业务持续规划及其在我国防灾事业的应用展望

突发性灾害事件威胁着城市的发展,面对越来越严峻的防灾减灾形势,欧美、日本等发达国家的业务持续规划(Business Continuity Plan,BCP)在城市公共安全建设中发挥着越来越重要的作用。依据欧美和日本制定的BCP规范、指南以及规划成果,系统介绍了BCP的内涵、特点及内容,并探讨了与其他城市防灾减灾相关规划的关系,最后介绍了目前BCP在国外的发展情况、在城市防灾中的作用和效果,并总结BCP对我国城市公共安全建设和灾害应急管理的启示,以及未来在我国的应用展望。目前我国尚未将BCP运用于城市防灾减灾中,而这种新规划的防灾减灾观点和做法都值得我们学习和借鉴,将来应将其应用范围拓展。     

大别山革命老区旅游地“乡土—生态”系统韧性演化规律及影响机制

探讨旅游地“乡土—生态”系统演化,为理解人地关系地域系统结构与功能演变提供了新思路。通过构建“乡土—生态”系统韧性评价体系,解析2005—2019年大别山革命老区旅游地“乡土—生态”系统韧性的演化阶段、过程、路径及机制。结果显示：（1）研究区旅游地“乡土—生态”系统经历了利用、保存、释放、重组适应性循环过程,分别对应旅游地迅速发展期（2005—2009年）、发展成熟期（2010—2012年）、发展过渡期（2013—2016年）和再发展初期（2017—2019年）。（2）在适应性循环过程中研究区县域的数量结构经历了以“较低水平韧性为主→高水平韧性为主”的转变,县域“乡土—生态”系统韧性水平呈波动上升趋势。（3）2005—2019年研究区旅游地“乡土—生态”系统韧性演化的驱动因子由经济层面转向社会文化层面。在内外源因素的作用下,旅游地“乡土—生态”系统韧性通过乡土资源禀赋（向心凝聚力）、经济发展基础（核心推动力）、社会保障功能（重要支撑力）和自然环境本底（基础约束力）的四维驱动,以人的行为为媒介在相互作用和掣肘中演进,当韧性指数超过阈值时其内核组织将打破原有边界、自我调适实现“路径突破”,进入下一阶段适应性循环,以此促进旅游地的可持续发展。     

冻融作用下寒温带针叶林土壤碳氮矿化过程研究

以大兴安岭落叶松林土壤为研究对象,设置8℃恒温和-5-8℃冻融循环（1个冻融循环为在-5℃培养24 h,后在8℃培养24 h）2个处理,进行30 d的室内培养实验,探讨了寒温带针叶林土壤在冻融交替时期的碳氮矿化过程及其相互关系。结果表明,培养温度和培养时间对土壤碳矿化速率和碳矿化累积量均有显著影响。第1次和第5次冻融循环后,冻融处理土壤的碳矿化速率显著高于恒温培养下土壤的碳矿化速率;第7次和第15次冻融循环后,冻融土壤碳矿化累积量显著低于恒温土壤的碳矿化累积量。土壤氮矿化速率没有受到培养温度、培养时间以及二者交互作用的影响,但培养时间和培养温度对土壤净氮矿化累积量有显著的影响。第5、7、15次冻融循环后,冻融处理的土壤无机氮净矿化累积量低于恒温培养的土壤无机氮净矿化累积量。经过30 d的培养,恒温处理下的土壤碳、氮矿化累积量（碳累积量：92.82μg·g-1,氮累积量73.76 mg·kg-1）是冻融处理下（碳累积量：65.51μg·g-1,氮累积量33.45 mg·kg-1）的1.42倍和2.21倍。土壤碳矿化累积量与土壤净氮矿化累积量均为正相关关系,但在相同的碳释放量下冻融循环处理土壤累积的无机氮较少。以上结果表明,冻融循环减少了大兴安岭寒温带落叶松林土壤碳排放和无机氮的累积,有利于土壤碳的固持和减少养分的流失。     

