加拿大危险废物进出口管理

加拿大是较早参与签订危险废物越境转移国际公约的国家之一,到现在已经形成了较为完善的法律管理体系。加拿大的市、省、联邦三级政府都要对废物管理负责,并在管理当中起到不同的作用。加拿大于1992年就制定出台了《危险废物进出口管理规定》,并于2005年修订为《危险废物和危险性可再生利用材料进出口管理规定》。以2005年修订后的文本为基础,概述了该规定的目标、框架、一般规定和主管部门等,并对规定中的通知、合同、保险部分等进行了详细介绍。最后总结了值得中国借鉴和学习的特点等。     

北京市低影响开发设施植物应用现状与评价优化

植物是多种雨水源头减排设施基本的构成要素,其生长情况与应用效果很大程度上影响着海绵城市的功能和效果。以北京市21个海绵城市项目中72个低影响开发（LID）设施的植物景观作为研究对象展开建成后评估。通过实地调查法,对LID设施内植物的应用种类与频度、配置模式、观赏特性等方面进行分析;采用层次分析法从植物生态习性、雨水功能性与观赏性3个方面构建LID设施植物景观评价体系,并对10组典型设施的植物群落综合效益进行评价。结合评价分析结果,提出综合效益高的植物配置模式及优化思路,以期为北京市和中国北方地区LID设施的植物景观优化提供参考。     

氨氮浓度对MBBR工艺中微生物群落结构的影响

采用移动床生物膜反应器（moving bed biofilm reactor,MBBR）处理模拟废水,考察进水氨氮浓度（20,30,50,100,200 mg/L）对MBBR工艺处理效果的影响,并利用16S rDNA高通量测序技术,分析微生物群落结构变化。结果表明:氨氮浓度为30~100 mg/L时,氨氮浓度越小,越有利于氨氮的去除,对COD去除率影响较小。氨氮浓度为20,50,200 mg/L时,Ottowia为第1优势菌属,相对丰度分别为66.76%、34.40%、53.88%,而氨氮浓度为30,100 mg/L时,Ottowia优势地位被Arcobacter、Hydrogenophaga等取代,说明微生物群落结构发生波动性变化可能与各类起反硝化作用的菌属和Ottowia菌属争夺优势地位有关。与自养型硝化作用有关的菌属相对丰度稳定在0.3%左右,相对丰度受氨氮浓度影响不大,高浓度氨氮对硝化菌属产生的抑制作用,可能是对其微生物活性的抑制。通过研究发现,进水氨氮浓度对MBBR生物膜中的微生物群落结构有一定的影响。     

链长和官能团对全氟有机酸降解路径的影响

考察了碳链长度和官能团对高强UV/SO₃^2-体系降解全氟有机酸的影响,选取典型全氟有机酸PFOA和PFOS,探明其降解机制.结果表明,高强UV/SO₃^2-体系可高效降解5种全氟有机酸.全氟有机酸的降解速率随着碳链长度的增加而增加.官能团对全氟有机酸的降解有重要影响,全氟羧酸在体系中的降解速率显著快于全氟磺酸.全氟羧酸是从与羧基相连的α碳上的氟原子开始,通过逐步脱CF₂单元的形式生成短链全氟羧酸进行降解.全氟磺酸主要有三条降解路径：脱磺酸基、α位脱氟以及中心C—C键断裂.     

Characterization of Fe5(AsO3)3Cl2(OH)4·5H2O, a new ferric arsenite hydroxychloride precipitated from FeCl3–As2O3–HCl solutions relevant to arsenic immobilization

Tooeleite(Fe6(As03)4 SO4(OH)4·4 H_2 O) is widely precipitated for direct As(III) removal from sulfate-rich industrial effluents.However,whether or not Fe(III)-As(III)-Cl(-I) precipitate is produced in chloridizing leaching media for As immobilization is almost unknown.This work founded the existence of ferric arsenite(hydroxy)chloride as a new mineral for As(III)removal.Its chemical composition and solid characterization were subsequently studied by using scanning electron microscope with an energy dispersive spectrometer(SEM-EDS),X-ray diffraction(XRD),infrared(FT-IR),Raman spectroscopy and thermogravimetric(TG)curve.The results showed the formation of a yellow precipitate after 3-days reaction of Fe(III)/As(III) with molar ratio≈1.7 in chloride solution at pH 2.3 neutralized with NaOH.Compared with tooeleite,chemical analysis and solid characterization indicated that Cl(-I)replaces S04(-II) producing ferric arsenite hydroxychloride with formula Fe5(As03)_3-Cl_2(OH)4·5 H_2 O.This new plate shaped solid showed better crytallinity than tooeleite,although it has similar morphology and characteristic bands to tooeleite.The FT-IR bands at 628,964 cm-1 and the Raman bands at 448,610,961 cm-1 were assigned to Fe-O or As(Ⅲ)-O-Fe or As(Ⅲ)-O bending/stretching vibration,indicating that both arsenite and chloride substituted for the position of sulfate for ferric arsenite hydro xychloride produced due to the lack of the SO_4~(2-) vibrations.Cl-(I) also contributed to increase As removal efficiency in aqueous sulfate media under acidic pH conditions via the probable formation of sulfatechloride ferric arsenite.     

