河北省某大型焦化厂地下水中多环芳烃的污染特点、源解析及生态风险评价

为研究焦化厂地下水中美国EPA优先控制的16种多环芳烃(PAHs)的分布特点和污染来源,本研究联合使用统计技术、正定矩阵因子分析(PMF)模型和风险商值法,深入分析了焦化厂地下水中PAHs的分布规律,定量解析了PAHs的污染来源,并且对其生态风险进行了科学评价.结果表明,焦化厂地下水中16种PAHs的总检出率较高,达到46.7%.地下水中∑₁₆PAHs的浓度范围是n.d.～444.9μg·L^-1,均值为1.88μg·L^-1.不同生产车间地下水中PAHs的浓度存在明显差异,其中污染最重的车间位于焦油精制区,地下水中∑₁₆PAHs的浓度为444.92μg·L^-1.应用PMF源解析模型,识别出该焦化厂地下水中PAHs有二类污染源：一是石油的燃烧源,二是煤和生物质燃烧以及石油类的泄漏,二种污染源对焦化厂地下水中PAHs的贡献率分别为38.6%和61.4%.焦化厂地下水中∑₁₆PAHs处在高生态风险等级,且有53.4%的地下水采样点单体PAHs的生态风险处在高风险等...     

Novel Co-Mg-Al-Ti-O catalyst derived from hydrotalcite-like compound for NO storage/decomposition

Catalysts of Co_1.5Mg_1.5/Al_0.9Ti_0.1O and Co_1.5Mg_1.5/AlO were successfully prepared by calcinations of corresponding hydrotalcite-like compounds at 800℃ for 4 hr. The derived oxides were of spinel phase and a small quantity of Ti substitution did not change the crystal purity. Their catalytic performance for the NO storage/decomposition was investigated. Ti incorporation enhanced the NO decomposition activity while has an opposite effect on the storage capacity of catalyst. In situ FT-IR spectra of the catalysts showed that the final adsorption species on the catalysts was coordinated nitrates/nitrites. In addition, NO storage/decomposition mechanism has been discussed on the basis of these observations.     

Soil warming effect on net ecosystem exchange of carbon dioxide during the transition from winter carbon source to spring carbon sink in a temperate urban lawn

The significant warming in urban environment caused by the combined effects of global warming and heat island has stimulated widely development of urban vegetations. However, it is less known of the climate feedback of urban lawn in warmed environment. Soil warming effect on net ecosystem exchange (NEE) of carbon dioxide during the transition period from winter to spring was investigated in a temperate urban lawn in Beijing, China. The NEE (negative for uptake) under soil warming treatment (temperature was about 5℃ higher than the ambient treatment as a control) was -0.71 μmol/(m².sec), the ecosytem was a CO₂ sink under soil warming treatment, the lawn ecosystem under the control was a CO₂ source (0.13 μmol/(m².sec)), indicating that the lawn ecosystem would provide a negative feedback to global warming. There was no significant effect of soil warming on nocturnal NEE (i.e., ecosystem respiration), although the soil temperature sensitivity (Q₁₀) of ecosystem respiration under soil warming treatment was 3.86, much lower than that in the control (7.03). The CO₂ uptake was significantly increased by soil warming treatment that was attributed to about 100% increase of α (apparent quantum yield) and A_max (maximum rate of photosynthesis). Our results indicated that the response of photosynthesis in urban lawn is much more sensitive to global warming than respiration in the transition period.     

改良剂对4种木本植物的铅锌耐性、亚细胞分布和化学形态的影响

本研究以4种耐铅锌木本植物夹竹桃(Nerium oleander)、栾树(Koelreuteria paniculata)、泡桐(Paulownia)和苎麻(Boehmeria)为材料,在不同改良剂浓度下(CK组:100%铅锌矿渣±少量磷肥、改良一:85%铅锌矿渣±10%泥炭土±5%菌肥±少量磷肥、改良二:75%铅锌矿渣±20%泥炭土±5%菌肥±少量磷肥),进行了耐性木本植物富集与转移能力以及Pb、Zn在4种木本植物不同部位的亚细胞分布和化学形态分析.结果表明:14种植物种植后基质中重金属的浓度基本低于种植前,夹竹桃与苎麻改良一与改良二之间差异不显著,泡桐改良二效果显著优于改良一,栾树改良一效果显著优于改良二;4种植物地上部对Pb、Zn的富集系数都比较低,但具有较高的转移系数,适当的基质改良有利于提高植物对Pb、Zn的富集与转移能力.2Pb、Zn在4种植物各部位的亚细胞分布以细胞壁组分和可溶性组分为主,在线粒体、叶绿体和细胞核等细胞器组分中分布较少;与CK组相比,两改良组使可溶性组分对Pb的滞留作用和细胞壁对Zn的滞留作用在增强.3Pb在植物各部位的化学形态以盐酸、氯化钠和乙醇提取态为主,其他化学形态含量极少;Zn则以残留态、盐酸、醋酸、氯化钠、水和乙醇提取态这6种形态存在,且都具较高分配比例.与CK组相比,两改良组使植物各部位活性较弱的Pb的化学形态比例减少,活性较强的化学形态比例增加;Zn则是根部活性较强的化学形态比例增加,地上部活性较强的化学形态比例减少.     

