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181.
中国地区生物质燃烧释放的含碳痕量气体   总被引:10,自引:0,他引:10  
为了研究中国地区生物质燃烧不同阶段释放的各种妆胆气体排放比与排放因子,建立了动态与静态燃烧室以及CH4、COS、CO、及CO2的采样、富集、分析方法;然后对典型乔木、灌木与草的地上部分生物质进行规模不同的燃烧实验,测得痕量 排放比和排放因子,根据全国森林生态系统碳贮量的估计及火灾统计资料,初步测算了中国地区生物质向大气中释放含碳痕量气体量。  相似文献   
182.
重金属对方形网纹溞的毒性研究   总被引:2,自引:0,他引:2  
在静置换水条件下,研究了重金属对方形网纹的急性毒性和生活周期毒性。Hg2+、Cu2+、Cr6+和Zn2+在25±1℃下对方形网纹的4shEC50分别为0.0100、0.0254、0.144和0.2828mg/L。Hg2+对方形网纹的7d生活周期毒性试验,以存活、生长和生殖为毒性指标,未觉察反应浓度(NOEC)为5·9μgNL,最低觉察反应浓度(LOEc)为11.83μg/L,其毒性阈限在二者之间。重金属对方形网纹与大型及鱼类的急性毒性比较和Hg2+对类生活周期的毒性比较均表明方形网纹较为敏感。  相似文献   
183.
不同水肥管理对太湖流域稻田磷素径流和渗漏损失的影响   总被引:16,自引:0,他引:16  
于2010和2011年在太湖流域开展了为期2年的田间定位试验,对2种灌溉模式(常规连续淹灌与干湿交替节灌)和4种施肥管理(不施氮、常规尿素、控释BB肥与树脂包膜尿素)条件下稻田田面水和渗漏水总磷(TP)、溶解态磷(DP)和颗粒态磷(PP)浓度的动态变化及磷素径流和渗漏损失进行了研究.结果表明:田面水TP和DP浓度变化趋势相同,均在施肥后1 d达到最高值,之后急剧下降;渗漏水TP和DP浓度变化趋势也相同,均在施肥后7 d达到最高值,然后逐渐下降.PP是田面水磷素的主要形态,DP是渗漏水磷素的主要形态.节灌降低了田面水和渗漏水磷浓度但对DP/TP影响不大,同时降低了TP径流流失量(24.7%~57.4%)和渗漏淋失量(21.0%~25.3%).施氮增加了田面水和渗漏水的磷浓度,也导致了更高的TP径流和渗漏损失.与常规尿素相比,控释BB肥提高了田面水和渗漏水的磷浓度及TP损失量,而树脂包膜尿素降低了田面水和渗漏水的磷浓度和TP损失量.综上,干湿交替节灌结合树脂包膜尿素施用能有效降低稻田磷素径流和渗漏损失,削减农业面源污染.  相似文献   
184.
青霉菌GX2对蒽醌染料的吸附作用   总被引:27,自引:1,他引:27  
GX2生长菌体对 4种蒽醌染料均表现出优良的吸附性能 ,但由于染料分子的结构不同 ,吸附速率和吸附率也表现出一定的差异 .染料对菌体的生长具有一定的抑制作用 ,但即使在很高的染料浓度下 ,GX2生长菌体仍表现出很强的吸附性能 .对 250mg/L活性艳蓝KN-R的吸附率高达 100% ,对 400mg/LKN R的吸附率也可达91.4% .在 0~2%范围内 ,随着盐度 (NaCl)的增加 ,菌体干重增加 ;颗粒状菌团的直径却随之减小 ,比表面积增大 ,对GX2生长菌体的染料吸附表现出较为明显的促进作用 .碳源浓度通过影响菌体的生长而影响染料吸附 ,当培养基中的葡萄糖浓度大于 2.5g/L时 ,即可使浓度为 120mg/L的活性艳蓝KN R溶液完全脱色 .生长菌体具有比静止活体和死体更好的吸附性能 .  相似文献   
185.
The aggregation and dispersion behaviors of carbon nanotubes (CNTs) can regulate the environmental spread and fate of CNTs, as well as the organic pollutants adsorbed onto them. In this study, multi-walled carbon nanotubes (MWNTs) and single-walled carbon nanotubes (SWNTs) were surface modified with humic acids from di erent sources and with surfactants of di erent ionic types. The dispersion stability of surface modified CNTs was observed by UV-Vis spectrophotometry. The e ect of humic acid and surfactant dispersion on the adsorption of atrazine by CNTs was investigated by batch equilibrium experiments. Both humic acid and surfactant could e ectively disperse MWNTs, but not SWNTs, into stable suspensions under the studied conditions. Surface modified CNTs had a greatly reduced capacity for adsorption of atrazine. The inhibitory e ect of peat humic acid was relatively stronger than that of soil humic acid, but the two surfactants had a similar inhibitory e ect on atrazine adsorption by the two CNT types. Increases in surfactant concentration resulted in rapid decreases in the adsorption of atrazine by CNTs when the surfactant concentration was less than 0.5 critical micelle concentration.  相似文献   
186.
