区域水战略方案选优的动态组合评价模型研究

水安全危机是人类进入新世纪以来在生存及发展方面所面临的最严重挑战之一。研究科学合理的水安全战略成为区域可持续发展的重大课题。针对区域水战略问题涉及众多因素且各因素之间动态关联的特点,提出了基于水战略方案优选的兼容度极大化动态组合评价模型（CMM—DCEM）,并将其成功地应用于我国广东省北江下游及其三角洲地区水安全战略方案优选评价。评价结果及模型基于不确定性的敏感性分析结果证明：CMM—DCEM实现了主、客观赋权方法以及单一评价模型的融合,使用实码加速遗传算法求解目标函数,克服了传统的组合评价方法计算繁琐的不足,评价过程更加科学合理。     

榆林地区植被时空分异特征及其影响因素研究

植被作为反映陆地生态系统和气候的重要指标,对研究全球或区域生态环境变化具有重要作用。以地处黄土高原生态脆弱区的榆林市为研究区,基于地理探测器模型,选取坡向、坡度、气温、降水和土壤类型5类自然因子,土地利用类型、人口密度和GDP 3类人文因子,分析榆林地区植被空间分异特征及其驱动力,并揭示了促进植被生长影响因子的最适宜特征。结果表明,（1）研究区2000—2018年植被覆盖趋向改善,NDVI呈现增加趋势,增速为0.11/10a,2008年以后植被增长较为明显;NDVI在2018年中高等级（0.6—0.8）面积比2000年中高等级面积明显增加;中高等级集中于榆林市东部黄土丘陵区,中低等级（0.2—0.4）集中于榆林市西北部的风沙区,植被覆盖呈现东部高西北低的空间分布特征。（2）人口密度和气温因子较好地解释植被NDVI空间分异性,是影响NDVI空间分异性的主要因子,GDP、土地利用类型和坡度是次级影响因子,其他因子对NDVI空间分异存在间接影响;坡向、降水和土壤类型因子与其他自然、人文因素对植被空间分布影响存在显著性差异。（3）自然、人文因子对榆林市NDVI的影响存在交互作用,因子之间的交互...     

On-road motor vehicle emissions and fuel consumption in urban driving conditions

This paper reports on the analysis of on-road vehicle speed, emission, and fuel consumption data collected by four instrumented vehicles. Time-, distance-, and fuel-based average fuel consumption, as well as CO, HC, NOx, and soot emission factors, were derived. The influences of instantaneous vehicle speed on emissions and fuel consumption were studied. It was found that the fuel-based emission factors varied much less than the time- and distance-based emission factors as instantaneous speed changed. The trends are similar to the results obtained from laboratory tests. The low driving speed contributed to a significant portion of the total emissions over a trip. Furthermore, the on-road data were analyzed using the modal approach. The four standard driving modes are acceleration, cruising, deceleration, and idling. It was found that the transient driving modes (i.e., acceleration and deceleration) were more polluting than the steady-speed driving modes (i.e., cruising and idling) in terms of g/km and g/sec. These results indicated that the on-road emission measurement is feasible in deriving vehicle emissions and fuel consumption factors in urban driving conditions.     

地带性土壤对苯胺吸附行为的研究

土壤作为挥发性有机污染物的源与汇,研究污染物在其中的吸附行为对探明污染物环境归趋和生态风险意义深远.以苯胺为代表性污染物,在综合分析我国12种地带性土壤的基本理化性质基础上,探讨苯胺在土壤-水界面分配规律以及该吸附行为与土壤理化性质之间的关系.结果 表明:1)12种地带性土壤对于苯胺的吸附能力差异明显,其中,黑龙江黑土...     

双氯芬酸在水环境中光降解的初步研究

考察了在模拟太阳光照射下,双氯芬酸初始浓度、pH值、光强、温度、丙酮和双氧水对双氯芬酸光解的影响,并通过淬灭实验初步探讨了双氯芬酸光解.结果表明,双氯芬酸的光降解过程符合准一级动力学方程.光解速率随着双氯芬酸初始浓度的降低、光强的增强以及温度的升高而增大.当pH值从3变化到5时,反应速率常数变大;pH值从5变到8时,反应速率常数变小,再继续增大pH值,反应速率常数增大.水环境中存在的双氧水和丙酮对双氯芬酸的光解具有促进作用.最后,通过淬灭实验表明双氯芬酸的光解过程包括直接光解以及通过活性氧物种进行的自敏化光解.     

