Adsorption of Cr(Ⅲ) from acidic solutions by crop straw derived biochars

Cr（Ⅲ） adsorption by biochars generated from peanut, soybean, canola and rice straws is investigated with batch methods. Adsorption of Cr（Ⅲ） increased as pH rose from 2.5 to 5.0. Adsorption of Cr（Ⅲ） led to peak position shifts in the FFIR-PAS spectra of the biochars and made zeta potential values less negative, suggesting the formation of surface complexes between Cr^3＋ and functional groups on the biochars. The adsorption capacity of Cr（Ⅲ） followed the order： peanut straw char 〉 soybean straw char 〉 canola straw char 〉 rice straw char, which was consistent with the content of acidic functional groups on the biochars. The increase in Cr^3＋ hydrolysis as the pH rose was one of the main reasons for the increased adsorption of Cr（Ⅲ） by the biochars at higher pH values. Cr（llI） can be adsorbed by the biochars through electrostatic attraction between negative surfaces and Cr^3＋, but the relative contribution of electrostatic adsorption was less than 5%. Therefore, Cr（Ⅲ） was mainly adsorbed by the biochars through specific adsorption. The Langumir and Freundlich equations fitted the adsorption isotherms well and can therefore be used to describe the adsorption behavior of Cr（Ⅲ） by the crop straw biochars. The crop straw biochars have great adsorption capacities for Cr（Ⅲ） under acidic conditions and can be used as adsorbents to remove Cr（Ⅲ） from acidic wastewaters.     

马超营断裂带及其北侧熊耳群火山岩的变质作用

本文论述了熊耳山南坡的马超营断裂带及其北侧熊耳群火山岩的区域变质作用、动力变质作用和热液变质作用的特点.火山岩的变质作用及其强度在空间分布上表现出不均匀性,一般在断裂带内发育且强度大,断裂带北侧变质程度低、强度小;马超营断裂带对区内熊耳群火山岩的变质作用特征起着一定程度的控制作用;变质作用具有多次叠加、改造的特征,一般区域变质作用较早较普遍,动力变质和热液变质作用偏晚和较局限,每次大的构造运动都伴随着后两者的发生.     

大连市居民头发典型重金属富集特征研究

测定了大连市居民102份头发样品中Pb、Cd、Hg、As等重金属含量,评估了其暴露风险,并对头发中重金属的含量与年龄、性别的关系进行了分析.结果表明,大连市居民头发中Pb、Cd、Hg、As含量均低于中国居民头发中重金属的建议正常值上限,4种重金属暴露风险较低.男性头发中Cd、Pb和As的平均含量明显高于女性(p0.05),其中As平均含量差异达到极显著水平(p0.01).PCA分析显示样本分布集中在第一排序轴和第二排序轴中间,表明性别并不是影响头发中重金属含量的主要因素.19～35岁年龄组居民头发中Cd和Pb含量最高,且均与56～75岁年龄组呈现显著差异(p0.05);As和Hg在56～75岁年龄组居民头发中含量最高,与其它组比较均达到了显著水平(p0.05).PCA和Pearson分析表明4种重金属间相关性较好,大连市居民对4种重金属暴露途径基本相同.     

How farmers develop local ecological knowledge for on-farm tree management: The perspectives of some farming communities of Ghana

Scientific insights into what it means to manage on-farm trees by local farmers, is an essential step towards documenting local ecological knowledge for sustainable landscape management. A study was therefore conducted in the Kumawu Forest District in the Ashanti Region of Ghana to assess how farmers conceptualise on-farm tree management and develop local knowledge for it. Using a case study approach, data were collected through informal interviews and focus group discussions with 120 farmers drawn from 15 communities who were involved in the management of three cropping systems; cocoa, maize and cassava-cocoyam-plantain mix. It was observed that the farmers regard on-farm tree management as a continuous process which occurs in three phases of the farming cycle; land preparation, crop cultivation and fallow management. For each of the three phases, farmers are guided by specific principles that ensure enough light penetration in-between tree crowns in the land preparation phase, suitable spacing between trees and crops in the crop cultivation phase and adequate tree regeneration in the fallow phase. The decisions made during the selection of tree species, spacing of trees adjudged suitable for any particular cropping system and recruitment of saplings prior to the fallow phase of farming constitute tree management. Farmers develop tree management knowledge by studying the physical characteristics of species, matching them to ecological functions they could perform and how they are likely to respond to treatments meant to control or enhance their development. Species are then subjected to trial and recommended or otherwise.     

