Size distribution, characteristics and sources of heavy metals in haze episod in Beijing

Size segragated samples were collected during high polluted winter haze days in 2006 in Beijing, China. Twenty nine elements and 9 water soluble ions were determined. Heavy metals of Zn, Pb, Mn, Cu, As, Cr, Ni, V and Cd were deeply studied considering their toxic effect on human being. Among these heavy metals, the levels of Mn, As and Cd exceeded the reference values of National Ambient Air Quality Standard （GB3095-2012） and guidelines of World Health Organization. By estimation, high percentage of atmospheric heavy metals in PM2.5 indicates it is an effective way to control atmospheric heavy metals by PM2.5 controlling. Pb, Cd, and Zn show mostly in accumulation mode, V, Mn and Cu exist mostly in both coarse and accumulation modes, and Ni and Cr exist in all of the three modes. Considering the health effect, the breakthrough rates of atmospheric heavy metals into pulmonary alveoli are： Pb （62.1%） 〉 As （58.1%） 〉 Cd （57.9%） 〉 Zn （57.7%） 〉 Cu （55.8%） 〉 Ni （53.5%） 〉 Cr （52.2%） 〉 Mn （49.2%） 〉 V （43.5%）. Positive matrix factorization method was applied for source apportionment of studied heavy metals combined with some marker elements and ions such as K, As, SO42- etc., and four factors （dust, vehicle, aged and transportation, unknown） are identified and the size distribution contribution of them to atmospheric heavy metals are discussed.     

Mechanism of Cu(Ⅱ) adsorption inhibition on biochar by its aging process

Biochar exposed in the environment may experience a series of surface changes, which is called biochar aging. In order to study the effects of biochar aging on Cu（Ⅱ） adsorption, we analyzed the surface properties before and after biochar aging with scanning electron microscopy（SEM） coupled to an energy-dispersive X-ray spectrometer（EDX） and diffuse reflectance infrared Fourier transform spectroscopy（DRIFTS）, and then explored the influence of the aging process on Cu（Ⅱ） adsorption by batch experiments. After the aging process, the oxygen concentration, phenolic hydroxyl groups, aromatic ethers and other oxygen-containing functional groups on the biochar surface increased, while carboxyl groups slightly decreased. Thus, over a range of pH, the cation exchange capacity（CEC） and adsorption capacity of Cu（Ⅱ） on the aged biochar were smaller than those of new biochar,indicating that when biochar is incubated at constant temperature and water holding capacity in the dark, the aging process may inhibit Cu（Ⅱ） adsorption. Meanwhile, the dissociation characteristics of oxygen-containing functional groups changed through the aging process, which may be the mechanism by which the biochar aging process inhibits the Cu（Ⅱ） adsorption. Carboxyl groups became more easily dissociated at low pH（3.3–5.0）,and the variation of maximum adsorption capability（qm） of Cu（Ⅱ） on the old biochar was enlarged. Phenolic hydroxyl groups increased after the aging, making them and carboxyl groups more difficult to dissociate at high pH（5.0–6.8）, and the variation of qmof Cu（Ⅱ） on the aged biochar was reduced.     

Cadmium accumulation and tolerance of two castor cultivars in relation to antioxidant systems

To investigate the effects of Cd on tolerance and antioxidant activities of castor, two different castor（Ricinus communis L.） cultivars（Zibo No. 5 and Zibo No. 8） were used for a hydroponic experiment（0, 1 and 2 mg/L Cd） and a pot experiment using Cd-contaminated soil（34 mg/kg） with the addition of ethylenedinitrilotetraacetic acid（EDTA）. The results indicated that there were significant differences between the two cultivars with respect to Cd uptake in shoots（113–248 mg/kg for Zibo No. 5 and 130–288 mg/kg Zibo No. 8）, biomass tolerance indexes（64.9%–74.6% for Zibo No. 5 and 80.1%–90.9% for Zibo No. 8） in the hydroponic experiment and survival rates（0% for Zibo No. 5 and 100% for Zibo No. 8）determined by the addition of EDTA in the pot experiment, suggesting that Zibo No. 8 has higher tolerance than Zibo No. 5. Moreover, the castor cultivars have low bioconcentration factors（4.80% for Zibo No. 5 and 5.43% for Zibo No. 8） and low translocation factors（〈1%）.Consequently, Zibo No. 8 can participate in Cd phytostabilization in highly Cd-polluted areas. The results indicated that glutathione（GSH） as a non-enzymatic antioxidant, and antioxidant enzymes including superoxide dismutase（SOD）, catalase（CAT） and guaiacol peroxidase（GPX）, were cultivar- and dose-dependent. The higher tolerance of Zibo No. 8compared with Zibo No. 5 can be attributed to the higher GSH levels in the root and higher GPX activity in the leaf.     

