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.     

腐殖酸-高岭土复合体形成机制及对三氯乙烯的吸附

为探究土壤中有机组分与无机矿质组分相互作用的机制,以腐殖酸代表有机质、高岭土代表无机矿质,制备不同有机质含量的腐殖酸-高岭土复合体模拟样品,进行三氯乙烯的吸附实验研究.结果表明,各吸附剂样品对三氯乙烯的吸附符合Freundlich等温模型,且吸附量的实际值与理论叠加值有明显差异,说明复合体样品中腐殖酸与高岭土之间存在相互作用.结合红外光谱、比表面积孔分析等多类表征,推测腐殖酸与高岭土相互作用的机制为:腐殖酸含量较低时,腐殖酸分子首先分布于高岭土表面的活性位点上,随着腐殖酸含量的增加(有机质-矿质质量比O/M为0.02~0.04),部分腐殖酸分子进入高岭土表面的孔隙,达到相对稳定后腐殖酸分子继续作用于高岭土表面形成第一层腐殖酸分子膜(O/M为0.04~0.08),随着腐殖酸含量继续增加(O/M为0.08~0.10),更多的腐殖酸分子通过与第一层腐殖酸膜相互作用而在高岭土表面进行第二层叠加,同时第一层被压缩,第二层叠加相对稳定后(O/M为0.10~0.16),仍有部分腐殖酸叠加至第二层之上进行第三层叠加,随后内层腐殖酸进一步被压缩(O/M为0.16~0.24),但可能仍有少量腐殖酸分子和聚集体继续下一层叠加.     

金属氧化物颗粒/水界面上NOM吸附机制的研究

以腐殖酸作为天然有机物(NOM)的代表,研究了腐殖酸分子在金属氧化物(赤铁矿)颗粒/水界面上的吸附特征,分析了pH值和离子强度对界面吸附配位反应的影响,及它们对赤铁矿颗粒表面吸附密度和团聚体粒径的影响.结果表明,吸附密度随pH值的升高而减少,随离子强度的升高而增大;颗粒团聚体粒径随pH值的升高先增大后减小,随离子强度的升高而增大.pH=4时吸附密度最大,为6.22 mg/m2,但此时团聚体粒径最小;pH=5时吸附密度较小,但团聚体粒径较大;pH=8为配位反应等电点,吸附密度和团聚体粒径均较小;pH=10吸附密度最小,为0.50 mg/m2,团聚体粒径也较小.应用SS/SF混合模型初步分析了赤铁矿颗粒/水界面上腐殖酸分子的吸附构型.当pH值较低时,构型多为链状和环状;当pH值较高时,构型多为扫尾状.离子强度越高,链状和扫尾状构型越多;离子强度越低,环状构型越多.     

富里酸和胡敏酸在蒙脱石上的吸附特性

为进一步揭示有机污染物在黏土矿物上的迁移转化规律,运用1H核磁共振光谱、高效体积排阻色谱、扫描电镜、比表面分析以及傅里叶变换红外光谱等多种分析技术综合分析了富里酸和胡敏酸在蒙脱石上的吸附行为. 结果表明,由于不同官能团与蒙脱石的亲和性不同,富里酸和胡敏酸在吸附过程中均产生组分分级,大分子被优先吸附在蒙脱石表面. 由于疏水性作用,蒙脱石对疏水性更强的胡敏酸的吸附量更大. 蒙脱石吸附富里酸后比表面积和孔容分别下降3.67m2/g和0.005cm3/g,而吸附胡敏酸后则均略微增大,说明具有较大颗粒尺寸的胡敏酸更多地堆积在蒙脱石外表面,而富里酸则更易进入蒙脱石孔隙. 蒙脱石吸附富里酸和胡敏酸后溶液pH分别升高了0.44和0.41,说明发生了配体交换反应. 蒙脱石对富里酸和胡敏酸的吸附量随pH增大和离子强度的降低而减少,表明羟基能够抑制富里酸/胡敏酸负电基团与蒙脱石表面羟基的配体交换反应,而盐离子则能降低蒙脱石和腐殖质间的静电斥力.      