Systematic Temporal Patterns in the Relationship Between Housing Development and Forest Bird Biodiversity

As people encroach increasingly on natural areas, one question is how this affects avian biodiversity. The answer to this is partly scale‐dependent. At broad scales, human populations and biodiversity concentrate in the same areas and are positively associated, but at local scales people and biodiversity are negatively associated with biodiversity. We investigated whether there is also a systematic temporal trend in the relationship between bird biodiversity and housing development. We used linear regression to examine associations between forest bird species richness and housing growth in the conterminous United States over 30 years. Our data sources were the North American Breeding Bird Survey and the 2000 decennial U.S. Census. In the 9 largest forested ecoregions, housing density increased continually over time. Across the conterminous United States, the association between bird species richness and housing density was positive for virtually all guilds except ground nesting birds. We found a systematic trajectory of declining bird species richness as housing increased through time. In more recently developed ecoregions, where housing density was still low, the association with bird species richness was neutral or positive. In ecoregions that were developed earlier and where housing density was highest, the association of housing density with bird species richness for most guilds was negative and grew stronger with advancing decades. We propose that in general the relationship between human settlement and biodiversity over time unfolds as a 2‐phase process. The first phase is apparently innocuous; associations are positive due to coincidence of low‐density housing with high biodiversity. The second phase is highly detrimental to biodiversity, and increases in housing density are associated with biodiversity losses. The long‐term effect on biodiversity depends on the final housing density. This general pattern can help unify our understanding of the relationship of human encroachment and biodiversity response. Patrones Sistemáticos Temporales en la Relación entre Desarrollos Urbanos y la Biodiversidad de Aves de Bosque     

长江口-浙闽沿岸沉积色素的分布特征及其指示意义

利用高效液相色谱法分析了长江口-浙闽沿岸表层沉积物中的色素组成和含量,探讨了海洋初级生产力、浮游植物功能类群和浮游植物色素保存效率的空间分布特征及其影响因素.结果表明,沉积物中的色素类型主要为沉积绿素(chloropigments,Chlorins)[包括叶绿素a(chlorophyll-a,Chl-a)及其降解产物(pheopigments,Pheo-a),如脱镁叶绿素a(pheophytin-a,PHtin-a)、脱镁叶绿酸a(pheophorbide-a,PHide-a)、焦脱镁叶绿素a(p Pheophytin-a,p PHtin-a)、甾醇绿素酯(sterol chlorin esters,SCEs)和胡萝卜醇绿素酯(carotenol chlorin esters,CCEs)].Chlorins高值区呈南北两大斑块状分布,可能主要是受到长江冲淡水及浙闽沿岸泥质区上升流输运的营养盐的影响.研究区域内类胡萝卜素整体上无明显趋势性变化,在长江口以及浙闽沿岸各呈现一个高值区.基于沉积物中特征类胡萝卜素比例估算得到的浮游植物功能类群中硅藻、甲藻、定鞭藻、青绿藻、隐藻和蓝藻的相对贡献分别为48.8%±17.4%、10.7%±11.5%、8.1%±7.2%、18.6%±8.2%、9.4%±6.4%和4.3%±3.2%.对营养盐水平、水体盐度等外界环境的偏好导致硅藻和甲藻比例离岸降低,青绿藻、隐藻和蓝藻比例离岸增加.Chl-a/Pheo-a比值的分布表明,较高的沉积速率以及季节性的底层水体缺氧事件导致了近岸海域(长江口最大浑浊带外缘、杭州湾湾口以及浙闽沿岸上升流区)具有较高的沉积色素保存效率,这些沉积色素保存效率较高的区域可能是进行海洋生态环境历史重建的理想区域,而杭州湾水体通过舟山群岛与外部海水进行水体交换时造成的较差沉积环境可能是导致杭州湾外海具有较低沉积色素含量和较低保存效率的主要原因.     

