6:2氟调羧酸在蚯蚓体内的毒理效应及代谢转化

以赤子爱胜蚓(Eisenia fetida)为受试生物,通过活体与离体实验,研究6:2氟调羧酸(6:2FTCA)在蚯蚓体内的毒理效应和代谢转化机制.结果表明,6:2FTCA对蚯蚓体内丙二醛(MDA)含量和过氧化物酶(POD)活性无显著影响,但能够使过氧化氢酶(CAT)活性提高,使超氧化物歧化酶(SOD)和谷胱甘肽转移酶(GST)活性显著升高,说明6:2FTCA对蚯蚓产生了氧化胁迫效应.6:2FTCA在蚯蚓细胞色素P450(CYP450)和GST酶提取液中的降解动力学均符合一级动力学模型,在CYP450(0.014/h)酶液中的降解速率明显高于GST (0.006/h),其终端全氟羧酸(PFCAs)代谢产物为全氟己酸(PFHxA)、全氟戊酸(PFPeA)和全氟丁酸(PFBA),说明CYP450和GST参与了6:2FTCA在蚯蚓体内的代谢转化,且CYP450贡献大于GST.蚯蚓肠道好氧微生物对6:2FTCA具有显著的降解效果,终端PFCAs降解产物为PFHxA和PFPeA,而肠道厌氧微生物对6:2FTCA无降解作用.     

A CFD based explosion risk analysis methodology using time varying release rates in dispersion simulations

A full probabilistic Explosion Risk Analysis (ERA) is commonly used to establish overpressure exceedance curves for offshore facilities. This involves modelling a large number of gas dispersion and explosion scenarios. Capturing the time dependant build up and decay of a flammable gas cloud size along with its shape and location are important parameters that can govern the results of an ERA. Dispersion simulations using Computational Fluid Dynamics (CFD) are generally carried out in detailed ERA studies to obtain these pieces of information. However, these dispersion simulations are typically modelled with constant release rates leading to steady state results. The basic assumption used here is that the flammable gas cloud build up rate from these constant release rate dispersion simulations would mimic the actual transient cloud build up rate from a time varying release rate. This assumption does not correctly capture the physical phenomena of transient gas releases and their subsequent dispersion and may lead to very conservative results. This in turn results in potential over design of facilities with implications on time, materials and cost of a project.In the current work, an ERA methodology is proposed that uses time varying release rates as an input in the CFD dispersion simulations to obtain the fully transient flammable gas cloud build-up and decay, while ensuring the total time required to perform the ERA study is also reduced. It was found that the proposed ERA methodology leads to improved accuracy in dispersion results, steeper overpressure exceedance curves and a significant reduction in the Design Accidental Load (DAL) values whilst still maintaining some conservatism and also reducing the total time required to perform an ERA study.     

Improving the stability,lithium diffusion dynamics,and specific capacity of SrLi2Ti6O14 via ZrO2 coating

SrLi2Ti6O14 (SLTO) coated with different amount of ZrO2 was successfully prepared. The as-obtained composites are stacked by a series of particles with a pure phase structure and a good crystallinity. Furthermore, ZrO2 coating not only enhances the structural stability of the materials but also facilitates the diffusion of lithium through the SEI film. As a result, the redox polarization was reduced, and the reversibility of the electrochemical reaction was enhanced. Particularly, SLTO-ZrO2-2 sample delivers a high initial lithiation capacity of 283.6 mA h g-1, and the values maintain at 251.7, 228.0, 207.4, 175.3, and 147.7 mA h g-1 at the current densities of 0.13, 0.26, 0.54, 1.31, and 2.62 A g-1, respectively. Our experiment also confirmed that SLTO materials coated with ZrO2 are suitable for high power density applications, and the lithiation specific energy efficiency of SLTO-ZrO2-2 is 200％as high as that of pure SLTO at a power density of 1257 W kg-1.     

应用电致化学发光分子探针技术对微小原甲藻的检测

以双特异分子探针技术(NPA-SH)为基础,运用电致化学发光技术(ECL)和磁性微球分选技术对其进行改进,成功建立了用于赤潮藻类定性定量分析的电致化学发光分子探针(ECL-MP)检测新技术.设计微小原甲藻特异性NPA探针并对其进行联吡啶钌和生物素标记,优化磁性微球使用量,在ECL检测装置中启动电化学反应,建立光信号与微小原甲藻细胞数目间的ECL-MP分析曲线并对其进行验证.结果表明,标记后的NPA探针具有一定的特异性和实用性;4μg是检测20μL目标藻杂交混合液的最适磁性微球使用量;在最适条件下,微小原甲藻细胞数的线性分析范围6.25×102～4×104个;比较ECL-MP和显微计数方法的样品检测结果,在95%置信区间内二者无显著差异(t-检验).ECL-MP方法为实现微小原甲藻现场样品的快速准确检测提供了一种新方法.     