Effect of natural aquatic humic substances on the photodegradation of bisphenol A

The photochemical degradation of bisphenol A (BPA) was studied in the presence of natural humic substances from different origins under simulated solar irradiation. BPA underwent insignificant direct photolysis in neutral water, but rapid photosensitized degradation in four humic substances solutions via pseudo-first-order reaction occurred. The photo-degradation rate of BPA was insensitive to the different initial BPA concentrations and was inhibited in aerated solution compared with the deoxygenated medium. The reactive oxygen species (ROS) such as ·OH and ¹O₂ produced from excitation of humic substances under irradiation was determined from the quenching kinetic experiment using molecular probe. The five main intermediate photoproducts of BPA in Nordic lake fulvic acid (NOFA) were tentatively identified using gas chromatography/mass spectrometer (GC/MS). Based on the identification of ROS and the analysis of photoproduct formation, the possible phototransformation pathways of BPA were proposed, involving the direct photolysis due to the energy transfer from the triplet state humic substance (³HS*) to BPA molecules and hydroxyl radical addition and oxidation as well. Translated from Acta Scientiae Circumstantiae, 2005, 25(6): 816–820 [译自: 环境科学学报]     

胺基官能基化的HMS吸附水体中的腐殖酸

研究了胺基表面官能化前后的HMS(hexagonal mesoporous silica)对腐殖酸的吸附, Freundlich方程拟合结果表明,表面官能化后吸附常数K值由0.56提高至105,反映出表面官能化能显著改善HMS对腐殖酸的吸附,且低pH值条件下吸附效果更佳.表征结果显示,腐殖酸分子主要吸附在表面胺化HMS的中孔孔道内,并首先占据吸附剂中较大的中孔孔道.吸附动力学结果显示腐殖酸在表面胺化的HMS上吸附符合二级动力学,吸附速率主要受孔道内扩散控制.     

聚硅酸铝铁复合絮凝剂性能的研究

利用铝盐和铁盐与聚硅酸形成复合絮凝剂可以优势互补的特点,制备了不同n(Al):n(Fe)摩尔比的聚硅酸铝铁复合絮凝剂(PAFSS),并对其性能进行了研究。当n(Al):n(Fe)=1:3时,PAFSS对腐植酸的絮凝去除率可达92.9%,且形成的絮体粒度最大,其中位粒径为110滋m。PAFSS的红外光谱图中有M(Fe和Al)—O—Si振动峰出现,表明金属盐和聚硅酸成键聚合。通过对腐植酸溶液和絮凝出水的Zeta电位测定,及对PAFSS絮凝腐植酸的絮凝过程中的粒度变化的在线分析,结果表明PAFSS具有较强的电中和性能,且絮体具有较强的抗破碎能力。     

除草剂2,4-D在胡敏酸上的吸附

报道了除草剂2，4－D在胡敏酸上的吸附，结果表明：2，4－D在胡敏酸上的吸附符合非线形的Freundlich吸附等温线，胡敏酸的粒径，含是,到及环境温度对2，4－D的吸附均有影响，2，4－D在胡敏酸上的吸附量随胡敏酸的粒径变小以及其含量的增加而增大，并随环境温度的升高而降低。     

Partitioning of water soluble organic carbon in three sediment size fractions： Effect of the humic substances

Water soluble organic carbon (WSOC) in sediments plays an important role in transference and transformation of aquatic pollutants. This article investigated the inherent mechanisms of how sediemnt grain size affect the partitioning coeffcient (k) of WSOC. Influences of NaOH extracted humic substances were particularly focused on. Sediments were sampled from two cross-sections of the middle Yellow River and sieved into three size fractions (< 63 μm, 63-100 μm, and 100--300 μm). The total concentration of WSOC in sediments (CWSOC) and k were estimated using multiple water-sediment ratio experiments. Results show that CWSOC ranges from 0.012 to 0.022 mg/g, while k ranges from 0.8 to 3.9 L/kg. Correlations between the spectrum characteristics of NaOH extracted humic substances and k were analyzed. Strong positive correlations are determined between k and the aromaticity indicators of NaOH extracted humic substances in different sediment size fractions. Comparing with finer fractions (< 63 μm), k is higher in larger size fractions (63--100 and 100--300 μm) related to higher aromaticity degree of NaOH extracted humic substances mostly. While negative relationship between k and the area ratio of fourier transform infrared spectroscopy (FT-IR) at 3400 and 1430 cm-1 implied that the lowest k was related to the highest concentration of the acidic humic groups in particles < 63 μm. WSOC in finer fractions (< 63 μm) is likely to enter into pore water, which may further accelerate the transportation of aquatic contaminants from sediment to water.     

