珠江三角洲机动车排放控制措施协同效应分析

预测了2015年珠江三角洲机动车空气污染物和温室气体排放量,设计了6类单一控制、技术控制、结构控制以及综合控制措施的情景,并运用基准线年排放清单编制和协同效应坐标系法分析了污染物与温室气体减排的协同效应.结果表明,按目前机动车保有量增长趋势,2015年污染物和温室气体将以18%~120%的幅度增加;各控制措施下污染物和温室气体排放量均有下降,且均具有正向的协同效应,但减排的贡献差异较大.6类单一控制措施中淘汰黄标车和结构性控制措施分别对各污染物和温室气体的削减效果最明显,减排幅度均在40%以上,且正向协同效应突出,但相比其他措施,结构性控制措施实施难度大.     

崇明东滩芦苇湿地温室气体排放通量及其影响因素

通过静态箱-气相色谱法对崇明东滩芦苇群落在生长周期内的3种温室气体——CH₄、N₂O和CO₂的排放、吸收特征进行研究. 结果表明:芦苇群落湿地CH₄排放通量受温度影响较大,夏季排放通量明显高于其他季节,年均排放通量为74.46μg/(m2·h);N₂O年均排放通量为2.22μg/(m2·h),冬季排放通量最大;CO₂的吸收率季节变化明显,年均排放通量为-101.93mg/(m2·h). 温度、芦苇植株光合作用及呼吸作用是影响CH₄产生和排放的主要因素;而沉积物氮素不足和限制,则是促使芦苇群落表现出对N₂O吸收的原因;芦苇的光合作用及土壤呼吸作用随温度和季节的变化是控制芦苇湿地CO₂的排放和吸收的主要因素. 芦苇植株发达的通气组织是CH₄和N₂O由大气向沉积物扩散的通道,同时分子扩散过程也是沉积物产生的CH₄、N₂O和CO₂扩散到大气中的途径和方式.      

矿化垃圾生物覆盖层减少垃圾填埋场CH4、N2O和CO2释放的效应研究

对利用矿化垃圾构建生物覆盖层以削减填埋场温室气体的释放问题进行了深入研究,分析了环境因素对CH4释放的作用,考察了作为生物覆盖层材料的矿化垃圾的厚度变化对CH4氧化的影响.结果表明,温度为5～45℃时,矿化垃圾对CH4的氧化速率平均值分别约为黏性土和砂性土的2.35和4.71倍,CH4氧化速率随温度的升高而增加,并在35℃时达到最大值.当含水率w为16％ ～ 24％时,纯矿化垃圾覆盖层、半矿化垃圾覆盖层和砂性土覆盖层CH4氧化能力均达到最大.砂性土覆盖层和半矿化垃圾覆盖层CH4释放通量平均值分别为纯矿化垃圾覆盖层的329.8倍（P＜0.05）和91.7倍（P＜0.05）,添加矿化垃圾填料会增加覆盖层N2O释放通量,纯矿化垃圾覆盖层N2O（以N计）释放通量平均值分别为半矿化垃圾覆盖层和砂性土覆盖层的2.1倍（P＜0.05）和3.5倍（P＜0.05）.     

互花米草入侵盐沼湿地CH4和N2O排放日变化特征研究

甲烷（CH4）和氧化亚氮（N2O）是导致全球气候变暖的2种重要温室气体,探索其源汇及地域排放特征一直是全球变化研究领域的核心内容。CH4和N2O通量的日变化研究是正确估算大时间尺度下CH4和N2O排放量的基础。利用静态箱法原位观测了江苏沿海芦苇（Phragmites australis）、盐蒿（Suada salsa）、光滩、水面以及互花米草（Spartina alterniflora）入侵湿地CH4和N2O排放的日变化特征。结果表明,1）互花米草湿地地上部生物量为1.70 kg·m^-2,土壤有机碳质量分数为13.55 g·kg^-1;分别是芦苇和盐蒿湿地的2.50-3.43和2.15-4.15倍。2）互花米草和芦苇湿地土壤10 cm处氧化还原电位（Eh）有明显日变化,最低值出现在3：00,最高值出现在12：00;光滩和盐蒿湿地没有明显的日变化。3）互花米草湿地 CH4日平均排放通量为0.52 mg·m^-2·h^-1,是其他湿地的2.12-6.40倍;N2O日平均通量为-3.24μg·m^-2·h^-1,显著低于盐蒿湿地、光滩和水面（P＜0.05）。互花米草和芦苇湿地CH4排放通量最高值（0.73 mg·m^-2·h^-1和0.30 mg·m^-2·h^-1）出现在15：00,最低值（0.37 mg·m^-2·h^-1和0.17 mg·m^-2·h^-1）出现在3：00,均与土壤孔隙水中CH4浓度呈显著负相关（P＜0.05）。互花米草湿地CH4排放通量与10 cm土温、Eh和生态系统CO2净交换量（NEE）显著正相关（P＜0.05）。互花米草和芦苇湿地N2O通量9：00-18：00为负值,21：00—6：00为正值,均与NEE呈显著负相关（P＜0.05）。盐蒿湿地、光滩和水面CH4和N2O排放通量没有明显日变化特征。互花米草入侵提高了沿海湿地CH4排放,但降低了N2O排放,植物对CH4传输作用以及向根际传输O2和易分解有机物是导致互花米草和芦苇湿地CH4和N2O排放表现出日变化特征的原因。     

N2O emission from a sequencing batch reactor for biological N and P removal from wastewater

Nitrous oxide （N2O） is a greenhouse gas that can be released during biological nitrogen removal from wastewater. N2O emission from a sequencing batch reactor （SBR） for biological nitrogen and phosphorus removal from wastewater was investigated, and the aims were to examine which process, nitrification or denitrification, would contribute more to N2Oemission and to study the effects of heterotrophic activities on N2O emission during nitrification. The results showed that N2O emission was mainly attributed to nitrification rather than to denitrification. N2O emission during denitrification mainly occurred with stored organic carbon as the electron donor. During nitrification, NaO emission was increased with increasing initial ammonium or nitrite concentrations. The ratio of N2O emission to the removed ammonium nitrogen （N2O- N/NH4-N） was 2.5% in the SBR system with high heterotrophic activities, while this ratio was in the range from 0.14% to 1.06% in batch nitrification experiments with limited heterotrophic activities.     

