基于成组生物毒性测试的PM2.5毒性

为了准确评估PM_(2.5)的综合生物毒性,采用发光细菌急性毒性、斑马鱼胚胎急性毒性和体外人肺腺癌细胞(A549)毒性试验对常州市冬季雾-霾天、冬季正常天和夏季这3个时间段的PM_(2.5)进行生物毒性评价,并结合大气理化指标进行分析.结果表明,3个时间段的PM_(2.5)均表现出急性毒性或发育毒性.冬季雾-霾天、冬季正常天和夏季PM_(2.5)对发光细菌的毒性单位(toxicity unit,TU)值分别为1. 74(有毒)、1. 19(有毒)和0. 92(微毒);对斑马鱼胚胎的TU值从大到小排列为:冬季正常天(TU=1. 14,有毒)、冬季雾-霾天(TU=0. 79,微毒)和夏季(TU=0,无毒);对A549的TU值为:冬季雾-霾天(TU=0. 61,微毒)夏季(TU=0. 38,微毒)冬季正常天(TU=0. 31,微毒).在发育毒性方面,除夏季PM_(2.5)样品,其余2个时间段的PM_(2.5)均对斑马鱼胚胎发育有影响,主要表现出心包囊肿、脊椎弯曲和尾部畸形.平均毒性(average toxicity,Av Tx)、毒性指数(toxic print,Tx Pr)和最敏感测试(most sensitive test,MST)综合毒性评价方法表明冬季雾-霾天和冬季正常天PM_(2.5)均表现出有毒,夏季则表现出微毒,以冬季雾-霾天PM_(2.5)样品的综合毒性最高.此外,3种测试生物对PM_(2.5)污染物的敏感度排序为发光细菌斑马鱼胚胎 A549.理化指标和生物毒性的相关性分析结果表明,PM_(2.5)中所含的污染物对生物毒性效应产生影响,可为PM_(2.5)生物毒性综合评价和人体健康风险评估提供依据.     

六类餐饮源排放PM2.5化学成分谱

大气颗粒物源成分谱可以表征源排放颗粒物的理化特征,为受体模型开展来源解析研究提供基础数据.餐饮油烟排放是室内外环境大气污染的来源之一,当前餐饮源排放PM_2.5的化学成分谱仍然缺乏.该研究分别在成都市、武汉市和天津市采集了29组6种餐饮源（居民烹饪、火锅店、烧烤店、职工食堂、中餐馆、商场综合餐饮）排放的PM_2.5样品,分析无机元素、离子、碳、多环芳烃（PAHs）等化学组分,并构建了餐饮源排放颗粒物化学成分谱.结果表明:①餐饮源排放PM_2.5化学成分中的主要组分为OC（有机碳）、EC（元素碳）、Ca、Al、Fe、NH₄+、SO₄2-、NO₃-、Na+、K+、Mg2+和Cl-,其中w（OC）最高,为41.67%~57.91%.②餐饮源排放PM_2.5的PAHs中,3环和4环占比较高,其中芴（Flu）、菲（Phe）、荧蒽（Fla）、芘（Pyr）的质量分数相对其他物质较高.研究显示:餐饮源排放PM_2.5中OC/EC约为15.99~67.61,在一定程度上可以用来表征餐饮源排放;Fla/（Fla+Pyr）和InP/（InP+BghiP）多集中在0.45~0.55之间,或可作为标识餐饮源的特征比值.      

利用GC/MS代谢组学技术检测纳米TiO2对多头绒泡菌代谢途径的扰动作用

纳米TiO_2(n TiO_2)具有广泛的应用价值.但n TiO_2在阳光或紫外线下具有很强的氧化作用,可对细胞产生强烈的毒害作用,因此其对生态环境的可能破坏作用值得关注.有关n TiO_2在暗环境中对生物的毒性作用报道还不多,还不能全面揭示n TiO_2的毒性作用机理.代谢组学分析是发现代谢差异、识别被干扰的代谢途径、了解n TiO_2毒性作用机理、评估n TiO_2细胞毒性的重要手段.本文采用GC/MS(气相色谱/质谱)技术检测了n TiO_2在暗环境下对多头绒泡菌原质团(单细胞)代谢组的影响,根据多变量识别模式分析发现了60余个被n TiO_2显著干扰的代谢物.这些代谢物涉及糖代谢、氨基酸代谢、核苷酸代谢、多胺生物合成、次生代谢途径等,为全面了解n TiO_2对细胞的毒性作用机理提供了有益补充.     

