MTBE Transport Screening Analysis in Vadose Zone Risk and Liability Apportionment Assessment

The problem of allocating liability cleanup costs is an arduous task when more than one potentially responsible party has contributed to the groundwater plume. This problem is most likely to be encountered when dealing with methyl- tert -butyl-ether (MTBE) contamination, as MTBE is seen to travel large distances in underlying aquifers. There has been a signi®cant effort in the recent past to develop liability allocation methodologies that incorporate fate and transport behavior and toxicological characteristics of the contaminants. The application of such methods often requires estimation of contaminant input from the vadose zone into the underlying aquifer. A screening level analysis is presented here to develop preliminary insights on relative mass contributions arising from different source types. The analysis illustrates how different vadose zone conceptualizations lead to vastly different contaminant loadings. Parametric studies indicate that the contaminant flux into the aquifer is very sensitive to changes in water infiltration rates. Hence, a reliable estimate of this parameter is critical for equitable allocation of remedial costs. Conceptual model formulation, should focus on identifying whether the fuel present in the aquifer can flow as a separate phase. It is also important to obtain reliable estimates for fluid saturations at the site.     

MTBE Transport Screening Analysis in Vadose Zone Risk and Liability Apportionment Assessment

The problem of allocating liability cleanup costs is an arduous task when more than one potentially responsible party has contributed to the groundwater plume. This problem is most likely to be encountered when dealing with methyl-tert -butyl-ether (MTBE) contamination, as MTBE is seen to travel large distances in underlying aquifers. There has been a significant effort in the recent past to develop liability allocation methodologies that incorporate fate and transport behavior and toxicological characteristics of the contaminants. The application of such methods often requires estimation of contaminant input from the vadose zone into the underlying aquifer. A screening level analysis is presented here to develop preliminary insights on relative mass contributions arising from different source types. The analysis illustrates how different vadose zone conceptualizations lead to vastly different contaminant loadings. Parametric studies indicate that the contaminant flux into the aquifer is very sensitive to changes in water infiltration rates. Hence, a reliable estimate of this parameter is critical for equitable allocation of remedial costs. Conceptual model formulation, should focus on identifying whether the fuel present in the aquifer can flow as a separate phase. It is also important to obtain reliable estimates for fluid saturations at the site.     

川中丘陵区高富集氮、磷沟渠植物的筛选

选择7种川中丘陵区常见沟渠植物(酸模、菖蒲、黑麦草、水芋、美人蕉、水蓼、野薄荷)作为研究对象,盆栽试验研究了不同植物对氮、磷的吸收能力,以期筛选出适应川中丘陵区沟渠生长的高富集氮、磷植物。结果表明:(1)不同沟渠植物地上部生物量(以干质量计)为0.43~1.38kg/m2,其中美人蕉最大,菖蒲最小。(2)不同沟渠植物地上部全氮为4.50~14.35g/kg,其中水芋最高,水蓼最低;不同沟渠植物地上部全磷为0.80~2.15g/kg,其中水芋最高,野薄荷最低。(3)不同沟渠植物地上部全氮吸收量为2.88~15.66g/m2,其中美人蕉最高,其次为水芋;不同沟渠植物地上部全磷吸收量为0.48~2.04g/m2,其中美人蕉和水芋地上部全磷吸收量最高,水蓼、黑麦草和酸模次之,菖蒲和野薄荷最低。     

Sensitivity Analysis of Dispersion Models for Point and Area Sources

The body of information presented in this paper is directed to air quality managers in industry and government contemplating modeling emissions from complex sources under the bubble concept.

Point and area source algorithms of PAL, RAM, and ISC-ST were analyzed to show the effect of various input assumptions on model output. Several important parameters were varied individually; receptor grid spacing, emission release height, area source size and source type. Each of these parameters was varied over a range of values while all other modeling parameters, both physical and meteorological, were held constant. The outputs of each model are plotted for easy comparison.

Results indicate that it would be inappropriate to make certain assumptions regarding source characteristics without knowing the behavior of each model. The graphs show how the model predictions can vary for different input parameters when applied to point and area sources. The paper presents general rules of thumb for evaluating model results for many applications such as the bubble concept, emissions banking, offsets, and new source reviews. The results serve as a guide in selecting and using models for both point and area sources.     

