基于生命周期评价的土地利用环境影响评价综述

土地利用过程会引起一系列生态环境问题,如生物多样性破坏、生态支持功能衰弱、自然生态环境破坏等.介绍了国内外生命周期评价中土地利用研究的发展历程,总结了生命周期评价中不同土地利用方式——土地占用及土地转变使用用途对生物多样性破坏、生态支持功能衰弱、自然生态破坏3个方面的评价方法、计算模型及应用实例,并对目前生命周期评价中关于土地利用的环境影响评价存在的问题进行了分析.     

稻田土菌群驯化对稻秆两步发酵产甲烷效果的影响

为提高稻秆的降解率及其厌氧发酵甲烷产量,采用高氨氮畜禽废水作为氮源以驯化稻田土壤微生物,优化其降解稻秆的初始pH值,并评估水解产物液体发酵产甲烷性能.结果表明,混合组驯化的微生物产纤维素酶活性及对稻秆木质素的降解率高于其它组及先前文献报道,分别达到4.01 IU和51.96%,且后期水解液中总有机碳（Total organic carbon, TOC）及还原糖含量最高.随着初始pH值的提高,稻秆中纤维素、半纤维素和木质素的降解率显著增加,稻秆水解液中的挥发性脂肪酸（Volatile fatty acids, VFAs）和TOC含量均显著增加,并在第7 d达到最高值.将水解稻秆7 d的水解液进行厌氧发酵显示,在初始pH=9.0条件下累积甲烷产量达到最大,为37.60 mL·mL^-1水解液.本实验结果表明, 驯化的稻田土微生物在碱性条件下可以更有效地降解稻秆,提高水解液中TOC及VFAs含量,从而提高厌氧发酵的甲烷产量.     

Effects of cultivation strategies on the cultivation of Chlorella sp. HQ in photoreactors

Heterotrophic cultivation caused high level of ROS and high lipids accumulation. HMTC is the best culture strategy for improving the microalgal biomass. Chlorella sp. HQ had great nutrient removal capacity under five culture strategies. The effects of cultivation strategies (including autotrophic cultivation (AC), heterotrophic cultivation (HC), fed-batch cultivation (FC), heterotrophic+ autotrophic two-stage cultivation (HATC), and heterotrophic+ mixotrophic two-stage cultivation (HMTC)) on the growth and lipid accumulation of Chlorella sp. HQ and its total nitrogen (TN) and total phosphorus (TP) removal in secondary effluent were investigated in column photoreactors. The results showed that the TN and TP removal rates ranged between 93.72%–95.82% and 92.73%–100%, respectively, under the five different strategies. The microalgal growth potential evaluated by the maximal growth rate (R_max) was in the order of HMTC>HC>FC>AC>HATC. The values of biomass, total lipid yield, triacylglycerols (TAGs) yield, and total lipid content of the microalga cultivated in the last 5 d increased significantly, but the TAGs productivities of the five strategies were lower than those in the first 7 d. Compared with all the other cultivation strategies, the TAGs productivity and yield after 12 d of cultivation under the heterotrophic condition reached the highest values accompanying the highest level of intracellular reactive oxygen species (ROS), in which the TAGs yield reached 40.81 mg/L at the end of the cultivation period. The peaks in TAGs yield and ROS level suggested that HC was beneficial for lipids accumulation via regulating the cellular redox status and exerting ROS stress on microalgal cells. In summary, HMTC was the best cultivation strategy for improving the microalgal biomass and HC was the best strategy for microalgal TAGs accumulation to produce biodiesel.     

苯酚对两种微囊藻生长的作用效应

用不同浓度的苯酚处理无毒铜绿微囊藻和有毒铜绿微囊藻。结果显示不加苯酚处理时，有毒藻生长量明显高于无毒藻；100μg／mL的苯酚促进无毒藻生长而抑制有毒藻的生长；苯酚浓度增至200μg／mL，无毒藻的生长才受到抑制。高浓度苯酚胁迫下的藻细胞：光合速率大幅度降低；可溶性蛋白含量减少；细胞膜透性增大；超氧阴离子(O2^-)产生速率和丙二醛(MDA)相对含量升高；超氧化物歧化酶(SOD)活性降低。这些变化有毒藻较无毒藻更显著。表明：有毒微囊藻是水华中的优势种群；两种藻中有毒藻对苯酚的敏感性更大。     