信息化助力成都市大气污染防治闭环管理

从大气环境质量问题出发,基于"现状、科研、对策、执行、评估"五步业务闭环管理工作法,建设成都市数智环境系统—大气大数据应用。在对数据量化分析、科学预测的基础上提出改善环境质量目标和量化措施,同时落实监管责任,实现市县乡三级调度和精细化网格监管全覆盖,变被动善后为主动预防,从而实现科技治霾和精准管控,切实决策大气环境质量问题。     

温度对沉水植物腐解释放DOM及微生物群落多样性的影响

在5,10,20,35℃下研究了黑藻和马来眼子菜腐解过程中DOM的特性、细菌和真菌群落结构多样性的变化.结果表明,腐解结束时5,10,20,35℃下黑藻的干物质剩余量分别为初始干物质质量的59.13%、43.91%、32.61%和29.57%,马来眼子菜的干物质剩余量分别为初始干物质质量的69.13%、51.3%、30.87%和29.57%.升高温度一定程度上促进了植物有机碳和全氮释放,对全磷无明显影响（P>0.05）.采用平行因子分析法得到黑藻中含有2种类腐殖酸组分C1、C2和1种类蛋白质组分C3,马来眼子菜中含有3种类腐殖酸组分C1、C2和C3.温度升高使得腐解水体中DO和电导率的变化程度加剧,总体上4种温度下2种植物腐解水体中DO均呈现先下降后上升的趋势.通过高通量测序得到腐解前期（0~16d）参与黑藻和马来眼子菜腐解的主要细菌分别为变形菌门（Proteobacteria）和拟杆菌门（Bacteroidetes）;腐解中后期（16~68d）参与黑藻和马来眼子菜腐解的细菌分别以厚壁菌门（Phylum Firmicutes）和变形菌门（Proteobacteria）为主,温度对细菌群落结构无明显影响,而参与2种植物腐解的真菌均以子囊菌（Ascomycetes）最为活跃.     

Water regime-nitrogen fertilizer incorporation interaction: Field study on methane and nitrous oxide emissions from a rice agroecosystem in Harbin, China

Water regime and nitrogen (N) fertilizer are two important factors impacting greenhouse gases (GHG) emission from paddy field, whereas their effects have not been well studied in cold region. In this study, we conducted a two-year field experiment to study the impacts of water regime and N fertilizer on rice yields and GHG emissions in Harbin, China, a cold region located in high latitudes. Our results showed that intermittent irrigation significantly decreased methane (CH₄) emission compared with continuous flooding, however, the decrement was far lower than the global average level. The N₂O emissions were very small when flooded but peaked at the beginning of the disappearance of floodwater. The N fertilizer treatments increased CH₄ emissions at low level (75kgN/ha). But both CH₄ and N₂O emissions were uninfluenced at the levels of 150kgN/ha and 225kgN/ha. Rice yields increased under intermittent irrigation and were highest at the level of 150kgN/ha. From our results, we recommended that the intermittent irrigation and 150kgN/ha as the ideal water regime-nitrogen fertilizer incorporation for this area to achieve low GHG emissions without impacting rice yields.     

Effect of drainage on CO2, CH4, and N2O fluxes from aquaculture ponds during winter in a subtropical estuary of China

Aquaculture ponds are dominant features of the landscape in the coastal zone of China.Generally,aquaculture ponds are drained during the non-culture period in winter.However,the effects of such drainage on the production and flux of greenhouse gases(GHGs)from aquaculture ponds are largely unknown.In the present study,field-based research was performed to compare the GHG fluxes between one drained pond(DP,with a water depth of 0.05 m)and one undrained pond(UDP,with a water depth of 1.16 m)during one winter in the Min River estuary of southeast China.Over the entire study period,the mean CO_2flux in the DP was(0.75±0.12)mmol/(m~2·hr),which was significantly higher than that in the UDP of(-0.49±0.09)mmol/(m~2·hr)(p0.01).This indicates that drainage drastically transforms aquaculture ponds from a net sink to a net source of CO_2in winter.Mean CH_4and N_2O emissions were significantly higher in the DP compared to those in the UDP(CH_4=(0.66±0.31)vs.(0.07±0.06)mmol/(m~2·hr)and N_2O=(19.54±2.08)vs.(0.01±0.04)μmol/(m~2·hr))(p0.01),suggesting that drainage would also significantly enhance CH_4and N_2O emissions.Changes in environmental variables(including sediment temperature,p H,salinity,redox status,and water depth)contributed significantly to the enhanced GHG emissions following pond drainage.Furthermore,analysis of the sustained-flux global warming and cooling potentials indicated that the combined global warming potentials of the GHG fluxes were significantly higher in the DP than in the UDP(p0.01),with values of739.18 and 26.46 mg CO_2-eq/(m~2·hr),respectively.Our findings suggested that drainage of aquaculture ponds can increase the emissions of potent GHGs from the coastal zone of China to the atmosphere during winter,further aggravating the problem of global warming.     

生态文明建设融入高校思政课教学的实践分析研究

针对融入高校思政课的生态文明建设教育现状进行调查。调查结果显示,高校学生缺少生态文明建设的全方位认知,情感缺位与知行脱节较为严重。造成高校学生生态文明建设教育出现问题的原因包括:缺少对生态文明建设的认知与认同感、高校对生态文明建设教育的重视程度不高以及社会不良生态文明行为严重制约了生态文明教育的开展;试图从营造良好的校园生态文明氛围、强化生态文明建设知识的挖掘深度、因地制宜地编写生态文明建设思政课教材、加强高校学生生态实践能力、把握新媒体带来的机遇等方面开拓出一条崭新的生态文明建设实践道路,为早日实现"美丽中国"的生态文明建设目标奠定基础。