灰渣X射线衍射物相等进行了分析.结果表明,氯化物的加入均使得97％以上的Cd分布于飞灰中,且随氯化物含量的增加在飞灰中的分布逐渐增加.有机氯PVC和无机氯NaCl含量的变化对Cd迁移分布的影响没有显著差别.PVC对Cd迁移分布影响受温度影响显著,550℃时Cd在飞灰中分布为80.51%,850℃时Cd在飞灰中的分布上升为97.91%,但在温度超过CdCl₂的熔点568℃后温度的影响较小.NaCl对Cd的迁移分布受温度影响不明显,加入NaCl后550℃时Cd在飞灰中分布为95.02%,1 000℃时在飞灰中的分布为96.58%.氯化物存在下停留时间对Cd迁移分布没有显著影响.底渣和飞灰的SEM/EDS和XRD分析表明,PVC和NaCl对Cd迁移转化作用机理不同.     

典型污染源中多环麝香的污染特征

合成麝香是一类近十多年才引起人们关注的有机污染物.合成麝香广泛分布于环境中.难降解,易生物富集,对水生生物和人体均呈现一定的生物毒性.文章对某一化妆品厂生产车闯内、外及工厂外的上、下风向大气中多环麝香进行了定性定量分析,结果表明,除ATⅡ之外,大气中检测出了五种多环麝香,其中作为对照点的上风向多环麝香总浓度为5.43ng/m3,而工厂室内、外及下风向的多环麝香浓度范围为17.25～5543.4ng/m3;气固分配实验研究发现,超过68.43%的多环麝香分布于气相中.     

浅论海洋沉积物标准的几个问题

简要介绍了海洋沉积物质量基准的研究方法，重点讨论了平衡分配法在确定沉积物基准研究中的广泛用途。理论计算结果与两个海湾多年的监测结果相吻合。     

Combined UV-biological degradation of PAHs

The UV-photolysis of PAHs was tested in silicone oil and tetradecane. In most cases, the degradation of a pollutant provided within a mixture was lower than when provided alone due to competitive effects. With the exception of anthracene, the larger pollutants (4- and 5-rings) were always degraded first, proving that UV-treatment preferentially acts on large PAHs and thereby provides a good complement to microbial degradation. UV-photolysis was also found to be suitable for treatment of soil extract from contaminated soils. The feasibility of UV-biological treatment was demonstrated for the removal of a mixture of phenanthrene and pyrene in silicone oil. UV-irradiation of the silicone oil led to 83% pyrene removal but no phenanthrene photodegradation. Subsequent treatment of the oil in a two-phases partitioning bioreactor (TPPB) system inoculated with Pseudomonas sp. was followed by complete phenanthrene biodegradation but no further pyrene removal. Totally, the combined process allowed 92% removal of the PAH mixture. Further work should focus on characterizing the photoproducts formed and studying the influence of the solvent on the photodegradation process.     

2种常规水稻Cd、Zn吸收与器官分配的生育期变化：品种、土壤和Cd处理的影响

Cd在土壤-作物-膳食食物链中的迁移是人类对环境Cd暴露及其健康风险的主要途径,而水稻是子粒Cd积累最强的大宗作物之一.采用全生育期淹水盆栽试验研究了2种常规水稻(高Cd吸收品种“苏香粳1号”和低Cd吸收品种“99-22”)在添加Cd(2mg·kg-1)和不添加Cd处理下对2种土壤(红沙泥田,乌栅土)中Cd、Zn的吸收及其生育期变化.结果表明:1)常规水稻对Cd、Zn的吸收积累受土壤、品种和外源Cd的影响.Cd处理、土壤、品种间的正交互作用(高Cd吸收品种植于高Cd处理且Cd有效性高的红壤中)使常规稻植株Cd/Zn比成数十倍提高,从而使子粒Cd/Zn比产生强烈升高;2)水稻对Cd、Zn的吸收强度因不同生育期而异,Cd吸收的主要时期是分蘖期和成熟期,而Zn吸收的主要时期则是分蘖期、抽穗期和灌浆期.在整个生育期中,水稻Cd吸收伴随着对Zn的排斥现象,这在高Cd吸收下尤为强烈;3)水稻各器官对Cd、Zn的吸收分配无论是同品种的生育期间抑或同生育期时的不同品种间均有显著差异.Cd积累量为根系>穗粒>茎叶,而Zn却表现为茎叶>根系、穗粒.观察到水稻吸收的Cd在生育后期向穗粒的强烈运移.相对于低Cd吸收品种来说,Cd向穗粒转运较强,而Zn的转运较弱是高Cd吸收品种子粒Cd积累强而Cd/Zn比高的植株因素.     