Analysis of climatological and air quality observations from Greater Athens Area

In this paper, the climatological and air quality observations obtained for the periods 1974–1990 and 1983–1990, respectively, in the Greater Athens Area, are analyzed. During this period, 80 air pollution episodes, which lasted 210 d in total, were detected. The analysis of the observations allows the interpretation of air quality characteristics in terms of the climatological and meteorological factors. The importance of some characteristic indices for air pollutant dispersion conditions, such as mixing height, ventilation coefficient, temperature at 850 hPa, and temperature inversions, is discussed. The results show that the air quality in the Athens Basin is strongly affected by the meteorological conditions, especially those which are in favor of local circulations. The worst air pollution episodes are associated with anticyclonic conditions and/or advection of warm air masses.     

海门市城区二氧化氮污染物浓度呈上升趋势的调查与分析

通过调查海门市城区所有NOX和NO2排放源,从排放情况和NO2月浓度变化情况分析,得出了海门市城区NO2污染物浓度呈上升趋势的结果。     

Patagonian Fjord Ecosystems in Southern Chile as a Highly Vulnerable Region: Problems and Needs

Southern Chile encompasses one of the most extensive fjord regions of the world, the Patagonia, currently exposed to natural and anthropogenic perturbations. These fjord ecosystems provide important services to humans, which have not been adequately measured and valued. As a consequence, ecosystem services are commonly ignored in public policy design and in the evaluation of development projects. Here we tackle questions that are highly relevant for the nation’s development, namely (1) understanding fjord functioning, and (2) developing management strategies based on ecosystem services, in order to secure simultaneous and adequate use of these ecosystems which area influenced by ecological (e.g., biogeochemical) and productive (e.g., aquaculture, fisheries) processes. We also seek to strengthen the analysis of fjord ecosystem value from the economical (including coastal zoning), socio-cultural, institutional, and governmental points of view. In addition, the investigation of current and future effects of climate change on this large region offers a unique opportunity to understand the social and economic consequences of a global phenomenon at local to regional scales. Biogeochemical and socio-economic models will be used to simulate future scenarios under a gamut of management options.     

生化制药类建设项目环评的重点分析

通过分析徐州市某一生化制药建设项目的环评实例,确定了该类项目的环评重点和难点在于工程分析和污染物的排放分析,尤其是由于废水污染物具有种类多、排放不稳定的特点。同时,结合环保“三同时”建设中的废水处理工程的调试分析,评价了该类建设项目的污水处理设施的技术经济性、可行性。     

石油污染土壤中芘高效降解菌群的筛选及降解特性研究

从长期受石油污染土壤中驯化筛选到能以芘为惟一碳源生长的混合菌群GP3,其主要由假单胞菌株GP3A(Pseudomonas sp.)和菌株GP3B(Pandoraea pnomenusa)组成.采用摇瓶振荡培养方法,研究了不同环境条件对混合菌GP3降解芘效能的影响.结果表明,在30℃,150 r/min振荡培养下,混合菌GP3对15 mg/L芘的7 d降解率为90.6%.混合菌GP3降解芘的最适宜温度为35℃,最佳pH值为6.2.加入低浓度葡萄糖(100 mg/L)或菲(10 mg/L)作为共代谢底物,均可提高GP3对芘的降解率.混合菌对芘的降解速率(PDR)与芘的初始浓度呈正相关.研究重金属离子胁迫下GP3对芘的降解时发现,10 ms/L Zn2 的存在对芘降解效能影响较小,Cu2 对芘的降解有抑制作用,Cd2 对混合菌GP3有很强的毒性.     

固定化微生物菌种的筛选与鉴定

以菲、芘作为降解对象 ,对多种菌株进行筛选 ,从中挑选出降解率最高的两株菌 ,细菌和真菌各一株 ,并对其生长曲线进行测定 ,为菌种的固定化提供了一定的依据。同时对菌种进一步鉴定 ,细菌为动胶杆菌 (Zoogloeasp .) ,在 72h内对菲、芘的降解率为 87 82 %和 4 9 2 2 % ;真菌为镰刀菌 (Fuariumsp .) ,在 2 16h内对菲、芘的降解率为 93 32 %和 96 2 9%。     

