多巴胺非共价改性碳纳米管超滤膜的制备及抗污染性能

利用多巴胺(DA)的自聚合特性对多壁碳纳米管(MWCNT)进行非共价改性,制备了多巴胺改性碳纳米管超滤膜(PDA/MWCNT),并对其抗污染性能进行了系统研究.采用X射线光电子能谱、傅里叶红外光谱、接触角测量仪和扫描电镜对PDA/MWCNT膜进行亲水性和化学组成的表征.选取大肠杆菌菌液为目标污染物,研究了不同改性条件对PDA/MWCNT膜抗污染性能及抗蛋白黏附能力的影响.结果表明,DA成功引入到MWCNT表面.DA与MWCNT交联时间为5h、DA浓度1g/L、MWCNT负载量2.17mg/cm²时,MWCNT膜的接触角由改性前112.79°降至8.4°.改性后PDA/MWCNT膜表面的氧元素含量为改性前的2.9倍,膜的亲水性得到显著改善.膜通量较改性前提高1倍,膜的抗污染性能、抗菌性及抗蛋白黏附能力得到显著提高,错流冲洗后的膜通量恢复率从56.62%增加到88.74%.     

AGRICULTURAL LAND USE IMPACTS ON BACTERIAL WATER QUALITY IN A KARST GROUNDWATER AQUIFER1

ABSTRACT: The impact on water quality by agricultural activity in karst terrain is an important consideration for resource management within the Appalachian Region. Karst areas comprise about 18 percent of the Region's land area. An estimated one-third of the Region's farms, cattle, and agricultural market value are on karst terrain. The purpose of this study was to compare fecal bacteria densities in karst groundwater impacted by two primary agricultural land uses in central Appalachia. Fecal bacteria densities were measured in cave streams draining two primary land management areas. The first area was pasture serving a beef cow-calf operation. The second area was a dairy. Neither area had best management practices in place for controlling animal wastes. Median fecal coliform and fecal streptococcus densities were highest in cave streams draining the dairy. Median fecal coliform densities in the dairy-impacted stream were greater than 4,000 CFU/100 ml and the median fecal coliform densities in the pasture-impacted streams were less than 10 CFU/100 ml. Median fecal streptococcus densities in the same streams were greater than 2,000 CFU/100 ml and 32 CFU/100 nil, respectively. A second dairy, with best management practices for control of animal and milkhouse waste, did not appear to be contributing significant amounts of fecal bacteria to the karst aquifer. It was concluded that agriculture was affecting bacterial densities in the karst aquifer. New management practices specifically designed to protect karst groundwater resources may be one way to protect the groundwater resource.     

POTENTIAL EFFECTS OF CLIMATE CHANGE ON AGRICULTURAL WATER USE IN THE SOUTHEAST U.S.1

ABSTRACT: Climate change has the potential to have dramatic effects on the agricultural sector nationally and internationally as documented in many research papers. This paper reports on research that was focused on a specific crop growing area to demonstrate how farm managers might respond to climate-induced yield changes and the implications of these responses for agricultural water use. The Hadley model was used to generate climate scenarios for important agricultural areas of Georgia in 2030 and 2090. Linked crop response models indicated generally positive yield changes, as increased temperatures were associated with increased precipitation and CO2. Using a farm management model, differences in climate-induced yield impacts among crops led to changes in crop mix and associated water use; non-irrigated cropland received greater benefit since irrigated land was already receiving adequate moisture. Model results suggest that farm managers will increase cropping intensity by decreasing fallowing and increasing double cropping; corn acreage decreased dramatically, peanuts decreased moderately and cotton and winter wheat increased. Water use on currently irrigated cropland fell. The potential for increased water use through conversion of agriculturally important, but currently non-irrigated, growing areas is substantial.     

聚醚废水处理工艺研究

研究了中和混凝-厌氧十好氧-生物活性炭组合工艺,在不同工况和运行参数条件下处理聚醚废水的效果．结果表明,中和混凝能有效地降低生物处理的污泥负荷,调节pH值6．7,聚合氯化铝的投加量为l00mg/L时．聚醚废水COD去除率可达28％,当进水的COD为3000～4000mg/L时,聚醚废水经此组合工艺处理后,COD的总去除率达96％以上,出水COD值约150mg/L.     