青霉菌GX2对蒽醌染料的吸附作用

GX2生长菌体对 4种蒽醌染料均表现出优良的吸附性能 ,但由于染料分子的结构不同 ,吸附速率和吸附率也表现出一定的差异 .染料对菌体的生长具有一定的抑制作用 ,但即使在很高的染料浓度下 ,GX2生长菌体仍表现出很强的吸附性能 .对 250mg/L活性艳蓝KN-R的吸附率高达 100% ,对 400mg/LKN R的吸附率也可达91.4% .在 0～2%范围内 ,随着盐度 (NaCl)的增加 ,菌体干重增加 ;颗粒状菌团的直径却随之减小 ,比表面积增大 ,对GX2生长菌体的染料吸附表现出较为明显的促进作用 .碳源浓度通过影响菌体的生长而影响染料吸附 ,当培养基中的葡萄糖浓度大于 2.5g/L时 ,即可使浓度为 120mg/L的活性艳蓝KN R溶液完全脱色 .生长菌体具有比静止活体和死体更好的吸附性能 .     

Diverse molecular compositions of dissolved organic matter derived from different composts using ESI FT-ICR MS

Dissolved organic matter (DOM) derived from various composts can promote significant changes of soil properties. However, little is known about the DOM compositions and their similarities and differences at the molecular level. In this study, the molecular compositions of DOM derived from kitchen waste compost (KWC), green waste compost (GWC), manure waste compost (MWC), and sewage sludge compost (SSC) were characterized by electrospray ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS). The molecular formulas were classified into four subcategories: CHO, CHON, CHOS, and CHONS. The KWC, MWC, and SSC DOM represented the highest fraction (35.8%-47.4%) of CHON subcategory, while the GWC DOM represented the highest fraction (68.4%) of CHO subcategory. The GWC DOM was recognized as the nitrogen- and sulfur-deficient compounds that were less saturated, more aromatic, and more oxidized compared with other samples. Further analysis of the oxygen, nitrogen-containing (N-containing), and sulfur-containing (S-containing) functional groups in the four subcategories revealed higher organic molecular complexity. Comparison of the similarities and differences of the four samples revealed 22.8% ubiquitous formulas and 17.4%, 11.1%, 10.7%, and 6.3% unique formulas of GWC, KWC, SSC, and MWC DOM, respectively, suggesting a large proportion of ubiquitous DOM as well as unique, source-specific molecular signatures. The findings presented herein provide new insight into the molecular characterization of DOM derived from various composts and demonstrated the potential role of these different compounds for agricultural utilization.     

气象因素对环境空气质量达标的影响分析

以天津市为例,分析地面风场、大气层结及天气形势等主要污染气象参量的特征及其与环境空气质量的相关关系;估算高、低污染潜势的天气背景对大气污染物浓度的影响幅度;提出在天气气候分类的基础上,建立气象条件标准化分级,评估气象条件对环境空气质量影响水平的方法。研究表明:天津市采暖季高污染的天气形势出现的频率约为34%,而非采暖季高污染的天气形势出现的频率约为16%,ISCLT3模型模拟结果显示相应于相同的污染源排放数据库由于采暖季和非采暖季气象条件不同引起的SO2全市平均浓度的差异约在10%以上。污染源源强相对稳定的条件下,高污染潜势的天气背景对空气污染的加剧作用大于低污染潜势的天气背景对空气污染的减轻作用。     

