小麦秸秆驱动菱铁矿热解制备磁性生物质碳及其吸附Cd2+活性

以小麦秸秆和菱铁矿为原料,在500℃下热处理改性,制备了一种C-Fe_3O_4复合材料.采用FTIR、XRD、SEM、BET、磁化率仪对C-Fe_3O_4复合材料(以下统称复合材料)进行表征.考察了接触时间、初始pH、初始Cd~(2+)浓度、离子强度对Cd~(2+)去除率的影响,结合吸附前后表征结果分析了复合材料对Cd~(2+)的吸附机制.结果表明:复合材料及单独煅烧制备的小麦秸秆炭的比表面积分别为23.38 m~2·g~(-1)和7.20 m~2·g~(-1),孔容积分别为1.04×10-1cm~3·g~(-1)和2.23×10-2cm~3·g~(-1),平均孔径分别为17.74 nm和12.38 nm;红外光谱显示复合材料和小麦秸秆炭表面富含羧基、羟基等具有金属离子吸附活性的官能团;磁化率测试结果显示复合材料的质量磁化率为42 900×10~(-8)m~3·kg~(-1).复合材料对Cd~(2+)的吸附动力学用准二级动力学模型拟合度最好;吸附等温线符合Freundlich模型;pH在3.0~6.0之间,吸附容量随pH增大而升高,pH在6.0~9.0之间,吸附容量趋于稳定;pH在4.0~9.0之间,解析量随pH增大而减少;离子强度从1 mmol·L~(-1)增至100 mmol·L~(-1),Cd~(2+)的吸附容量略有减少,解析率由0.51%提升至8.5%;说明复合材料主要通过表面络合作用及离子交换去除溶液中的Cd~(2+).此外,复合材料的磁化性能使其在固液分离方面比一般的吸附材料具有很大优势.     

脱硫石粉贮存库气化装置改造

对火电厂脱硫石粉贮存库运行过程中散装机出料口下料缓慢,进气母管及气化槽体中进粉等问题进行了分析,提出了改造对策,石粉贮存库气,石粉贮存气化装置改造后运行效果良好,以60t罐车为例,石粉的装车为例,石粉的装车时间同原来的30min减少到15min.     

Environmental and economic assessment of biomass sourcing from extensively cultivated buffer strips along water bodies

Buffer strips represent oblong land elements along water bodies playing an important role for the water quality management of the surface water. In the policy context buffer strips are referred to as land with defined farming restrictions aiming at protecting the water course. In the current EU agricultural policy framework the majority of the decisions regarding subsidy schemes for buffer strips is taken on the member country level, which results in great differences between the EU members with regard to this water protection measure. If incentives for farmers for establishing and maintaining buffer strips are in place, they are usually linked to the harvest ban on the buffer strip. Such protection model can be endangered by volatile and rising prices for agricultural products. However, buffer strip can represent a valuable source of different ecosystem services, including biomass provision. If harvesting under certain restrictions would be allowed, the biomass could generate additional revenue that might contribute to securing buffer strips existence and consequently maintaining their protection function.This study aimed at assessing the costs and environmental consequences of biomass mobilizing from buffer strips. It dealt with different scenarios of biomass sourcing from extensively cultivated buffer strips in the Netherlands. In 12 scenarios, the cultivation of grass or cereal mixes (including multiple harvesting or perennial cultivation) for different valorisation chains (ensiling or fodder & bedding) was assessed. Both total net cultivation costs as well as the hectare based environmental performance (using the Life Cycle Assessment methodology) were evaluated. Additionally, the environmental impact of electricity production through anaerobic digestion of biomass from buffer strips was compared with the impact from digestion of classic grass silage and the impact profile of Dutch electricity mix.The results indicate ensiling as the scenario generating more net costs and higher environmental impacts as compared to fodder & bedding. In the latter, the cereal cultivation represents a better solution from economic perspective, while grass shows lower environmental impacts. Moreover, optimizing grass cultivation through switching to perennial mode contributes to strong improvements of the economic performance and contributes to additional reduction of environmental impacts, and consequently delivers the best environmental and economic solution. Moreover, the comparison with the Dutch electricity mix shows that biomass from buffer strips, if used in anaerobic digestion, can, in terms of environmental performance, compete with classic silages and contribute to reduced environmental damage.     

Microalgae cultivation using an aquaculture wastewater as growth medium for biomass and biofuel production

Microalgae as a main feedstock has attracted much attention in recent years but is still not economically feasible due to high algal culture cost. The objective of this study was to develop a comprehensive eco-friendly technology for cultivating microalgae Platymonas subcordiformis using aquaculture wastewater as growth medium for biomass and biofuel production. Platymonas subcordiformis was grown in pretreated flounder aquaculture wastewaters taken from different stages. Each of wastewater contained different levels of nutrients. The biomass yield of microalgae and associated nitrogen and phosphorous removal were investigated. The results showed that algal cell density increased 8.9 times than the initial level. Platymonas subcordiformis removed nitrogen and phosphorus from wastewater with an average removal efficiency of 87%–95% for nitrogen and 98%–99% for phosphorus. It was feasible to couple the removal of nitrogen and phosphorus from wastewater to algal biomass and biofuel production. However, further studies are required to make this technologies economically viable for algae biofuel production.     