天津市环境空气中细粒子的污染特征与来源

于2006年8─12月,在天津市中心城区采集细粒子(PM_2.5)并测定其中水溶性无机离子和元素的质量浓度,应用因子分析与多元线性回归技术解析PM_2.5的来源. 结果表明:ρ(PM_2.5)月均值为103.9～217.4 μg/m3,呈冬季最高、夏季最低的特征. 水溶性无机离子质量浓度占ρ(PM_2.5)的比例为24.90%～49.76%,其中ρ(SO₄2－),ρ(NO₃－),ρ(NH₄+)与ρ(Cl－)之和约占离子总质量浓度的90%. 在夏季,二次粒子质量浓度占ρ(PM_2.5)比例最大,这与SO₂向SO₄2-,NO₂向NO₃-的转化率升高有关. PM_2.5中Cl富集主要与燃煤等人为排放有关, 海盐源对Cl－的贡献不足20%. 天津PM_2.5中含量最高的元素为Si,约占元素总质量浓度的28.4%. 微量元素中以Zn和Pb的含量最高,二者主要来自燃煤和机动车排放. 源解析结果表明,二次污染、化石燃料燃烧、土壤尘和建筑粉尘是天津市环境空气中PM_2.5的主要来源,贡献率分别为53.4%,25.8%,12.3%和8.6%.      

Distribution of rare earth elements in PM10 emitted from burning coals and soil-mixed coal briquettes

Emission from burning coals is one of the major sources of the airborne particles in China. We carried out a study on the rare earth elements (REEs) in the inhalable particulate matter (PM₁₀) emitted from burning coals and soil-coal honeycomb briquettes with different volatile contents and ash yields in a combustion-dilution system. Gravimetric analysis indicates that the equivalent mass concentration of the PM₁₀ emitted from burning the coals is higher than that emitted from burning the briquettes. The ICP-MS analysis indicates that the contents of total REEs in the coal-burning PM₁₀ are lower than those in the briquette-burning PM₁₀. In addition, the contents of the light rare earth elements (LREEs) are higher than those of the heavy rare earth elements (HREEs) in the PM₁₀ emitted from burning the coals and briquettes, demonstrating that the REEs in both the coal-burning and briquette-burning PM₁₀ are dominated by LREEs. The higher contents of total REEs and LREEs in the coal-burning PM₁₀ are associated with the higher ash yields and lower volatile contents in the raw coals. A comparative analysis indicates that the La/Sm ratios in the PM₁₀ emitted from burning the coals and briquettes, being lower than 2, are lower than those in the particles from gasoline-powered vehicle emission.     

我国典型土壤中铜对白符跳(Folsomia candida)的毒性阈值及其预测模型

为确定我国土壤中Cu对白符跳的毒性阈值并建立其预测模型,以外源添加的方式研究了我国9种典型土壤（江西红壤、安徽黄棕壤、重庆紫色土、云南黄红壤、湖南水稻土、山东潮土、黑龙江黑土、新疆灰漠土、陕西垆土）中Cu对模式生物——白符跳（Folsomia candida）存活率与繁殖率的影响.结果表明:白符跳存活率对Cu毒害的敏感性远低于繁殖率.9种土壤中基于w（TCu）实测值推导的土壤Cu对白符跳繁殖率的EC₅₀（半数效应浓度）变化范围为65~668 mg/kg,表明不同土壤中Cu的毒性阈值差异显著,但基于w（Cu_Ca）（Cu_Ca为CaCl₂溶液提取的Cu）推导的不同土壤中EC₅₀的差异有所减小.相关性分析表明,基于w（TCu）实测值推导的EC₅₀值与土壤pH、w（CaCO₃）均呈显著正相关,相关系数分别为0.801和0.670.进一步利用回归分析建立了基于pH和w（OM）的土壤Cu对白符跳繁殖的EC₅₀预测模型——lg（EC₅₀）=0.213+0.288pH+0.016 w（OM）,基于该模型预测与推导的EC₅₀值之间相关性较好.研究显示,氯化钙提取态Cu的存在能在一定程度上解释不同土壤中Cu对白符跳繁殖的EC₅₀值的差异,pH和w（OM）可较好地预测不同土壤中Cu对白符跳繁殖的EC₅₀值.      