汽车制造项目环境影响评价技术要点分析

本文在实际开展汽车制造项目环境影响评价的基础上,对汽车制造项目生产工艺及产污环节进行梳理,重点对废气、废水、固废、噪声源强核算过程和方法进行解析,对污染防治措施论证内容进行探讨,同时从清洁生产水平分析、政策相符性分析等方面的技术要点进行总结整理,梳理了目前汽车制造项目环评文件编制的要点核心,指出汽车整车制造项目环境影响评价中应关注的重点问题,主要在于挥发性有机废气源强和含氮、磷及重金属废水源强核算、物料平衡等,为下阶段汽车制造项目建设和环境管理提供参考。     

一株丙烯酰胺高效降解菌的筛选及其降解性能

从污水处理厂的活性污泥中,分离、筛选出1株高效降解丙烯酰胺的菌株A18,经16S rDNA序列分析鉴定该菌株属于Delftia tsuruhatensis,它可以降解苯胺.以丙烯酰胺为惟一碳源的无机盐培养基中,以菌株细胞的增长和丙烯酰胺的降解为依据,通过实验得出A18菌株的最适生长条件:温度为30℃,pH为7.0.在最适生长条件下,当丙烯酰胺的初始浓度约为1 000 mg/L时,菌株A18对丙烯酰胺的48 h降解率达到100％.     

氯氰菊酯降解真菌的筛选及其降解特性研究

用富集培养的方法从农药厂污水排放口的污泥中分离筛选到3株以氯氰菊酯为唯一碳源进行生长的真菌,分别命名为TS-203、TS-205和TS-306。经鉴定3株真菌分别属于土生曲霉组(Aspergillus terreus)、毛链孢属(M onilochaetes)和镰孢霉属(Fusarium)。分别测定了不同碳源、pH、培养温度及氯氰菊酯浓度对真菌生长量和降解能力的影响。结果表明,以氯氰菊酯为唯一碳源且浓度为50~150 mg/L,pH 6.0~8.0,培养温度30~40℃时,真菌的生长量较大,降解效果较好。本研究对氯氰菊酯农药残留的生物修复研究和应用具有十分重要的意义,可为今后治理氯氰菊酯残留污染提供参考。     

一株多环芳烃降解菌的筛选及其降解特性

微生物修复是治理土壤多环芳烃(polycyclic aromatic hydrocarbons, PAHs)污染的主要方法,而高效降解菌筛选是微生物修复技术的重要基础。从北京焦化厂土壤中筛选分离得到一株PAHs降解菌Q3,通过生理生化和16S rDNA等分析手段鉴定其为Rhodococcus rhodochrous。结果表明：该菌株对芘的耐受能力较强,可降解初始浓度为200 mg·L⁻¹的芘;该菌株具有降解广谱性,可利用苯并[a]芘、苯并[b]荧蒽、二苯并[a,h]蒽、苯并[g,h,i]苝等9种PAHs为唯一碳源进行代谢,特别是对苯并[a]芘等高环PAHs具有较好的降解效果;此外,该菌株可有效降解模拟液中的混合PAHs,并且对野外被PAHs长期污染的土壤具有较好的强化修复效果。投加菌株处理后的处理组与对照组相比,土壤PAHs总去除率提高了24%。以上结果表明该菌株对环境中被PAHs污染的土壤具有较好的强化修复潜力,可为PAHs污染土壤的微生物修复技术提供技术参考。     

微生物絮凝剂有效真菌的筛选

通过真菌培养基（马铃薯培养基），对旱田土壤和活性污泥中的微生物进行筛选分离，得到3株絮凝率超过67％的菌株，其中絮凝率超过75％的高絮凝活性菌株1株——MZ52。将MZ52在产絮凝剂的培养基中进行发酵培养后，对1000mg／L高岭土悬浮液絮凝，得出MZ52菌产絮凝剂最佳培养条件，分别为摇床转速160r／min，培养时间90h，初始pH值为8．0，培养温度为40℃。     