关于发展生物质产业的几点思考

我国生物质产业自20世纪70年代开始起步。乙醇汽油和沼气利用是生物质能开发中的重点。虽然生物质产业的关键技术基本成熟。但是当考虑不再用粮食作为原料的时候，技术转换等一系列问题也会随之而来。技术瓶颈仍然是限制我国生物质产业发展的一大因素。我国政府为解决能源短缺问题，缓解环境压力．同时为消化陈粮。在扶持生物质产业发展的过程中一直充当了“埋单者”的角色．这也引发了以粮食为加工原料的燃料乙醇项目的大量上马．粮油价格上涨的趋势开始波及我国。因此。从粮食问题是否让位于能源问题．政府是否继续充当“埋单者”的角色。生物质产业污染治理的角度出发．认为：今后发展生物质产业不能只盯住能源短缺的问题而忽视粮食安全问题。要从技术层面解决原料限制和成本过商的难题。同时政府对生物质产业发展应有科学规划和管理。     

A Two-Part Measure of Degree of Invasion for Cross-Community Comparisons

Abstract:  Invasibility is a critical feature of ecological communities, especially for management decisions. To date, invasibility has been measured in numerous ways. Although most researchers have used the richness (or number) of exotic species as a direct or indirect measure of community invasibility, others have used alternative measures such as the survival, density, or biomass of either a single or all exotic species. These different measures, even when obtained from the same communities, have produced inconsistent results and have made comparisons among communities difficult. Here, we propose a measure of the degree of invasion (DI) of a community as a surrogate for community invasibility. The measure is expressed as 2 independent components: exotic proportion of total species richness and exotic proportion of total species abundance (biomass or cover). By including richness and abundance, the measure reflects that the factors that control invasibility affect both of these components. Expressing exotic richness and abundance relative to the richness and abundance of all species in a community makes comparisons across communities of different sizes and resource availability possible and illustrates the importance of dominance of exotic species relative to natives, which is a primary management concern associated with exotic species.     

中国发展生物质能源的战略措施思考

能源是人类社会赖以生存和发展的重要资源.随着中国经济的持续发展,能源与环境对经济发展的制约作用逐渐得到显现,能源问题与环境问题已经成为国家发展的战略性问题.因此发展生物质能是解决中国能源紧张的重要突破口.发展生物质能的战略措施是建立生物质能源的产业体系,即相对于传统产业体系的第二产业体系.具体战略阶段是:2000-2010年实验探讨阶段(初级阶段);2020-2030年推广应用阶段(发展阶段):2030年-2050年优化提出阶段(提高阶段).生物质能源的发展战略有助于"三农"问题的解决即农村小康社会的建设;有助于减轻环境压力;有助于维护国家能源安全.     

基于GO法的LNG接收站气化外输系统可靠性分析

为保障液化天然气(LNG)接收站工艺系统生产的安全,基于GO法原理,对某接收站气化外输系统进行可靠性分析。在对系统工艺流程分析的基础上建立GO图,并采用概率公式算法分别对该系统进行可靠性定性与定量分析。结果表明:GO图简单实用,能够直观准确地表征系统工艺流程。GO运算得出气化外输系统的平均工作概率为0.977 814,平均维修时间为58 h,系统可连续稳定运行107天以上。由于数据是基于保守原则确定基本事件的,因此,计算所得可靠性结果可以作为气化外输系统安全可靠性的下限。     

Environmental benefits from the use of the residual biomass in nurseries

Every year, nurseries waste about 40 t of residual biomass for each ha of potted plants cultivation. The European nursery sector deals with about 90,000 ha of cultivated land and 120,000 ha of nurseries, with a turnover of 19.8 billion Euros in 2011. In recent years, a number of Italian projects highlighted that GHG (greenhouse gas) emissions for the nursery sector range between 37 tCO₂eq/ha/year and 45 tCO₂eq/ha/year for potted plants, mainly due to the consumption of electric energy, plastics and peat. Moreover, other studies analyse the impacts associated to nurseries, recommending best practices for energy reductions and waste recycle or reuse. Therefore, the present work focused its attention to the possible environmental benefits associated to the reuse of residues (wood and substrate) of potted plants that are discarded from the nursery production chain. GHG emissions and fossil energy requirement were quantified by considering the CO₂eq (CO₂ equivalent) and the CER (cumulative energy requirement) respectively, in order to assess the environmental impacts of two different scenarios proposed for the materials recovery. Final results highlighted that the solutions which are able to recover the substrate and the wood allow impact reductions compared to landfill disposal. In particular, the scenario consisting in the immediate separation of the substrate from the root-plant system and the successive chipping of wood for energetic reuse, allows higher savings than those obtainable through shredding and subsequent wind separation. Moreover, for what concerns the CO₂eq, an adequate use of the residual biomass make it possible to compensate the GHG emissions of the nurseries up to 15%.