DNBP生产废水处理工艺探讨

4,6二硝基邻仲丁基苯酚(DNBP)生产过程产生的废水,采用化学与生物处理组合工艺,结合生产实际,分流治理,使DNBP得以充分的回收。纳米TiO2负载活性炭、臭氧催化氧化,降低COD、增加废水的可生化性。针对废水中的可溶性有机物,培养特效菌群生化处理,出水稳定,达国家二级排放标准。     

粉煤灰处理Cr6+废水的试验研究

利用电厂粉煤灰进行了处理含铬(VI)废水试验,探讨了粉煤灰投加量、pH值、接触时间、温度和含铬浓度等因素对除铬效果的影响。结果表明,在废水pH=10左右、Cr6+浓度<100mg/L,粉煤灰的用量140g/L时,在常温下吸附处理2h,对铬的去除率可达到72%以上。粉煤灰吸附处理含铬废水符合Freundlich等温式,以物理吸附为主。对于低浓度含铬(VI)的废水,处理后可达标排放。     

活性污泥缺氧转化1-2-7-三氨基-8-羟基-3-6-萘二磺酸简

1-2-7-三氨基-8-羟基-3-6-萘二磺酸（TAHNDS）作为偶氮染料的脱色产物很难被常规的厌氧-好氧染料废水处理工艺所去除。研究了未经驯化的活性污泥对TAHNDS的缺氧转化效果。结果表明,只有在特定的缺氧条件下（ORP在-50~-150 mV之间）,TAHNDS才能被活性污泥所降解转化。当浓度在10~80 mg/L范围内,TAHNDS可在72 h内转化93%以上。加入100 mg/L的硝酸盐和0.64 mmol/L的氧化还原介体蒽醌-2-磺酸钠（AQS）可将40 mg/L的TAHNDS的转化时间从84 h缩短到36 h。光谱及HPLC-MS分析表明,TAHNDS在缺氧条件下主要是通过脱氨基和脱磺酸作用生成已知可好氧生物降解的3,5-二氨基-4-羟基萘-2-磺酸。因此,缺氧处理有望作为预处理工艺促进废水中TAHNDS的完全降解。     

固定化菌种降解2,6-二叔丁基酚的研究

用前期研究中获得的2,6二叔丁基酚(简2,6DTBP)降解菌(Aeromonassp.),进行了对2,6二叔丁基酚的降解性能等研究。结果表明菌株经固定化包埋后,降解底物2,6DTBP的能力大大提高。在100.0mg/L的初始浓度下其降解率在12d可达到81%。通过对固定化菌株的降解反应过程的动力学分析,其对底物的降解反应符合一级动力学特征,当2,6DTBP初始浓度为100mg/L时,固定化菌种其动力学常数为0.1232,半衰期为5.63day。扫描电镜观察到菌种在海藻酸钙包埋载体中能良好地生长和繁殖。     

减排六氟化硫应对全球气候变化

SF6为目前认为具有最高温室气体暖化潜势的气体,也是《京都议定书》控制的6种温室气体之一,对气候的影响能力不可忽视。SF6气体的应用所造成的温室效应与环境污染问题,已备受全球关注,sF6减排已成为社会责任。减少sF6气体排放量,是控制温室气体排放的重要手段之一。随着sF6气体使用量的增加和使用范围的扩大,在合理使用和管理sF6气体的同时,研究逐步减少sF6气体使用比例,减少sF6气体排放量,减少其对温室效应贡献的应对策略,保护我们赖以生存的环境已显得十分迫切。     

Coupled anaerobic/aerobic biodegradation of 2,4,6 trichlorophenol

Degradation of 2, 4, 6-trichlorophenol(TCP) with co-immobilizing anaerobic granular sludge and isolated aerobic bacterial species was studied in coupled anaerobic/aerobic integrated reactors. The synergism of aerobes and anaerobes within co-immobilized granule might facilitate degrading the TCP and exchange of anaerobic metabolites 4-CP, which promoted system organic removal efficiency and recovered from organic shock-loads more quickly. The bionmass specific activities experiment further confirmed that strict anaerobes be not affected over the crsurse of this experiment by the presence of an oxic environment, aerobic activity predominated in the outer co-immobilized grange layers,while the interior was characterized by anaerobic activity. The co-immobilized granule could thus enable both aerobic and anaerobic microbes function in the same reactor and thereby integrate the oxidative and reductive catabolism.