Copper biosorption on immobilized seaweed biomass： Column breakthrough characteristics

The biosorption of copper by the brown seaweed Sargassum baccularia,immobilized onto polyvinyl alcohol(PVA)gel beads, was investigated with fixed-bed experiments.Laboratory-scale column tests were performed to determine breakthrough curves with varying flow rates and feed concentrations.A theoretical fixed-bed model,known as the Bohart-Adams equation,was evaluated in simulating the experimental breakthrough curves.The Bohart-Adams model qualitatively predicted the breakthrough trends.PVA- immobilized seaweed biomass beads were amenable to efficient regeneration with aqueous solution containing the chelating agent ethylenediaminetetraacetic acid(EDTA).The biosorbent retained most of its original uptake capacity over three cycles of use.The excellent reusability of the biosorbent could lead to the development of a viable metal remediation technology.     

草原土壤的碳氮分布与CO2排放通量的相关性分析

利用静态暗箱法,对内蒙古锡林河流域的贝加尔针茅(Stipa baicalensis)、羊草(Leymus chinensis)、大针茅(Stipa grandis)、克氏针茅(Stipa krylovii)等草原群落样地的CO₂排放通量进行了测定;同时采集各样地的不同层次土壤混合样,分析其中有机碳和全氮的含量,探讨其与CO₂排放的相关性.结果发现:不同样地群落的CO₂排放与其土壤中不同层次的有机碳和全氮含量呈高度正相关,相关系数(R)均0.8以上,说明在环境因子相对稳定的情况下,土壤有机碳和全氮含量直接或间接地决定生态系统CO₂排放通量的变化.另外,土壤不同层次的有机碳和全氮含量随深度增加递减,其中70%以上集中在0～30cm土层中,说明它们主要是来自地表有机质的分解;在0～100cm的土层中,土壤有机碳和全氮的总含量从贝加尔针茅草原、大针茅草原、羊草草原和克氏针茅草原依次减少,表明降水量、蒸发量和干燥度是影响土壤有机碳、全氮分布的重要因子.     

Evaluation of the International Vehicle Emission （IVE） model with on-road remote sensing measurements

Intemational Vehicle Emissions （IVE） model funded by U.S. Environmental Protection Agency （USEPA） is designed to estimate emissions from motor vehicles in developing countries. In this study, the IVE model was evaluated by utilizing a dataset available from the remote sensing measurements on a large number of vehicles at five different sites in Hangzhou, China, in 2004 and 2005. Average fuel-based emission factors derived from the remote sensing measurements were compared with corresponding emission factors derived from IVE calculations for urban, hot stabilized condition. The results show a good agreement between the two methods for gasoline passenger cars＇ HC emission for all 1VE subsectors and technology classes. In the case of CO emissions, the modeled results were reasonably good, although systematically underestimate the emissions by almost 12%-50% for different technology classes. However, the model totally overestimated NOx emissions. The IVE NOx emission factors were 1.5-3.5 times of the remote sensing measured ones. The IVE model was also evaluated for light duty gasoline truck, heavy duty gasoline vehicles and motor cycles. A notable result was observed that the decrease in emissions from technology class State II to State I were overestimated by the IVE model compared to remote sensing measurements for all the three pollutants. Finally, in order to improve emission estimation, the adjusted base emission factors from local studies are strongly recommended to be used in the IVE model.     

冻融循环对含铁材料稳定砷污染土壤的影响

为分析冻融循环对污染土壤砷（As）的稳定化性能的影响,投加4种含铁材料（FeSO4、FeS、Fe2（SO4）3和Fe0）对土壤中的As进行稳定化处理,并通过实验室模拟冻融过程,研究4种含铁材料稳定化处理后土壤中无定形氧化铁含量、氧化铁活化度、pH和As的浸出毒性随冻融循环的变化。结果表明：4种含铁材料稳定化土壤无定形氧化铁含量与氧化铁活化度随冻融循环的变化趋势基本一致;冻融循环降低了无定形氧化铁的含量,促进了铁氧化物的结晶老化。与未冻融土壤相比,冻融循环增加了稳定化土壤As的浸出毒性,但在冻融后期,As浸出毒性的增加量呈降低的趋势。4种含铁材料稳定化土壤As的浸出毒性随冻融循环表现出不同的变化趋势。1% Fe0稳定化土壤经过冻融循环As的稳定性最高,1% FeSO4和1% Fe2（SO4）3稳定化土壤次之,而1% FeS稳定化土壤最低。因此,冻融循环增加了稳定化土壤As再释放的环境风险,Fe0用做冻融地区As污染土壤稳定化药剂较为合适。     

