Estimation of daily PM2.5 concentration and its relationship with meteorological conditions in Beijing

When investigating the impact of air pollution on health, particulate matter less than 2.5 μm in aerodynamic diameter(PM_(2.5)) is considered more harmful than particulates of other sizes. Therefore, studies of PM_(2.5) have attracted more attention. Beijing, the capital of China,is notorious for its serious air pollution problem, an issue which has been of great concern to the residents, government, and related institutes for decades. However, in China,significantly less time has been devoted to observing PM_(2.5) than for PM_(10). Especially before 2013, the density of the PM_(2.5) ground observation network was relatively low, and the distribution of observation stations was uneven. One solution is to estimate PM_(2.5) concentrations from the existing data on PM_(10). In the present study, by analyzing the relationship between the concentrations of PM_(2.5) and PM_(10), and the meteorological conditions for each season in Beijing from 2008 to 2014, a U-shaped relationship was found between the daily maximum wind speed and the daily PM concentration, including both PM_(2.5) and PM_(10). That is, the relationship between wind speed and PM concentration is not a simple positive or negative correlation in these wind directions; their relationship has a complex effect, with higher PM at low and high wind than for moderate winds.Additionally, in contrast to previous studies, we found that the PM_(2.5)/PM_(10) ratio is proportional to the mean relative humidity(MRH). According to this relationship, for each season we established a multiple nonlinear regression(MNLR) model to estimate the PM_(2.5) concentrations of the missing periods.     

Algal uptake of dissolved organic nitrogen in wastewater treatment plants

The algal uptake of dissolved organic nitrogen(DON) in the anaerobic–anoxic–oxic(A_2O)process was investigated in this study. Anaerobic, aerobic and effluent DON samples from two wastewater treatment plants(WWTPs) were separated into hydrophilic and hydrophobic fractions using a DAX-8 resin coupled with an anion exchange resin and a nanofiltration(NF)pretreatment. Hydrophilic DON accounted for 66.66%–88.74% of the entire DON for the two plants evaluated. After a 15-day incubation, 16.95%–91.75% DON was bioavailable for algal growth, and untreated samples exhibited higher DON bioavailability, with 52.83% DON average uptake rates, compared with the hydrophilic and hydrophobic fractions(45.53% and 44.40%, respectively) because the pretreatment caused the inorganic salt to be resistant to algae. Anaerobic untreated samples, hydrophilic fractions and hydrophobic fractions showed higher DON reduction rates and higher biomass accumulation compared with the other DON fractions due to the decomposition of resistant organics by anaerobic and anoxic bacteria.DON in aerobic and effluent samples of plant A was more bioavailable than that of plant B with usages of 27.49%–55.26% DON. DON bioavailability in the anaerobic–anoxic–oxic process decreased in the following order: anaerobic effluent aerobic. The DON contents were reduced after anaerobic treatment in the two plants. The EEM-PARAFAC model identified three DON components, including two humic acid-like substances and one protein-like substance in plant A and two protein-like substances and one humic acid-like substance in plant B.     

pH-dependent release characteristics of antimony and arsenic from typical antimony-bearing ores

The pH-dependent leaching of antimony (Sb) and arsenic (As) from three typical Sb-bearing ores (Banxi, Muli and Tongkeng Antimony Mine) in China was assessed using a pH-static leaching experiment. The pH changes of the leached solutions and pH-dependent leaching of Sb and As occurred in different ways. For the Banxi and Muli Sb ores, alkaline conditions were more favorable for the release of Sb compared to neutral and acidic conditions, but the reverse was true for the pH-dependent release of As. For the Tongkeng Sb ore, unlike the previous two Sb-bearing ores, acidic conditions were more favorable for Sb release than neutral and alkaline conditions. The ores with lower Sb and As contents released higher percentages of their Sb and As after 16 day leaching, suggesting that they are the largest potential sources of pollution. This work may provide key information on the geochemistry of Sb and As in the weathering zone.     