土壤,沉积物中微量金属形态分配预测初步研究

本文讨论了土壤、沉积物中微量金属的形态分配预测问题。对已有的一些工作进行了总结,并以我国东部平原为例,建立了土壤微量金属多元回归相分配预测摸型。     

袁河流域不同土地利用方式下河流浮游细菌群落结构特征

于2018年8月采集袁河上游至下游的16个采样点表层水样,基于高通量测序技术分析土地利用方式下河流浮游细菌群落特征并对比土地利用与水化学指标对浮游细菌群落的影响差异.结果表明：①袁河优势浮游细菌群落为变形菌门（Proteobacteria,35.17%）,放线菌门（Actinobacteria,33.99%）和拟杆菌门（Bacteroidetes,17.59%）,其中Bacteroidetes丰度随流向显著降低;②受农田和建设用地增加的影响,袁河上、下游河段细菌群落多样性均随流向呈升高趋势;中游河段浮游细菌群落多样性由于湖库滞留作用明显下降;③水域和林地是土地利用方式中最佳组合因子,土地利用方式显著影响浮游细菌群落,两者相关系数为0.4797,土地利用方式对浮游细菌群落的方差解释量为31.3%;④土地利用方式对浮游细菌群落的影响大小与水化学指标相近,同时存在土地利用方式与水化学的交叉影响（方差解释量为10.9%）,表明在袁河浮游细菌群落的形成中,质量效应与物种分选机制并存.本研究表明,在河流浮游细菌研究中要重视流域土地利用方式造成的外源细菌输入差异,以及土地利用方式输入的不同水化学成分对浮游细菌的分选作用.     

Organic aerosol molecular composition and gas–particle partitioning coefficients at a Mediterranean site (Corsica)

Molecular speciation of atmospheric organic matter was investigated during a short summer field campaign performed in a citrus fruit field in northern Corsica(June 2011). Aimedat assessing the performance on the field of newly developed analytical protocols, this work focuses on the molecular composition of both gas and particulate phases and provides an insight into partitioning behavior of the semi-volatile oxygenated fraction. Limonene ozonolysis tracers were specifically searched for, according to gas chromatography–mass spectrometry(GC–MS) data previously recorded for smog chamber experiments. A screening of other oxygenated species present in the field atmosphere was also performed. About sixty polar molecules were positively or tentatively identified in gas and/or particle phases. These molecules comprise a wide range of branched and linear, mono and di-carbonyls(C_3–C7),mono and di-carboxylic acids(C_3–C_18), and compounds bearing up to three functionalities.Among these compounds, some can be specifically attributed to limonene oxidation and others can be related to α- or β-pinene oxidation. This provides an original snapshot of the organic matter composition at a Mediterranean site in summer. Furthermore, for compounds identified and quantified in both gaseous and particulate phases, an experimental gas/particle partitioning coefficient was determined. Several volatile products, which are not expected in the particulate phase assuming thermodynamic equilibrium, were nonetheless present in significant concentrations. Hypotheses are proposed to explain these observations, such as the possible aerosol viscosity that could hinder the theoretical equilibrium to be rapidly reached.     

Trace element partitioning in ashes from boilers firing pure wood or mixtures of solid waste with respect to fuel composition,chlorine content and temperature

Trace element partitioning in solid waste (household waste, industrial waste, waste wood chips and waste mixtures) incineration residues was investigated. Samples of fly ash and bottom ash were collected from six incineration facilities across Sweden including two grate fired and four fluidized bed incinerators, to have a variation in the input fuel composition (from pure biofuel to mixture of waste) and different temperature boiler conditions. As trace element concentrations in the input waste at the same facilities have already been analyzed, the present study focuses on the concentration of trace elements in the waste fuel, their distribution in the incineration residues with respect to chlorine content of waste and combustion temperature.Results indicate that Zn, Cu and Pb are dominating trace elements in the waste fuel. Highly volatile elements mercury and cadmium are mainly found in fly ash in all cases; 2/3 of lead also end up in fly ash while Zn, As and Sb show a large variation in distribution with most of them residing in the fly ash. Lithophilic elements such as copper and chromium are mainly found in bottom ash from grate fired facilities while partition mostly into fly ash from fluidized bed incinerators, especially for plants fuelled by waste wood or ordinary wood chips. There is no specific correlation between input concentration of an element in the waste fuel and fraction partitioned to fly ash. Temperature and chlorine content have significant effects on partitioning characteristics by increasing the formation and vaporization of highly volatile metal chlorides. Zinc and cadmium concentrations in fly ash increase with the incineration temperature.