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The Hammett approach, applied to the reaction of various classes of aromatic compounds with the radicals Cl2-*, Br2-*, *NO2, SO3-*, and SO4-* yielded good predictive models, supported by high values of the correlation coefficient r2 in the case of phenols with Cl2-* and of phenolates with *NO2 and SO3-*. Lower but statistically significant correlation coefficients could be obtained for benzoates with Cl2-*, phenolates with Br2-*, and benzoates and anisoles with SO4-*.  相似文献   

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Buchpr?sentationen

Stoffhaushalt von Auen?kosystemen: B?den und Hydrologie, Schadstoffe, BewertungenHrsg: K. Friese, B. Witter, G. Miehlich, M. Rode Verlag: Springer Verlag, Heidelberg, 2000, 434 S., 196 Abb., 79 Tabellen, ISBN 3-540-67068-8, DM 169,-  相似文献   

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Daily particle samples were collected in Chillán, Chile, at six urban locations from September 1, 2001, through September 30, 2003. Aerosol samples were collected using monitors equipped with a Sierra Andersen 246-b cyclone inlet on Teflon filters. Average concentrations of coarse particulate matter (PM10) for the 2001-2003 period ranged from 43.4 microg/m3 to 81.8 microg/m3 across the six sites. Annual PM10 concentration levels exceeded the European Union concentration limits. Mean PM10 levels during the cold season (April through September) were more than twice as high as those observed in the warm season (October through March). Average contributions to PM10 from organic matter, soil dust, nitrate (NO3-), elemental carbon, ammonium (NH4+), and sulfate (SO4(2-)) were 31%, 27%, 11%, 8%, 7%, and 5%, respectively. The chemical analyses indicated that carbonaceous substances were the most abundant components of PM10 in cold months, whereas crustal material was the most abundant component of PM10 during warm months. Higher concentration levels were observed in the downtown area suggesting a clear anthropogenic origin, whereas in the rural sites the source was mainly natural, such as resuspended soil dust associated with traffic on unpaved roads and agricultural activities.  相似文献   

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We report seasonal variation in CH(4) and N(2)O emission rate from solid storage of bovine manure in Delhi as well as emission factors and emission inventory from manure management systems in India. Emission flux observed in the year 2002-2003 was 4.29+/-1, 4.84+/-2.44 and 12.92+/-4.25 mg CH(4)kg(-1)dung day(-1), as well as 31.29+/-4.93, 72.11+/-16.22 and 6.39+/-1.76 microgN(2)O kg(-1)dung day(-1) in winter, summer and rainy seasons, respectively. CH(4) emission factors varied from 0.8 to 3.3 kg hd(-1)year(-1) for bovines and were lower than IPCC-1996 default values. N(2)O emission factors varied from 3 to 11.7 mg hd(-1)year(-1) from solid storage of manure. Inventory estimates were found to about 698+/-27 Gg CH(4) from all manure management systems and 2.3+/-0.46 tons of N(2)O from solid storage of manure for the year 2000.  相似文献   

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1—2-7-三氨基-8-羟基-3—6-萘二磺酸(TAHNDS)作为偶氮染料的脱色产物很难被常规的厌氧-好氧染料废水处理工艺所去除。研究了未经驯化的活性污泥对TAHNDS的缺氧转化效果。结果表明,只有在特定的缺氧条件下(ORP在-50~-150mV之间),TAHNDS才能被活性污泥所降解转化。当浓度在10—80mg/L范围内,TAHNDS可在72h内转化93%以上。加入100mg/L的硝酸盐和0.64mmol/L的氧化还原介体蒽醌-2-磺酸钠(AQS)可将40mg/L的TAHNDS的转化时间从84h缩短到36h。光谱及HPLC—MS分析表明,TAHNDS在缺氧条件下主要是通过脱氨基和脱磺酸作用生成已知可好氧生物降解的3,5-二氨基4-羟基萘-2-磺酸。因此,缺氧处理有望作为预处理工艺促进废水中TAHNDS的完全降解。  相似文献   

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The objective of this study was to evaluate the capacity of two bacterial strains isolated, cultivated, and purified from agricultural soils of Veracruz, Mexico, for biodegradation and mineralisation of malathion (diethyl 2-(dimethoxyphosphorothioyl) succinate) and α- and β-endosulfan (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6-9-methano-2,4,3-benzodioxathiepine-3-oxide). The isolated bacterial strains were identified using biochemical and morphological characterization and the analysis of their 16S rDNA gene, as Enterobacter cloacae strain PMM16 (E1) and E. amnigenus strain XGL214 (M1). The E1 strain was able to degrade endosulfan, whereas the M1 strain was capable of degrading both pesticides. The E1 strain degraded 71.32% of α-endosulfan and 100% of β-endosulfan within 24 days. The absence of metabolites, such as endosulfan sulfate, endosulfan lactone, or endosulfan diol, would suggest degradation of endosulfan isomers through non-oxidative pathways. Malathion was completely eliminated by the M1 strain. The major metabolite was butanedioic acid. There was a time-dependent increase in bacterial biomass, typical of bacterial growth, correlated with the decrease in pesticide concentration. The CO2 production also increased significantly with the addition of pesticides to the bacterial growth media, demonstrating that, under aerobic conditions, the bacteria utilized endosulfan and malathion as a carbon source. Here, two bacterial strains are shown to metabolize two toxic pesticides into non-toxic intermediates.  相似文献   

