海洋油气开发工程环评中公众参与探讨

根据我国环境影响评价公众参与现状和海洋油气开发工程公众参与实践,对海洋油气开发工程环评中公众参与进行初步探讨。目前海洋油气开发工程公众参与存在的问题主要有:相关公众界定较难、公众主要是在环评机构主导下的被动参与、信息不对称使公众难以正确表达意见、相关公众中个人的环境素养和法制意识不高。根据存在的问题,建议通过以下方法提高海洋油气开发工程环评公众参与水平:研究制定海洋工程公众参与技术方法规范;掌握好公众参与时机,尽早启动,调动公众主动参与;科学确定公众范围,选择好公众参与对象;结合实际选择公众参与方式。     

锰矿尾渣改性壳聚糖对Pb~(2+)的吸附

将工业废弃物锰矿尾渣与壳聚糖混合制得一种高效吸附剂,并应用扫描电镜、X射线衍射对其结构进行了表征.采用正交表设计试验,分别考察了 pH值、吸附时间、温度、复合吸附剂的投加量等4个影响因素对Pb2+吸附的影响,最伟吸附条件为:pH值为7,吸附时间为40 min,温度为20℃,复合吸附剂的投加量为0.10 g.处理后的水符合国家污水综合排放标准(GB8978-1996)中的一级标准.复合吸附剂时Pb2+的吸附符合Langmuir和Freundlich吸附等温方程.     

Pollution influences on atmospheric composition and chemistry at high northern latitudes: Boreal and California forest fire emissions

We analyze detailed atmospheric gas/aerosol composition data acquired during the 2008 NASA ARCTAS (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites) airborne campaign performed at high northern latitudes in spring (ARCTAS-A) and summer (ARCTAS-B) and in California in summer (ARCTAS-CARB). Biomass burning influences were widespread throughout the ARCTAS campaign. MODIS data from 2000 to 2009 indicated that 2008 had the second largest fire counts over Siberia and a more normal Canadian boreal forest fire season. Near surface arctic air in spring contained strong anthropogenic signatures indicated by high sulfate. In both spring and summer most of the pollution plumes transported to the Arctic region were from Europe and Asia and were present in the mid to upper troposphere and contained a mix of forest fire and urban influences. The gas/aerosol composition of the high latitude troposphere was strongly perturbed at all altitudes in both spring and summer. The reactive nitrogen budget was balanced with PAN as the dominant component. Mean ozone concentrations in the high latitude troposphere were only minimally perturbed (<5 ppb), although many individual pollution plumes sampled in the mid to upper troposphere, and mixed with urban influences, contained elevated ozone (ΔO₃/ΔCO = 0.11 ± 0.09 v/v). Emission and optical characteristics of boreal and California wild fires were quantified and found to be broadly comparable. Greenhouse gas emission estimates derived from ARCTAS-CARB data for the South Coast Air Basin of California show good agreement with state inventories for CO₂ and N₂O but indicate substantially larger emissions of CH₄. Simulations by multiple models of transport and chemistry were found to be broadly consistent with observations with a tendency towards under prediction at high latitudes.     

Response of methane emission to invasion of Spartina alterniflora and exogenous N deposition in the coastal salt marsh

