青海湖黑马河黄土的高密度光释光测年

西风环流与亚洲季风交互控制下的青海湖流域,对气候变化响应敏感。该区广泛分布的黄土记录了古环境古气候信息,但其在不同时间尺度上的沉积模式和沉积连续性尚不明晰。本文以青海湖西南的黑马河黄土剖面（HMHW）为研究对象,通过高密度光释光（optically stimulated luminescence,OSL）测年,结合粒度、磁化率和色度指标探讨其环境演变特征。结果表明：（1）黑马河黄土的沉积模式以快速堆积为主,集中于较冷的末次冰消期（13—12 ka）和晚全新世（~2 ka）;（2）早中全新世（11—4 ka）存在~7 ka的沉积间断;（3）黑马河黄土剖面（HMHW）的土壤粒度组分,以体积占68.68%的粉砂为主,砂次之,黏粒最少;整个剖面的平均粒径和亮度低值对应古土壤层,高值对应黄土层;磁化率的最大值在115 cm处为74.30×10 ^?8 m ³·kg ^?1,110 cm处的OSL年代为(1.52±0.16) ka,指示晚全新世（~2 ka）有古土壤发育。     

山东淄博佛村黄土沉积多指标记录的气候环境演变过程

对山东省淄博市寨里镇佛村黄土剖面(FC剖面)进行粒度、磁化率及色度等沉积学指标分析,结果表明:(1)FC剖面6个光释光样品年龄结果介于3.02±0.45—100.99±13.58 ka,说明FC剖面是末次间冰期以来的沉积物;(2)根据沉积物粒度频率分布曲线和粒度组成特征,并与伊犁黄土、黄土高原黄土对比,可判知FC剖面为风成沉积物;(3)FC剖面磁化率与色度曲线具有相似的变化趋势,较好指示了黄土沉积时的冷暖干湿变化;(4)根据粒度中值粒径(Md)、低频磁化率(χlf)、土壤颜色(L~*,a~*)、环境敏感组分(56.23—112.20μm)等气候代用指标并结合光释光测年结果,将FC剖面划分为5个部分,分别对应于深海同位素MIS1—MIS5时期。1、3、5部分分别对应MIS1、MIS3早期、MIS5阶段,夏季风强盛,气候较暖湿,发育古土壤;2部分对应MIS2和MIS3中晚期阶段,4部分对应MIS4阶段,冬季风强盛,气候较干冷,堆积黄土。     

川西高原甘孜黄土-古土壤容重的特征及其古环境意义

川西高原一带黄土沉积广泛分布,研究该地区黄土-古土壤序列的容重对于理解黄土沉积过程,探讨青藏高原东部地区的环境演化具有重要意义。论文详细分析了甘孜地区末次间冰期以来的典型黄土-古土壤序列的容重变化,结果表明该区土壤容重在1.63—2.53 g?cm~(-3)变化,黄土地层中容重较大,平均为2.01 g?cm~(-3);古土壤地层中容重较小,平均为1.94 g?cm~(-3)。土壤容重与磁化率、粒度2μm组分具有很好的负相关关系,而与平均粒径、粒度63μm组分呈明显正相关,可能表明了土壤化过程和沉积过程对土壤容重的影响;进一步的环境指标相关分析表明甘孜黄土-古土壤容重可以作为西风和高原冬季风变化的替代性指标。详细研究该区黄土的容重变化将有助于深入理解区域环流的演化过程和高原内部的干旱化历史。     

中国第四纪黄土古环境研究若干进展

随着技术进步和多方位研究进展,第四纪古环境研究向着多元古环境替代指标、高分辨率古气候研究、气候变化的多种驱动因素等方面发展。文章总结了中国黄土古环境研究中的主要替代性指标,包括黄土磁化率、黄土粒度、植物硅酸体、孢粉组合、蜗牛化石、碳氧同位素和^10Be、黄土与古土壤。概述了当前对黄土—古土壤的时间标尺、末次冰期的短尺度气候事件以及东亚古季风变化机制的认识。     

西风区黄土–古土壤的碳酸盐含量对磁化率影响研究

本文选择伊犁盆地塔勒德黄土– 古土壤序列,系统地开展了沉积物碳酸盐和磁化率等指 标研究,初步探讨了伊犁黄土碳酸盐含量对磁化率增减的影响机制。研究发现,塔勒德古土壤 中低频磁化率值中明显低于黄土层,且较黄土高原古土壤值小,频率磁化率也远小于黄土高原; 碳酸盐含量在S₁ 层中含量明显高于黄土,且较黄土高原古土壤高,与剖面磁化率负相关,在古 土壤中相关度更显著。去除碳酸盐的设计实验显示加入蒸馏水后沉积物磁化率值变化在10％以 内;加入醋酸（HAc）后样品磁化率值均增加,其最大增幅达12.89%（黄土）,古土壤的磁化 率增加9% 以上;加入稀盐酸后影响程度不一,在黄土中约在15%,而对古土壤影响较大,最大 可达35%,表明沉积物中碳酸盐含量对磁化率的影响不仅是简单的稀释作用,还与干旱气候环 境下碳酸盐化、次生碳酸盐化作用相关。     