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1-2-7-三氨基-8-羟基-3-6-萘二磺酸(TAHNDS)作为偶氮染料的脱色产物很难被常规的厌氧-好氧染料废水处理工艺所去除。研究了未经驯化的活性污泥对TAHNDS的缺氧转化效果。结果表明,只有在特定的缺氧条件下(ORP在-50~-150 mV之间),TAHNDS才能被活性污泥所降解转化。当浓度在10~80 mg/L范围内,TAHNDS可在72 h内转化93%以上。加入100 mg/L的硝酸盐和0.64 mmol/L的氧化还原介体蒽醌-2-磺酸钠(AQS)可将40 mg/L的TAHNDS的转化时间从84 h缩短到36 h。光谱及HPLC-MS分析表明,TAHNDS在缺氧条件下主要是通过脱氨基和脱磺酸作用生成已知可好氧生物降解的3,5-二氨基-4-羟基萘-2-磺酸。因此,缺氧处理有望作为预处理工艺促进废水中TAHNDS的完全降解。  相似文献   

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人类为了生存,不断地从生活环境中摄取营养物质,同时把废弃物送回环境。环境本身通过扩散、微生物的分解和植物的光合作用等为我们进行处理。这些元素、无机物乃至有机物经常反复地进行着“生物→环境→生物”的循环。随着工业和科学技术的发展,人类生存环境(指水、土、大气)中的元素及其化合  相似文献   

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为了消除氰化物对环境污染的影响,我们曾采用了无氰电镀工艺,其中有光亮性酸性镀铜和焦磷酸盐镀铜,由于这些镀层结合力不好,不能直接在钢铁件上电镀,目前,我们采用HEDP镀铜工艺作为Cu-Cu-Ni-Cr自动线的预镀工艺和N.M宽温度全光亮酸性镀铜作中间镀层。并采用了厚铜薄镍。实  相似文献   

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混凝-水解-接触氧化-气浮工艺处理印染废水   总被引:1,自引:0,他引:1  
采用混凝-水解酸化-接触氧化-气浮工艺,处理印染废水,运行结果表明:对CODcr SS、色度的去除率分别为91.5%、92%、90%,出水达到《纺织染整工业水污染排放标准》(GB4287—92)的一级标准。  相似文献   

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Background, aim, and scope  

2,2-bis(chlorophenyl)-1,1,1-trichloroethane (DDT) metabolites, other than those routinely measured [i.e., 2,2-bis(chlorophenyl)-1,1-dichloroethylene (DDE) and 2,2-bis(chlorophenyl)-1,1-dichloroethane (DDD)], have recently been detected in elevated concentrations not only in the surface water of Teltow Canal, Berlin, but also in sediment samples from Elbe tributaries (e.g., Mulde and Havel/Spree). This was paralleled by recent reports that multiple other metabolites could emerge from the degradation of parent DDT by naturally occurring organisms or by interaction with some heavy metals. Nevertheless, only very few data on the biological activities of these metabolites are available to date. The objective of this communication is to evaluate, for the first time, the cytotoxicity, dioxin-like activity, and estrogenicity of the least-studied DDT metabolites.  相似文献   

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针对在"低钠焙烧水浸提取偏钒酸钠-离子交换树脂提纯-氯化铵沉钒"生产钒工艺下产生的废水的高盐度,可生化性差,使用传统的方法难以达到排放标准等特点,提出了"混凝-砂滤-活性炭过滤-微滤-反渗透"集成技术处理钒冶炼废水。考察了混凝沉淀的最佳条件,同时重点探讨了操作压力、运行时间和pH等操作参数对膜运行效果的影响。反渗透出水的COD为20.7 mg/L,Cl-为176 mg/L,电导率为387μS/cm,除盐率达到99.4%,总铬、六价铬和总钒等重金属的去除率都达到99%以上,远远低于国家规定的排放标准,该出水能回用于大部分生产工序;浓缩液也能回用于成球工艺和烟气处理工序,实现了钒冶炼废水的零排放。具有比较可观的经济价值和广阔的应用前景。  相似文献   

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混凝-水解酸化-好氧-混凝工艺处理印染废水   总被引:1,自引:0,他引:1  
采用“混凝-水解酸化-好氧-混凝”工艺处理印染废水,当进水COD为800—1200mg/L时,出水可达到国家《污水综合排放标准》(GB1978--1996),其中COD指标甚至达到江苏地方标准《太湖地区城镇污水处理厂及重点工业行业主要水污染物排放限值》(DB32/T1072--2007)。  相似文献   

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厌氧-吹脱-好氧-吸附法处理酱油废水   总被引:5,自引:0,他引:5  
针对酱油废水的高CODCr、高色度、高挥发酸以及含盐的特点,设计了用厌氧-吹脱-好氧-吸附法处理酱油废水的工艺。实验结果表明,该工艺对酱油废水的处理有较好的处理效果。当厌氧进水的CODCr分别为6000~8000和1500~2000mg/L,色度分别为5000和1800倍左右时,厌氧反应的水力停留时间(HRT)分别为3~4和2d,吹脱池的停留时间为16h,气水比为0.01m^3/L,好氧反应器和煤渣吸附池的停留时间分别为14~18和14~16h时,该流程对废水CODCr的总平均去除率分别达到90%和82.7%左右,对色度的总平均去除率分别为76.7%和86.5%。  相似文献   

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