沸石生物联合吸附再生工艺中溶解性有机物的特性变化

利用三维荧光技术(EEM)和凝胶过滤色谱法(GFC)研究了沸石生物联合吸附再生(ZCS)工艺中溶解性有机物(DOM)在系统中的变化规律.结果表明,生活污水DOM中主要的荧光物质有类蛋白质(荧光峰A和B)和类腐殖质(荧光峰C),经ZCS工艺处理后,荧光峰B较峰A的强度降低更多,说明类蛋白质的组成结构发生了变化;荧光峰C削...     

改良型AO法组合工艺中有机物的三维荧光分析

采用三维荧光(EEM)光谱技术,对上海竹园第二污水处理厂改良型AO法组合工艺运行过程中的各种溶解性有机物(DOM)进行分析,并对比研究传统好氧活性污泥法曝气池出水和A/O脱氮工艺硝化池出水DOM的EEM光谱的迁移变化特性.结果表明,各种DOM中主要的荧光物质有类蛋白质(荧光峰A和B)及类腐殖质(荧光峰C),经改良型AO法组合工艺处理后,荧光峰的强度降低了14％～60％,同时类蛋白质和腐殖质的结构也发生了变化;腐殖酸溯源表明DOM中的腐殖酸以微生物代谢产生的带有荧光基团的腐殖酸类为主.     

荧光光谱与OUR联用表征内源呼吸过程

采用荧光光谱与耗氧速率(OUR)相结合的方法,探究了内源呼吸过程中微生物代谢状态变化的典型特征。结果表明,OUR变化率曲线中的拐点可以将内源呼吸划分为3个阶段。通过荧光光谱监测发现,在2~4 d时胞外聚合物(EPS)出现了突然增多的现象,疏松结合的胞外聚合物(LB-EPS)中峰A(Ex/Em=230 nm/(334~338)nm)、峰B(Ex/Em=(280~285)nm/(334~344)nm)的荧光强度分别升高了447%、128%,紧密结合的胞外聚合物(TB-EPS)中峰A、峰B的荧光强度分别升高了471%和128%,且COD的去除率在第4天达到最大为91.7%,表明位于此区域的微生物活性高、代谢状态好且污染物去除率高。LB-EPS和TB-EPS的荧光特性及OUR变化率可以指示内源呼吸3个不同阶段的变化,但TBEPS对内源呼吸过程的划分更为准确,而OUR变化率在实际操作中更具有意义。     

猪场沼液处理过程中溶解性有机质的光谱学特征

猪场沼液无序排放会导致严重的水环境问题,探索猪场沼液处理过程中有机物变化的检测方法,可以为养殖废水处理和排放管控提供技术支撑。利用三维荧光光谱法和紫外—可见分光光度法对猪场沼液处理过程中溶解性有机物(DOM)的光学参数进行分析。结果表明:猪场沼液DOM的三维荧光图谱显示其主要存在类腐殖质、类色氨酸和类酪氨酸3类物质,以类腐殖质物质为主;经AO处理后猪场沼液中的类色氨酸物质部分转化为类酪氨酸物质;经序批式生物膜反应器(SBBR,由SBBR1和SBBR2组成)工艺处理后,类色氨物质全部被分解转化。猪场沼液经SBBR2和氧化塘处理后,DOM浓度和各荧光组分含量有所升高,需要进一步调试优化。DOM在254nm处的光吸收系数(A254)、各特征荧光峰强度以及特征荧光峰总强度与TN、溶解性有机碳(DOC)均具有显著正相关性,因此利用猪场沼液DOM的光谱学特征,不仅可以指示废水中DOM成分的转化状况,也可作为判断工艺流程处理效果的依据,还能较好地表征TN和DOC,具有广泛的应用前景。     

