长期石油污染土壤腐殖质组成的研究

选择1口开采约20a的废弃油井,在距离井口0.5、1.5、2.5、3.5、4.5、5.5、6.5、7.5和10.5 m处进行多点采样,应用腐殖质组成修改法和Simon-Kumada法,分别研究了上述长期不同程度石油污染土壤的全土及不同结合形态腐殖质组成.结果表明,土壤石油含量随距井口距离加大而降低,最远处(10.5 m)和最近处(0.5 m)分别为0.08 g/kg和153.3 g/kg.随石油含量增加,土壤有机碳和水溶性有机碳含量增加;全土腐殖质中,可提取腐殖质(HE)含量和胡敏酸(HA)含量下降而胡敏素(HM)含量增加, HA/HE的百分比(PQ 72.0%～8.05%)下降而HM/HE(31.4～76.7)增加;不同结合形态腐殖质中,松、稳结合态腐殖质(HⅠ、HⅡ)的含量呈下降趋势而紧结合态腐殖质(HⅢ)的含量增加, HⅠ/HⅡ(0.19～0.39)呈增加趋势,而HⅠ/HⅢ(0.032～0.003)和HⅡ/HⅢ(0.096～0.009)下降, HⅠ、HⅡ的PQ(3.21%～1.42%、58.1%～35.5%)也下降,并且HⅠ的PQ变化幅度小于HⅡ;水溶性有机质(WSOM)的色调系数(△logk)下降而HA则变化不大.以上结果说明,随石油污染程度增加,土壤HM的形成增强而HA形成减弱,对HA形成的影响主要表现为对稳结合态HA形成的抑制作用, WSOM分子结构趋于复杂而HA没有明显变化.     

中国能源生产与消费趋势预测和碳排放研究

为合理、科学地对能源结构进行调整和优化,提出了能源结构的双组份模型。由统计检验估计法,对模型中的能源生产与消费的相关系数进行了预测估计。依据中国统计年鉴2008年数据,对我国2014年能源生产与能源消费的预测结果分别为24.26×108t标准煤及27.15×108t标准煤。利用预测的能源消费总量、结构与碳排放量之间的关系式——即单位能耗碳排放系数的表达式,预测中国2012年的碳排放量为21.87×108t标准煤,且有上升趋势,并提出了相关的能源对策。     

Debrominated, hydroxylated and methoxylated metabolism in maize (Zea mays L.) exposed to lesser polybrominated diphenyl ethers (PBDEs)

A hydroponic experiment was conducted to investigate the debrominated, hydroxylated and methoxylated metabolism of polybrominated diphenyl ethers (PBDEs, BDE-15, -28 and -47) in maize. A total of six debrominated metabolites (de-PBDEs), seven hydroxylated PBDEs (OH-PBDEs, including two unidentified OH-di-PBDEs and one unidentified OH-tri-PBDE) and four methoxylated PBDEs (MeO-PBDEs) were determined in the exposed plants. The metabolic products were detected in maize only after 12 h of exposure to the PBDEs. However, the concentration of each type of the metabolites (de-PBDEs, OH-PBDEs or MeO-PBDEs) decreased at the later exposure time, possibly due to further metabolism. The removal of a bromine atom or the introduction of a hydroxyl/methoxy group was easier at the ortho-positions on the biphenyl structure than at the para-positions. Concentration ratios of the total debrominated, hydroxylated or methoxylated metabolites to the parent congener (BDE-28 or -47) generally followed the order of leaves > stems ? roots, and MeO-PBDEs > de-PBDEs ? OH-PBDEs. These results suggest that metabolism occurred preferentially in leaves and stems than in roots. Less transformation and shorter elimination half-life of OH-PBDEs would contribute to the lower concentrations of OH-PBDEs than of de-PBDEs or MeO-PBDEs in maize.     

污水土地处理系统流态影响因素及优化

在污水土地处理系统的反应器模型中进行流态实验,使用正交分析理论及停留时间分布(RTD)分析理论,探索管网、集水层和承托层对反应器体积效率及推流的影响,并对反应器构造进行优化。使用正交实验分析发现,各因素对体积效率的影响程度顺序为:承托层>集水层>管网,管网与承托层的影响有明显的交互作用;集水层对推流有影响,并且管网与集水层有很显著的交互作用。使用RTD分析各因素交互作用发现,采用全网布水与集水时,集水层及承托层对流态的影响都不大。管网布设为过水断面的一半(半网)时,集水层的集水作用及承托层的布水作用可以增加反应器体积效率。"半网-有集水层-有承托层"的体积效率最高,流态最接近推流形式,其无因次平均停留时间为1.093,轴向扩散系数为0.037,属于低扩散程度。     

京津冀区域生态资产负债核算研究

开展生态资产负债核算研究对自然资源资产负债表编制具有重要意义。以京津冀13个地市为例,通过计算生态产品供给价值变化以及生态足迹、生态承载力和生态赤字来分析其生态资产负债变化情况。核算结果表明,2012年京津冀生态产品供给的期初价值为4686亿元,期末价值为4990亿元,当期增加340亿元。京津冀生态足迹和生态承载力分别为4451.06万hm2和1932.68万hm2,生态赤字为3167.8万hm2。生态赤字较大的城市分别是北京市、天津市、石家庄市和保定市,生态赤字较小的城市分别为秦皇岛市和承德市。北京市人口增长过快和资源消耗量过大是生态赤字的重要原因。京津冀区域在发展方面引起的生态资产变化,需要引起高度重视。     

