呼伦贝尔地区草原表层土壤中总有机碳与有机质初探

通过非分散红外线吸收法测定呼伦贝尔地区具有代表性的16个草原表层土壤(0~20 cm)中总有机碳、溶解性有机碳,使用重铬酸钾容量法测定有机质,并对其总有机碳与有机质水平及两者相关性进行了分析。初步分析了造成各样品之间总有机碳水平差异的原因。结果表明,只以打草场作为利用方式的土壤总有机碳含量较常年放牧场的总有机碳含量高。从草原类型和土壤类型上看,草甸草原总有机碳含量明显高于典型草原,黑钙土总有机碳含量明显高于栗钙土。综上,过度放牧会使草原土壤总有机碳大量释放。总有机碳含量与有机质含量有显著正相关性,相关系数达到0.902。     

Chemical Compositions and Sources of Organic Matter in Fine Particles of Soils and Sands from the Vicinity of Kuwait City

Fine particles in the atmosphere from soil and sand resuspension contain a variety of organic compounds from natural biogenic and anthropogenic matter. Soil and sand samples from various sites near Kuwait city were collected, sieved to retain the fine particles, and extracted with a mixture of dichloromethane and methanol. The extracts were derivatized and analyzed by gas chromatography-mass spectrometry in order to characterize the chemical compositions and sources of the organic components. The major inputs of organic compounds were from both natural biogenic and anthropogenic sources in these samples. Vegetation was the major natural source of organic compounds and included n-alkanols, n-alkanoic acids, n-alkanes, sterols and triterpenoids. Saccharides had high concentrations (31–43%) in the sand dune and seafront samples, indicating sources from decomposed vegation materials and/or the presence of viable microbiota such as bacteria and fungi. Vehicular emission products, leakage of lubricating oils, discarded plastics and emissions from cooking operations were the major anthropogenic inputs in the samples from the urban areas. This input was mainly UCM, n-alkanes, hopanes, plasticizers and cholesterol, respectively.     

Sampling and Analysis of Organic Compounds in Diesel Particulate Matter

The fraction of atmospheric semi-volatile organic compounds (SVOC) is partitioned between the gaseous and particulate phases. Certain of these compounds eg. polynuclear aromatic hydrocarbons (PAH) and their derivatives have been shown to exhibit mutagenic or carcinogenic properties. Emissions from diesel engines are an important source of these contaminants. In a dilution chamber, we studied a diesel engine emissions. It is shown firstly, that the gaseous fraction is predominant (by up to 20 times) with respect to the particulate phase. Secondly, the polar compounds, neglected in the majority of previous studies, are the predominant species. A test campaign was carried out in Paris-Porte d'Auteuil which yielded similar results to the laboratory experiments.     

BDE-47在土壤矿物质与有机质上的吸附解吸特征

以多溴联苯醚典型单体2,2′,4,4′?四溴联苯醚（BDE?47）为研究对象,阐明了其在土壤矿物质与有机质上的吸附解吸行为及特征。结果表明：土壤中无机矿物质对BDE?47的吸附贡献不大,而有机质是调控BDE?47在土壤中吸附行为的关键组分;有机质对BDE?47的吸附能力与其有机碳含量和物理化学特性相关;BDE?47在腐殖酸上的解吸存在显著的滞后现象。     

室内可吸入颗粒物中的部分有机化合物

室内环境问题越来越引起关注,但是室内可吸入颗粒物中的有机化合物研究较少,尤其是其中的酯类物质,更是被研究者忽略.主要采用气相色谱法及色质联用法对采集的室内可吸入颗粒物样品进行分析,得出了颗粒物中的脂肪烃、芳香烃和酯类物质的种类及浓度,并且分析了这些有害物质的来源.     

Critical Loads of Acidity for Forest Soils and Relationship to Forest Decline in the Northern Czech Republic

Critical load calculations in the Czech part of 'the Black Triangle' show exceedance of critical load in 75% of the forest area. A comparison with forest damage data shows an insignificant tendency toward more forest damage in areas with high exceedance. We conclude that high exceedance of critical load is a probable contributing factor to forest damage in the area.     