Effects of advanced oxidation pretreatment on residual aluminum control in high humic acid water purification

Due to the formation of disinfection by-products and high concentrations of Al residue in drinking water purification, humic substances are a major component of organic matter in natural waters and have therefore received a great deal of attention in recent years. We investigated the effects of advanced oxidation pretreatment methods usually applied for removing dissolved organic matters on residual Al control. Results showed that the presence of humic acid increased residual Al concentration notably. With 15 mg/L of humic acid in raw water, the concentrations of soluble aluminum and total aluminum in the treated water were close to the quantity of Al addition. After increasing coagulant dosage from 12 to 120 mg/L, the total-Al in the treated water was controlled to below 0.2 mg/L. Purification systems with ozonation, chlorination, or potassium permanganate oxidation pretreatment units had little effects on residual Al control; while UV radiation decreased Al concentration notably. Combined with ozonation, the effects of UV radiation were enhanced. Optimal dosages were 0.5 mg O3/mg C and 3 hr for raw water with 15 mg/L of humic acid. Under UV light radiation, the combined forces or bonds that existed among humic acid molecules were destroyed; adsorption sites increased positively with radiation time, which promoted adsorption of humic acid onto polymeric aluminum and Al(OH)3(s). This work provides a new solution for humic acid coagulation and residual Al control for raw water with humic acid purification.     

基于非对称场流分离技术的水环境腐殖酸聚集特性研究

腐殖酸的聚集特性是影响其去除率及与其它污染物相互作用的重要因素,本文采用非对称场流分离技术对腐殖酸组分进行分离,配合示差折光检测器及多角度激光光散射器,对腐殖酸分子量的分布规律进行研究,探讨了水环境的化学条件对腐殖酸荷电状态和聚集状态的影响规律.结果表明,腐殖酸具有自我凝聚的特性;在p H较低和溶液离子强度较高时,腐殖酸胶粒的Zeta电位绝对值减小而分子量增大,腐殖酸胶粒聚集程度增大;随腐殖酸浓度增大,腐殖酸胶粒的Zeta电位绝对值减小,腐殖酸分子发生聚集而使胶粒分子量增大.当离子强度达到0.08mol·L-1,或浓度达到15 mg·L-1时,腐殖酸分子不仅靠氢键聚集在一起,还可能发生分子间的缔合.     

荧光猝灭滴定法研究土壤腐殖质与氨基甲酸酯类农药相互作用

为研究氨基甲酸酯类农药在溶解有机质参与下的迁移转化过程,利用荧光猝灭滴定法研究了土壤HS(腐殖质)与氨基甲酸酯类农药的相互作用. 结果表明,呋喃丹和西维因的荧光都能不同程度地被FA(富里酸)和HA(腐殖酸)猝灭,主要猝灭机理为静电结合猝灭. 采用静态猝灭模型计算出氨基甲酸酯类农药与HS的K(结合常数),lg K由大到小为呋喃丹-HA(4.96)>西维因-HA(4.93)>呋喃丹-FA(4.72)>西维因-FA(4.68). HA与氨基甲酸酯类农药的lg K明显大于FA与氨基甲酸酯类农药,表明HS与氨基甲酸酯类农药间的作用力有疏水作用. 进一步研究表明,氢键作用对HS与氨基甲酯类农药结合有一定的影响.      

