密度场干涉测量及其条纹处理计算

本文将普通纹影仪改造成激光差分干涉仪,并用于火焰等密度场的显示与测量。编制了条纹预处理和细化软件系统,并对干涉条纹进行了处理和细化计算。另外,针对细化后的条纹,编制了密度场的计算软件,并对蜡烛火焰和超声速轴对称绕流流场进行了计算,得到了密度场定量的结果。     

喷出火焰引起可燃性墙面燃烧问题的研究

应用传热学的有关知识,从理论上分析了通过外墙窗口喷出的火焰对可燃性墙面的引燃及墙面上的火焰传播等问题,并对这些问题进行了实验研究,结果表明：喷出火焰比较容易引燃可燃性墙面,使墙面上出现垂直向上的火焰传播现象。     

大气降尘中水溶性有机物组成与含量的研究

本文为了研究各个地区大气降尘中水溶性有机物的组成与含量,从离地表２０ 米处的电网绝缘子表面采集九个大气降尘样品,对其水溶性部分用有机溶剂进行有机物的分离萃取,求出有机物的含量,采用ＸＲＰＤ 进行物相鉴定,确定有机物的组成可分为有机酸、有机酸钾盐、有机碱·盐酸盐加合物,尿素与尿素·硝酸盐加合物等四类,并对其影响ＣａＳＯ４·２Ｈ２Ｏ 的溶解度进行一系列实验,结果表明这四类有机物对ＣａＳＯ４·２Ｈ２Ｏ 溶解度的提高均有显著影响,可提高４０ ％ － ６０ ％ ,与实际降尘样品中其溶解度平均提高５０ ％ 左右相一致。由于大气降尘中普遍存在来自土壤与燃煤飞灰所排放的ＣａＳＯ４·２Ｈ２Ｏ,研究有机物的组成与含量,这对了解局部地区环境酸化（ 湿沉降） 有其重要性。     

寒区芦笋复合高效种植技术

在寒区种植多年生蔬菜芦笋能安全越冬,一年种植,多年收获。由于种植芦笋前期植株小,易造成土地资源的浪费和水土流失,针对这一特点,本文着重探讨了如何有效利用芦笋与其它作物进行复合种植的技术     

Kinetic study of heterogeneous ozonolysis of alachlor, trifluralin and terbuthylazine adsorbed on silica particles under atmospheric conditions

To better understand the atmospheric behaviour of pesticides, heterogeneous ozonolysis of three herbicides (alachlor, terbuthylazine and trifluralin) adsorbed on silica particles were performed in a flow reactor. The experimental setup used in this study and previously validated (Pflieger et al., 2009) has been specially developed to investigate extremely slow reactivity. The pesticides were adsorbed on particles using a gas/solid adsorption equilibrium, in order to simulate atmospheric conditions. After exposure to ozone concentrations ranging from 5 to 41 ppm during 90 min to 6 h, the kinetics were calculated by comparing the initial and the remaining amounts of pesticides adsorbed on silica particles. This work offers the first results of heterogeneous ozonolysis of alachlor and trifluralin adsorbed on mineral particles. Although alachlor and terbuthylazine were expected to react with ozone, no degradation was observed which leads to a lifetime higher than 8 months towards ozonolysis (for 40 ppb of O₃). A significant degradation of trifluralin adsorbed on silica particles by heterogeneous ozonolysis was observed. The experimental data could be fit by both the Langmuir–Rideal and the Langmuir–Hinshelwood models resulting in atmospheric lifetimes (towards heterogeneous ozonolysis) of 40 and 32 days respectively (for 40 ppb of O₃). These results are discussed and compared to other studies.     

Fate of tetrabromobisphenol A and hexabromocyclododecane brominated flame retardants in soil and uptake by plants

The fate of tetrabromobisphenol A (TBBPA) and hexabromocyclododecane diastereomers (α-, β-, and γ-HBCD) and uptake by plants (cabbage and radish) was investigated. In a short-term (8 weeks) experiment, sorption to soil matrix resulted in 90% decline in recovery of these compounds in the experimental soil. However, nearly 50% of initial HBCDs recovered in mixed cabbage-radish treatments, which suggested that interspecific plant interactions might enhance the bioavailability of HBCDs. Although both plant species could uptake TBBPA and HBCDs, cabbage showed greater accumulating ability. Up to 3.5-10.0-fold higher HBCD concentrations were observed than TBBPA concentrations in all plant tissues, and the distribution of HBCDs in plant tissues was diastereomer-specific. The predominance of α-HBCD in shoot tissues for both species might be attributed to diastereomer-specific translocation of HBCDs, shift in diastereomer pattern and/or selective metabolization of γ-HBCD within plants. The results showed that strong sorption to soil particles reduced the potential of human exposure to BFRs in the soil. However, plants increased the exposure risk by uptaking these compounds and by enhancing their bioavailability. The results also provide insight into transport mechanisms of TBBPA and HBCD diastereomers in soil-plant systems.     