垃圾渗滤液处理工艺中有机污染物的三维荧光光谱

利用荧光发射和三维荧光光谱研究了三峡库区某垃圾堆场的渗滤液及其处理工艺出水溶解性有机质(DOM)的荧光光谱特性。堆场渗滤液的DOM含有类酪氨酸、色氨酸及紫外区类富里酸,特征荧光峰中心位于E_x/E_m=275 nm/305 nm,为高激发波长类酪氨酸,与前人的研究结果并不一致,这可能与垃圾的堆放期有关。渗滤液和各处理工艺出水的荧光指数f_450/500均大于1.9,表明腐殖质主要为微生物源。渗滤液在处理前后荧光峰特征和强度均发生明显改变,类蛋白荧光强度与DOC值变化趋势基本一致。生化处理工艺中,类蛋白荧光强度降低了66.4%～95.5%,紫外区类富里酸荧光强度只降低了28.8%,显示类蛋白质具有良好的可生化性,而类富里酸相对较难生化降解。三维荧光光谱能反映渗滤液处理过程中污染物的种类、性质和数量等变化信息,能快速地进行定性分析、定量评价。     

煤热解废水典型工艺流程中芳香化合物的降解特性

选取河南某低阶煤热解废水处理典型工艺流程为研究对象,探讨了各单元对芳香化合物的降解特性。通过降解效能对比发现,SBR工艺对酚类(96.13%)和氮杂环类化合物(78.13%)的降解能力最高,故其为芳香化合物降解的核心单元。通过凝胶色谱、紫外-可见光光谱和三维荧光光谱对全流程废水特性的表征,推测出其分子质量在3 kDa左右,荧光峰在Ex/Em=(300～370) nm/(400～450) nm的腐殖酸物质是煤热解废水关键的难生化物质。各单元的统计分析结果表明,废水处理效果不佳的原因在于酸化、气浮、好氧及强氧化单元。在此基础上,根据最新研究结果和成功案例对现有工艺提出了针对性改进方案。以上结果可为类似的废水处理工程提供参考。     

造纸工业园区污水处理厂溶解性有机物迁移转化规律

在对某造纸工业园区污水处理厂污染物变化规律分析的基础上,采用UV-vis光谱、凝胶色谱和三维荧光等指纹图谱手段对溶解性有机物(DOM)特性进行表征。结果表明,该工业园区污水处理厂能够有效去除以造纸废水为主的混合污水中的有机污染物。UV-vis光谱和凝胶色谱分析表明:水解酸化可将大分子有机物分解成小分子,腐殖化程度降低;高级氧化深度处理后小分子物质所占比例明显增加。三维荧光光谱结果表明,DOM中主要的荧光物质包括色氨酸类蛋白质、芳香族类蛋白质、类腐殖酸、类富里酸物质和酪氨酸类蛋白质。水解酸化可以提高芳香族类蛋白质、类腐殖酸和类富里酸的含量。高级氧化则能有效降低类蛋白质和类腐殖酸物质的含量。     

氯消毒对城市污水中DOM的三维荧光特性影响

在城市污水二级出水氯消毒过程中,通过对溶解性有机物(DOM)的三维荧光光谱(3DEEM)分析及反应过程中三卤甲烷(THMs)生成量的连续测定,分析各类荧光物质随加氯反应时间的变化规律,探讨其与THMs生成量之间的关系,以此来推测THMs的主要前驱物质。结果表明,加氯后0～6 h内,各反应时间点三维荧光光谱图的等高线的密集程度较原二级出水明显降低,荧光峰的荧光强度减少40%～70%,说明DOM与氯发生反应,芳香构造化程度及不饱程度降低,从而失去荧光特性。其中,简单芳香族蛋白质(酪氨酸类)、腐殖酸类及富里酸类物质在加氯前后荧光强度变化较大,是生成THMs的主要前驱物质。THMs的生成量随反应时间的增加呈现明显的上升趋势,15 min内各类荧光特性有机物的荧光强度减少约50%左右,同时生成了50.17%的THMs。     

生物强化组合工艺处理河水的三维荧光及生物多样性分析

通过对受污染地表水进行生物滤池-臭氧预氧化-生物活性炭滤池工艺处理,考察生物强化条件下该项工艺对河水中主要污染物的净化效果,并采用EEM光谱技术进行了溶解性有机物变化和去除规律分析,利用PCR-DGGE技术进行各单元中微生物多样性对比分析。结果表明,生物强化组合工艺系统出水水质主要指标已达到/接近地表水环境质量标准(GB 3838-2002)Ⅳ类限值,生物强化滤池填料中微生物多样性指数和物种数均高于其他工艺单元。受污染河水DOM中主要的荧光物质有类芳香族蛋白质(荧光峰A、B和E)及类腐殖酸(荧光峰C)及类富里酸(荧光峰D),其中,A峰、B峰与E峰的中心位置分别位于225/340 nm、275/336 nm和225/298 nm,各特征荧光峰强度发生明显改变表明,污水中溶解性有机物的含量随系统处理过程而变化。     