Effects of humic acid on recoverability and fractal structure of alum-kaolin flocs

Particle surface characteristics, floc recoverability and fractal structure of alum-kaolin flocs were investigated using in situ particle image velocimetry (PIV) and microbalance with or without humic acid. Experimental results indicated that the zeta potential of kaolin particle surface after adsorption of humic acid was related with humic acid concentration and its acid-base bu ering capacity. Adsorption of humic acid resulted in more negative electrophoresis on the particle surface. Coagulant dosages for particles to form flocs would increase with increasing humic concentration. PIV was used to evaluate floc structural fragmentation, floc surface erosion as well as recoverability after high shear. It was found that the floc size during the steady phase of growth was small, while the regrowing capability decreased in the presence of humic acid. The recoverability was closely related with floc breakage modes including floc structural fragmentation and floc surface erosion. The fractal dimensions of alum-kaolin flocs by mass-size method based on microbalance would decrease with increasing humic concentration. This study proved that humic acid had adverse influences on the performance of coagulation process.     

猪粪稻秸超高温预处理促进后续堆肥腐殖化条件优化

以猪粪稻秸为原料,设计超高温预处理温度（75,85,95℃）、时间（2,4,8h）和通风量（0.3,0.6,0.9L/kgTS·h）的三因素三水平正交试验,研究不同超高温预处理条件对猪粪稻秸理化特性及后续模拟堆肥腐殖质生成的影响,结果表明,温度、时间和通气量对猪粪稻秸后续高温堆肥腐殖化系数影响各不相同,各因素对后续好氧发酵累腐殖化系数的影响大小顺序为大小顺序为预处理时间 > 温度 > 通气量;最佳超高温预处理条件为：预处理温度为95℃,停留时间为4h,通气量为0.6L/（kgTS·h）,与CK相比,最佳预处理参数下猪粪稻秸后续高温发酵60d腐殖化系数提高119%,腐殖质、胡敏酸含量分别增加105%、116%,而富里酸含量降低17.2%,结合预处理前后物料理化特性变化规律分析,表明超高温预处理促进了大分子有机物降解为可溶性有机碳,促进了木质纤维素组分降解溶出,促使其更多转化为多酚,同时增加了腐殖质前体还原糖、氨基酸的含量,从而有利于腐殖质的生成.     

固液界面NOM吸附中疏水效应的影响研究

文章以腐殖酸和纳米Fe2O3为对象,着重研究了腐殖酸分子在纳米Fe2O3表面的吸附过程中的疏水效应,借助红外光谱和热重等分析方法研究了腐殖酸吸附前后的疏水性随溶液环境变化的规律。结果表明,当离子强度为0、0.005、0.01和0.05 mol/kg,pH值从7变到12时,纳米Fe2O3吸附溶解性腐殖酸分子后形成的复合体的热失重量随着pH值的升高先减小后增大。当pH值从7升高到10时,亲水性降低,疏水性增强;当pH值从10升高到12时,亲水性增强,疏水性降低。当离子强度为0.001 mol/kg,pH值从7变到12时,复合体的热失重量随着pH值的升高而减小,亲水性降低,疏水性增强。当pH值为定值,离子强度变化时,纳米Fe2O3吸附溶解性腐殖酸分子后形成的复合体的热失重量随着离子强度的增加不断变化,曲线呈现出波动趋势,亲、疏水性在交替变化。红外光谱分析结果说明,对纳米Fe2O3吸附溶解性腐殖酸分子后形成的复合体的亲疏水性起主要影响的官能团可能是亲水性的羟基-OH、羰基C=O和疏水性的CH2烷烃。     

Preliminary study on treatment of waste organic matter from livestock by bacteria-mineral technology