橡胶坝对河流沉积物氮转化功能基因丰度和营养盐的影响

沉积物氮转化功能微生物是河流脱氮和水体净化的重要生物因素.为探讨橡胶坝对沉积物氮转化功能基因丰度及氮营养盐的影响,本研究以沂河沂水城区蓄水段为研究对象,从橡胶坝前不同距离采集沉积物,利用实时荧光定量PCR（qPCR）方法研究了沉积物的反硝化功能基因（nirS、nirK、nosZ）、厌氧氨氧化功能基因（AMX）和反硝化型甲烷厌氧氧化功能基因（pmoA）的丰度及沉积物营养盐特征.结果表明：橡胶坝促进了沉积物中nirK、nirS、nosZ和pmoA基因的聚集,反硝化功能基因nirK、nirS、nosZ丰度在坝前120 ~330 m范围内较高;橡胶坝促进了沉积物NH4+、NO3-、TN、TP、TOC、有机质（OM）等营养盐的滞留,主要在120 ~360 m区域聚集,多元线性回归模型拟合度较高.相关分析表明,16S rRNA、nirK、nirS、nosZ、pmoA基因丰度与环境因子NH4+、NO3-、TN、OM、TOC、孔隙度呈正相关;PCA分析结果表明,随着沉积物环境因子主成分的增长,氮转化功能基因丰度主成分呈升高趋势.橡胶坝可促进沂河沉积物氮素等营养盐的滞留和氮转化功能微生物的聚集.     

干湿交替对土壤DOM特性及重金属释放的影响

以典型Cu和Zn污染农田土壤为研究对象,利用土壤培养实验、光谱学方法以及流动搅拌实验,以阐明土壤干湿交替对重金属污染土壤中土壤溶解性有机质(DOM)特性及重金属释放动力学行为的影响。结果表明,土壤pH、DOM含量及其芳香性随着土壤含水率升高而增大,而干湿交替主要影响土壤中DOM的含量,对pH和SUVA₂₅₄值的影响很小。重金属释放动力学研究表明,土壤含水率越高越有利于Cu和Zn的稳定,干旱过程则会促进其释放,但仅在初次湿润到干旱过程中对其释放特性产生影响,后期干湿交替循环影响很小,且不同干湿交替频率和强度具有类似影响。在同等条件下,Zn的释放比Cu更快,受干湿交替影响更小。本研究结果可为重金属污染土壤修复工作提供参考。     

A value proposition: Resource recovery from faecal sludge—Can it be the driver for improved sanitation?

There is currently a lack of access to affordable sanitation in urban areas of Sub-Saharan Africa. This study evaluated the potential for resource recovery from innovative faecal sludge treatment processes to generate a profit that could help sustain the sanitation service chain. A total of 242 interviews were conducted in Accra, Ghana; Dakar, Senegal; and Kampala, Uganda to compare markets in different cultural and regional contexts. Products identified to have potential market value include dry sludge as a fuel for combustion, biogas from anaerobic digestion, protein derived from sludge processing as animal feed, sludge as a component in building materials, and sludge as a soil conditioner. The market demand and potential revenue varied from city to city based on factors such as sludge characteristics, existing markets, local and regional industrial sectors, subsidies, and locally available materials. Use as a soil conditioner, which has been the most common end use of treated sludge, was not as profitable as other end uses. These findings should help policy and decision makers of sanitation service provision to design financially viable management systems based on resource recovery options.