低浓度CO2在聚苯胺/Y分子筛复合材料上的吸附

根据原位聚合方法将不同量的苯胺分别聚合在Y分子筛上,得到3种聚苯胺(PANI)/Y分子筛复合材料PANI-Y~(-1)、PANI-Y-2及PANI-Y-3,用傅立叶红外及氮气吸附实验表征了材料的结构特征,探讨了复合材料对常压下低浓度CO_2的吸附及再生性能.结果表明,苯胺在Y分子筛上成功聚合,复合材料的比表面积分别为52、54和35 m2·g~(-1),孔道由大孔和少量中孔组成,微孔极少.PANI负载量越大,材料的孔容越低.20℃下,初始体积分数为10%的CO_2在复合材料与Y分子筛上的吸附符合Logistic模型,吸附量的顺序为PANI-Y-2(2.09 mmol·g~(-1))PANI-Y-3(1.79 mmol·g~(-1))PANI-Y~(-1)(1.07 mmol·g~(-1))Y分子筛(0.80 mmol·g~(-1)),复合材料对CO_2的吸附受PANI负载量和比表面积的共同影响.在2%~10%的范围内,CO_2在复合材料上的吸附量随初始体积分数增加而增加;在25~65℃下,吸附量随温度升高而降低.80℃下,PANI-Y-2的4次热再生效率较差,仅68%;采用氨水/热再生相结合的方式脱附CO_2,再生率提高到94%.     

某集约化肉鸡饲养场PM2.5中抗生素抗性基因的分布特征

集约化家禽饲养场是抗生素抗性基因(ARGs)的重要来源,而PM_(2.5)作为ARGs可能向人体暴露的重要途径还未得到很好地研究.本文采集了集约化肉鸡饲养场舍内PM_(2.5)和粪便以及舍外PM_(2.5)样品,利用荧光定量PCR(q PCR)进行一类整合子(int I1)、总细菌(16S r DNA)和6类共19种ARGs丰度的检测.结果显示,除blaGES-1和blaSHV-1之外,其余17种ARGs在6类样品中均有检出.磺胺类、四环素类、大环内酯类和氨基糖苷类抗性基因在舍内粪便中丰度较高,达到1. 04×109～3. 27×1010copies·g-1,粪便是饲养场PM_(2.5)中ARGs的主要来源.舍内PM_(2.5)中以磺胺类和大环内酯类抗性基因丰度较高,分别为(8. 9±1. 9)×107copies·m-3和(5. 6±3. 1)×107copies·m-3,且舍内PM_(2.5)中ARGs丰度明显高于舍外. PM_(2.5)质量浓度与16S r DNA、int I1和ARGs丰度呈显著正相关,表明集约化饲养场中PM_(2.5)是空气传播细菌、ARGs和int I1的储存库和传播者. 6类样品中int I1丰度均高于ARGs,同时int I1和ARGs的共存关系表现出了多药耐药性的威胁,易对饲养人员和家禽健康及周边空气环境造成危害.     

宁东基地大气PAHs污染特征及呼吸暴露风险

利用主动观测技术对宁东能源化工基地大气PM_2.5、PM_1.0和气相中的PAHs浓度水平、族谱特征、时空分布及来源进行研究,并基于该观测数据对居民呼吸暴露健康风险进行评估.结果表明,宁东基地大气PM_2.5、PM_1.0及气相中∑₁₆PAHs浓度范围分别为：17.95~325.12ng/m³、12.66~311.96ng/m³和26.33~97.88ng/m³,年均浓度分别为（99.42±117.48）ng/m³、（78.88±100.58）ng/m³和（57.89±47.39）ng/m³.宝丰基地冬夏季大气PM_2.5、PM_1.0和气相中∑₁₆PAHs浓度水平均明显高于英力特;宝丰和英力特基地冬季大气PM_2.5、PM_1.0中∑₁₆PAHs浓度水平均明显高于夏季浓度.宁东基地大气中∑₁₆PAHs的浓度水平要高于国内外其他城市,大气PAHs污染较为严重.源解析表明夏季宁东基地PAHs的主要排放源是工业煤燃烧和机动车尾气,冬季则主要来自工业煤燃烧和木材、薪柴等生物质燃烧排放.宁东基地人群暴露于大气PAHs可能会造成平均冬季每百万人中约有33~2628人罹患癌症,夏季每百万人中约有11~834人罹患癌症的风险.     

