炼油废水微生物燃料电池启动及影响因素

以炼油废水为碳源,构建双室填料型微生物燃料电池,考察接种液、外接电阻等电池启动条件,以及电导率、pH值和缓冲溶液强度等溶液性质对电池产电性能的影响。利用微生物燃料处理炼油废水,COD去除率(52±4)%,含油量去除率(81.8±3)%;利用废水中存在的原生菌即可启动电池,但启动期长,外加接种液可快速启动电池;启动时外接电阻的大小对电池稳定运行后的输出功率有明显影响,对电池内阻影响相对较小,当启动外接电阻为2 000Ω,电池输出功率最大,为288 mW/m3;随阳极溶液电导率电池增大,电池内阻降低,输出功率升高;pH值变化对电池阳极电势影响较大,进而影响电池输出,当溶液pH为9时,电池输出电压最大(388 mV),pH过高或过低均不利于电池产电;随着缓冲强度的增大,电池输出电压增大,且PBS缓冲强度的增大可从电导率增大和改善质子传递条件两方面提高电池的输出功率。     

Acetamiprid,carbendazim, diuron and thiamethoxam sorption in two Brazilian tropical soils

Sorption of acetamiprid ((E)-N1-[(6-chloro-3-pyridyl)methyl]-N2-cyano-N1-methylacetamidine), carbendazim (methyl benzimidazol-2-ylcarbamate), diuron (N-(3,4-dichlorophenyl)-N, N-dimethyl urea) and thiamethoxam (3-(2-chloro-thiazol-5-ylmethyl)-5-methyl-[1,3,5]oxadiazinan-4-ylidene-N-nitroamine) was evaluated in two Brazilian tropical soils, Oxisol and Entisol, from Primavera do Leste region, Mato Grosso State, Brazil. To describe the sorption process, batch experiments were carried out. Linear and Freundlich isotherm models were used to calculate the K _d and K _f coefficients from experimental data. The K _d values were utilized to calculate the partition coefficient normalized to soil organic carbon (K _oc ). For the pesticides acetamiprid, carbendazim, diuron and thiamenthoxan the K _oc (mL g^{? 1}) values ranged in both soils from 98 – 3235, 1024 – 2644, 145 – 2631 and 104 – 2877, respectively. From the studied pesticides, only carbendazim presented correlation (r² = 0.82 and p < 0.01) with soil organic carbon (OC) content. Acetamiprid and thiamethoxam showed low sorption coefficients, representing a high risk of surface and ground water contamination.     

西藏东南部森林可燃物特点及气候变化对森林火灾的影响

根据西藏林芝地区的DEM数据和植被分布数据分析了该地区可燃物的水平分布和垂直分布规律,并根据火发生纪录分别计算了火发生周期和发生概率,根据火灾高发期的降水和气温数据分析降水和气温的变化趋势,本地区易发生火灾的可燃物主要有高山松云南松林,草甸灌丛,云冷杉林等.该地区的火灾轮回期为17178 a,火发生概率为0.00006,远远低于东北林区,但由于该地区处于高海拔地区,生态系统脆弱,林木蓄积量大,积累能量高,潜在的火强度高.林芝地区夏季降水减少,火灾高发期(2～5月)降水有所增加,但增温明显,气温升高对高海拔地区的影响比低海拔地区更大,对于森林可燃物而言,气温增高使高海拔地区的森林火险增大,森林防火面临的形势更加严峻.     

固相萃取-高效液相色谱-质谱联用法用于地表水中类固醇激素测定

建立了固相萃取-高效液相色谱-质谱联用法对雌三醇、氟哌噻吨、炔雌醇、雄烯二酮、雌二醇、雌酚酮、睾酮共7种类固醇激素的检测方法。样品经C18萃取小柱富集净化,采用内标法定量时,方法的检出限为0.66～1.95 ng/L,R0.998,回收率为78.5%～94.6%,相对标准偏差为1.1%～7.7%。采用该方法对上海市地表水进行测定,在2个采样点中检出雌酚酮(1.88 ng/L)和雄烯二酮(1.48 ng/L)。     