研究并探讨了蔬菜作物在施用耐氨固氮菌后的生长、生理反应及增产的效果和原因。试验结果表明施用耐氨固氮菌显著增加了蔬菜苗期生物量、叶面积和叶片的叶绿素含量,同时还增强了植株的根系活力,并有明显的增产效果。耐氨固氮菌促进增产的作用不仅与其本身的固氮作用有关,还可能与其分泌出某些生长刺激物(或激素)有关。  相似文献   
187.
以近20种水溶性染料为研究对象,选择正辛醇-水分配系数(Kow)、分子最高占据轨道能(EHOMO)及分子最低空轨道能(ELUMO)等理化参数,建立了染料的定量结构-光催化降解反应活性关系模型,得到定量关系式为:lgk=0.016 28×lgKow 0.132 46×(ELUMO-EHOMO)-2.148 56,很好地表示反应活性与结构之间的定量关系,为水溶性染料的光催化降解活性预测提供了有效的工具.  相似文献   
188.
研究了乐果在颗粒物表面上吸附的动力学特征,观察了颗粒物的性质对吸附行为的影响.结果表明,乐果在3种颗粒物上的吸附过程均符合一级动力学规律,其相关系数在0.986 2~0.990 5,达到极显著水平.颗粒物的性质与吸附量相关分析发现,不同颗粒物对乐果的吸附程度是由颗粒物的有机质、粘粒、阳离子交换容量(CEC)和pH等理化特征综合作用的结果.pH对吸附行为影响的实验结果指出,随着体系的pH逐渐增大,颗粒物对乐果的吸附能力增强.  相似文献   
189.
To study whether the urinary 1-hydroxypyrene (1-OHP) could be the biomarker of atmospheric PAHs, a small-scale pilot study was carried out on the relation of 1-OHP vs PAHs with the traffic policemen in Beijing of smokers and nonsmokers to be subgroups in both the exposure and control groups. Both the PAHs and 1-OHP were analyzed with high performance liquid chromatography (HPLC). The ambient concentrations of PAHs were different at the different sites (the average sum of PAHs (TPAH) were 12.36, 16.27, 18.37 ng/m3 at the suburban residential, police station and high traffic area, respectively.), but considerably lower than the personal-exposure concentrations (the average TPAH were 65.84 and 47.28 ng/m3 for patrol cars and inspection station, respectively). Pyrene was correlated well with BaP and the summed PAHs (TPAH), with the correlation coefficients (R) of 0.79, 0.87 for ambient level and 0.92, 0.96 for personal exposure, respectively. The average of 1-hydroxypyrene of smokers and nonsmokers were 0.39, 0.15 μmol/mol creatinine in control group and 0.57, 0.33 μmol/mol creatinine in exposure group, respectively. The better correlation of pyrene to BaP and TPAH especially for personal exposure samples indicated that the probability of urinary 1-hydroxypyrene, the metabolite of pyrene, to be the biomarker of total PAH. Nonsmokers in the exposure and control groups had indistinguishable levels of 1-OHP, presumably because the ambient levels of pyrene were so similar (the average were 3.25, 3.20 ng/m3 at the police station and high traffic area, respectively.). Smokers in the control group had significantly higher 1-OHP than that of the nonsmokers, but showed indistinguishable differences in the exposure group. These results suggested that urinary 1-OHP could be a biomarker of PAHs only when the level of PAHs was at a relatively higher level. Smoking as an important influencing factor need to be controlled carefully.  相似文献   
190.
Dye wastewater containing heavy metal ions is a common industrial effluent with complex physicochemical properties.The treatment of metal–dye binary wastewater is difficult.In this work,a novel in-situ ferrite process(IFP) was applied to treat Methylene Blue(MB)–Cu(II)binary wastewater,and the operational parameters were optimized for MB removal.Results showed that the optimum operating conditions were OH/M of 1.72,Cu~(2+)/Fe~(2+)ratio of 1/2.5,reaction time of 90 min,aeration intensity of 320 mL/min,and reaction temperature of40°C.Moreover,the presence of Ca~(2+)and Mg~(2+)moderately influenced the MB removal.Physical characterization results indicated that the precipitates yielded in IFP presented high surface area(232.50 m2/g) and a multi-porous structure.Based on the Langmuir model,the maximum adsorption capacity toward MB was 347.82 mg/g for the precipitates produced in IFP,which outperformed most other adsorbents.Furthermore,IFP rapidly sequestered MB with removal efficiency 5 to 10 times greater than that by general ferrite adsorption,which suggested a strong enhancement of MB removal by IFP.The MB removal process by IFP showed two different high removal stages,each with a corresponding removal mechanism.In the first brief stage(5 min),the initial high MB removal(~95%)was achieved by predominantly electrostatic interactions.Then the sweep effect and encapsulation were dominant in the second longer stage.  相似文献   
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