The present study dealt with relationships between the degradation and humification process that the organic matter underwent during bacteria-mineral technology.An inverse correlation was found between the protein,lipid,and some of the humification indices considered,suggesting that the humification theory is actually humic substances produced from simple-structured natural organic substrates.Weight-average molecular weight (Mw),number-average molecular weight(Mn),and the ratio Mw/Mn of dissolved organic matters at difierent stages of the process were measured by gel permeation chromatography.The results showed that Mn and Mw increased with reaction time from 352 to 17,191,and from 78,707 to 104,564,respectively.The ratio of Mn/Mw decreased from 223.3 to 6.1.This reflected the growth of the polymerization degree of dissolvable organic matters in the process;furthermore,it indicated the formation of complex molecules (humic substances) from more simple molecules.Bacteria-mineral water(BMW) (the effluent of the process) treatments can exert hormone-like activity for enhanced seed germination of wheat and rice and greatly improved chlorophyll synthesis in wheat and rice leaves.Major polyamines (plant regulators) putrescine,spermidine,and spermine,were found in BMW by a high performance liquid chromatography (HPLC) method,which may explain the hormone-like activity of BMW.     

水生腐殖酸分子量分布研究——Ⅱ.腐殖酸凝胶色谱图峰加宽效应校正

研究了串联凝胶色谱系统的峰加宽效应.在该系统中,单分散标样的GPC谱图为低流出体积一侧较宽的不对称形式,以峰流出体积为界,这样的谱图可视作两个半侧正态函效的拼接.峰加宽效应还随淋出体积增大而加强,简单的直线方程可近似地描述分辨因子h随淋出体积的变化规律.在此基础上建立了腐殖酸GPC谱图峰加宽效应的校正方法.并根据实测结果计算了两个水生腐殖酸样品的分子量分布.     

不同源胡敏酸对磺胺嘧啶紫外光降解的影响及作用机制

研究了紫外光照条件下不同来源的胡敏酸（HA）,包括标准品胡敏酸（SPHA）、水稻土胡敏酸（SDHA）、泥炭土胡敏酸（NTHA）和落叶覆盖地胡敏酸（LYHA）对抗生素磺胺嘧啶（SDZ）光降解的影响以及主要活性物种对其光降解效能的贡献.结果表明：SDZ在纯水中及与HA共存条件下,其光降解过程均符合一级动力学模型,且HA对SDZ的光降解具有促进作用,其促进效果从大到小为SPHA > SDHA > NTHA > LYHA.通过羟基自由基（·OH）和单线态氧（¹O₂）淬灭实验发现,不同来源HA产生·OH和¹O₂的能力具有一定差异性.同等背景条件下,SPHA产生的·OH量相对较多,其对SDZ光降解的贡献率（26.97%）最大,而LYHA贡献相对较小（9.33%）.同时,¹O₂对SDZ光降解起主导作用,其降解贡献率为41.33%~51.95%.     

Kinetics of photoelectrocatalytic degradation of humic acid using B2O3·TiO2/Ti photoelectrode

An innovative photoelectrode, B₂O₃·TiO₂/Ti electrode, was prepared by galvanostaticanodisation. The morphology and crystalline texture of the B₂O₃·TiO₂ film on electrode were examined by acomic force microscopy (AFM) and X-ray diffraction respectively. The examination results indicated that the anatase was the dominant component. The kinetics of photoelectrocatalytic(PEC) degradation of humic acid(HA) was investigated; the results demonstrated that effects from strongness to weakness on the photoelectrocatalytic degraded rate of humic acid: power of UV-lamp, area of TiO₂ film, bias, original concentration of humic acid solution. The optimum conditions were power of UV-lamp 125 W, area of TiO2 film 42.0 cm² , bias 1.4 V, original concentration of humic acid solution 5 mg/L in this PEC reaction system.     

腐殖酸对水中多壁碳纳米管凝聚特性的影响

以多壁碳纳米管(MWNTs)稳定悬浮液为对象,研究了腐殖酸(HA)对水中MWNTs凝聚特性的影响.结果表明,采用SDS超声分散法制备的MWNTs稳定悬浮液具有较强的稳定性,投加电解质可通过压缩双电层机制使其发生凝聚,并符合经典的DLVO理论.HA存在时,可通过增大MWNTs颗粒间的空间位阻效应和亲水性,抑制凝聚反应发生,从而提高其在水中的稳定性.Ca2+可与HA发生络合桥联作用,导致MWNTs颗粒粒径的大幅提高,强化凝聚发生.水中MWNTs的分散和凝聚性质将受到有机物性质和电解质种类等复杂因素的影响.