Rate-Limited Desorption of Volatile Organic Compounds from Soils and Implications for the Remediation of a Louisiana Superfund Site

The rates of desorption of trichloroethylene (TCE) and 1,3-dichlorobenzene (DCB) from a silty soil at a Superfund site and a silty-clayey soil from an uncontaminated bottomland hardwoodswamp in Baton Rouge, Louisiana were studied in laboratory batchsystems. The effect of the age of soil contamination was studiedusing a laboratory-spiked soil incubated for 3 days, 3 months and5 months. An empirical non-linear model was used to describe thebi-phasic nature of desorption with one fraction (labile) beingreleased in relatively short periods of time (typically 24–100 hr) and a second fraction (non-labile or irreversible) beingresistant to desorption. The non-linear model parameters, viz.,the fraction of the chemical released rapidly (F), and the firstorder desorption rate coefficients, k ₁ and k ₂respectively for the labile and slowly released fractions weredetermined by fitting the experimental data to the model. Thedata fit the model well as indicated by the high r ² values.The estimate of k ₁ was good. However, the values of k ₂are known with less precision due to the limited duration of theexperiment and number of samples taken at long times. In addition, desorption kinetics of 3 and 5-month old contaminatedsoils showed that progressively less amount of contaminant was available for facile desorption (lower F) compared to freshly contaminated soil. The labile fraction had desorption rate constants of the order of 10^-1 h^-1, whereas the slowlyreleased fraction had rate constants of the order of 10^-4 h^-1 in accord with literature reported values for a varietyof other compounds and soils. Possible mechanisms describing these rates and implications for the site clean up are discussed.     

磨盘山水库溶解性有机质光谱特性及来源分析

结合紫外可见吸收光谱与三维荧光光谱法,利用平行因子分析方法研究哈尔滨市磨盘山水库水体中的溶解性有机质（DOM）。结果表明,水体DOM吸收系数α355平均值为（4.71±0.66）m-1,表明水库中有色溶解性有机质（CDOM）较高;水库水体DOM存在3个荧光组分,分别为类腐殖质C1（345 nm、440 nm）、类腐殖质C2（285 nm、405 nm）和类富里酸组分C3（275 nm、475 nm）;C1、C3呈现显著的正相关性,自生源指数与C1呈显著的负相关性;类腐殖质的荧光强度在深层水体中逐渐增加,且深层水体的腐殖化程度较高,较为稳定;水库中心水体中DOM的自生源特征较其他区域明显,浮游植物和细菌的有机体降解产物增加。     

土壤中石油类有机污染物检测方法研究进展

在系统地归纳总结了国内外研究者所采用的各种分析方法基础上,指出了现有实验分析中存在的问题及发展趋势。主张尽量使用和开发仪器分析检测方法,并建议尽快规范土壤中石油类有机污染物的定性定量分析方法,尽早解决目前常用分析方法中存在的各种问题,为土壤石油污染防治提供有效保障。     

北疆部分区域土壤pH、可溶性总盐及有机质含量调查

对北疆4个区域土壤的pH、可溶性总盐及有机质含量状况进行了调查和评价。监测结果表明,调查区的pH为7.20-10.58,多属于碱性至强碱性土壤;可溶性总盐量为0.012％。12.834％,多属于中度盐渍化土壤;土壤表层有机质含量为0.16％-21.09％,1-6级土壤均含有机质,总体水平相对较低,但山区土壤中有机质含量较高。部分农田存在土壤次生盐渍化重、肥力低的问题。古尔班通古特沙漠中的风沙土等具有盐渍化轻、肥力低的特点。     

屏蔽门对地铁站台颗粒物分布的影响研究

通过2018年1月的污染天和非污染天在上海人民广场地铁站对装有屏蔽门系统的1号线站台和装有安全门系统的2号线站台上的颗粒物数量浓度进行监测并作对比研究,结果表明:污染天和非污染天,安装屏蔽门系统的站台颗粒物数量浓度相对于安全门系统分别降低2.08%~35.44%和5.69%~51.31%。屏蔽门站台的颗粒物浓度表现为后站台>前站台>中站台;安全门系统颗粒物浓度无规律。屏蔽门系统站台的颗粒物在人体内的沉积量要低于安全门系统,站台两端的颗粒物在人体内的沉积量高于站台中间。     