双氯芬酸和醋氨酚对稀有鮈鲫早期生活阶段的毒性效应

随着非甾体抗炎药（NSAIDs）的持续使用与排放,世界各地的地表水、海水、地下水、污水厂进出水中均已频繁检测到该类药物,这对生态系统中各种非靶标生物造成了一定威胁.本研究评价了两种典型的非甾体抗炎药-双氯芬酸（Diclofenac）和醋氨酚（Acetaminophen）对中国特有物种稀有鮈鲫（Gobiocypris rarus）早期生活阶段的毒性效应.实验结果显示,醋氨酚的毒性较弱,当浓度达到48.4 mg·L^-1（NOEC）时,稀有鮈鲫的孵化率、死亡率、异常率、全长和干重均未表现出明显的中毒症状;而双氯酚酸的毒性则较强,当浓度达17.8 mg·L^-1（LC₁₀）时,即可导致稀有鮈鲫孵化率下降,当浓度达到10.2 mg·L^-1（LOEC）时,即可造成幼鱼外观和行为的显著异常,表明双氯芬酸对稀有鮈鲫的孵化和生长均产生了一定的致毒效应.同时,根据稀有鮈鲫和几种常用模式生物之间的孵化率、孵化后存活率、体长和双氯芬酸敏感性的比较结果,可认为稀有鮈鲫适用于污染物对鱼类早期生活阶段毒性效应的评估.     

Secondary organic carbon quantification and source apportionment of PM10 in Kaifeng, China

During 2005, the filter samples of ambient PM₁₀ from five sites and the source samples of particulate matter were collected in Kaifeng, Henan Province of China. Nineteen elements, water-soluble ions, total carbon (TC) and organic carbon (OC) contained in samples were analyzed. Seven contributive source types were identified and their contributions to ambient PM₁₀ were estimated by chemical mass balance (CMB) receptor model. Weak associations between the concentrations of organic carbon and element carbon (EC) were observed during the sampling periods, indicating that there was secondary organic aerosol pollution in the urban atmosphere. An indirect method of “OC/EC minimum ratio” was applied to estimate the concentration of secondary organic carbon (SOC). The results showed that SOC contributed 26.2%, 32.4% and 18.0% of TC in spring, summer-fall and winter, respectively, and the annual average SOC concentration was 7.07 μg/m³, accounting for 5.73% of the total mass in ambient PM₁₀. The carbon species concentrations in ambient PM₁₀ were recalculated by subtracting SOC concentrations from measured concentrations of TC and OC to increase the compatibility of source and receptor measurements for CMB model.     

燃煤锅炉颗粒物化学组成排放特征

本研究收集了兰州市不同吨位燃煤锅炉颗粒物排放样品,分析并评估了锅炉烟气中水溶性无机离子、碳质组分、水溶性有机物(WSOC)以及多环芳烃(PAHs)的排放水平、排放特征及其影响因素.结果表明,SO_4~(2-)、Cl~-和Ca~(2+)是燃煤锅炉样品中最主要的水溶性离子,分别占水溶性离子总和的35. 13%、23. 16%和22. 20%.不同吨位燃煤锅炉样品的OCEC及其热解成分谱较为相似,OC1、OC2、OC3、OC4、EC1、EC2和EC3分别占TC的1. 04%、8. 26%、20. 09%、6. 78%、51. 08%、7. 09%和5. 66%,其中EC1的含量最高,是最主要的碳质组分. WSOC/TC和WSOC/OC分别为0. 09±0. 07和0. 23±0. 12,且不同吨位锅炉之间差异较大.菲(Phe)、芘(Pyr)和苯并(k)荧蒽(Bk F)是PAHs的3个主要成分,分别占PAHs总和的16. 69%、11. 93%和10. 66%.不同吨位燃煤锅炉所排放颗粒物中水溶性离子、OCEC以及WSOC均与锅炉吨位大小无明显线性相关,随着吨位的增加PAHs轻组分含量减小.     