Spartina alterniflora exhibits great invading potential in the coastal marsh ecosystems. Also, nitrogen (N) deposition shows an apparent increase in the east of China. To evaluate CH₄ emissions in the coastal marsh as affected by the invasion of S. alterniflora and N deposition, we measured CH₄ emission from brackish marsh mesocosms vegetated with S. alterniflora and a native plant, Suaeda salsa, and fertilized with exogenous N at the rates of 0 and 2.7 g N m^?2, respectively. Dissolved porewater CH₄ concentration and redox potentials in soils as well as aboveground biomass and stem density of plants were also monitored. The averaged rate of CH₄ emission during the growing season in the S. alterniflora and S. salsa mesocosms without N application was 0.88 and 0.54 mg CH₄ m^?2 h^?1, respectively, suggesting that S. alterniflora plants significantly increased CH₄ emission mainly because of higher plant biomass rather than stem density compared to S. salsa, which delivered more substrates to the soil for methanogenesis. Exogenous N input dramatically stimulated CH₄ emission by 71.7% in the S. alterniflora mesocosm. This increase was attributable to enhancement in biomass and particularly stem density of S. alterniflora driven by N application, which transported greater photosynthesis products than oxygen into soils for CH₄ production and provided more pathways for CH₄ emission. In contrast, there was no significant effect of N fertilization on CH₄ emission in the S. salsa mesocosm. Although N fertilization significantly stimulated CH₄ production by increasing S. salsa biomass, no significant increase in stem density was observed. This fact, along with the low gas transport capacity of S. salsa, failed to efficiently transport CH₄ from wetlands into the atmosphere. Thus we argue that the stimulatory or inhibitory effect of N fertilization on CH₄ emission from wetlands might depend on the gas transport capacity of plants and their relative contribution to substrates for CH₄ production and oxygen for CH₄ oxidation in soil.     

Impact of permanent inundation on methane emissions from a Spartina alterniflora coastal salt marsh

To understand the effect of water level on CH₄ emissions from an invasive Spartina alterniflora coastal brackish marsh, we measured CH₄ emissions from intermittently and permanently (5 cm water depth) inundated mesocosms with or without N fertilizer added at a rate of 2.7 g N m^?2. Dissolved CH₄ concentrations in porewater and vertically-profiled sediment redox potential were measured, as were aboveground biomass and stem density of S. alterniflora. Mean CH₄ fluxes during the growing season in permanently inundated mesocosms without and with N fertilizer were 1.03 and 1.73 mg CH₄ m^?2 h^?1, respectively, which were significantly higher than in the intermittently inundated mesocosms. This response indicates that prolonged submergence of sediment, up to a water depth of 5 cm, stimulated CH₄ release. Inundation did not greatly affect aboveground biomass and stem density, but did significantly reduce redox potential in sediment, which in turn stimulated CH₄ production and increased the CH₄ concentration of porewater, resulting in higher CH₄ emission in the mesocosm. Our data showed that the stimulatory effect of shallow, permanent inundation on CH₄ emission in S. alterniflora marsh sediment was due primarily to an improved methanogenic environment rather than an increase in plant-derived substrates and/or the number of gas emission pathways through the plant’s aerenchymal system.     

硬脂酸改性磁铁矿在含油污水处理中的应用

研究了水溶液中硬脂酸改性后磁铁矿吸附石油的特性,测定了温度、改性剂用量和时间等因素对改性以及吸附的影响,并对吸附后磁铁矿进行了再生。通过对红外图谱、扫描电镜图谱等的分析,对改性及吸附机理进行了探讨。结果表明,硬脂酸改性磁铁矿的最佳改性条件为常温20℃,改性时间45 min,改性剂用量硬脂酸与磁铁矿的质量比为4%,改性过程中伴随着物理和化学变化,硬脂酸在磁铁矿表面形成了双分子层包覆。改性后的磁铁矿表面湿润性降低,改性磁铁矿吸附石油符合Langmu ir型吸附等温线,最大吸附量为749.23 mg/g,最大去除率达93%。对饱和吸附后的改性磁铁矿经再生处理后,石油去除率稳定在85%。     

Ni-Y分子筛对燃料油中二苯并噻吩的吸附性能研究

以Y型分子筛为载体,采用液相离子交换法制备Ni-Y分子筛吸附剂。采用电感耦合等离子体发射光谱(ICP)、低温液氮吸附法、X射线衍射(XRD)等手段对Ni-Y分子筛进行表征,使用静态吸附方法考察吸附条件对分子筛吸附燃料油中二苯并噻吩性能的影响,并使用Langmuir-Freundlich(L-F)方程对分子筛的吸附等温线进行拟合。结果表明,Ni2+离子的改性对分子筛的孔道结构影响不显著。吸附过程中,吸附时间、剂油比以及芳烃类物质的干扰,都对吸附效果有较大影响。利用L-F方程拟合,计算出25℃时Ni-Y分子筛对二苯并噻吩的饱和吸附量为72.9 mg/g。     