基于视频图像的交通枢纽综合体人体检测

针对交通枢纽综合体人体检测的问题,提出一种基于梯度方向直方图(HOG)人体模型特征的检测算法。该方法通过提取人体样本库的HOG特征,用支持向量机算法(SVM)对样本的HOG特征进行分类训练。为了提高算法的精确度和适用性,以南京南站的监控视频为依据建立交通枢纽综合体人体样本库。并以南京南站监控视频和校园拍摄的人员视频作为测试集。结果证明,本算法可以有效识别交通枢纽综合体各种特征人体。     

纳米氧化锌粒径对人工湿地性能及微生物群落的影响

纳米颗粒(nanoparticles,NPs)具有较小的粒径(1～100 nm),其生物毒性与粒径的大小紧密相关.在进水COD约200. 0 mg·L~(-1),NH_4~+-N约12. 5 mg·L~(-1)和溶解性总磷约4. 0 mg·L~(-1)的条件下连续运行28 d,研究了3种不同粒径的纳米氧化锌(ZnO NPs)对水平潜流人工湿地微生物群落结构和多样性的影响,同时结合湿地脱氮性能的变化,探讨了湿地中微生物群落结构和多样性与其处理性能的相互关系.结果表明,3种粒径(15、50和90 nm)的ZnO NPs(10 mg·L~(-1))对COD的去除无明显差异,而对脱氮则表现出明显的粒径效应.高通量测序发现,人工湿地系统中硝化菌属的丰度明显低于反硝化菌属,硝化过程是制约湿地脱氮性能的关键因素.暴露于不同粒径的ZnO NPs后,微生物群落结构发生不同程度的变化,与较大粒径(50 nm和90 nm)的ZnO NPs相比,15 nm的ZnO NPs对硝化菌属的抑制更为显著.     

Start-up of the anammox process from the conventional activated sludge in a hybrid bioreactor

The anaerobic ammonium oxidation (anammox) process was successfully started up from conventional activated sludge using a hybrid bioreactor within 2 months. The average removal efficiencies of ammonia and nitrite were both over 80%, and the maximum total nitrogen removal rate of 1.85 kg N/(m³.day) was obtained on day 362 with the initial sludge concentration of 0.7 g mixed liquor suspended solids (MLSS)/L. Scanning electron microscope (SEM) observation of the granular sludge in the hybrid reactor clearly showed a high degree of compactness and cell sphericity, and the cell size was quite uniform. Transmission electron microscope photos showed that cells were round or oval, the cellular diameter was 0.6--1.0 μupm, and the percentage of the anammoxosome compartment was 51%--85% of the whole cell volume. Fluorescence in situ hybridization analysis (FISH) indicated that anammox bacteria became the dominant population in the community (accounting for more than 51% of total bacteria on day 250). Seven planctomycete 16S rRNA gene sequences were present in the 16S rRNA gene clone library generated from the biomass and affiliated to Candidatus Kuenenia stuttgartiensis and Candidatus Brocadia sp., a new anammox species. In addition, the average effluent suspended solid (MLSS) concentrations of outlets I (above the non-woven carrier) and II (below the non-woven carrier) were 0.0009 and 0.0035 g/L, respectively. This showed that the non-woven carrier could catch the biomass effectively, which increased biomass and improved the nitrogen removal rate in the reactor.     

2016年1月京津冀地区大气污染特征与多尺度传输量化评估

基于大气环境监测数据和WRF-CAMx模式,分析了 2016年1月京津冀城市的大气污染特征,开展了 PM2.5跨界传输量化评估研究.结果表明,2016年1月京津冀地区PM2.5、PM10、SO2、NO2和CO的平均浓度分别为89.5μg·m-3、135.61μg·m-3、57.55 μg·m-3、60.79 μg·m-...     

Characteristics of volatile compounds removal in biogas slurry of pig manure by ozone oxidation and organic solvents extraction

Biogas slurry is not suitable for liquid fertilizer due to its high amounts of volatile materials being of complicated composition and peculiar smell. In order to remove volatiles from biogas slurry efficiently, the dynamic headspace and gas chromatography-mass spectrometry were used to clear the composition of volatiles. Nitrogen stripping and superfluous ozone were also used to remove volatiles from biogas slurry. The results showed that there were 21 kinds of volatile compounds in the biogas slurry, including sulfur compounds, organic amines, benzene, halogen generation of hydrocarbons and alkanes, some of which had strong peculiar smell. The volatile compounds in biogas slurry can be removed with the rate of 53.0% by nitrogen stripping and with rate of 81.7% by the oxidization and stripping of the superfluous ozone. On this basis, the removal rate of the volatile compounds reached 99.2% by chloroform and n-hexane extraction, and almost all of odor was eliminated. The contents of some dissolved organic compounds decreased obviously and however main plant nutrients had no significant change in the biogas slurry after being treated.