城市浅水湖泊沉积物磷形态分布及其与间隙水磷的关系

研究了典型城市浅水湖泊莫愁湖沉积物中磷形态及间隙水中TDP、PO43--P含量的垂向分布情况,沉积物中IP是TP的主要组成部分,与湖泊富营养化密切相关的Fe-P占IP的30%左右,Or-P占TP的30%左右。柱状沉积物中磷形态的垂向分布规律比较复杂,但基本上随深度先增后减的趋势。沉积物中TPI、P、Or-P、Ca-P、Fe-P、DP之间都具有极显著的正相关关系,但与Al-P、Oc-P的相关关系不明显,间隙水中TDP、PO43-P浓度与沉积物中Or-P含量具有显著的正相关关系,但相关程度并不高,与其他形态则没有明显的相关关系。     

CFB锅炉多点排放二氧化硫污染预测

循环流化床锅炉（CFB）多点排放时,直接测量分析对环境的影响较为困难。为了确定其中SO2对环境的影响,通过对鼢在CFB锅炉生产过程中的生成、转化和大气中的扩散分析,建立了多点排放的SO2污染预测正态分布模型。模型结果表明,多点排放时大气SO2的浓度分布仍满足正态分布特征,并较好地反映了最大落地浓度及位置,这对于依据区域大气SO2总量控制,确保和提高设备与工艺系统的清洁生产能力提供了可行依据。     

Severity of emergency natural gas distribution pipeline incidents: Application of an integrated spatio-temporal approach fused with text mining

The transportation of natural gas often relies on pipelines which require constant monitoring and regular maintenance to prevent spills or leaks. Pipeline incidents could pose a huge adverse impact on people, the environment, and society. Numerous efforts have been invested to identify contributing factors to pipeline incidents so that countermeasures could be developed to proactively prevent some incidents and reduce incident severities or impacts. However, the countermeasures may need to vary for different incidents due to the potential heterogeneity between incidents, and such heterogeneity is likely related to the geology, weather, and built environment which vary across space and time domain. The objective of this study is to revisit the correlates of pipeline incidents, focusing on the spatial and temporal patterns of the correlations between natural gas pipeline incident severity and contributing factors. This study leveraged an integrated spatio-temporal modeling approach, namely the Geographically and Temporally Weighted Ordered Logistic Regression (GTWOLR) to model the natural gas pipeline incident report data (2010–2019) from the U.S. Pipeline and Hazardous Material Safety Administration. Text mining was performed to extract additional information from the narratives in reports. Results show several factors have significant spatiotemporally varying correlations with the pipeline incident severity, and these factors include excavation damage, gas explosion, iron pipes, longer incident response time, and longer pipe lifetime. Findings from this study are valuable for pipeline operators, end-users, responders to jointly develop localized strategies to maintain the natural gas distribution system. More implications are discussed in the paper.     

南京城市夜间景观照明的城市生态学分析

选取了南京市4个典型的功能区,根据实地观测与文献资料分析及问卷调查相结合的方法,分析了各个区域景观照明的亮度、美观程度、存在的不利影响和突出问题等.并计算出南京市民对4个区域景观照明的亮度满意度、美观满意度和综合满意度得分,结合区域的功能和特点对其各项得分进行解析.最后针对实地踏看和数据分析所发现的区域景观照明在能源分...     

辽河盘锦段与河口海域水体氮素分布特征及其与溶解氧的关系

选取辽河盘锦段至河口近岸海域区域进行研究水体中氨氮、硝酸盐氮和亚硝酸盐氮的分布特征及其与溶解氧的关系进行研究。结果表明水中氮素含量高于海水,且氨氮表现尤为突出,可能与水体中溶解氧含量和微生物环境、海水的稀释和迁移有很大关系;河水中氮素与溶解氧的呈显著负相关,而海水中氮素与溶解氧的关系不明显。这可能与海水的质化作用有关。     

漓江沉积柱芯有机氯农药垂向分布特征与来源

用GC/ECD内标法定量法首次测定了广西桂林漓江沉积柱中19种有机氯农药(OCPs)的含量,结果表明:漓江沉积柱芯中OCPs浓度范围为4.75～489.4ng/g(均值43.26ng/g),在国内处于中等污染水平。OCPs、HCHs表现出下游污染程度高于上游,但DDTs则相反,这是由于上游的取样点蚂蟥洲附近有大量餐饮业造成的。沉积柱垂直分布表明,漓江近期受到人为污染影响。总体上漓江沉积物中HCHs污染大于DDTs,符合当地的农药使用历史。同分异构体比值表明研究区DDT主要是历史使用农药残留并得到了较好的降解,且以厌氧生物降解为主,当地在使用三氯杀螨醇可能性不大;沉积物中工业六六六尚未降解完全,同时周围可能有林丹输入。     

澎溪河流域水中碳素分布特征的研究

面对三峡库区日益突出的环境问题,研究人员做出众多研究,但对库区河流碳的赋存形态及其影响研究报道较少.在2019年春夏两季通过现场采样室内分析的方式测定了各形态碳含量,重点分析了澎溪河流域水中碳素的分布特征.结果 表明:澎溪河流域碳含量总体呈现上游低下游高,春季低夏季高的分布特点,两季TOC均值均超过水体富营养化标准达1...     

不同区域城市排水系统中H2S的溢出规律

通过对广州、兰州和昆明等城市排水系统中H2S的溢出浓度、管网参数与水质指标等进行实地监测,考察不同区域城市排水系统中H2S溢出规律.结果表明,不同城市排水系统中H2S的溢出浓度与当地居民生活习惯相关,并具有明显的时段特征;在相同监测时段内,不同区域H2S溢出浓度与溶解氧浓度(DO)、有机物浓度、硫化物浓度、硫酸盐浓度以及污水流量有关.单样本K-S检验结果表明,不同区域城市排水系统H2S的溢出浓度具有相同分布规律,均近似服从正态分布.独立样本t检验结果表明,广州与兰州H2S的溢出浓度没有显著差异,但与昆明的H2S溢出浓度则具有显著差异.     

Characterization and sources of PAHs in an urban river system in Beijing,China

Water samples from 20 locations on rivers in the Tongzhou District of Beijing were collected four times from July 2005 to March 2006. In addition, sediment samples were collected in July 2005. All samples were analyzed for 16 US Environmental Protection Agency (EPA) priority pollutants polycyclic aromatic hydrocarbons (PAHs). The concentration, distribution, seasonal variation, and sources of the 16 PAH compounds identified in the water samples, suspended particles, and surface sediments were then evaluated. The concentrations of PAHs in the water and suspended particle and surface sediment samples ranged from 87.3 to 1,890 ng l⁻¹, 1,330 to 27,700 ng g⁻¹, and 156 to 8,650 ng g⁻¹, respectively. These results demonstrated that rivers in the Tongzhou District of Beijing had a high level of PAH pollution, especially in the suspended particles. The highest and lowest concentrations of PAHs in the water samples were observed in summer and spring. However, the seasonal variations in the concentration of PAHs in the suspended particles were more complicated. The dominant compounds in the water, suspended particle, and surface sediment samples were two-, three- and four-ring PAH compounds, respectively. Ratio analysis illustrated that fuel-burning was the primary source of PAHs in the study area. Gasoline, diesel, coal, and coke oven sources were identified and the contributions of the different fuel-burning sources were then calculated using factor analysis and multiple linear regression. These analyses revealed that coal combustion, gasoline combustion plus coke oven emission, and diesel combustion accounted for 38.8%, 38.5%, and 22.7% of the PAHs in suspended particles, respectively.