Trends in Fish Community Structure,Biomass, and Production in Three Algoma,Ontario, Lakes

Long-term (i.e. >10 years) whole community fish dataincluding catch-per-unit-effort, abundance, biomass, andproduction from three lakes were used: 1) to examine variabilityin fish population and community measures among years using wholelake assessments of fish populations derived from mark recaptureexperiments, 2) to assess implications arising from monitoringindividual species vs. the whole fish community, and 3) toascertain whether, in fisheries assessments (science) a commonlyused surrogate measure, [catch-per-unit-effort (CPUE)] reflectedannual changes in the fish assemblage, and thus may be a goodestimator of abundance. High, long-term variability was evident in the abundance andbiomass of a fish species in our lakes, yet the communityremained relatively stable in terms of its biomass andproduction. Changes in total fish community biomass appear drivenby large species, which, relative to small fish species, remainstable among years. Among years, species richness remainedstable; however, fish species changed in the community. AnnualCPUE was found to be a suitable surrogate for abundance (N) ofsmall fishes; CPUE x mean weight of the catch (bCPUE) was asuitable surrogate for biomass (B) of large fishes. Prior toconcluding that a change in a fish population has occurred as aresult of a stressor, care must be taken to critically examinethe level of population assessment in order to avoid acceptingpotentially invalid conclusions.     

苎麻麻骨水溶物的溶出影响因素及其组成

为探讨生物质材料吸附重金属过程中溶出物的溶出规律及成分,以苎麻麻骨为材料,在实验室模拟其吸附Cd2+废水条件下,考察溶出时间、温度、pH、苎麻麻骨粒径及ρ(Cd2+)对苎麻麻骨水溶物DOC溶出量的影响,通过气相色谱-质谱法对溶出物成分进行鉴定,并利用扫描电子显微镜(SEM)、红外光谱(FTIR)、热重分析(TGA)等技术对溶出物溶出前后苎麻麻骨表面物化性质进行了表征. 结果表明:在弱酸性(pH为5)条件下,苎麻麻骨DOC溶出量高于65.90 mg/L. 各因素对DOC溶出量的影响程度不同,以粒径及温度的影响最大,随着粒径由1 mm增至20 mm,DOC溶出量由78.37 mg/L迅速降至60.14 mg/L,降低了18.23 mg/L;升温可促进苎麻麻骨DOC溶出量的增加,随着温度由5 ℃升至55 ℃,DOC溶出量增加了13.63 mg/L. 提取液pH、溶出时间、ρ(Cd2+)对DOC溶出量的增加量分别为5.08、4.60、3.11 mg/L. 溶出物溶出前后苎麻麻骨表面无显著变化,但溶出后的苎麻麻骨表面易溶于水的官能团数量显著减少. 溶出物中鉴定出9类物质(共19种化合物),以酮类和酯类居多,表明苎麻麻骨表面不带电.      

Influence of phenol on ammonia removal in an intermittent aeration bioreactor treating biologically pretreated coal gasification wastewater

A laboratory-scale intermittent aeration bioreactor was investigated to treat biologically pretreated coal gasification wastewater that was mainly composed of NH_3-N and phenol.The results showed that increasing phenol loading had an adverse effect on NH_3-N removal;the concentration in effluent at phenol loading of 40 mg phenol/(L·day) was 7.3 mg/L, 36.3%of that at 200 mg phenol/(L·day). The enzyme ammonia monooxygenase showed more sensitivity than hydroxylamine oxidoreductase to the inhibitory effect of phenol, with32.2% and 10.5% activity inhibition, respectively at 200 mg phenol/(L·day). Owing to intermittent aeration conditions, nitritation-type nitrification and simultaneous nitrification and denitrification(SND) were observed, giving a maximum SND efficiency of 30.5%.Additionally, ammonia oxidizing bacteria(AOB) and denitrifying bacteria were the main group identified by fluorescent in situ hybridization. However, their relative abundance represented opposite variations as phenol loading increased, ranging from 30.1% to 17.5%and 7.6% to 18.2% for AOB and denitrifying bacteria, respectively.     

生物质废物热解过程中气相产物的生成及等离子体重整研究

针对松木屑的热解以及产物的等离子体重整进行研究。热解温度分别为400,500,600,700,800℃时,在加热30 min的条件下,主要气体产物是H2、CO、CH4和CO2,热解气的总生成量的摩尔分数由46.11%(400℃)增至80.12%(800℃)。介质阻挡放电等离子体重整结果显示,随着放电功率的增加,CH4和CO2的转化率以及H2/CO的摩尔比都呈现增长趋势,控制等离子体重整条件有助于获得高品位能源。     

生物质活性炭辅助微波处理氨氮废水研究

以花生壳为原料,分别使用程序控温法和微波法制备生物质活性炭.采用高分辨电子扫描电镜(SEM)和氮吸脱附曲线对花生壳活性炭进行了表征.结果表明,微波法制备的花生壳活性炭比表面积大于程序控温法制备的花生壳活性炭比表面积,且微波法制备活性炭成本远低于程序控温法.将制得的两种活性炭和商用活性炭分别辅助微波处理氨氮废水,确定了生物质活性炭辅助微波处理氨氮废水的最佳条件.初步讨论了活性炭辅助微波处理氨氮废水的机理.     

Forest-based biomass supply potential and economics for the pellet production in Nepal

In the current study, the potential of forest-based biomass supply for the pellet production in Nepal is investigated. This study showed that about 2.76 million tonnes (Mt) biomass in the form of pellets are potentially available from forest-based biomass. Considering a processing capacity of 6 tonnes (t)/hr of a pellet plant, the production cost of the pellets was calculated to be $43.53/t. Pellets are generally used as fuel to produce thermal energy in industries, which helps to save the economy and the environment of the country.     

甘肃河西荒漠能源植物资源利用与产业化研究

从生物质能源开发利用意义开始,对河西地区的自然资源现状做了调查及分析,并对河西地区实施荒漠能源产业进行研究。分析了河西地区的自然环境特征、区域现状和人类不合理活动等多种因素作用下,自然资源出现的一系列问题;针对各类生态系统中存在的问题,提出了科学、合理的发展荒漠能源产业的对策建议。     

生物质气化技术及其在西部地区的应用浅析

生物质气化技术作为环保、高效地利用生物质资源的重要方式,正受到广泛关注。文章围绕生物质气化的原理、气化炉的分类和特点展开论述;分析了影响生物质气化过程的若干关键因素,并综述了生物质气化技术在国内外的研究与应用现状;最后结合西部地区实际生物质资源状况,展望了生物质气化技术在西部地区的应用前景。     

我国生物质废物污染现状与资源化发展趋势

我国的生物质废物具有产生量大、可降解有机物含量高的特点,如果能对其进行有效的利用,不但能减少污染,还将会有助于缓解我国能源短缺的现状。介绍了我国生物质废物的污染现状及生物质废物资源化的主要途径,指出我国生物质废物资源化中存在的问题,并提出今后的发展方向及发展对策。     

生物质转化能源技术的发展现状及趋势探讨

能源短缺问题已成为制约经济社会发展的瓶颈,研究开发新的能源代替传统不可再生能源成为急需要解决的焦点问题。生物质能是由植物的光合作用固定于地球上的太阳能,通过生物质能转换技术可以高效地利用生物质能源,生产各种清洁燃料,替代煤炭、石油和天然气等燃料。对近些年生物质能源技术的发展现状进行了简要讨论,指出了生物质能的利用具有广阔的发展前景,在不久的将来,生物质能源必将成为能源结构中重要一部分,实现能源结构良好可持续发展。