剩余污泥超声预处理后水解酸化特性

为探讨剩余污泥超声预处理后的水解酸化特性,考察了0.6 W/mL、5 min和1 W/mL、5 min 2种超声预处理条件下污泥水解酸化过程有机质、氮、磷的释放情况。实验结果表明,2种超声预处理均可促进污泥水解酸化,并且0.6 W/mL比1 W/mL的超声预处理更有利于SCOD的释放、VFAs的产生以及氮和磷的释放;水解酸化初期,超声预处理比未经超声预处理的污泥在有机质、氮、磷释放率上差异非常明显,随着水解酸化的进行,有机质和氮释放率差异仍很明显,而磷释放程度逐渐接近;经0.6 W/mL超声预处理,污泥水解酸化3 d后,SCOD释放率、VFAs浓度、TN释放率和NH4+-N释放率分别是未经处理污泥的1.85、2.63、1.85和1.41倍,而TP和PO43--P释放率较未经处理污泥仅分别多2.44和1.23个百分点。研究表明,控制适宜的声能密度、超声时间和水解酸化进程是超声预处理强化剩余污泥水解酸化效果的关键。     

Efficiency and Economy of a New Agricultural Rainwater Harvesting System

Shortage of water is the key limiting factor for agricul-tural development of Beijing. Rainwater harvesting (RWH) could provide an alternative water source for greenhouse agriculture, but local natural and socioeconomic conditions challenge the applica-tion of the technology. This article analyses the advantages and disadvantages of different types of greenhouse RWH in Beijing,and describes a new greenhouse RWH system demonstrated in 2008 in Huairou, a suburb district of Beijing. It analyses the ef-ficiency, cost-benefit ratios and limiting factors of the new system.The results show that with the new system, RWH efficiency can be as high as 66% (of total rainfall) and the rainwater usage rate can reach 69% of total water usage. The ratio of benefit to cost of government investment can be 1.84, and the ratio of benefit to cost of a farmer's investment could be 1.68 provided the project is designed to save water and also increase income. However, the price of groundwater for agriculture directly influences the potential for applying and scaling up the project. If the RWH system does not increase the farmers' incomes at the current water price, they will not use it until the water price rises to a critical point, which is de-termined by external factors. This article also suggests a number of measures to increase the efficiency of the system in order to apply it on a large scale.     

Isolation and characterization of two novel psychrotrophic decabromodiphenyl ether-degrading bacteria from river sediments

Decabromodiphenyl ether (BDE-209) is a brominated flame retardant and a priority contaminant. Currently, little information is available about its significance in the environment, specifically about its susceptibility to aerobic biotransformation at low temperature. In this work, five phylogenetically diverse BDE-209-degrading bacterial strains were isolated from river sediments of northern China. These strains were distributed among four different genera—Acinetobacter, Pseudomonas, Bacillus and Staphylococcus. All five isolates were capable of growing on BDE-209, among which two isolates show better growth. By detailed morphological, physiological, and biochemical characteristics and 16S rDNA sequence analysis, the two strains were identified and named as Staphylococcus haemolyticus LY1 and Bacillus pumilus LY2. The two bacteria can grow in mineral salt medium containing BDE-209 substrate across the temperatures ranging from 2.5 to 35 °C, with an optimum temperature of 25 °C which could be considered as psychrotrophs accordingly. The degradation experiment showed that more than 70.6 and 85.5 % of 0.5 mg/L BDE-209 were degraded and the highest mineralization efficiencies of 29.8 and 39.2 % were achieved for 0.5 mg/L BDE-209 by S. haemolyticus LY1 and B. pumilus LY2, respectively. To the best of our knowledge, this is the first demonstration for the biodegradation of BDE-209 by two psychrotrophic bacteria isolated from environment.