环境因子对小球藻生长及其CO2固定的影响

通过测定不同SO2、NO以及不同烟尘浓度条件下,小球藻ZY-1的生长速率及其对CO2的固定速率,研究烟气中NO和SO2及烟尘等环境因子对小球藻ZY-1的生长及其CO2固定效果的影响.研究结果表明,烟气中的SO2是以增加培养液中的SO24-浓度及降低pH值的形式来影响ZY-1的生长及其对CO2的固定的.当SO2体积浓度大于50×10-6时,需要进行烟气脱硫或控制培养液pH值变化来消除其影响;烟气中NO的体积浓度不高于300×10-6时,不影响ZY-1的生长及其对CO2的固定,可作为氮源供ZY-1生长用;对经过一般除尘处理的烟气,在利用小球藻ZY-1固定CO2时可不考虑溶解性烟尘的影响.研究结果证明利用小球藻ZY-1固定烟气中的CO2是可行的.     

北京城市大气CO2浓度变化特征及影响因素

北京大气CO₂浓度日变化强烈,全年北京时间15:00时前后为全天最低值,最高值则出现在夜间,日变化幅度为23.2～39.0μmol·mol^-1,夏季和秋季日变化幅度比冬季和春季大.北京城区大气CO₂浓度季节变化明显,最大值出现在冬季,月平均浓度为421.5～441.0μmol·mol^-1;最小值则在夏季,月平均浓度367.4～371.6μmol·mol北京CO₂浓度的季节变化幅度明显高于附近的华北兴隆区域站和瓦里关山大陆本底站等的相应值,其原因是北京CO2浓度季节变化主要受人为取暖活动控制,同时植被的季节变化也起一定作用.1993～1995年北京大气CO₂浓度上升较快,平均增长率为3.7%·a^-1,1995年平均浓度达到最高,为409.7±25.9μmol·mol,随后缓慢下降.     

The effects of pesticides on greenhouse workers and their produced products

Pesticides are chemicals used in agriculture but are known to produce adverse effects on humans. In this study, blood activities of superoxide dismutase (SOD), catalase (CAT), aspartate transaminase (AST), alanine transaminase (ALT), gamma-glutamyl transaminase, lactate dehydrogenase (LDH), and levels of malondialdhyde (MDA) were determined in 44 greenhouse workers (24 tomato workers, 20 clove workers) and in tomato (24 samples) and clove (20 samples) products. At the end of this study, blood MDA levels and activities of ALT, AST, and LDH levels in greenhouse workers were significantly increased while SOD and CAT activity levels fell significantly. Pesticide residues were not found in agricultural worker blood. Malathion residues (average 0.8?ppm) were detected in tomatoes (8 samples) in these greenhouses. Data suggest that the health of the greenhouse workers may be adversely affected by pesticides.     

我国原铝冶炼行业温室气体排放模型

我国原铝冶炼行业产业集中度较低,生产水平参差不齐,随着国内原铝产量不断增加,原铝行业碳排放及其计算方法备受关注. 针对我国原铝冶炼过程原料类型、能源结构复杂的特点,对国内外已有碳排放核算框架进行细化,从物料、工序、工艺3个层面构建了复杂的原铝冶炼系统温室气体排放计算模型. 在广泛文献调研的基础上,选取典型原铝冶炼企业开展现场调研及专家咨询,进而形成模型的基础数据库. 利用上述模型对我国2011年原铝冶炼过程碳排放进行核算. 结果表明:综合考虑氧化铝生产工艺结构、电解铝行业分布区域的电网能源结构,我国原铝冶炼系统CO₂排放因子(以铝锭计)为14.70t/t. 电解铝生产过程电耗相关排放占70%,南方电网区域电解铝生产电耗相关CO₂排放分别比华中、华北地区低13%、30%. 原铝冶炼行业可通过优先选用碳排放因子较低的物料、淘汰落后氧化铝工艺、开发引进低温低电压工艺技术等手段,进一步实现物料、工序及工艺的多层次温室气体减排.      

It's a dirty job but someone has to do it: The role of marine benthic macrofauna in organic matter turnover and nutrient recycling to the water column

Benthic macrofaunal populations through their feeding, bioturbation, burrow construction and sediment irrigation activities have profound influences on organic matter inputs to marine sediments (biodeposition) and on the vertical distribution of deposited organic matter within the sediment. These effects in turn influence the rates and pathways of organic matter mineralisation, and element cycles. Similarly, bioturbation, burrow construction and burrow irrigation are major determinants of sediment-water column fluxes of oxygen and nutrients.

In this review, I discuss the influences of the different benthic macrofaunal feeding (functional) groups on mineralisation processes and sediment-water column fluxes of particulate and dissolved nutrients. How these effects influence diagenic processes, the balance between aerobic and anaerobic processes, and the redox status of the surficial sediments. Finally, I discuss some of the limitations of the predominantly laboratory techniques which have been used to study “macrofaunal effects” and how this hinders the inclusion of the effects in quantitative sediment biogeochemical models.