浑太水系水体中不同粒径有机胶体荧光光谱特性

将超滤系统与孔径(相对分子质量)为100×103和1×103超滤膜结合,对浑太水体中总溶解有机质(DOM)进行分级,并运用三维荧光光谱技术对不同级有机质的荧光光谱特性进行了对比分析.结果表明,浑太水系水体的荧光图谱表现为紫外光区类腐殖质、可见光区类腐殖质、类色氨酸(短波和长波激发峰)4个荧光峰,其中,类腐殖质荧光物质主要赋存于胶体形态(相对分子质量<100×103)和真溶解态(相对分子质量<1×103)中,由于类蛋白物质与水体中胶体的相互作用,使得胶态类蛋白荧光物质也占有相当大的比例.峰、枯两水期相比,丰水期由于陆源汇流的冲击作用,阻止了胶体颗粒的凝聚,使DOM中小胶态和真溶解态有机质所占的质量分数较高.通过比较不同粒径有机质的荧光指数、生物源指数、腐殖化指数以及DOM与荧光强度的相关性分析可以得出,真溶解态中腐殖质主要源自于内源作用,而胶态腐殖质具有陆源特征,新产生的有机质在真溶解态中占有更大的比例,水体中类腐殖质是溶解有机碳(DOC)的主要来源,但由于浑太水系各采样断面存在不同程度的污染,类蛋白物质对DOC的贡献也不能忽略.     

南昌市湖泊水体中不同粒径胶体的三维荧光光谱特征研究

基于切向流超滤系统及三维荧光光谱(3D-EEM)技术,结合平行因子分析法(PARAFAC)及自组织映射神经网络(SOM),对南昌市典型湖泊水体中不同粒径胶体的荧光物质组分、来源及结构等进行分析.通过PARAFAC解谱发现,各粒径胶体主要由5种荧光组分组成,即类腐殖质组分(C1~C3)及类蛋白质组分(C4~C5).其中,类腐殖质组分主要集中在小分子量(1~10 k Da)胶体中,而类蛋白质组分则主要存在于大分子量(100 k Da~0.45μm)胶体中.同时,利用光谱指数(FI、BIX、HIX、UV254)表征胶体组分来源及其特性,结果表明,大分子量胶体以自生源为主,而小分子量胶体的腐殖化程度及芳香性更高,这与其较高比例的类腐殖质组分有关.经SOM训练,探讨了不同粒径分级胶体在SOM映射图中的分布情况,其结果与PARAFAC所得结果一致,即小分子量胶体及大分子量胶体主要分别映射于SOM的下部和上部,而类蛋白质荧光峰强度占总荧光强度的比例为自右上至左下方向递减.PARAFAC与SOM的有效结合,可为了解水体中的物质组成、掌握胶体在水环境中的环境行为及其与污染物在水体中的归趋作用提供数据支持.     

堆放垃圾渗滤液水溶性有机物的荧光特性

为揭示堆放垃圾渗滤液物质组成特性及其变化规律,采用三维荧光光谱,对4个不同垃圾堆场渗滤液水溶性有机物(DOM)进行了研究.结果显示,堆放垃圾渗滤液样品S1中含有2类蛋白荧光峰:类酪氨酸荧光峰和类色氨酸荧光峰,其他3个样品(S2、S3及S4)只含有类色氨酸荧光峰,此外还出现了类腐殖质荧光峰,且不同样品中该峰的数目、类型及位置均存在差异,显示渗滤液样品S1只含有类蛋白类物质,而其他3个样品除此之外还含有类腐殖质物质,且腐殖化程度各异.类蛋白类物质-Hg(II)配位研究显示,与类色氨酸荧光峰相比,类酪氨酸荧光峰更易受介质微环境改变影响;室温培养模拟研究显示,与类腐殖质物质相比,类蛋白类物质更易发生降解.三维荧光光谱可以有效表征堆场渗滤液DOM物质组成及其变化规律.     

利用PARAFAC及SOM研究不同来源及粒径胶体的三维荧光光谱特征

利用三维荧光光谱法(3D-EEM)结合平行因子分析(PARAFAC)和自组织神经网络分析(SOM),解析了不同来源水体中不同粒径胶体的荧光特性,同时与挑峰法进行比较,以期寻找一种更好的分析天然胶体来源、粒径、荧光特性间关系的方法.基于PARAFAC模型,研究区水体中不同粒径胶体共解析出2个类腐殖质荧光峰(C1和C3)及3个类蛋白荧光峰(C2、C4和C5).其中,300 k Da~1μm分级胶体荧光强度最高,C1、C2、C3组分的荧光强度随粒径增大而增强,C4、C5组分的荧光强度随粒径增大而减弱.不同来源胶体(生活污水:进水和出水;农业污水:大盈和天恩桥;天然水体:吴淞口)的荧光强度变化大致规律为:吴淞口进水大盈天恩桥出水.SOM分析结果与PARAFAC一致,且可视化程度更高,但EEM-SOM模型存在输入变量多、兼具挑峰法缺点的问题.而PARAFAC-SOM模型不仅兼具了前两者的优点,还具有输入变量少、运行时间短、可靠性高等优点.同时,该模型还成功应用于胶体其他理化参数的分析(Parameters-SOM模型),使得前期工作结果系统性更强、更直观.因此,PARAFAC-SOM模型是相对较好的分析天然胶体来源、粒径、荧光特性间关系的方法.     