城市生活垃圾露天焚烧PM2.5及其组分排放特征

利用稀释采样系统,针对桶内燃烧和自然堆积两种常见露天焚烧方式,分别对橡塑类、纸类和木竹类这3种组分生活垃圾露天焚烧PM_(2.5)排放特征进行实测,计算PM_(2.5)、OC、EC、水溶性离子和无机元素排放因子.结果表明,木竹类生活垃圾PM_(2.5)排放因子(7.44±0.76)g·kg~(-1)最高,纸类PM_(2.5)排放因子(2.72±0.52)g·kg~(-1)最低.桶内燃烧的条件会造成更多污染物排放.在不同的燃烧方式下,橡塑类和纸类生活垃圾在桶内燃烧的条件下PM_(2.5)排放因子是自然堆积燃烧的2.5~3.5倍.PM_(2.5)中OC和EC为主要组成成分,PM_(2.5)组分构成占比约为46.6%~67.2%.不同垃圾组分OC/EC比率差异较大,但该比率受焚烧条件影响较小,有助于解析不同组分垃圾焚烧排放贡献.水溶性离子中NH+4离子、Cl-离子含量最高,在PM_(2.5)中所占比例范围分别为2.28%~6.35%和1.04%~14.31%.无机元素中Ca、K、Fe和Ba元素排放因子较高.重金属元素中Zn元素排放因子最高,Cu、Cr、Sb和Pb等元素也有一定富集.Zn元素含量主要由燃烧方式决定,桶内燃烧大约是自然堆积燃烧的20倍左右.     

Chemical compositions of PM2.5 aerosol during haze periods in the mountainous city of Yong'an, China

Haze phenomena were found to have an increasing tendency in recent years in Yong'an, a mountainous industrial city located in the center part of Fujian Province, China. Atmospheric fine particles (PM_2.5) in the urban area during haze periods in three seasons (spring, autumn and winter) from 2007 to 2008 were collected, and the mass concentrations and chemical compositions (seventeen elements, water soluble inorganic ions (WSIIs) and carbonaceous species) of PM_2.5 were determined. PM_2.5 mass concentrations did not show a distinct difference among the three seasons. The carbonaceous species organic carbon (OC) and elemental carbon (EC) constituted up to 19.2%-30.4% of the PM_2.5 mass during sampling periods, while WSIIs made up 25.3%-52.5% of the PM_2.5 mass. The major ions in PM_2.5 were SO₄^2-, NO₃^- and NH₄⁺, while the major elements were Si, K, Pb, Zn, Ca and Al. The experimental results (from data based on three haze periods with a 10-day sampling length for each period) showed that the crustal element species was the most abundant component of PM_2.5 in spring, and the secondary ions species (SO₄^2-, NO₃^-, NH₄⁺, etc.) was the most abundant component in PM_2.5 in autumn and winter. This indicated that dust was the primary pollution source for PM_2.5 in spring and combustion and traffic emissions could be the main pollution sources for PM_2.5 in autumn and winter. Generally, coal combustion and traffic emissions were considered to be the most prominent pollution sources for this city on haze days.     