空气和废气中醛酮污染物的气相色谱测定

以２,４－二硝基肼酸性饱和溶液吸收空气和废气中的醛和酮所形成的腙衍生物用毛细管气相色谱分析。本法预处理回收率在９４％以上,最低检测限为０．０５－０．１ｎｇ,可测定空气和车间空气中挥发性和半挥发性醛和酮类污染物。     

邻苯二甲酸二乙基己酯与双酚A联合染毒对小鼠学习记忆障碍及淀粉样前体蛋白酶解通路的影响

研究邻苯二甲酸二乙基己酯(diethylhexyl phthalate, DEHP)与双酚A(bisphenol A, BPA)联合染毒对小鼠学习记忆障碍及淀粉样前体蛋白(APP)酶解通路的影响。选用昆明种小鼠80只,随机分为空白对照(CT)组、BPA染毒组(1 mg·L^(-1))、不同浓度的DEHP染毒组(100、250和500 mg·kg(-1))、不同浓度的DEHP染毒组(100、250和500 mg·kg^(-1))与联合染毒组。经口灌胃染毒,以0.01 mL·g(-1))与联合染毒组。经口灌胃染毒,以0.01 mL·g^(-1)的剂量灌胃,7次/周,持续6周。使用Morris水迷宫、避暗、跳台的行为学实验方法检测2种污染物单独及联合染毒对小鼠学习记忆的影响;检测小鼠大脑组织中丙二醛(MDA)的含量和单胺氧化酶(MAO)、过氧化氢酶(CAT)、乙酰胆碱酯酶(AChE)的活性;采用酶联免疫分析(ELISA)法检测脑组织中的β、γ-分泌酶活性和Aβ_(1-42)的含量;Western Blot法检测APP、PS1、BACE1和Tau的蛋白表达水平;免疫组化法观察小鼠脑组织海马区HE染色情况。行为学测试结果表明,与CT组比较,单独染毒处理组小鼠学习记忆能力出现障碍,空间探索能力较弱;联合染毒组与单独染毒组相比,小鼠于目标象限停留时间短,穿台次数少,差异具有统计学意义(P<0.05);生化学指标结果显示,随着毒物浓度增加,脑组织中MAD含量、MAO和AChE活性逐渐增加,CAT活性逐渐降低,联合染毒组的变化更为明显,染毒处理组β、γ-分泌酶活性和Aβ_(1-42)含量增加,联合染毒组比单独染毒组酶活性增加更明显;各组差异均具有统计学意义(P<0.05)。DEHP与BPA单独染毒,对小鼠脑组织均显示有神经毒性作用,会造成小鼠学习记忆功能障碍;随着联合染毒组DEHP浓度的增加,联合染毒组与对应剂量的单独染毒组相比,小鼠行为学测试结果与生化指标变化更加明显,采用效应相加模型对其联合毒性作用进行评价,表现为协同作用;染毒组小鼠脑组织神经递质明显减少,具体机制可能与氧化应激及APP酶解通路的作用有关。     

砷形态在湖水中垂直分布的研究

本文以天津水上公园湖泊作为研究现场，通过采样分析，研究了湖水中砷酸盐、亚砷酸盐、一甲基胂酸盐和二甲基胂酸盐的垂直分布及其影响因素。结果表明水上公园湖泊中砷酸盐是溶解态砷的主要存在形式，其垂直分布与悬浮物、叶绿素ａ、磷酸盐的浓度、水文等诸因素密切相关；一甲基胂酸盐含量保持相对稳定；光致转化是影响水中亚砷酸盐垂直分布差异的一个因素。     

大气颗粒物上多环芳烃的识别和源解析的进展

本文对当前大气颗粒物上ＰＡＨｓ的识别和源解析的定量及定性和半定量的方法进行了综述，定性及半定量方法简便易行，但误差大；化学质量平衡法结果较准确具体，但ＰＡＨｓ会发生化学反应而降解，并且没有各种燃烧源较完整的ＰＡＨｓ成份谱，这已成为ＣＭＢ广泛推行的障碍；多元统计方法不考虑ＰＡＨｓ的降解，但要求数据量大，国内外的科学工作者用不同的方法和手段，使ＰＡＨｓ来源的识别和源解析工作有了一定进展。