海洋巨藻(Durvilaea potatorum)生物吸附剂对Hg~(2 )的吸附动力学研究

对经特殊的稳定化预处理所得的海洋巨藻 (Durvillaeapotatorum)生物吸附剂对Hg2 的吸附动力学进行了研究 ,报导了不同Hg2 初始浓度、温度以及生物吸附剂平均粒径下动态吸附量与时间的关系 .结果显示 ,各吸附动力学曲线呈优惠型 ;当生物吸附剂平均粒径为 0 .45mm时 ,Hg2 的半饱和时间tS均不超过 6 0min ;Hg2 初始浓度和生物吸附剂粒径越小 ,吸附温度越大 ,达到吸附平衡所需的时间越短 .在测试范围内 ,生物吸附剂的平衡吸附容量与粒径和温度无关 .同时考察了吸附过程中的传质效应并对液膜传质系数kL进行了关联 ,结果表明 :当吸附时间t≤tS时 ,Hg2 的吸附速率为液膜传质控制 ;在测试范围内 ,kL为 0 .0 40 7～ 0 .112cm/s.本研究结果为利用海洋巨藻 (Durvillaeapotatorum)生物吸附剂处理含汞废水的规模化应用提供了一定的依据 .图 5表 2参 11     

Processing and Properties of Mixtures of PHB-V with Post-consumer LDPE

Mixtures of poly-β-(hydroxybutyrate-co-valerate) PHB-V with virgin and post-consumer low density polyethylene (LDPE) were prepared by melt mixing in proportions of 100/0, 90/10, 80/20, 70/30 and 0/100 (wt/wt%). The mixtures were analysed by infrared spectroscopy, differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), melting flow index (MFI), tensile tests, scanning electron microscopy (SEM) and biodegradation in simulated soil. The DMTA and DSC curves of post-consumer LDPE suggested that this polymer was a mixture of LDPE and linear low density polyethylene (LLDPE). Virgin and post-consumer LDPE had lower MFI than PHB-V, but the blends showed higher index as the content of LDPE increased. The addition of LDPE reduced the tensile strength and Young’s modulus of the mixtures compared with PHB-V. SEM indicated poor interfacial adhesion between PHB-V and LDPE. PHB-V degraded slow and gradually, while both LDPE showed virtually no degradation under the conditions studied. The biodegradability of the blends depended on their composition and of the type of LDPE. LDPE improved the biodegradability of the mixtures.     

规划环评中景观非生态功能影响评价实例

以景观概念作为融合自然与社会、科学与美学、理性与感性的结合点,研究了景观非生态功能的内涵及其评价技术理论框架,从景观功能中提炼出景观非生态功能概念,初步完成景观非生态功能评价指标体系的构建.评价技术体系设计突出环境影响评价中现状评价的客观性以及影响预测的科学性.以人感尺度下的评价对象——景观单元概念为创新点,该评价体系补充并完善了现有景观评价体系的技术链条,在保证评价精度的前提下,简化并规范了评价工作流程.该评价体系沿用现有环境影响评价所广泛采用的现状评价、影响源分析、影响预测评价及措施建议的技术思路,基本能满足现行技术规范的要求.以武汉市后官湖生态宜居新城规划环评为例,验证了该体系的可操作性,为我国规划环评在景观评价技术领域的发展提供理论和实践参考.      

ARCGIS‐SWAT: A GEODATA MODEL AND GIS INTERFACE FOR SWAT1

This paper presents ArcGIS‐SWAT, a geodata model and geographic information system (GIS) interface for the Soil and Water Assessment Tool (SWAT). The ArcGIS‐SWAT data model is a system of geodatabases that store SWAT geographic, numeric, and text input data and results in an organized fashion. Thus, it is proposed that a single and comprehensive geodatabase be used as the repository of a SWAT simulation. The ArcGIS‐SWAT interface uses programming objects that conform to the Component Object Model (COM) design standard, which facilitate the use of functionality of other Windows‐based applications within ArcGIS‐SWAT. In particular, the use of MS Excel and MATLAB functionality for data analysis and visualization of results is demonstrated. Likewise, it is proposed to conduct hydrologic model integration through the sharing of information with a not‐model‐specific hub data model where information common to different models can be stored and from which it can be retrieved. As an example, it is demonstrated how the Hydrologic Modeling System (HMS) ‐ a computer application for flood analysis ‐ can use information originally developed by ArcGIS‐SWAT for SWAT. The application of ArcGIS‐SWAT to the Seco Creek watershed in Texas is presented.     