三峡库区消落带水体DOM不同分子量组分三维荧光特征

本研究利用超滤技术和三维荧光光谱,以三峡库区典型消落带水体溶解性有机质(DOM)不同分子量组分为对象,分析和讨论了不同分子量级分的组成差异和输入来源.结果表明,该区域DOM分子量分布情况较为分散,但胶体(M_r1×10~3~0.22μm)和真溶态组分(M_r1×10~3)均对DOC总质量贡献相当.不同分子量级分中均存在A、C、B、T峰,其相对含量分配均呈现出一致趋势,即真溶态(M_r1×10~3)低分子量组分(M_r1×10~3~10×10~3)中分子量组分(M_r10×10~3~30×10~3)高分子量组分(M_r30×10~3~0.22μm).另外,DOM随超滤分子量等级降低,FI和BIX值增加,"内源"输入特征增强;腐殖化程度降低(HIX值下降).陆源输入主要影响高、中分子组分,而内源输入主要影响低分子及真溶态部分.同时,沿岸不同土地利用类型对水体DOM性质和组成影响明显.土地利用类型多样性、生态景观结构复杂程度越高,水体DOM不同分子量等级中各荧光组分也越复杂.     

不同粒径黄河沉积物中可提取腐殖质的含量分布及光谱特性

测定了黄河表层沉积物3种粒径组分（Ⅰ：100～300 μm;Ⅱ: 63～100 μm;Ⅲ: <63 μm）中总有机碳和可提取腐殖质的含量,分析了可提取腐殖质的紫外-可见吸收光谱、红外光谱和三维荧光光谱特征,探讨了不同粒径组分沉积物中可提取腐殖质含量分布及其化学组成特性.结果表明,沉积物有机质主要为粘土矿物吸附的天然腐殖质成分,总有机碳中可提取腐殖质的比例随沉积物有机质与矿物质相互作用的增强而降低,顺序为Ⅰ>Ⅱ>Ⅲ.3种粒径组分沉积物中可提取腐殖质的紫外-可见吸收光谱相似但相对峰强不同;红外光谱主要有5个吸收峰,各吸收峰面积百分含量的计算结果表明酚、醇及羧酸类官能团为主要的活性官能团,占可提取腐殖质组成的75%以上;三维荧光光谱主要有3个荧光峰,除了典型的类腐殖质荧光峰（峰A和峰C）外,还有源于小分子类蛋白或酚类物质的荧光峰（峰T′）.比较3种粒径组分沉积物中可提取腐殖质的紫外-可见、红外及三维荧光光谱的特征参数,发现Ⅰ、Ⅱ组分沉积物中可提取腐殖质的芳香度高,脂肪族和芳香族含量高于Ⅲ组分,而Ⅲ组分沉积物可提取腐殖质中酚、醇及羧酸类活性基团含量相对较高.     

滇池流域入湖河流溶解性有机质的分布及来源

基于三维荧光光谱和平行因子分析方法,探究了2018年滇池流域主要入湖河流丰水期和枯水期水体溶解性有机质（DOM）组成,并结合主成分分析和多元线性回归分析对河流中DOM各荧光组分的相对贡献进行了定量分析.结果表明：入滇河流水体DOM包含5种荧光组分,分别为类腐殖质荧光组分C1、C3、C5和类蛋白色氨酸荧光组分C2、C4,且5种荧光组分之间具有同源性,污染严重河流水体DOM的荧光强度相对较高;荧光指数、自生源指数、腐殖化指数综合表明,入滇河流水体DOM的内源特性较强,自生源特征明显,生物可利用性较高,腐质化程度低,分子结构不稳定.主成分分析和多元线性回归分析结果显示：枯水期DOM的荧光组分中类腐殖物质的平均贡献率占30.1%,类蛋白色氨酸物质的平均贡献率占69.9%;丰水期DOM组分中类腐殖物质的平均贡献率占54.3%,类蛋白色氨酸物质的平均贡献率占45.7%.     