柴油车尾气微粒的燃烧性能

采用热解质量分析方法（TGA）对机动车柴油发动机尾气微粒（PM）的燃烧性能进行了研究。分别在空气和氮气条件下对柴油微粒的失重情况进行了测试。实验表明，柴油微粒的起始失重温度Tb为200℃左右，起始氧化温度Tox为410-450℃，最大失重温度Tmax为650℃-700℃，其可挥发组分（VOC）含量为48%-55%，增加氧气浓度仅在调温时对微粒燃烧有利。     

固定化微生物脱氮技术

在废水生物脱氮中 ,利用载体固定、形成颗粒污泥等固定化微生物技术可在增加生物脱氮速度、节省碳源、减少后曝气等方面提供有效的方法 ,并实现单级生物脱氮     

中国环境战略与政策发展进程、特点及展望

本文系统回顾了中国环境战略与政策的发展进程,总结了中国环境战略与政策的特点及变化特征,并进一步提出新时期中国环境保护战略与政策的推进方向。中国环境战略与政策与经济社会发展同步,主要分为探索起步阶段(1972—1983年)、初创建立阶段(1984—1991年)、框架完善阶段(1992—2002年)、提升发展阶段(2003—2012年)、改革突破阶段(2013年至今)五个阶段,而随着中国环境战略与政策的发展,环境战略理念与环境政策导向都发生了转变。文章指出,未来中国环境保护战略与政策要应对新情况、解决新问题,需着眼于满足人民群众美好生活的需求,重视推动制度重构和绿色转型,推动走上生态优先、绿色发展的新路,强化制度政策的内生动力,加强政策统筹协同。     

Particulate matter pollution in Kunshan High-Tech zone: Source apportionment with trace elements, plume evolution and its monitoring

Particulate matter(PM) in the Kunshan High-Tech zone is studied during a three-month campaign. PM and trace elements are measured by the online pollution monitoring, forecastwarning and source term retrieval system AS3. Hourly measured concentrations of PM_(10), PM_(2.5) and 16 trace elements in the PM_(2.5) section(Ca, Pb, Cu, Cl, V, Cr, Fe, Ti, Mn, Ni, Zn, Ga, As, Se, Sr, Ba)are focused. Source apportionment of trace elements by Positive Matrix Factorization modeling indicates that there are five major sources, including dust, industrial processing, traffic,combustion, and sea salt with contribution rate of 23.68%, 21.66%, 14.30%, 22.03%, and 6.89%,respectively. Prediction of plume dispersion from concrete plant and traffic emissions shows that PM_(10) pollution of concrete plant is three orders of magnitude more than that of the traffic. The influence range can extend to more than 3 km in 1 hr. Because the footprint of the industrial plumes is constantly moving according to the local meteorological conditions, the fixed monitoring sites scattered in a few hundred meters haven't captured the heaviest pollution plume at the local scale of a few km~2. As a more intensive monitoring network is not operationally possible, the use of online modeling gives accurate and quantitative information of plume location, which increases the spatial pollution monitoring capacity and improves the understanding of measurement data. These results indicate that the development of the AS3 system, which combines monitoring equipment and air pollution modeling systems, is beneficial to the real-time pollution monitoring in the industrial zone.     

浑河流域沈抚段氮素污染综合溯源研究

通过对浑河流域沈抚段水体样品和主要污染源样品采集及检测,结合氮氧双稳定同位素及SIAR模型,统计分析研究区域氮素污染现状及氮素污染来源,绘制典型污染源的δ15N、δ18O特征分布图并估算其贡献率,准确追踪和定量外来性氮,从而更好地控制进入浑河流域的氮负荷.结果表明,浑河流域沈抚段受排污口、支流输入、工业废水的影响较大,氮素污染严重.研究区域δ15N值在-5.23‰~33.8‰范围内波动,δ18O值变化范围较大,为-4.12‰~61.54‰.工业废水对氮素贡献率为20.6%~96.3%,贡献率最高,其次是生活污水与粪便、化学肥料、土壤,贡献率分布范围分别为0.3%~29.4%、1.2%~33.5%、1.7%~30.1%,大气沉降对氮素贡献率最低,为0~7.2%.考虑大气污染及污废水排放规律能更准确的确定氮素的污染来源.