焦化废水生化处理过程中溶解性有机物及毒性变化规律

焦化废水中的溶解性有机物(DOM)作为废水污染物和毒性的主要来源受到广泛关注。厌氧-缺氧-好氧(A-A-O)生物法联合混凝沉淀工艺在焦化废水处理中被广泛应用。于2018年4,7和11月分别采集4座焦化废水处理厂废水,采用光谱学分析手段和水生生物急性毒性试验对A-A-O联合混凝沉淀处理过程中焦化废水的DOM和毒性变化进行分析。结果表明,焦化废水中含有大量不饱和芳香性物质,其中类色氨酸、络氨酸物质占主导,其次为类溶解性微生物代谢产物、类富里酸物质和类腐殖酸类物质;未经处理的焦化废水对藻类和大型溞的急性毒性等级为中毒至高毒。A-A-O联合混凝沉淀处理可去除90%以上的类色氨酸、络氨酸和类富里酸物质,但对类腐殖酸类物质去除率相对较低,仅为约80%,关键去除段为缺氧段和好氧段;该工艺对焦化废水急性毒性削减率为80.51%~94.30%,关键削减段为厌氧段。Pearson相关性分析结果显示,焦化废水溶解性总有机碳(TOC)、类腐殖酸类物质荧光组分C1和类富里酸类物质荧光组分C4与废水急性毒性存在显著正相关关系,可利用其作为水样急性毒性初筛的指示性指标。可为焦化废水生化处理的效能优化和废水毒性控制及安全评估提供科学支撑。     

七虎林河流域上游溶解性有机质光谱特性分析

七虎林河源头区地表腐殖质随着径流的冲刷进入水体,形成了天然有机质(NOM),其中,溶解性有机质(DOM)易对河流水质造成影响。为了研究七虎林河中DOM的时空分布特征及其对水质的影响,开展了6次采样,分析了水体及土壤吸收光谱和荧光光谱特征参数,利用平行因子(PARAFAC)算法解析了水体DOM的特性及来源。结果表明：七虎林河上游水体五日生化需氧量(BOD₅)、高锰酸盐指数(COD_Mn)、化学需氧量(COD)、可溶性有机碳(DOC)的浓度分别为1.4 mg/L±0.2 mg/L、6.1 mg/L±3.0 mg/L、21 mg/L±8 mg/L、7.0 mg/L±3.2 mg/L,BOD₅/COD平均值为0.08,说明流域内水体DOM的可生化性差,对水质影响较小。光谱特征参数紫外吸收系数(SUVA₂₅₄)、荧光指数(FI)、腐殖化指数(HIX)、生物源指数(BIX)分析结果表明,七虎林河上游云山水库库上林区河段DOM的物质组成与水库及库下河段差异显著。库上河段DOM的芳香碳含量更高、分子量更大、自生源组分...     

溶解性有机碳对微库仑法测定水中可吸附有机卤素的影响

微库仑法测水样中可吸附有机卤素(AOX)受多种因素影响,其中溶解性有机碳(DOC)的影响非常显著。DOC对微库仑法2种前处理方法(双柱法和振荡法)的影响差异很大。双柱法受DOC影响较小,当DOC浓度小于1 000 mg/L时,AOX加标回收率范围为94.0%~104%。振荡法受DOC影响较明显,随着DOC浓度的升高,AOX回收率持续下降,当DOC浓度达到1 000 mg/L时,AOX加标回收率下降至72.1%,但DOC浓度小于100 mg/L时,AOX加标回收满足方法要求。进一步研究发现,DOC对振荡法的影响主要由于竞争吸附降低了活性炭对AOX的吸附容量,而非吸附速率,虽然增大活性炭用量可在一定程度上减小DOC对AOX测定的影响,但对样品进行稀释是减少DOC影响的最简单高效的办法。同时,DOC对不同类型的有机卤代物影响不同,有机溴受DOC影响程度小于有机氯。     