Algal biomass derived biochar anode for efficient extracellular electron uptake from <Emphasis Type="Italic">Shewanella oneidensis</Emphasis> MR-1

The development of cost-effective and highly efficient anode materials for extracellular electron uptake is important to improve the electricity generation of bioelectrochemical systems. An effective approach to mitigate harmful algal bloom (HAB) is mechanical harvesting of algal biomass, thus subsequent processing for the collected algal biomass is desired. In this study, a low-cost biochar derived from algal biomass via pyrolysis was utilized as an anode material for efficient electron uptake. Electrochemical properties of the algal biochar and graphite plate electrodes were characterized in a bioelectrochemical system (BES). Compared with graphite plate electrode, the algal biochar electrode could effectively utilize both indirect and direct electron transfer pathways for current production, and showed stronger electrochemical response and better adsorption of redox mediators. The maximum current density of algal biochar anode was about 4.1 times higher than graphite plate anode in BES. This work provides an application potential for collected HAB to develop a cost-effective anode material for efficient extracellular electron uptake in BES and to achieve waste resource utilization.

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活性污泥对甲醛废水的净化性能

采用微生物法处理低浓度甲醛废水达标排放是比较经济的方法之一.在研究中采用序批式活性污泥法(SBR)工艺,考察了曝气时间、进水甲醛浓度、进水 pH 和水温对微生物净化低浓度甲醛废水的影响.结果表明,随着曝气时间的延长,活性污泥对甲醛的去除率增大.进水甲醛浓度在 40～120 mg/L 范围内,随着浓度升高甲醛污泥负荷增加,微生物对甲醛的降解速率增加,但对甲醛的去除率降低.活性污泥在 pH 为 5～7 的中性和弱酸性环境中对甲醛的降解速率较高.在15～35℃范围内,污泥对废水中甲醛的去除率随温度升高而上升,微生物对甲醛的降解速率随温度升高呈指数递增趋势.     

CO2捕集回收技术研究

主要介绍了常用的胺化合物吸收法、钙基吸收剂法、金属氧化物法等CO2捕集回收技术的最新研究进展及存在的问题,综合对比了各种方法的优缺点:胺化合物吸收法吸收速率快,但再生能耗较高,因此开发"高效低耗"的复合吸收剂成为研究的重点;钙基吸收剂法在高温环境下对CO2的吸收有较好的效果,但吸收剂的碳酸化转化率及热稳定性是有待解决的关键问题;金属氧化物法具有高的CO2吸收效率,但成本较高.在此基础上,探索了CO2捕集回收技术改进工艺,提出改善吸收剂性能、开发高效低耗的CO2选择性吸收剂将成为今后CO2捕集回收技术的研究方向.     

Approaching the binding between Cu(II) and aerobic granules by a modified titration and µ-XRF

Interactions between metals and activated sludge can substantially affect the fate and transport of heavy metals in wastewater treatment plants. Therefore, it is important to develop a simple, fast and efficient method to elucidate the interaction. In this study, a modified titration method with a dynamic mode was developed to investigate the binding of Cu(II), a typical heavy metal, onto aerobic granules. The titration results indicated that pH and ionic strength both had a positive effect on the biosorption capacity of the granular sludge. The µ-XRF results demonstrated that the distribution of metals on the granular surface was heterogeneous, and Cu showed strong correlations and had the same “hot spots” positions with other metal ions (e.g., Ca, Mg, Fe etc.). Ion exchange and complexing were the main mechanisms for the biosorption of Cu(II) by aerobic granules. These results would be beneficial for better understanding of Cu(II) migration and its fate in wastewater treatment plants.     

Microbial flocculant and its application in environmental protection

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