三维荧光光谱区域积分法解析辽河七星湿地水体DOM组成及来源

监测了七星湿地水体水质,采用三维荧光光谱技术结合荧光区域积分(FRI)分析法研究七星湿地水体中溶解性有机物(DOM)荧光特性,分析了DOM组成、腐殖化程度、污染来源等与其他水质指标之间的相关性。结果表明,七星湿地对于支流水体有一定的净化作用,出水CODCr满足GB 3838—2002的Ⅴ类水质标准,氨氮及总磷仍然是水体中的主要污染物;荧光指数(f450/500)平均值为1.82,表明七星湿地DOM主要是生物来源;腐殖化指数(rB,D)整体较低,表明湿地水体腐殖化程度较高,有机物污染较为严重。通过荧光区域积分法将荧光光谱图划分为五大类,其中芳香性蛋白类物质Ⅱ相对浓度最高,占DOM总量的37.51%~54.2%,其主要与生活污水排放有关;DOC浓度与芳香蛋白类物质Ⅰ、芳香蛋白类物质Ⅱ、溶解性微生物代谢产物及腐殖质类物质有较高相关性;TP浓度则与芳香蛋白类物质Ⅱ呈显著正相关,与富里酸类物质和腐殖酸类物质显著相关。三维荧光光谱区域积分法可用于水体中DOM组成及污染物来源研究。     

辽河流域与英国中部河湖水体中溶解有机质的荧光特性

运用三维荧光光谱技术对辽河流域和英国中部水体中溶解有机质(DOM)的荧光光谱特性进行了分析.结果表明,辽河流域各研究水体中DOM包含4种荧光组分,即类色氨酸、类酪氨酸、可见光区和紫外光区类腐殖质,通过对荧光特性定量指标的分析可知,辽河流域各研究断面水体中类腐殖质物质内源作用大于陆源,DOM具有较强的新近自生源,各河流水体中DOM腐殖化程度顺序为:浑河中游海城河中游蒲河下游太子河下游.相比之下,英国河湖中,除了River Tame含有以上4种荧光组分外,其它水体中均没有发现类酪氨酸荧光物质,甚至在River Tern中仅含有类腐殖质荧光物质,河湖中DOM含有较少的新近自生源组分,以陆源影响为主.另外,辽河流域水体中类蛋白与类腐殖质荧光峰强度比值大于英国各河流水体的平均值.由此可以推断,辽河流域各研究断面大量污染物的输入,是造成其严重内源污染的主要原因,从而使水体中DOM含量增加,英国各河流断面其DOM主要来自于水体本身存在的大量微生物和浮游植物的代谢活动以及土壤有机质经雨水的冲刷流入水体的贡献.     

夏季太湖CDOM光学特性空间差异及其来源解析

为进一步探究夏季太湖CDOM（有色溶解性有机质）光学特性在空间分布上的差异性与其来源的关系,对其紫外-可见吸收及三维荧光光谱特性进行了分析研究,在此基础上进一步分析了CDOM吸尘系数及其荧光组分（C1、C2、C3、C4）强度和各水质参数间的相关性.结合主成分分析法探讨了CDOM的来源以及与各参数指标[ρ（DOC）除外]之间的来源关系.结果表明:CDOM吸收系数α（355）、S值（光谱斜率）变化范围分别为3.27~8.27 m-1和0.011~0.021 nm-1;太湖西部、北部及南部湖区CDOM丰度较大,S值较低,受陆源输入的影响较为明显.CDOM的三维荧光光谱揭示其中含有两种类蛋白质组分C1和C2以及类腐殖质组分C3和C4,并且以类蛋白质组分为主.此外,大部分采样点的荧光指数（FI）为1.70~2.01,自生源指数（BIX）大于1,腐殖化指数（HIX）小于0.6,r_（T/C）（荧光峰T与荧光峰C荧光强度比值）小于2,表明夏季太湖CDOM内源特性相对强烈.研究显示,除ρ（DOC）外,CDOM与其他水质参数在第一主成分上（贡献率为90.8%）均存在显著相关关系,说明各水质参数的来源存在相似性,并且受生物自生源影响更为显著.      

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.     

Decomposition of alachlor by ozonation and its mechanism

Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.     

Enzymatic oxidation of aqueous pentachlorophenol

The influence of the nonionic surfactant Tween 80 on pentachlorophenol （PCP） oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration （CMC）. Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.     

基于综合水质标识指数和对应分析法的校园河道水质评价

以三峡大学的校园河道求索溪为研究对象,利用综合水质标识指数法确定求索溪水质类别,分析其水质时空变化规律,并利用对应分析法得出求索溪中不同监测点的主要污染因子.研究结果表明:求索溪整体的综合水质标识指数为7.423,整体水质为劣V类(地表水环境质量标准GB 3838-2002)且黑臭.从时间变化来看,求索溪4月份的水质最差,5月份次之,4、5月份所有监测点的水质都劣于V类且黑臭;8月份水质最好,水质为Ⅳ类;从空间分布来看,8个监测点综合水质标识指数均超过6.0,水质为劣V类,其中6号监测点的水质相对最好,监测点3号的水质相对最差;对应分析法得出求索溪的整体水体污染程度受总氮因子的影响最大,其次为总磷.该研究拟为求索溪及类似校园河道的水环境治理研究提供基础依据和参考.     