The ignored emission of volatile organic compounds from iron ore sinter process

Iron ore sintering is a major source of gaseous and particulate pollutants emission in iron smelt plant. The aim of present study is to characterize the volatile organic compounds(VOCs) emission profiles from iron ore sintering process. Both sinter pot test and sinter simulation experiment were conducted and compared. Out results showed that sinter process produced large quantity of VOCs together with NOxand SO_2. VOCs and NO were produced simultaneously in sinter pot test from 3 to 24 min after ignition, flowed by SO_2 production from 15 min to the end of sintering. Total VOCs(TVOC) concentration in sinter flue gas was affected by the coal and coke ratio in sinter raw material. The maximum TVOC concentration was 34.5 ppm when using 100% coal as fuel. Sinter simulation experiments found that the number of VOCs species and their concentrations were found by sinter temperature. The largest VOCs species varieties were obtained at 500 °C. Benzene, toluene,xylene and ethylbenzene were major VOCs in sinter flue gas based on the results from both simulation test and sinter pot. It thus demonstrated that in addition to NO_x, SO_2 and metal oxide particles, sinter flue gas also contained significant amount of VOCs whose environmental impact cannot be ignored. Based on our work, it is timely needed to establish a new VOC emission standard for sinter flue gas and develop advanced techniques to simultaneously eliminate multi-pollutants in iron ore sinter process.     

2,3,7,8-Tetrachlorodibenzo-p-dioxin promotes migration ability of primary cultured rat astrocytes via aryl hydrocarbon receptor

Emerging evidence showed that 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) could induce expression of certain reactivation-associated genes in astrocytes, however, the consequent cellular effects and molecular mechanisms are still unclear. During the process of astrocyte reactivation, migration is a critical cellular event. In the present study, we employed wound-healing assay and Transwell® motility assay to explore the effects of TCDD on cell migration in primary cultured rat cortical astrocytes. We found that upon TCDD treatments at relative low concentrations (10^? 10 and/or 10^? 9?mol/L), the ability of primary astrocytes to migrate horizontally and vertically was promoted. In line with this cellular effect, the mRNA expression of two pro-migratory genes, including cell division cycle 42 (CDC42) and matrix metalloproteinase 2 (MMP2) was induced by TCDD treatment. Dioxin exerts its toxic effects mainly through aryl hydrocarbon receptor (AhR) pathway. So the role of AhR pathway in the pro-migratory effects of TCDD was examined using an AhR antagonist, CH223191. We found that application of CH223191 significantly reversed the pro-migratory effects of TCDD. Interestingly, the basal ability of horizontal migration as well as basal levels of CDC42 and MMP2 expression were dramatically reduced suggesting a possible physiological role of AhR in maintaining the endogenous migration ability of the primary astrocytes. These findings support the notion that dioxin promotes astrocyte reactivation at molecular and cellular levels.     

糠醛渣对水中甲基橙的吸附性能

为了探究糠醛生产中的废料糠醛渣对水体中甲基橙的吸附性能和吸附机制,利用FT-IR（傅里叶变换红外光谱）和SEM（扫描电镜）对糠醛渣的结构特性进行表征,浅析糠醛渣对甲基橙的吸附机制;通过模拟试验,考察了吸附剂用量、pH、吸附时间和温度等因素对糠醛渣吸附甲基橙过程的影响;采用吸附动力学模型和吸附等温模型,进一步探讨了糖醛渣吸附机制.结果表明:①糠醛渣结构疏松多孔,表面具有丰富的官能团,有利于吸附.②糠醛渣能高效吸附水中甲基橙,在温度为293 K、pH为4~9、吸附剂用量为0.2 g时,糠醛渣对400 mg/L的甲基橙吸附效果最好;吸附过程在60 min左右达到平衡,并且较好地符合准二级动力学模型（R2=0.999 9）;吸附量随温度的升高而减少,表明该吸附过程为放热过程;在293 K时最大理论吸附量为54.35 mg/g,吸附数据更符合Langmuir吸附等温模型（R2=0.993 3）,表明糠醛渣对甲基橙的吸附主要为单层吸附.③糠醛渣可再生重复利用,吸附甲基橙后的糠醛渣用0.1 mol/L氢氧化钠溶液进行解吸再生试验,第5次使用时对甲基橙仍然具有较好的吸附效果.研究显示,糠醛渣在室温条件下、较宽的pH范围内能快速高效地吸附水中的甲基橙,并且重复利用性好,是一种在偶氮染料废水处理中具有发展前景的廉价、可再生生物质吸附材料.