贵州农村地区室内空气质量及细颗粒物污染特征

对贵州农村地区燃煤和燃柴典型村进行了室内外空气质量的监测,并对其中细颗粒物PM2.5的特征进行了研究。结果表明:燃煤家庭厨房和卧室PM2.5分别超过《环境空气质量标准》GB 3095—2012中标准限值(75μg/m3)的1.97、1.41倍,燃柴家庭分别超标0.74、0.06倍,而SO2、CO、NOx均低于标准限值。PAHs以燃煤村厨房最高,为53.92 ng/m3,燃柴村厨房为10.34 ng/m3,2种燃料所致PAHs均以中高环组分为主,对人体健康产生较大风险。PM2.5中氟和砷含量较低,低于参考浓度限值。燃煤村和燃柴村厨房内氟均值分别为0.14、0.11μg/m3,砷平均值分别为0.020、0.014μg/m3。需采取炉灶/燃料改良干预措施来降低农村室内空气污染物浓度,保障居民身体健康。     

关于核燃料循环建设项目竣工环境保护验收监测的思考

针对核燃料循环建设项目竣工环境保护验收监测活动中存在的问题作探讨,明确了验收监测活动的起点,建议加强验收监测方案编制的培训。指出应重视流出物的持续监测和环保设施运行效率的验证,验收监测方案应参考环评文件中的环境监测计划,结合设施运行后的现状合理编制,并重视与污染源项有关的其他监测问题。提出了进一步完善核燃料循环标准体系、持续加强环保验收能力建设等建议。     

燃料电池发电系统安全与标准化

燃料电池因具有高效、节能、环保等优点,在电动汽车、分布式电站、便携式备用电源等方面具有广泛的应用前景,而燃料电池的安全标准是燃料电池产品市场准入的重要保证。燃料电池发电系统的安全涉及机械危险、电气危险、热危险、化学危害、物理危险、设备故障危险、因不适当的人机工程学原理而导致的危险及人机界面危险、合理预见的误用、环境条件危险、污染等方面。本文介绍了国内外燃料电池发电系统安全技术以及标准化的现状。     

Pre-concentration of naturally occurring radionuclides and the determination of (212)Pb from fresh waters

A novel technique has been developed for determining the ²¹²Pb activity of fresh waters. This is of interest to environmental monitoring programmes that utilise gross α-activity methods to screen for anthropogenic radionuclides. The contribution from ²¹²Pb varies, and is difficult to experimentally measure due to its relatively short half-life (t_½ = 10.6 h) and low environmental activity (<0.1 Bq l⁻¹). The use of a three-stage technique that encompasses a unique form of pre-concentration, separation and analysis by liquid scintillation counting allows a lower detection limit of 0.006 Bq l⁻¹ with a chemical yield of 92.5 ± 5.6%. The measurement can be obtained within 7 h of sample collection, and is calculated using the radioactive decay of ²¹²Bi. Other naturally occurring radionuclides may also be extracted using the pre-concentration stage of the technique, with efficiencies above 90% at a range of pH values.     

稳恒磁场作用下微生物燃料电池的产电特性和电化学阻抗谱分析

对混合菌接种的双室微生物燃料电池加载磁场强度为175 mT的稳恒磁场,利用电化学交流阻抗等电化学分析方法,考察了在磁场作用下微生物燃料电池（MFC）产电性能的变化,分析了磁场对MFC各部分内阻的影响。加载磁场使已启动完成的MFC的产电明显增强,开路电压提高了10%。加载磁场后最大功率密度为2.08 W/m2,大于加载前的1.58 W/m2,表观内阻由170Ω降至80Ω。电化学阻抗谱分析确定了阳极、阴极和全电池的等效电路模型,拟合结果发现阳极极化内阻约为5Ω。加载磁场使MFC的阴极极化内阻由74.98Ω降至56.73Ω。     

Divestment discourse: war,justice, morality and money

The fossil fuel divestment movement has been a vibrant novel development in climate change politics in recent years, particularly in North America. Here, the character of the discourse used to promote divestment as a strategy is explored. The divestment discourse is shown to rest on four overlapping narratives, those of war and enemies, morality, economics and justice. All four are clearly discernible in statements from movement activists, in coverage of divestment campaigns by major news sources and in the movement’s aims, objectives and strategies covered in alternative media. The war narrative, with the formulation of fossil fuel companies as enemies to be overcome to ensure survival, is the dominant narrative. By polarising climate action and identifying an antagonist against which to mobilise, divestment discourse has articulated climate change as an explicitly political phenomenon, in contrast to the primarily consensus and collaboration-based approaches that have predominated in climate politics.