"Novel" brominated flame retardants in Belgian and UK indoor dust: implications for human exposure

Concentrations of several “novel” brominated flame retardants (NBFRs) are reported in indoor dust samples from Belgian houses (n = 39) and offices (n = 6) and from day-care centers and schools in the West Midlands of the UK (n = 36). Using a GC-ECNI/MS method, the following NBFRs were quantified: decabromodiphenyl ethane (DBDPE) (range <20-2470 ng g⁻¹), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) (range <0.5-1740 ng g⁻¹), tetrabromobisphenol A-bis(2,3-dibromopropylether) (TBBPA-DBPE) (range <20-9960 ng g⁻¹), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB) (range <2-436 ng g⁻¹) and bis(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (TBPH) (range <2-6175 ng g⁻¹). Hexachlorocyclopentadienyl-dibromocyclooctane (HCDBCO), another NBFR, was below the detection limit of 2 ng g⁻¹ dust in all dust samples. No correlation was detected between concentrations of NBFRs and PBDEs. The ratio of TBB:TBPH in the dust samples ranged from 0.01 to 4.77 (average 0.42), compared to the ratio present in the commercial flame retardant product FM 550 (TBB:TBPH = 4:1). Furthermore, no correlation was detected between concentrations in dust of TBB and TBPH. This may suggest different sources of these NBFRs, or similar sources but compound-specific differences in their indoor fate and transport. Exposure via dust ingestion was estimated for both adults and toddlers under low-end (5th percentile), typical (median), and high-end (95th percentile concentrations) scenarios. These were calculated assuming 100% absorption of intake dust and using mean dust ingestion (adults = 20 mg d⁻¹; for toddlers = 50 mg d⁻¹) and high dust ingestion (adults = 50 mg d⁻¹; for toddlers = 200 mg d⁻¹). Typical exposure with high dust ingestion estimates for adults were 0.01, 0.2, 0.01, 0.02 and 0.08 ng kg⁻¹ bw d⁻¹ and for toddlers 0.05, 1.9, 0.08, 0.4 and 1.12 ng kg⁻¹ bw d⁻¹ for BTBPE, DBDPE, TBB, TBPH and TBBPA-DBPE, respectively. Our results showed that, similar to PBDEs, toddlers have higher exposure to NBFRs than adults. This study documents the presence of NBFRs in indoor environments, and emphasizes the need to evaluate the health implications of exposure to such chemicals.     

Diamondback terrapins as indicator species of persistent organic pollutants: Using Barnegat Bay, New Jersey as a case study

The diamondback terrapin’s (Malaclemys terrapin) wide geographic distribution, long life span, occurrence in a variety of habitats within the saltmarsh ecosystem, predatory foraging behavior, and high site fidelity make it a useful indicator species for contaminant monitoring in estuarine ecosystems. In this study fat biopsies and plasma samples were collected from males and females from two sites within Barnegat Bay, New Jersey, as well as tissues from a gravid female and blue mussels (Mytilus edulis), which are terrapin prey. Samples were analyzed for persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), chlorinated pesticides, and methyl-triclosan. Terrapins from the northern site, Spizzle Creek, closest to influences from industrial areas, had higher POP concentrations for both tissues than terrapins from the less impacted Forsythe National Wildlife Refuge. Sex differences were observed with males having higher contaminant concentrations in fat and females in plasma. PCB patterns in terrapin fat and plasma were comparable to other wildlife. An atypical PBDE pattern was observed, dominated by PBDEs 153 and 100 instead of PBDEs 47 and 99, which has been documented in only a few other turtle species. The typical PBDE patterns measured in mussels, terrapin prey, suggests that the terrapin may efficiently biotransform or eliminate PBDE 47 and possibly PBDE 99. Plasma contaminant concentrations significantly and positively correlated with those in fat. This study addresses several aspects of using the terrapin as an indicator species for POP monitoring: site and sex differences, tissue sampling choices, maternal transfer, and biomagnification.     

石化企业浮顶罐大呼吸损耗核算方法分析

石化企业储罐无组织排放挥发性有机物(VOCs)带来严重的环境问题和油品损耗问题,以浮顶罐的大呼吸损耗为代表。在概述浮顶罐大呼吸损耗机理的基础上,以北京某石化企业的甲苯内浮顶罐为基准案例,对国内外4种核算公式进行了对比分析,考察了影响浮顶罐大呼吸损耗的因素,并提出有效的减耗措施。结果表明:采用我国推荐的公式进行核算更符合我国实际,需建立和完善以我国有机液体理化参数和储罐构造为基准的核算方法和软件;影响浮顶罐大呼吸损耗的主要因素包括油品性质、周转量、罐体直径、罐壁黏附系数等,其中罐壁黏附系数为关键影响因素。     

曝气+化学絮凝法预处理环氧丙烷废水简

根据环氧丙烷废水的特点,应用电化学法处理具有较高的可行性。运用电化学法处理PO废水前必须进行废水预处理,用以提高电流效率和延长极板寿命。采用曝气和化学絮凝结合的方法去除PO废水中的Ca²⁺,同时去除部分COD。对曝气、无机絮凝剂（PACl、PFS）和有机絮凝剂（PAM）对PO废水处理过程中的曝气量、曝气时间、投药量、复配和沉降时间等主要影响因子进行了实验研究,通过比较Ca²⁺、COD的去除效果、絮凝剂用量、沉降时间、处理成本等方面,在设定的实验参数下得到最佳预处理方案为：曝气量为2.5 L/min,曝气45 min,投加Na₂CO₃粉末24 kg/t 废水,充分混匀后加入PFS+PAM复配絮凝剂。本方案具有废水处理效果好（Ca²⁺的去除率为77.03%,COD的去除率为37.46%）、投药量少（（100+7.5）g/t废水）、沉降时间短（5 min）、处理成本低（0.675元/t废水）等优点。通过对比经预处理和不经预处理后电化学法对COD去除效果、电流和处理后阴极表面,验证了预处理方案的必要性与可行性。