闽江河口互花米草与短叶茳芏湿地土壤无机硫形态分布特征及其影响因素

选择闽江口鳝鱼滩不同淹水环境下两条样带(A样带,远离主潮沟且退潮后无积水;B样带,靠近主潮沟且退潮后有积水)上的短叶茳芏湿地和已被互花米草入侵(入侵前为短叶茳芏湿地)的互花米草湿地为研究对象,探讨不同类型湿地土壤无机硫赋存形态的分布特征及其主控因素.结果表明,B样带上互花米草湿地和短叶茳芏湿地土壤中的水溶性硫(H_2O-S)和吸附性硫(Adsorbed-S)含量总体上低于A样带,而盐酸可溶性硫(HCl-Soluble-S)和盐酸挥发性硫(HCl-Volatile-S)含量则高于A样带.短叶茳芏湿地和互米草湿地土壤中不同形态无机硫的含量在两条样带上整体均表现为HCl-Soluble-SH_2O-SAdsorbed-SHCl-Volatile-S,且二者的总无机硫含量分别占其TS含量的9.02%~15.50%和8.04%~12.73%.与短叶茳芏湿地相比,互花米草入侵分别使A样带土壤中H_2O-S、Adsorbed-S、HCl-Soluble-S、HCl-Volatile-S和总无机硫含量减少了35.2%、36.4%、16.8%、1.8%和26.12%;但使B样带表层土壤的总无机硫含量及0~20 cm土层的HCl-Soluble-S和HCl-Volatile-S含量分别增加了8.34%、15.34%和5.71%.研究发现,非长期淹水条件下,互花米草入侵后可降低湿地土壤有效硫的供给能力;长期淹水条件下,互花米草入侵可通过提高土壤中HCl-Soluble-S的含量增加金属硫化物沉淀,而挥发性硫含量的同步增加则可能对植被生长(特别是根系发育)产生不利影响.     

Distribution and chemical speciation of arsenic in different sized atmospheric particulate matters

The distribution and chemical speciation of arsenic (As) in different sized atmospheric particulate matters (PMs), including total suspended particles (TSP), PM₁₀, and PM_2.5, collected from Baoding, China were analyzed. The average total mass concentrations of As in TSP, PM₁₀, and PM_2.5 were 31.5, 35.3, and 54.1 µg/g, respectively, with an order of PM_2.5 >PM ₁₀ > TSP, revealing that As is prone to accumulate on fine particles. Due to the divergent toxicities of different As species, speciation analysis of As in PMs is further conducted. Most of previous studies mainly focused on inorganic arsenite (iAs^III), inorganic arsenate (iAs^V), monomethylarsonate (MMA), and dimethylarsinate (DMA) in PMs, while the identification and sensitive quantification of trimethylarsine oxide (TMAO) were rarely reported. In this study, a high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry system was optimized for As speciation including TMAO in PMs. An anion exchange column was used to separate MMA, DMA and iAs^V, while a cation exchange column to separate TMAO and iAs^III. Results showed that iAs^V was the dominate component in all the samples, corresponding to a portion of 79.2% ± 9.3% of the total extractable species, while iAs^III, TMAO and DMA made up the remaining 21%. Our study demonstrated that iAs^III accounted for about 14.4% ± 11.4% of the total extracted species, with an average concentration of 1.7 ± 1.6 ng/m³. It is worth noting that TMAO was widely present in the samples (84 out of 97 samples), which supported the assumption that TMAO was ubiquitous in atmospheric particles.     

Chemical composition, mass closure and sources of atmospheric PM10 from industrial sites in Shenzhen, China

Concentrations of atmospheric PM10 and chemical components (including twenty-one elements, nine ions, organic carbon (OC) and elemental carbon (EC)) were measured at five sites in a heavily industrial region of Shenzhen, China in 2005. Results showed that PM10 concentrations exhibited the highest values at 264 μg/m3 at the site near a harbor with the influence of harbor activities. Sulfur exhibited the highest concentrations (from 2419 to 3995 ng/m3) of all the studied elements, which may be related to the influence of coal used as fuel in this area for industrial plants. This was verified by the high mass percentages of SO42-, which accounted for 34.3%-39.7% of the total ions. NO3-/SO42- ratios varied from 0.64-0.71, which implies coal combustion was predominant compared with vehicle emission. The anion/cation ratios range was close to 0.95, indicating anion deficiency in this region. The harbor site showed the highest OC and EC concentrations, with the influence of emission from vessels. Secondary organic carbon accounted for about 22.6%-38.7% of OC, with the highest percentage occurring at the site adjacent to a coal-fired power plant and wood plant. The mass closure model performed well in this heavily industrial region, with significant correlation obtained between chemically determined and gravimetrically measured PM10 mass. The main constituents of PM10 were found to be organic materials (30.9%-69.5%), followed by secondary inorganic aerosol (7.9%-25.0%), crustal materials (6.7%-13.8%), elemental carbon (3.5%-10.8%), sea salt (2.4%-6.2%) and trace elements (2.0%-4.9%) in this heavily industrialized region. Principal component analysis indicated that the main sources for particulate matter in this industrial region were crustal materials and coal/wood combustion, oil combustion, secondary aerosols, industrial processes and vehicle emission.     