活性炭纤维的表面结构及其吸附模式

迄今的吸附模式,Henry定律、Langmuir模型、BET模型、D-R方程、D-A方程都分别适用于不同的表面结构,对于活性炭纤维（Activated Corbon Fiber,ACF）这种特殊的炭吸附材料适用于哪种吸附模型,未见有文献专题论述。本论文在对ACF材料进行了大量表面结构研究的基础上,对ACF的表面结构与颗粒活性炭（GranularActivated Carbon,GAC）的表面进行了对比,并尝试性地对适用于ACF的吸附模式进行了计算和比较,得到了一些有价值的结论。     

氧气和水蒸气对球状活性炭吸附SO2能力的影响

研究了Ｏ２和Ｈ２Ｏ对沥青基球状活性炭（ＰＳＡＣ）吸附ＳＯ２能力的影响。结果表明,Ｏ２和ＳＯ２占据不同的活性中心,而Ｈ２Ｏ和ＳＯ２占据同一类活性中心,且ＳＯ２与活性中心的结合能力比Ｈ２Ｏ强得多。Ｏ２或Ｈ２Ｏ均能提高ＰＳＡＣ对ＳＯ２的吸附能力。ＳＯ２吸附量的增加来源于ＳＯ２的化学吸附量。     

活性炭纤维吸附／热解吸／毛细管气相色谱法测定低浓度VOCs的方法

本文以活性炭纤维为吸附材料,建立了活性炭纤维吸附／二次热解吸 缩／毛细管气相色谱法测定空气中ＶＯＣＳ的方法,讨论了吸附剂的安全采样体积,湿度控制及分析方法的精密度,检出限和回收率。本法对苯,甲苯,四氯乙烯,对－二甲苯和苯乙类的最低可测浓度分别为０．１３,０．０２,０．１２,０．０５和０．０５μｇ．ｍ＾－３,适用于低浓度ＶＯＣＳ样品的测定。     

街谷地区CO污染现状分析

本文分析了典型街谷地区ＣＯ污染的现状及其浓度的垂直分布和水平分布的变化情景。由监测结果可知,街谷地区ＣＯ浓度是较高的,而且峰值出现在采暖期。     

Main particulate matter components in Saxony (Germany)

Aerosol filter samples have been collected nearby the industrialised basin of Leipzig in Saxony (Germany) at the research station Melpitz of the Institut für Troposphärenforschung e.V. (IfT). Time series (1992–1998) and a three year comparison (1995–1997) of two different aerosol filter sampling systems, the Sierra-Andersen-PM 10 high volume sampler (daily sample, PM 10 inlet) and the Rupprecht and Patashnik Co. Inc. Model Partisol 2000 (weekly sample, PM 10 and PM 2.5 inlet) are presented and discussed. The comparison of the different sampling systems and strategies yields small differences between the daily and weekly samples for mass and different ions, which may be influenced by sampling duration and flow rates. A general trend of change in aerosol composition was observed: Soot and Sulphate concentrations decreased whereas Nitrate and Ammonium concentrations increased. During summers the mass of coarse particles is higher than in other seasons. One reason could be found in the occurence of longer periods of dry ground surfaces enabling reemission of crustal and biological material. The time series have been integrated in a longer historical aerosol mass trend for Saxony and do show a good agreement. Since 1990 a significant downward trend in gravimetric mass concentration was found.     

海口市生活垃圾碳输出研究

生活垃圾的碳输出是城市生态系统碳循环的环节之一,而且与城市环境污染密切有关.研究生活垃圾碳输出是研究城市生态系统碳循环的基础工作,还有助于分析城市居民消费的环境影响.基于实地采样和数据收集获得的生活垃圾数据,分析了海口市生活垃圾碳输出的现状和趋势.结果表明,2001年海口市26.92×10⁴t生活垃圾的碳输出量为10.51×10⁴t,每人每天生活垃圾的碳输出量为0.326kg,其中31%左右的碳在填埋方式下转化成CH₄、CO₂和渗沥水中的有机物,69%左右的碳被长期固定.在被固定的碳中,约33%的来源于大气,这说明生活垃圾可能是碳汇.1991～1999年,海口市生活垃圾碳输出呈现明显增长趋势,年均增长率为9.55%,其中,可被固定在生活垃圾中的碳量增长趋势较为明显,年增长率达到13.23%.海口市生活垃圾碳增加与人均消费支出和人口数的增加呈显著相关,表明人均消费支出和人口数对生活垃圾碳输出具有一定的影响.