Effects of chitosan on growth of an aquatic plant (Hydrilla verticillata) in polluted waters with different chemical oxygen demands

Effects of chitosan on a submersed plant, Hydrilla verticillata, were investigated. Results indicated that H. venicillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand (COD). Superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD (980 mg/L) and decreased with low COD (63 mg/L), respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant cells from the control experiment (untreated with chitosan) were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.     

Removal of cadmium using MnO2 loaded D301 resin

MnO2 loaded weak basic anion exchange resin D301 （Anion exchange resin, macroreticular weak basic styrene） as adsorbent has been prepared and applied to the removal of cadmium. The adsorption characteristics have been investigated with respect to effect of pH, equilibrium isotherms, removal kinetic data, and interference of the coexisting ions. The results indicated that the Cd^2＋ could be efficiently removed using MnO2 loaded D301 resin in the pH range of 3-8 from aqueous solutions with the co-existence of high concentration of alkali and alkaline-earth metals ions. The saturate adsorption capacity of the Cd^2＋ was 77.88 mg/g. The adsorption process followed the pseudo first-order kinetics. The equilibrium data obtained in this study accorded excellently with the Langmuir adsorption isotherm.     

Evaluation of phytoextracting cadmium and lead by sunflower, ricinus, alfalfa and mustard in hydroponic culture

Soil contaminated with heavy metals cadmium(Cd)and lead(Pb)is hard to be remediated.Phytoremediation may be a feasible method to remove toxic metals from soil,but there are few suitable plants which can hyperaccumulate metals.In this study,Cd and Pb accumulation by four plants including sunflower(Helianthus annuus L.),mustard(Brassica juncea L.),alfalfa(Medicago sativa L.), ricinus(Ricinus communis L.)in hydroponic cultures was compared.Results showed that these plants could phytocxtract heavy metals, the ability of accumulation differed with species,concentrations and categories of heavy metals.Values of BCF(bioconcentration factor)and TF(translocation factor)indicated that four species had dissimilar abilities of phytoextraction and transportation of heavy metals.Changes on the biomass of plants,pH and Eh at different treatments revealed that these four plants had distinct responses to Cd and Pb in cultures.Measurements should be taken to improve the phytoremediation of sites contaminated with heavy metals,such as pH and Eh regulations,and so forth.     

Effect of coagulation pretreatment on the fouling of ultrafiltration membrane

The purpose of this study is to understand the effect and mechanism of preventing membrane fouling, by coagulation pretreatment, in terms of fractional component and molecular weight of natural organic matter （NOM）. A relatively higher molecular weight （MW） of hydrophobic compounds was responsible for a rapid decline in the ultrafiltration flux. Coagulation could effectively remove the hydrophobic organics, resulting in the increase of flux. It was found that a lower MW of neutral hydrophilic compounds, which could remove inadequately by coagulation, was responsible for the slow declining flux. The fluxes in the filtration of coagulated water and supernatant water were compared and the results showed that a lower MW of neutral hydrophilic compounds remained in the supernatant water after coagulation could be rejected by a membrane, resulting in fouling. It was also found that the coagulated flocs could absorb neutral hydrophilic compounds effectively. Therefore, with the coagulated flocs formed on the membrane surface, the flux decline could be improved.     

Penetration analysis of elements and bioleaching treatment of spent refractory for recycling

Acidithiobacillus ferrooxidans ATCC23270 and Acidithiobacillus thiooxidans TM-32 were used for bioleaching of spent refractories of aluminium and copper melting furnaces for their recycling.Firstly,penetration of elements into aluminium melting furnace refractory was investigated and it was found that up to 7 cm from surface was contaminated.Comparison on leaching efficiency by the strains ATCC23270 and TM-32 found that the strain ATCC23270 could treat larger amount of the refractories than the strain TM-32 could do.In the experiment of bioleaching of spent refractory aluminium melting furnace by the strain ATCC23270,high leaching efficiency were obtained on Al,Si,and Ca,and extremely low leaching performance was,however,shown on the rest of elements i.e.,Na,Mn,and Zn.Under the strain TM-32 use,relatively high leaching performance was recognized on Al,Si,Ca,Na,Mn,and Zn.In the experiment of bioleaching for spent refractory copper melting furnace,almost the same leaching trends were shown on Cu,Zn,Al,and Si under the strains ACTT23270 and TM-32 uses.