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121.
在一些特殊的河段或地形条件下,渗渠取水在供水安全保障方面发挥着重要作用。运用内梅罗污染指数法对海浪河某傍河型渗渠水源地附近的河水水质、渗渠运行期间的渗渠水水质,以及渗渠停用后渗渠周围地下水水质进行了对比分析,结果表明,渗渠运行期间河水的水质综合评分在1~2之间(Ⅱ类水),同期的渗渠水水质综合评分在0.5左右(Ⅰ类水),在渗渠停用后周围地下水水质综合评分在2左右(Ⅲ类水);可见,渗渠水质优于河水。因此,在适宜地段合理布设渗渠,可进一步保障供水安全。  相似文献   
122.
在实验室条件下,研究了海水中多环芳烃(PAHs)(含苊、菲、)浓度分别为90、900或9000 μg/L时,无瓣海桑(Sonneratia apetala)、秋茄(Kandelia candel)和木榄(Bruguiera gymnorrhiza)不同分解状态落叶碎屑对PAHs的吸附作用。结果显示:在相同PAHs浓度下,无瓣海桑、秋茄和木榄落叶碎屑对PAHs的吸附总量差异显著(p < 0.05),吸附率树种间也差异显著(p < 0.05)。当海水中PAHs的浓度为90和900 μg/L时,3种红树植物落叶碎屑对PAHs的吸附率均是无瓣海桑黑叶最高,分别为32.6%和35.1%。同一树种不同分解状态落叶碎屑对PAHs的吸附规律因树种而异:秋茄棕叶和黑叶对PAHs的吸附率均随着PAHs浓度的增加而增加;木榄棕叶和黑叶对PAHs的吸附率均随着PAHs浓度的增加,先上升(从90 μg/L到900 μg/L),然后下降(从900 μg/L到9000 μg/L);无瓣海桑棕叶对PAHs的吸附率是随着PAHs浓度的增加而增加,而黑叶却随着PAHs浓度的增加,吸附率先是上升,然后下降。3种红树植物同一分解状态的落叶碎屑对单个PAHs组分的吸附率规律存在差异。同一树种同一分解状态的落叶碎屑对不同PAHs组分的吸附规律也存在差异。  相似文献   
123.
The immobilization of co-contaminants of organic and inorganic pollutants by biochar is an efficient remediation strategy. However, the effect of biochar amendments on the bioaccessibility of the co-contaminants in dry versus flooded soils has rarely been compared. In batch experiments, bamboo-derived biochar(BB) had a higher sorption capacity for phenanthrene(Phe)/pyrene(Pyr)/zinc(Zn) than corn straw-derived biochar(CB), while CB had a higher sorption capacity for lead(Pb) than BB. After 150 days of incubation, the amendments of 2% CB, 0.5% BB and 2% BB effectively suppressed the dissipation and reduced the bioaccessibility of Phe/Pyr by 15.65%/18.02%, 17.07%/18.31%and 25.43%/27.11%, respectively, in the aerobic soils. This effectiveness was more significant than that in the anaerobic soils. The accessible Zn/Pb concentrations were also significantly lower in the aerobic soils than in the anaerobic soils, regardless of treatments.The Gram-negative bacterial biomass and the Shannon–Weaver index in the aerobic soil amended with 2% CB were the highest. The soil microbial community structure was jointly affected by changes in the bioaccessibility of the co-contaminants and the soil physiochemical properties caused by biochar amendments under the two conditions. Therefore, dry land farming may be more reliable than paddy soil cultivation at reducing the bioaccessibility of Phe/Pyr/Zn/Pb and enhancing the soil microbial diversity in the short term.  相似文献   
124.
Atmospheric aerosol particle samples were collected using an Ambient Eight Stage(Non-Viable) Cascade Impactor Sampler in a typical urban area of Beijing from 27 th Sep.to 5th Oct.,2009.The surface chemistry of these aerosol particles was analyzed using Static Time of Flight-Secondary Ion Mass Spectrometry(Static TOF-SIMS).The factors influencing surface compositions were evaluated in conjunction with the air pollution levels,meteorological factors,and air mass transport for the sampling period.The results show that a variety of organic ion groups and inorganic ions/ion groups were accumulated on the surfaces of aerosol particles in urban areas of Beijing;and hydrophobic organic compounds with short-or middle-chain alkyl as well as hydrophilic secondary inorganic compounds were observed.All these compounds have the potential to affect the atmospheric behavior of urban aerosol particles.PM1.1–2.1and PM3.3–4.7had similar elements on their surfaces,but some molecules and ionic groups demonstrated differences in Time of Flight-Secondary Ion Mass Spectrometry spectra.This suggests that the quantities of elements varied between PM1.1–2.1and PM3.3–4.7.In particular,more intense research efforts into fluoride pollution are required,because the fluorides on aerosol surfaces have the potential to harm human health.The levels of air pollution had the most significant influence on the surface compositions of aerosol particles in our study.Hence,heavier air pollution was associated with more complex surface compositions on aerosol particles.In addition,wind,rainfall,and air masses from the south also greatly influenced the surface compositions of these urban aerosol particles.  相似文献   
125.