生物炭在土壤中的老化及其吸附重金属的研究进展

综述了生物炭在土壤中的老化机制及主要影响因素方面的研究进展,指出生物炭的理化性质和结构表征在土壤中发生变化是其老化机制,生物炭的特性、土壤特性和环境条件等因素共同影响着生物炭的老化。总结了老化生物炭在土壤中对重金属吸附的影响,生物炭在老化过程中理化性质和结构表征的变化影响了生物炭-土壤体系对重金属的吸附,并且吸附能力因老化方式和重金属不同而存在差异。提出了开展多种重金属共存条件下老化生物炭的吸附效果和机理研究、针对生物炭田间实际老化过程对土壤重金属的吸附行为开展季节性和多年长期观测研究,以及对生物炭修复的重金属污染土壤在生物炭老化过程中可能造成的环境和健康风险开展综合、长期的跟踪研究与评估等展望。     

机动车排放尾气中挥发性有机污染物对环境空气质量影响初探

采用气相色谱/质谱检测技术,对汽油和柴油、汽油车和柴油车排放气体以及天津市环境空气中主要挥发性有机污染物(VOCs)的组成种类及比例进行探析.结果表明,机动车排放的尾气中主要有机污染物为芳香烃类、烷烃类和烯烃类化合物,其中芳香烃类含量最高;汽油车排放的芳香烃类化合物浓度高于柴油车排放的浓度;机动车尾气对交通区域空气质量的影响高于工厂区(非化工区)、生活小区和公园.     

颗粒物对污染源COD水质在线监测仪比对监测的影响

污水中的颗粒物是COD在线监测仪在比对监测时出现较大误差的原因之一,就颗粒物对COD在线监测仪是否产生影响以及影响效果进行了实验研究。研究结果表明,COD在线监测仪的预处理系统去除颗粒物会带来比对监测的误差,并且随着颗粒物浓度增加,误差增大;预处理系统过滤器尺寸也会对比对监测的误差产生影响,针对同一浓度水样,孔径越大误差越小,针对同一孔径过滤器则水样浓度越高误差越小。     

有机氯农药在湖北省菜地土壤中的污染研究

采集了湖北省武汉、宜昌、襄阳地区的45个菜地土壤样品,测定其中11种有机氯农药的残留量,并对其残留特征和污染来源进行了研究分析。结果表明,所有土壤样品中均检出有机氯农药,但大多数点位的污染物含量均低于相关标准限值,通过数据统计和因子分析法得出p,p’-DDT、p,p’-DDE为主要污染物。计算特征比值后发现,该地区滴滴涕污染可能源于传统工业滴滴涕和三氯杀螨醇的混合源,既有早期污染也有新污染的输入,六六六污染主要源于林丹,氯丹残留主要源于早期污染。     

Isotopic Composition as a Tool for Assessment of Origin and Dynamic of Organic Matter in Tropical Freshwater

The isotopic composition (¹³C and ¹⁵N) and C:N ratio of sediment and particulate were investigated to assess the origin and dynamic of the organic matter in two river basins located in the Parana State, Brazil. The main sources of organic matter, plants, litter and soil, were analyzed in the study. This study was carried out during the dry and wet seasons. Although organic matter contribution for the particulate material has been mixed, the main contribution in the two seasons for both rivers was autochthonous characterized by δ¹³C and C:N ratio values ranging from −31.0 to −21.8‰ and from 5.1 to 11.4, respectively. The soil with δ¹³C values ranging from −25.9 to −20.6‰, and C:N ratio from 10.2 to 15.8, was the main carbon source for the river sediment for the two tributaries in the wet and dry seasons. The sediment δ¹⁵N values for both the rivers in the wet season showed an ¹⁵N enrichment trend in most of studied sites when compared to the dry season values, suggesting major input of nutrients as dissolved organic nitrogen and sewage nitrate. In the dry season, ¹⁴N enriched compounds, could have been used by phytoplankton, causing ¹⁵N enrichment. The isotope and C:N ratio data clearly showed that the agricultural activity has been influencing the origin and dynamic of organic matter in the two rivers, with potential biochemical consequences for the lower basin of the major Tibagi river.