Soil erosion vulnerability under scenarios of climate land-use changes after the development of a large reservoir in a semi-arid area

Climate and land-use/cover changes (LUCC) influence soil erosion vulnerability in the semi-arid region of Alqueva, threatening the reservoir storage capacity and sustainability of the landscape. Considering the effect of these changes in the future, the purpose of this study was to investigate soil erosion scenarios using the Revised Universal Soil Loss Equation (RUSLE) model. A multi-agent system combining Markov cellular automata with multi-criteria evaluation was used to investigate LUCC scenarios according to delineated regional strategies. Forecasting scenarios indicated that the intensive agricultural area as well as the sparse and xerophytic vegetation and rainfall-runoff erosivity would increase, consequently causing the soil erosion to rise from 1.78 Mg ha^?1 to 3.65 Mg ha^?1 by 2100. A backcasting scenario was investigated by considering the application of soil conservation practices that would decrease the soil erosion considerably to an average of 2.27 Mg ha^?1. A decision support system can assist stakeholders in defining restrictive practices and developing conservation plans, contributing to control the reservoir's siltation.     

全氟和多氟烷基化合物的环境风险评估研究现状、不确定性与趋势分析

本研究系统梳理了国际学术界关于全氟和多氟烷基化合物(perfluoroalkyl and polyfluoroalkyl substances,PFASs)的术语、范畴和应用物质的界定与变迁,以PFASs的环境危害性评估和暴露评估为重心,综述评析当前关于PFASs环境风险评估研究现状、不确定性和发展趋势.总体上,PFASs风险评估正面临着物质谱系复杂、种类众多、衍生关系复杂、商业秘密及风险不确定的复杂局面.尽管长链PFASs的环境风险已获广泛认可,但以其替代品形式大量涌现的短链PFASs及各类短链氟调聚物的环境危害性、环境行为和暴露风险则尚存很多的不确定性与研究空白,国际社会对于PFASs的风险控制范畴值得商榷.PFASs替代物质的结构和风险信息因商业秘密及市场竞争因素而缺乏公开性和透明度,多数含氟和非氟替代品的环境风险尚有待识别.总之,国际上对PFASs风险评估研究呈现出由以全氟辛烷磺酸类化合物(perfluorooctane sulfonic acid,PFOS)和全氟辛酸类化合物(perfluorooctanoic acid,PFOA)等为代表的长链全氟烷基酸(perfluoroalkyl acids,PFAAs)逐步扩展到短链PFAAs,再扩展到其他非PFAAs的PFASs物种的发展趋势.当前亟待解决及未来将持续研究关注的主要问题:关于短链PFASs的生物累积性和环境迁移性等关键环境危害性的评估指标和方法的优化,以及其环境释放和多介质环境归趋;中性PFASs的环境归趋及其作为短链PFAAs潜在前体物质的转化与贡献;未来PFASs含氟或非氟替代品的风险识别和评估.     

湖北省主要固定燃烧源大气颗粒物及VOCs排放特征研究

于2014年1月至12月对湖北省9个城市21家典型企业的固定燃烧源进行了典型大气颗粒物及挥发性有机物(VOCs)的监测工作,研究了固定燃烧源大气颗粒物及VOCs的排放特征及其物质组成。结果表明:大气颗粒物年排放总量与装机容量呈正相关关系,颗粒物粒径越细占总颗粒物的质量百分比越低;不同燃料的锅炉废气中的PM10和PM2.5质量浓度表现为:石油焦煤生活垃圾,燃气锅炉废气中只检出PM1.0;焦化厂和炼铁厂锅炉废气中的VOCs以烯(炔)烃为主,各占79.21%和81.09%,乙烯占总VOCs的百分比最高,分别为69.13%和68.88%;燃油锅炉废气中的VOCs以烯(炔)烃(91.74%)为主,燃气锅炉废气中的VOCs以烯(炔)烃(37.96%)和醛脂(38.79%)为主;锅炉废气中VOCs的组分和浓度受锅炉使用类型和燃料类型差异的影响,排放废气中的VOCs浓度水平表现为:焦化厂锅炉炼铁厂锅炉,燃油锅炉燃气锅炉,且组分更复杂。     