城市污水生物处理过程中SMP与EPS的光谱特性和荷电特征

通过研究城市污水生物处理过程中可溶性微生物产物(SMP)和胞外聚合物(EPS)的光谱特性和荷电特征,进ー步阐明城市污水生物处理各阶段SMP和EPS的结构特征。结果表明:污水生物处理过程中SMP主要含有低激发波长类色氨酸和类腐殖酸,可能还含有高激发波长类色氨酸和类富里酸其中类腐殖酸物质在此过程中逐渐被降解。紧密黏附型胞外聚合物(TB-EPS)与松散附着型胞外聚合物(LB-EPS)主要含有类色氨酸、类富里酸和类腐殖酸。此外LB-EPS和TB-EPS还分别含有低激发波长类色氨酸和另一种类腐殖酸(λ_(Ex)/λ_(Em)=(420±425)nm/(470±475)nm)。SMP、LB-EPS和TB-EPS的荧光指数分别为1.78±2.13,1.57±1.68,1.21±1.40其来源分別主要是生物来源、生物来源和陆源、陆源。且LB-EPS的荧光指数在厌氧处理阶段降低表明其所含腐殖质的芳香性增强TB-EPS则相反。三者的Zeta电位值在-11~-24 mV内,且其绝对值随生物处理进行而降低其中TB-EEPS的Zeta电位值变化相对较小。     

Synchronous-scan fluorescence spectra of Chlorella vulgaris solution

The characterization of the Chlorella vulgaris solution was carried out using synchronous-scan spectroscopy. The range of concentration of algae and Fe(III) in aqueous solutions were 5 × 10⁸–8 × 10⁹ cells l⁻¹ and 10–60 μM, respectively. Effective characterization method used was synchronous-scan fluorescence spectroscopy. The wavelength difference (Δλ) of 90 nm was maintained between excitation and emission wavelengths; 90 nm was found to be the best Δλ for effective characterization of Chlorella vulgaris solution with or without quencher species (e.g., Fe(III), humic acid (HA)) for the first time. The peak was observed at about EX 236.6 nm/EM 326.6 nm for synchronous-scan fluorescence spectra. The fluorescence quenching of algae in system of algae–Fe(III)–HA was studied using synchronous-scan spectroscopy for the first time. Fe(III) was clearly the effective quencher. The relationship between I₀/I (quenching efficiency) and c (concentration of Fe(III) added) was a linear correlation for the algae solution with Fe(III). Also, Aldrich humic acid was found to be an effective quencher. pH effect on synchronous-scan fluorescence intensity of algal solution with Fe(III) and/or HA was evident.     

乌梁素海沉积物孔隙水中溶解有机质的荧光及紫外光谱研究

运用紫外可见光吸收光谱与荧光光谱研究乌梁素海沉积物孔隙水中溶解有机质的来源、结构及腐殖化程度。r_(A,C)、HIX、SUVA₂₈₀和SUVA₂₅₄等被用于表征DOM的腐殖化程度和芳香构化程度及结构,f_450/500用于指示DOM的来源。研究结果表明：腐殖化程度最高的点为湖泊东部的W4样点,腐殖化程度最低的为总排干影响区域的W1样点。E_253/203表明湖泊入口处沉积物孔隙水中有机质主要为不可取代的芳香环结构。荧光指数f_450/500为1.57～1.82之间。总体而言,f_450/500的值更接近于1.6,处于2个端源中间,说明乌梁素海DOM中的腐殖质主要来源于陆源输入。相关分析的结果表明, DOM的不同来源对其腐殖化程度产生影响。随着腐殖化值的增大,DOM的来源由生物源向陆源过渡。     

Chemical ionisation mass spectra of urea derivatives of diisocyanates

The mass spectrometric behaviour of 9-(N-methylaminomethyl)-anthracene derivatives of diisocyanates and the commercial prepolymer of hexamethylenediisocyanate, N,N′2-tris(6-isocyanatohexyl)imidodicarbonic diamide, was studied. Both positive and negative ion chemical ionisation mass spectra with methane as the reagent gas were investigated and the positive ion spectra were found to be the most informative. They all showed quasimolecular ions, (M+1)⁺, as well as fragments useful for identification purposes.     