小定鞭藻(Prymnesium parvum)藻华通常会使养殖的鱼类大量死亡,是一种常见的鱼毒性藻类。本文以海洋青鳉鱼(Oryzias melastigma)为受试生物,研究小定鞭藻胁迫对海洋青鳉鱼的急性毒性效应及抗氧化酶活性变化,以期揭示小定鞭藻对鱼类的安全阈值及致毒作用方式。研究结果表明,在浓度0.9×108~11.2×108/L范围内,随着小定鞭藻浓度的增加,其对海洋青鳉鱼的毒性越强,呈明显的剂量-效应关系。3、24、和48 h的半致死浓度LC50分别为5.62×108、1.58×108和1.44×108/L。当小定鞭藻浓度分别为1.87×108和2.8×108/L时,半致死时间LT50分别为41.75 h和6.5 h,最大无作用浓度为0.9×108/L,推测小定鞭藻藻华对鱼类的安全阈值为9×106/L。低浓度小定鞭藻胁迫可使海洋青鳉鱼的过氧化物歧化酶(SOD)活性降低,但不呈剂量-效应关系,高浓度小定鞭藻可诱导过氧化氢酶(CAT)活性升高,低浓度小定鞭藻可使海洋青鳉鱼丙二醛(MDA)含量升高,提示低浓度小定鞭藻胁迫可导致海洋青鳉鱼脂质过氧化,这可能是小定鞭藻对鱼类致毒作用的方式之一。  相似文献   
126.
火灾危险源与火灾隐患之辨析   总被引:5,自引:0,他引:5  
马锐  阚强  吴丹  王伟  倪照鹏 《安全》2005,26(6):18-20
通过归纳总结危险源定义和分类,引申出火灾危险源的定义和分类.就火灾隐患定义在不同领域的运用提出了广义和狭义火灾隐患之分,并就火灾危险源与火灾隐患之间的关系阐述了一些观点.  相似文献   
127.
Environmental Science and Pollution Research - The analysis and prediction of water quality are of great significance to water quality management and pollution control. In general, current water...  相似文献   
128.
宝鸡市街道尘埃磁学特征空间分布及环境意义   总被引:2,自引:0,他引:2  
张俊辉  王瑾  张健  房妮  夏敦胜 《环境科学》2015,36(5):1818-1826
对宝鸡市街道尘埃样品进行详细系统环境磁学实验分析并结合扫描电子显微镜研究表明,宝鸡市街道尘埃中磁性矿物含量高,主要的磁性矿物为多畴和假单畴的低矫顽力亚铁磁性矿物,同时含有少量的赤铁矿等高矫顽力的硬磁性矿物.污染来源主要以工业和交通等人为污染为主.街道尘埃的磁学特征表现出一定的空间变化规律揭示出污染的空间分布,划分为6个主要区域:A(创新路到高新八路区域)和B(东风路和马营路区域),磁性物质含量整体很高,揭示污染相对较重,污染源主要为"工业+交通";C区(火炬路到医康区域)磁性物质含量相对较高,是中度污染的区域,污染源主要为"交通";D(经二路与人民路区域)、E(清姜路和姜谭路西部区域)和F(陈仓区虢镇),磁性物质含量相对较低,揭示轻度污染,污染源主要为"交通".  相似文献   
129.
黑龙江省大气污染防治思路研究   总被引:2,自引:0,他引:2  
近年来,全国各地出现不同程度的雾霾天气,大气污染严重,黑龙江省部分城市大气也出现不同程度污染,本文通过分析导致大气污染的三个主要成因,即:气候条件不利于污染物扩散;煤炭消耗处于主导地位;机动车迅速发展.提出黑龙江省未来十年的大气污染防治思路和地区产业发展方向的几点建议,通过采取综合、系统的措施,完善大气污染治理制度和政策保障体系、建立分区管理、加强污染基础研究、发展绿色经济等多方面入手,冀希能够改善本省的空气质量.  相似文献   
130.
The use of surfactants to enhance plant-microbe associated dissipation in soils contaminated with polycyclic aromatic hydrocarbons(PAHs) is a promising bioremediation technology. This comparative study was conducted on the effects of plant-microbe treatment on the removal of phenanthrene and pyrene from contaminated soil, in the presence of low concentration single anionic, nonionic and anionic-nonionic mixed surfactants. Sodium dodecyl benzene sulfonate(SDBS) and Tween 80 were chosen as representative anionic and nonionic surfactants, respectively. We found that mixed surfactants with concentrations less than 150 mg/kg were more effective in promoting plant-microbe associated bioremediation than the same amount of single surfactants. Only about(m/m) of mixed surfactants was needed to remove the same amount of phenanthrene and pyrene from either the planted or unplanted soils, when compared to Tween 80. Mixed surfactants( 150 mg/kg) better enhanced the degradation efficiency of phenanthrene and pyrene via microbe or plant-microbe routes in the soils. In the concentration range of 60–150 mg/kg, both ryegrass roots and shoots could accumulate 2–3 times the phenanthrene and pyrene with mixed surfactants than with Tween 80. These results may be explained by the lower sorption loss and reduced interfacial tension of mixed surfactants relative to Tween 80, which enhanced the bioavailability of PAHs in soil and the microbial degradation efficiency. The higher remediation efficiency of low dosage SDBS-Tween 80 mixed surfactants thus advanced the technology of surfactant-enhanced plant-microbe associated bioremediation.  相似文献   
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