废旧塑料处置地沉积物中邻苯二甲酸酯污染特征及其生态风险

为了解废旧塑料处置活动对区域水体的影响,采用气相质谱联用仪(GC-MS),对河北省某废旧塑料处置地沉积物中16种PAEs(phthalate esters,邻苯二甲酸酯)的污染特征和生态风险进行了研究. 结果表明:研究样地的w(∑₁₆PAEs)为0.527~102 μg/g, 平均值为18.9 μg/g,其中,DEHP〔邻苯二甲酸(2-乙基己基)酯〕是PAEs最主要的污染单体,平均占w(∑PAEs)的66.6%. 对该处置地的污染物源分析表明,沉积物中PAEs主要来源于废旧塑料回收利用过程中的环境排放. 沉积物中w(DEHP)(14.2 μg/g)和w(DBP)(1.41 μg/g)(DBP为邻苯二甲酸二正丁酯)均超过各自环境风险限值(ERLs),w(DIBP)(DIBP为邻苯二甲酸二异丁酯)超过了美国华盛顿州颁布的沉积物质量警戒限值(0.610 μg/g). 研究显示,沉积物中DBP对鱼类的生态风险及DEHP对藻类和鱼类的生态风险水平不可接受,应引起足够重视.      

在线NaClO反洗对倒置A2O-MBR系统微生物群落的影响

为研究在线NaClO反洗对MBR系统微生物群落结构的影响,采用倒置A2O-MBR反应器分别经历稳定期、在线纯水反洗及在线NaClO反洗阶段,监测系统运行效果、膜污染状况以及微生物群落结构特征.结果表明,在线NaClO反洗阶段反应器对COD、氨氮、TN等的去除效果与反洗前相差无几.在线纯水反洗后平均膜污染速率较稳定期有所降低,而在线NaClO反洗阶段膜污染速率增加,EPS浓度最高,膜污染加剧. Chao指数、Simpson指数和Shannon指数结果表明,在线NaClO反洗后好氧池污泥的微生物多样性几乎不变,而滤饼层污泥的种群丰度略微升高,但微生物的种群多样性明显降低.好氧池和滤饼层污泥的微生物种群主要以变形菌门(Proteobacteria)为主,其次是拟杆菌门(Bacteroidetes).经在线NaClO反洗后,好氧池污泥的变形菌门和拟杆菌门种群相对丰度变化很小,而滤饼层污泥的种群组成变化明显,对氯消毒剂有一定抵抗性的变形菌门从53. 4%增加到77. 8%,而拟杆菌门从33. 4%减少至14. 5%.经在线NaClO反洗后,好氧池和滤饼层在科水平微生物群落分布上十分相似,固氮螺菌科、丛毛单胞菌科等相比NaClO反洗前明显增加,那些能够耐受NaClO处理的微生物种可能是在线NaClO反洗阶段膜污染加剧的主要原因.     

黄河源区鄂陵湖中多环芳烃的百年沉积记录

为研究黄河源区多环芳烃（PAHs）的污染历史,于2016年7月在鄂陵湖中采集了沉积物柱芯,采用²¹⁰Pb定年,利用气相色谱串联三重四级杆质谱仪（GC-MS/MS）分析了16种PAHs,运用有序聚类分析对PAHs的垂向分布进行分带,并采取主成分分析及多元线性回归定量分析了PAHs的来源.结果表明,鄂陵湖沉积柱的沉积速率为0.176cm/a,慢于青藏高原多数湖泊.总PAHs的含量为11.3~54.7ng/g,平均值为29.2ng/g,与其他高原和偏远地区湖泊沉积物相比,处于较低水平,可被视为PAHs的全球沉积物背景值.PAHs的垂向变化分为1948年以前、1948~1976和1976~2016年3个时间段,5~6环PAHs在1948~2016年间呈上升趋势,与青海省人口及大型牲畜数量显著相关,反映了鄂陵湖地区近70a来的人类活动以农牧业为主.PAHs来源分为本地源（23%）以及长距离迁移与本地混合源（77%）.本地源的垂向变化与5~6环PAHs一致,代表了青藏高原地区以牛粪饼为主要燃料的生物质燃烧源.