添加动物源氨基酸水解液研制生物有机肥

为改善生物有机肥性质,提高生物有机肥质量,采取在生物有机肥中添加外源氨基酸水解液以提升生物有机肥中功能微生物的数量.以病死猪酸解制得氨基酸水解液为生物有机肥外加原料,研究了氨基酸水解液添加量、有机肥种类（鸡粪、牛粪、中药渣）、发酵时间对功能菌株SQR9数量的影响.结果表明:当氨基酸水解液添加量为20%时固体发酵效果优于其他接种量,预发酵3 d后接种SQR9的功能菌数量明显高于未预发酵直接接菌,预发酵中肥料（以干质量计,下同）的最高功能菌数量可达4×108 CFU/g,而第0天接菌时肥料的最高功能菌数量仅为1.2×108 CFU/g.以腐熟鸡粪、牛粪、中药渣堆肥为载体,添加酸解氨基酸研制生物有机肥的最优接菌量分别为10.0%、7.5%、10.0%;SQR9菌株生长的最佳含水量为40%.此外,氨基酸水解液的添加可提高生物有机肥的w（TN）.研究显示,氨基酸水解液的添加能有效促进固态发酵过程中功能菌株数量的增加.      

原始红松林退化演替后土壤微生物功能多样性的变化

为了全面了解原始红松林退化演替为次生林后土壤生境及土壤微生物功能多样性的变化规律,以小兴安岭典型的原始阔叶红松林、退化演替后先锋阶段的白桦林及亚顶级阶段的硬阔叶林为研究对象,采用Biolog-ECO微平板检测法,分析三者0~ < 10 cm和10~20 cm表层土的土壤微生物功能多样性变化规律.结果表明:各林型土壤微生物的AWCD值（平均颜色变化率）随培养时间的延长而增加,培养初期表现为原始阔叶红松林>硬阔叶林>白桦林;培养末期表现为原始阔叶红松林>白桦林>硬阔叶林,三者的AWCD值在0~ < 10 cm土层分别为1.06、0.86、0.81,10~20 cm土层分别为0.68、0.47、0.45,原始林显著高于次生林（P < 0.05）,说明原始林土壤微生物对单一碳源的代谢活性显著高于次生林;同一林型下土壤微生物的AWCD值均表现为0~ < 10 cm土层显著高于10~20 cm土层（P < 0.05）. Shannon-Wiener多样性指数、Simpson指数、McIntosh指数和Richness丰富度指数也均表现为原始林显著高于次生林（P < 0.05）.原始林土壤微生物对各类碳源的综合利用强度均大于次生林,不同林型下土壤微生物群落的优势碳源类型存在一定的差异,碳水类、氨基酸类、羧酸类和多聚物类碳源是原始林退化演替后土壤微生物群落在碳源利用上发生变化的敏感碳源.      

针织服装功能性面料环保改进处理研究

为使服装产业推进绿色环保,实现可持续发展战略,需要对针织服装功能性面料环保方面进行改进处理.通过调查针织服装类别、功能性面料产业分布情况及面料应用范围,分析针织服装功能性面料对环境的影响.依据针织服装功能性面料环保标准,提出功能性面料环保改进处理方向,结合面料实际应用需求,采用绿色环保纤维对当前针织服装功能性面料的环保问题进行改进处理,并对改进过程中的难点进行分析,引进天丝和莫代尔实现针织服装功能性面料环保方面的改进.     

石油污染土壤生物修复过程中氮循环功能基因的动态检测

氮循环相关功能微生物在土壤发挥其生态功能中起着重要的作用.为定量分析其中的固氮细菌、反硝化细菌和硝化细菌在石油污染土壤生物修复过程中的演变情况,采用了实时定量PCR技术对其相关功能基因nifH、narG和amoA的拷贝数进行检测.结果表明,污染土壤中nifH、narG和amoA基因拷贝数及其占总16S rRNA基因拷贝数的比例远低于正常土壤,修复后土壤中的同类分析结果与正常土壤接近.表明石油污染物破坏了氮循环相关菌落结构,而生物修复则使其得以恢复.进一步分析了不同修复方式下氮循环功能基因的恢复情况以及土壤中石油烃降解率.也表明同时添加秸秆和菌剂具有最好的修复效果,处理40 d后其nifH、narG和amoA基因拷贝数（以干土计）分别恢复到2.68×106、1.71×106和8.54×104g-1,石油烃降解率达到48%.投加真菌-细菌复合菌剂的效果优于只投加细菌菌剂的效果.本研究结果表明氮循环功能基因的动态监测可以从基因和物种水平上反映土壤修复的效果,为土壤修复的监控和效果评估提供参考.