5氟尿嘧啶对蛋白核小球藻和羊角月芽藻生长及叶绿素含量的影响

近年来,抗癌药的环境污染特征及其生态风险引起了广泛关注。为获取典型抗癌药5氟尿嘧啶的基础生态毒性数据,以蛋白核小球藻(Chlorella pyrenoidosa)和羊角月芽藻(Selenastrum capricornutum)为受试生物,考察了5氟尿嘧啶对2种绿藻的生长和叶绿素含量的影响。结果表明,5氟尿嘧啶对蛋白核小球藻和羊角月芽藻的生长具有抑制作用,随着暴露浓度升高,细胞生长抑制率增强。5氟尿嘧啶对2种绿藻的96 h半数抑制浓度(EC50)分别为450.36 mg·L~(-1)和692.30 mg·L~(-1),属于低毒性物质。暴露96 h后,低浓度5氟尿嘧啶(32 mg·L~(-1))对蛋白核小球藻和羊角月芽藻叶绿素含量有一定的促进作用,高浓度5氟尿嘧啶(32~500 mg·L~(-1))则抑制了2种绿藻的叶绿素含量,且两者具有明显的负相关关系。和叶绿素b相比,叶绿素a对5氟尿嘧啶胁迫更为敏感。     

钻井用天然气发动机清洁生产效果浅析

某油田在钻探过程中成功应用济南柴油机厂3000系列天然气发动机,代替原有的柴油发动机进行各阶段的钻井作业,实践证明天然气发动机不但动力性、响应性不亚于柴油机,而且达到了降低生产成本、减少污染排放、营造健康舒适的工作环境的目的,是一项值得在钻井生产中推广应用的清洁生产实用技术.     

一种无奇异参数椭圆柱形电磁隐身斗篷的设计基础理论

目的研究无奇异参数的椭圆柱形超材料电磁隐身斗篷的设计方法。方法应用变换光学原理建立空间变换坐标表达式,推导出该斗篷的电磁参数张量,再采用Matlab软件验证所推导张量的无奇异性,最后采用有限元仿真软件验证该斗篷的电磁隐身性能。结果椭圆柱形斗篷具备良好的电磁隐身性能,并且其电磁参数张量的各个分量均无奇异性。结论设计出的空间坐标变换方式能够从理论上实现无奇异参数的超材料电磁隐身斗篷,这种方法也拓展了变换光学原理在超材料隐身装置设计方面的应用。     

风险管理标准在环境监测站的应用研究

环境监测是环保工作的重要组成部分,任务重、责任大、社会关注度高,基层环境监测站更处在风口浪尖,面临着监测质量风险、岗位职务风险、败诉追责风险、廉政纪检风险等一系列风险.2013年两高环境司法解释出台后,环境监测数据可直接作为司法证据,这对基层环境监测站提出更新、更高的要求.该文章介绍了运用《风险管理原则与实施指南》(GB/T 24353-2009)进行环境监测站风险管理的方法.     

Abatement of SO2-NOx binary gas mixtures using a ferruginous active absorbent: Part I. Synergistic effects and mechanism

A novel ferruginous active absorbent, prepared by fly ash, industrial lime and the additive Fe(VI), was introduced for synchronous abatement of binary mixtures of SO2–NOx from simulated coal-fired flue gas. The synergistic action of various factors on the absorption of SO2 and NOx was investigated. The results show that a strong synergistic effect exists between Fe(VI) dose and reaction temperature for the desulfurization. It was observed that in the denitration process, the synergy of Fe(VI) dose and Ca/(S + N) had the most significant impact on the removal of NO, followed by the synergy of Fe(VI) and reaction temperature, and then the synergy of reaction temperature and flue gas humidity. A scanning electron microscope(SEM) and an accessory X-ray energy spectrometer(EDS)were used to observe the surface characteristics of the raw and spent absorbent as well as fly ash. A reaction mechanism was proposed based on chemical analysis of sulfur and nitrogen species concentrations in the spent absorbent. The Gibbs free energy, equilibrium constants and partial pressures of the SO2–NOx binary system were determined by thermodynamics.     