厌氧氨氧化反应过程的三维荧光光谱解析

采用三维荧光光谱表征了厌氧氨氧化UASB反应器启动过程中和有机冲击负荷条件下的出水样品,应用平行因子分析方法解析样品中各主成分的三维荧光光谱图。研究结果表明,反应器启动阶段,出水中含有类蛋白质、类富里酸和类腐殖酸物质,主要源于接种污泥的菌体自溶和残留有机物厌氧发酵。随着反应器的运行,出水中的类蛋白质,类富里酸物质和类腐殖酸荧光物质逐渐减少。在有机冲击负荷条件下,出水中的类蛋白质组分迅速增加并成为反应器出水中的主要荧光物质。该研究为厌氧氨氧化的启动及运行控制的监控表征提供了新的方法。     

FT-IR spectra of humic substances extracted with dipolar aprotic solvents

Dipolar aprotic solvents (DMSO, DMF and Acetone) in mixtures with dilute HCl extract humic substances by an intermolecular H-bonds disruption mechanism. FT-IR spectra of extracts and difference spectra of unpurified and purified material and thermogravimetric analysis showed that dipolar aprotic solvents produce humic substances with low contents of inorganic impurities and structurally different from common extractants. DMSO and Acetone extract humus particurally rich in aliphatic and proteinaceous components as compared to common extractant.     

Polymer and invert emulsifying oil effects upon droplet size spectra of sprays

Abstract

A series of wind tunnel atomization studies were carried out to investigate the effects of polymer and invert suspension oil “drift control adjuvants” upon the droplet size distribution spectra produced by nozzles typically used in aerial and ground based spraying of pesticides. A D8–46 disc and core was used as a typical aerial application nozzle, and an 8003 fan nozzle was used for the ground based sprayers simulation. The droplet size spectra were evaluated in a wind tunnel using a Malvern 2600 laser particle size analyzer immediately upon mixing and at 15 minutes after re‐circulation through a pumping system. The addition of the polymer‐based adjuvants significantly increased the droplet size spectra parameters of the spray cloud, but all the polymer products showed signs of breakdown of their molecular arrangements in the liquid medium, as a result of agitation. The invert suspension oil adjuvant did not change the droplet size spectra markedly, nor did it show signs of breakdown of the internal liquid structure after re‐circulation.     

Theoretical evaluation of the configurations and Raman spectra of 209 polychlorinated biphenyl congeners

Though polychlorinated biphenyls (PCBs) have distributed as threats in the environment to human beings for several decades, monitoring of trace level PCBs in-field is still a challenge. As a potential method for monitoring PCBs at trace levels, Raman spectroscopy has been used to detect several PCBs in the laboratory. To facilitate the development of rapid detection of PCBs by Raman spectroscopy, it is essential to investigate the Raman spectra of all PCB congeners. Herein, the stable configurations and vibrational spectra of all the PCB congeners were calculated by Gaussian 03 program package. Based on molecular symmetry, PCBs are classified into seven groups. The structural features and the normal vibration modes for each group are discussed. Taking the C(2)-2 group as an example, the wavenumber ranges of the various normal vibration modes in the Raman spectra of PCBs were analyzed. The accuracy of calculated results was verified by experimental Raman spectra of PCB77 standard. This study can elucidate further information to promote the development of Raman spectroscopy in environmental monitoring.     

Physical properties,droplet spectra and deposits of oils used in pesticide sprays

Abstract

The influence of liquid properties on spray atomization and deposition characteristics was studied using two oils of different viscosities and volatilities. For a given volume of oil sprayed, insecticide diluent 585 (ID 585), a petroleum distillate of low viscosity and high volatility, provided numerous small droplets on Kromekote^® cards. However, volume of oil deposited was low. For the same volume of oil sprayed, Sun‐spray® 6N, a non‐volatile paraffinic oil of high viscosity provided fewer but larger droplets, and consequently, the volume of oil deposited was much higher on the cards. These observations are explained on the basis of viscosities and volatilities of the two oils.