粤港澳大湾区空气污染物的时空分布及其影响因素

基于粤港澳珠三角洲空气质量监测数据,利用克里金插值法和Spearman秩系数相关法分析了2015—2021年大湾区空气污染物的时空分布特征,利用灰色关联分析法分析了自然、社会因素对空气污染物的影响。结果表明,近7年大湾区的空气质量整体向好,PM10、PM2.5年均值分别为40.32、23.38$ \mathrm{\mu } $g·m−3,均低于新标准二级限值,O3、NO2、SO2年均值分别为51.68、33.45和6.61$ \mathrm{\mu } $g·m−3。其中,SO2质量浓度低于新标准一级限值,CO年均值为0.68$ \mathrm{m} $g·m-3,CO、PM2.5、NO2、PM10和SO2年均质量浓度呈下降趋势,降幅分别为23.67%、39.48%、27.02%、33.75%和41.21%,季节上表现为冬季最高、春秋季次之、夏季最低。O3年均质量浓度呈波浪上升趋势,升幅为14.54%,季节变化为：秋季>春季>冬季>夏季,O3质量浓度升高的原因可能是副热带高气压带和台风外围的大气环流形式等不利气象条件和O3前体物高排放逐渐升高等人为排放因素等共同影响的结果。O3的空间分布表现为东莞、深圳、港澳和江门南部等东部沿海地区高于中西部内陆地区,高值质量浓度达48~70 μg·m−3,其他污染物质量浓度呈“中西—东部”递减趋势。气温、日照时数和风速与CO、NO2、PM10、PM2.5和SO2质量浓度呈负相关,与O3 呈正相关,相对湿度与O3呈负相关,与其他污染物呈正相关,降水量对珠港澳三地污染物质量浓度影响不一。能源消耗、工业生产、人口和机动车数据等是影响大湾区空气质量的主要因素。本研究结果可为粤港澳大湾区在大气污染防治、环保策略制定等方面提供参考。     

氨氧化菌群的筛选及发酵条件的优化

利用选择性培养基对活性污泥进行连续驯化,筛选出氨氮去除效率较高且稳定的氨氧化菌群。采用聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)技术分析了氨氧化菌群在连续传代过程中菌群的结构差异,并对菌群的发酵培养基及发酵条件分别进行了正交优化和单因子优化。结果表明,该菌群的最佳发酵培养基为每升培养基中含碳酸盐缓冲液15mmol,硫酸铵4.2 mmol,磷酸盐缓冲液12.5 mmol,硫酸亚铁0.9μmol,氯化钙0.4 mmol,硫酸镁1.5 mmol;最佳发酵条件为:接种量为14%,装液量为60 mL/250 mL,温度为35℃。在此条件下,菌群对氨氮的去除效果较优化前提高了155%。     

润滑油高效降解菌的筛选及降解性能

实验以被石油污染的土壤为出发菌源,以润滑油为唯一碳源,经过筛选分离得到4株对润滑油具有降解能力的菌株。经过形态观察、生理生化实验初步鉴定发现,4株菌株分别为黄单胞菌属(Xanthomonas)、动胶菌属(Azotobac-ter)、假单胞菌属(Pseudomonas)和黄杆菌属(Flavobacterium),其中菌株G4为黄杆菌属,其润滑油降解效率最高。研究菌株G4降解性能的影响因素发现,实验中的各因素对润滑油降解率的影响大小依次为:温度>葡萄糖浓度>硫酸铵浓度>pH值。在温度20～40℃下,菌株G4对润滑油均具有一定的降解能力。在适宜的温度范围中,pH值5.0～9.0范围内,菌株G4的润滑油降解率随pH值的变化很小,且均在80%以上。菌株G4在以润滑油为唯一碳源时的最佳培养条件为:温度30℃,pH值为9.0,硫酸铵浓度为1.0 g/L。在此条件下培养36 h,100 mL的G4培养液对200μL润滑油的降解率可达84.6%。     

微生物絮凝剂产生菌的筛选及其絮凝特性

采用常规的微生物学方法,从垃圾渗滤液中筛选到一株高效微生物絮凝剂产生菌LB1,根据其形态学和生理生化特征初步鉴定该菌株属于假单胞菌属,命名为Pseudonomas sp. LB1。LB1所产微生物絮凝剂的絮凝特性的研究结果表明,LB1的最佳产絮凝时间为96 h,所产絮凝活性物质主要是其生长过程中的胞外分泌物和细胞生长后期的次级代谢产物,菌体细胞本身具有一定的助凝作用。LB1所产絮凝剂最佳加样量为3％（体积分数V/V）;对pH的适应范围较宽,在4～10之间具有较高的絮凝活性,均大于75％;温度为25℃时絮凝率为86.3％,在25～60℃之间,絮凝率基本保持稳定;LB1所产絮凝剂对几种废水具有较好的絮凝效果。