Polycyclic aromatic hydrocarbon concentrations, compositions, sources, and associated carcinogenic risks to humans in farmland soils and riverine sediments from Guiyu, China

The concentrations of 16 priority polycyclic aromatic hydrocarbons(PAHs) were measured in 23 farmland soil samples and 10 riverine sediment samples from Guiyu, China, and the carcinogenic risks associated with PAHs in the samples were evaluated. Guiyu is the largest electronic waste(EW) dismantling area globally, and has been well known for the primitive and crude manner in which EWs are disposed, such as by open burning and roasting. The total PAH concentrations were 56–567 ng/g in the soils and 181–3034 ng/g in the sediments.The Shanglian and Huamei districts were found to be more contaminated with PAHs than the north of Guiyu. The soils were relatively weakly contaminated but the sediments were more contaminated, and sediments in some river sections might cause carcinogenic risks to the groundwater system. The PAHs in the soils were derived from combustion sources,but the PAHs in the sediments were derived from both combustion and petroleum sources.     

环境应力筛选在反坦克导弹及火箭弹中的应用

目的针对工程实践经验和反坦克导弹及火箭弹武器装备,提出新的环境应力筛选条件,用于剔除装备的早期故障。方法结合反坦克导弹及火箭弹武器装备的特点,对GJB 1032进行科学裁剪,分别制定出反坦克及火箭弹的不同层次产品的环境应力筛选条件。结果通过分析试验验证,反坦克导弹及火箭弹实施环境应力筛选能够激发出产品的早期故障。结论环境应力筛选方案在某型反坦克武器及火箭弹武器装备中得到了成功应用。     

汞的树木年轮化学研究进展

由于可以有效揭示重金属污染的时间变化序列,近年来,树木年轮被广泛应用于环境重金属污染的历史追溯。年轮化学技术也被应用于示踪某地区的汞污染历史,本文系统介绍了利用树木年轮化学对汞污染积累历史进行追溯研究的相关研究成果,包括样品采集与处理、含量测定及数据分析,并对木质汞来源进行了讨论,最后对汞年轮化学研究的未来发展进行了展望。     

温岭市高架道路交通噪声空间分布规律与防治对策研究

为评价温岭市东环高架道路交通噪声的环境影响,采用实测法对东环高架附近代表性点位及不同时间段进行噪声监测,记录等效连续A声级(Leq),以及同步监测车流量、车型等相关数据.根据《声环境质量标准》(GB 3096-2008),由所得监测数据,推测其交通噪声空间分布规律.结果表明,噪声最大值发生于上下班高峰期,交通噪声则随距离的增加而衰减,而道路两侧高层建筑交通噪声随着高度的增加先由小变大后变小.此外,还为该高架道路交通噪声的防治提供一定的参考依据.     

探地雷达在加油站地下罐区泄漏检测中的应用

运用探地雷达进行加油站埋地罐区油品泄漏检测,先后对8座加油站进行了埋地罐区泄漏测试,发现某加油站埋地罐区的疑似泄漏区域,并对疑似泄漏区域进行了验证确认。     

生物质炭对邻苯二甲酸二丁酯污染土壤微生物群落结构多样性的影响

在邻苯二甲酸二丁酯(DBP)污染的不同类型土壤(有机质含量低的新垦红壤、有机质含量高的熟化红壤)中添加不同种类(稻草炭、毛竹炭)以及不同用量(0%、0.5%和2%)的生物质炭,温室种植上海青并在56 d后采集土样,采用磷脂脂肪酸法(PLFA)考察了土壤类型、生物质炭种类以及用量对土壤微生物群落结构多样性的影响.结果表明:对细菌、真菌及微生物总PLFA这三者的含量而言,熟化红壤显著(p0.05)高于新垦红壤,熟化红壤中添加2%稻草炭使其显著(p0.05)增加,新垦红壤中添加毛竹炭使其显著(p0.05)降低.新垦红壤中添加2%稻草炭对革兰氏阴性菌/革兰氏阳性菌比值的增加效果最显著(p0.05),添加2%毛竹炭对土壤微生物群落Shannon指数的降低效果最显著(p0.05).添加2%稻草炭对DBP污染土壤中微生物压力指数降低效果最显著(p0.05).生物质炭对熟化红壤中真菌/细菌、革兰氏阴性菌/革兰氏阳性菌及微生物群落Shannon指数均无显著影响.PCA分析表明,土壤有机质含量以及生物质炭的种类和用量均会对土壤微生物群落结构产生一定影响,且生物质炭的影响与土壤有机质含量密切相关.