离子液体与废水对青海弧菌Q67的混合毒性研究

以1-苄基—3-甲基咪唑四氟硼酸(IL1)和1-已基—3-甲基咪唑双(三氟甲基磺基)亚胺(IL2)及废水为混合物组分,以Vibrio qinghaiensis sp.-Q67为指示生物,采用均匀设计射线法设计不同浓度配比的IL1-IL2混合物体系及IL1-IL2-废水的混合物体系,应用微板毒性分析法系统测定这些混合物体系的浓度-效应数据,并以浓度加和与独立作用模型为加和参考模型分析毒性相互作用.结果表明:IL1-IL2的混合物体系具有拮抗或加和作用,且混合物毒性(pEC50值)与其中IL1的浓度比具有良好的线性关系;IL1-IL2-废水的混合物体系具有明显的协同或加和作用,且混合物pEC50值与其中废水的浓度比具有良好的线性关系.     

Chemical characteristics, oxidative potential, and sources of PM2.5 in wintertime in Lahore and Peshawar, Pakistan

The chemical characteristics, oxidative potential, and sources of PM_2.5 were analyzed at the urban sites of Lahore and Peshawar, Pakistan in February 2019. Carbonaceous species, water soluble ions, and metal elements were measured to investigate the chemical composition and sources of PM_2.5. The dithiothreitol (DTT) consumption rate was measured to evaluate the oxidative potential of PM_2.5. Both cities showed a high exposure risk of PM_2.5 regarding its oxidative potential (DTT_v). Carbonaceous and some of the elemental species of PM_2.5 correlated well with DTT_v in both Lahore and Peshawar. Besides, the DTT_v of PM_2.5 in Lahore showed significant positive correlation with most of the measured water soluble ions, however, ions were DTT-inactive in Peshawar. Due to the higher proportions of carbonaceous species and metal elements, Peshawar showed higher mass-normalized DTT activity of PM_2.5 compared to Lahore although the average PM_2.5 concentration in Peshawar was lower. The high concentrations of toxic metals also posed serious non-carcinogenic and carcinogenic risks to the residents of both cities. Principle component analysis coupled with multiple linear regression was applied to investigate different source contributions to PM_2.5 and its oxidative potential. Mixed sources of traffic and road dust resuspension and coal combustion, direct vehicle emission, and biomass burning and formation of secondary aerosol were identified as the major sources of PM_2.5 in both cities. The findings of this study provide important data for evaluation of the potential health risks of PM_2.5 and for formulation of efficient control strategies in major cities of Pakistan.     

Hg removal from flue gas over different zeolites modified by FeCl3

The elemental mercury removal abilities of three different zeolites (NaA, NaX, HZSM-5) impregnated with iron(III) chloride were studied on a lab-scale fixed-bed reactor. X-ray diffraction, nitrogen adsorption porosimetry, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and temperature programmed desorption (TPD) analyses were used to investigate the physicochemical properties. Results indicated that the pore structure and active chloride species on the surface of the samples are the key factors for physisorption and oxidation of Hg⁰, respectively. Relatively high surface area and micropore volume are beneficial to efficient mercury adsorption. The active Cl species generated on the surface of the samples were effective oxidants able to convert elemental mercury (Hg⁰) into oxidized mercury (Hg^2 +). The crystallization of NaCl due to the ion exchange effect during the impregnation of NaA and NaX reduced the number of active Cl species on the surface, and restricted the physisorption of Hg⁰. Therefore, the Hg⁰ removal efficiencies of the samples were inhibited. The TPD analysis revealed that the species of mercury on the surface of FeCl₃–HZSM-5 was mainly in the form of mercuric chloride (HgCl₂), while on FeCl₃–NaX and FeCl₃–NaA it was mainly mercuric oxide (HgO).     