Toluene decomposition performance and NOx by-product formation during a DBD-catalyst process

Characteristics of toluene decomposition and formation of nitrogen oxide (NO_x) by-products were investigated in a dielectric barrier discharge (DBD) reactor with/without catalyst at room temperature and atmospheric pressure. Four kinds of metal oxides, i.e., manganese oxide (MnOx), iron oxide (FeOx), cobalt oxide (CoOx) and copper oxide (CuO), supported on Al₂O₃/nickel foam, were used as catalysts. It was found that introducing catalysts could improve toluene removal efficiency, promote decomposition of by-product ozone and enhance CO₂ selectivity. In addition,NO_xwas suppressedwith the decrease of specific energy density (SED) and the increase of humidity, gas flow rate and toluene concentration, or catalyst introduction. Among the four kinds of catalysts, the CuO catalyst showed the best performance in NO_x suppression. The MnOx catalyst exhibited the lowest concentration of O₃ and highest CO₂ selectivity but the highest concentration of NOx. A possible pathway for NOx production in DBD was discussed. The contributions of oxygen active species and hydroxyl radicals are dominant in NOx suppression.     

浙江省畜禽养殖业废水污染特征及环境风险评估研究

根据国家畜禽养殖业水污染物排放标准意见征求工作,对浙江省8家不同规模的养猪场开展了监测分析。研究发现,废水中COD、TN、NH4－N和BOD5等主要污染因子平均浓度超出征求意见稿中直接排放限值;重金属元素Zn和As最大的超标倍数分别为3.87和0.7倍;废水的综合污染指数为7.23,为重度污染级。进一步验证了畜禽养殖业废水属高污染、高环境风险废水,要达到国家畜禽养殖业水污染物排放标准,需整体提升当前的畜禽养殖废水处理深度。     

Activated carbon enhanced ozonation of oxalate attributed to HO. oxidation in bulk solution and surface oxidation： Effect of activated carbon dosage and pH

Ozonation of oxalate in aqueous phase was performed with a commercial activated carbon（AC）in this work. The effect of AC dosage and solution pH on the contribution of hydroxyl radicals（HOU） in bulk solution and oxidation on the AC surface to the removal of oxalate was studied. We found that the removal of oxalate was reduced by tert-butyl alcohol（tBA） with low dosages of AC,while it was hardly affected by tBA when the AC dosage was greater than 0.3 g/L. tBA also inhibited ozone decomposition when the AC dosage was no more than 0.05 g/L, but it did not work when the AC dosage was no less than 0.1 g/L. These observations indicate that HOUin bulk solution and oxidation on the AC surface both contribute to the removal of oxalate. HOU oxidation in bulk solution is significant when the dosage of AC is low, whereas surface oxidation is dominant when the dosage of AC is high. The oxalate removal decreased with increasing pH of the solution with an AC dosage of 0.5 g/L. The degradation of oxalate occurs mainly through surface oxidation in acid and neutral solution, but through HOUoxidation in basic bulk solution. A mechanism involving both HOUoxidation in bulk solution and surface oxidation was proposed for AC enhanced ozonation of oxalate.     

基于MATLAB的城市表层土壤重金属污染空间分布的研究

为全面了解某城市表层土壤重金属污染的空间分布特征,对城市表层土壤中重金属元素As、Cd、Cr、Cu、Hg、Ni、Pb、Zn进行采样分析,采用域法识别特异值进行数据处理。通过Matlab软件,利用克里格法进行空间插值,绘出各重金属浓度与各坐标投影的一维空间分布图,并绘出全城等高地形图,再以数字大小标注样本点的污染浓度,拟合各元素浓度与海拔、平面坐标之间的关系模型,将重金属空间分布特征定量化、模型化。