有机物料投入对喀斯特地区土壤磷素赋存形态与含phoD基因细菌群落的影响

针对喀斯特地区有机物料盈余、土壤养分贫瘠和易流失的特点,设置长期有机物料还田小区定位试验,试验包括6个处理：不施肥对照（CK）、无机肥（NPK）、无机肥+玉米秸秆（NPKS）、无机肥+农家肥（NPKM）、无机肥+滤泥（NPKL）和无机肥+甘蔗灰（NPKA）.研究不同有机物料投入对土壤磷赋存形态和磷活化功能微生物（含有机磷矿化基因细菌）群落结构的影响.通过3 a断续的观测,结果表明,土壤全磷（TP）、速效磷（Olsen-P）和二钙磷（Ca₂-P）含量呈逐年增加趋势,而氯化钙磷（CaCl₂-P）含量呈先降低再增加的趋势;与不施肥对照相比,有机物料投入尤其是滤泥配施能显著提高土壤全氮（TN）、TP、Olsen-P、CaCl₂-P和Ca₂-P含量,其次是甘蔗灰和农家肥配施处理;相关分析表明,CaCl₂-P、Ca₂-P和Olsen-P均与土壤交换性钙（Ca-ex）含量显著正相关;冗余分析（RDA）表明土壤TN、Ca-ex、有机碳（SOC）和土壤全钾（TK）含量是影响土壤磷组分的关键因子.高通量测序分析含有机磷矿化基因（含phoD基因）细菌群落结果表明,与不施肥对照相比,秸秆还田配施无机肥处理显著增加土壤含phoD基因细菌丰富度,但各处理间含phoD基因细菌群落结构无显著差异.RDA分析结果表明,土壤Ca-ex、TK、Olsen-P、pH和SOC是驱动含phoD基因细菌群落变化的关键因子.总体上看,无机肥配施滤泥、甘蔗灰和农家肥是广西喀斯特地区农田土壤较为合适的养分管理方式.研究可为喀斯特地区有机废弃资源利用与土壤磷素管理提供科学依据.     

Hg0 removal from flue gas over different zeolites modified by FeCl3

The elemental mercury removal abilities of three different zeolites (NaA, NaX, HZSM-5) impregnated with iron (III) chloride were studied on alab-scale fixed-bed reactor. X-ray diffraction, nitrogen adsorption porosimetry, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and temperature programmed desorption (TPD) analy-ses were used to investigate the physicochemical properties. Results indicated that the pore structure and active chloride species on the surface of the samples are the key factors for physisorption and oxidation of Hg⁰, respectively. Relatively high surface area and micropore volume are beneficial to efficient mercury adsorption. The active Cl species generated on the surface of the samples were effective oxidants able to convert elemental mercury (Hg⁰) into oxidized mercury (Hg²⁺). The crystallization of NaCl due to the ion exchange effect during the impregnation of NaA and NaX reduced the number of active Cl species on the surface, and restricted the physisorption of Hg⁰. Therefore, the Hg⁰ removal efficiencies of the samples were inhibited. The TPD analysis revealed that the species of mercury on the surface of FeCl₃-HZSM-5 was mainly in the form of mercuric chloride(HgCl₂), while on FeCl₃-NaX and FeCl₃-NaA it was mainly mercuri coxide(HgO).     

深圳市PM2.5 化学组成与时空分布特征

于2008-12-30～2009-12-25,在深圳市宝安区、罗湖区和盐田区各设置一个采样点采集大气细粒子PM2.5,分析了PM2.5中主要的水溶性离子组分、有机碳和元素碳,同时结合气象条件,对深圳市PM2.5的化学组成及时空分布特征进行了研究.结果表明,深圳市PM2.5污染总体上呈现西高东低的空间分布特点,但是SO24-和NH4+的空间差异不大,说明深圳PM2.5污染具有明显的区域传输特征.OC/EC值自西向东逐渐升高,说明深圳西部地区受一次源排放影响更为显著.受亚热带海洋性季风气候的影响,深圳市PM2.5总体污染程度表现为秋冬高、夏春低的特点,各主要组分的质量浓度变化也均有类似的特征.与2004年深圳的类似观测结果比较发现,该地区脱硫措施显著降低了PM2.5中硫酸盐浓度,而机动车尾气对PM2.5的贡献变得更加重要.