中国东北末次冰期松原黄土的释光测年及其古气候意义初探

本文以中国东北松原黄土为研究对象,通过光释光测年建立其末次冰期年代标尺,并探讨磁化率和平均粒径这两个黄土研究中常用的气候替代性指标的可能指示意义。采用成熟的细颗粒石英单片再生(SAR)光释光(OSL)测年技术获得了松原剖面顶部5.5 m年代6个,并获得了2 cm间距的低频磁化率和平均粒径这两个常规参数。石英OSL测年相关检验证实了该技术测量松原黄土的可靠性。测年结果表明,松原剖面顶部5.5 m主要沉积于末次冰期的中晚期,即约5.5—1.8 m((52.18±3.47)—(27.76±1.77)ka)主要堆积于深海氧同位素阶段(MIS)3中晚期,而顶部1.8—0.4 m((27.76±1.77)—(20.61±1.31)ka)堆积于MIS2早期。磁化率自52.18±3.47 ka到27.76±1.77 ka经历了先小幅降低又小幅升高,波动幅度较小,而自27.76±1.77 ka以后,磁化率值呈整体下降并呈现大幅度摆动。平均粒径则自52.18±3.47 ka到46.80±3.13 ka呈明显变小趋势,自46.80±3.13 ka到约20 ka变化不大,自约20 ka以后,平均粒径由约40μm陡然增加至约140μm,并在之后稳定在这一水平。测试结果对比显示,磁化率和粒度的变化不具有明显的相位关系,且同黄土高原渭南剖面末次冰期磁化率和平均粒径的变化也表现出明显的不一致现象。因此,在对松原黄土剖面的研究中,将磁化率和平均粒径分别作为东亚夏季风和冬季风的替代性指标使用时要慎重。     

中亚则克台黄土剖面记录的末次冰期以来的环境演变

选取位于中亚伊犁盆地中东部的则克台（ZKT）黄土剖面作为研究对象,基于13 个光释 光年代构建了ZKT 剖面的年代框架,利用黄土沉积速率、粒度以及总有机碳含量重建了伊犁地区 末次冰期以来的环境演变记录。结果表明：（1）伊犁地区末次冰期以来的气候演化阶段可划分为 寒冷期（74.5~60 ka）、温湿期（60~30 ka）、寒冷期（30~11.5 ka）以及11.5 ka 以来的暖湿期, 该气候演化特征与深海氧同位素不同阶段气候特征较为一致;（2）MIS4 至MIS1 阶段则克台剖 面沉积速率呈递减趋势,分别为49 cm·ka^-1、32 cm·ka^-1、13 cm·ka^-1 和8 cm·ka^-1;（3）ZKT 剖面 代表的伊利地区环境演变特征可与格陵兰冰芯进行良好对比,北大西洋地区的快速气候波动信号 在伊犁地区气候记录相对清晰,在时间上呈同步变化。     

泾河中游将军村全新世剖面中钾素的地球化学特征及古气候意义

通过对泾河中游将军村全新世黄土地层中钾素、低频质量磁化率、频率磁化率、Rb/Sr与年代学综合分析,着重探讨了黄土中钾素的地球化学特征及其所揭示的古气候变化。研究表明：（1）速效钾、缓效钾具有很明显的古气候指示意义,可作为衡量东亚夏季风强弱的一种敏感参数或代用指标,并且对微弱的古气侯波动反映更灵敏。（2）近万年来将军村剖面所经历的古气候变化特征：早全新世（11.20—8.05 ka BP）气候逐渐趋于相对暖湿,但气候冷干/暖湿波动频繁交替;中全新世（8.05—3.10 ka BP）气候适宜;晚全新世前期（3.10—2.00 ka BP）气候偏凉干;晚全新世后期（2.00 ka BP—至今）气候再度转为偏暖湿。（3）将军村剖面全新世气候适宜期是渐变形成的,但大暖期却在约3.10 ka BP时以气候突变形式终结。     

湖南澧阳平原黑褐色土的稀土元素地球化学特征及其环境意义

通过对澧阳平原大量的野外考察、典型剖面玉成(YC)黑褐色土壤剖面的系统取样和室内粒度、稀土元素地球化学分析,以及OSL和AMS14C年代测定,探讨了黑褐色土的稀土地球化学特征,揭示了黑褐色土的形成年代、形成过程与形成环境.研究结果表明,黑褐色土层XREE变化范围分布在184.63-264.261μg·g-1,其平均值为207.93μg·g-1;低于剖面的∑REE总平均值219.87Pμg·g-1,与洞庭盆地的红土∑REE平均值(211.6μg·g-1)大体相当,但明显高于镇江下蜀黄土(207.7μg·g-1)和黄土高原黄土(159.2μg·g-1),表明YC剖面黑褐色土上经过了相对较强的风化成壤作用.YC剖面黑褐色土的稀土分布模式与该剖面黄土层、黄土高原黄土、镇江下蜀黄土和洞庭盆地风成红土等典型风成沉积物的分布模式具有一致性,而与河流沉积物、湖泊沉积物和基岩风化红土在稀土的分布模式上具有明显差别.而且,YC剖面沉积物粒度频率曲线呈明显的单峰分布,与典型河流相的双峰粒度频率分布存在显著差异;YC剖面位于澧阳平原中部台地上,比周边高5-10m,不可能是洪水作用沉积物;野外调查进一步表明,沉积物无水流作用痕迹;OSL和AMS14C年代测定表明,黑褐色土层形成的年代对应于23.8-10.6 ka BP,此年代对应于末次冰期的晚期,其形成于相对冷湿的气候环境.因此,黑褐色土层及其上、下部的黄土层均为风成堆积物.     

末次间冰期以来渭河盆地沉积相变化及其影响

渭河盆地南依秦岭、北邻黄土高原,保存了巨厚的风尘河湖相沉积序列,是研究新生代气候环境演化的理想场所.以位于西安凹陷区域的西安市鄠邑区正庄村获取的14 m钻孔岩心作为研究对象,通过与邻近的渭南黄土剖面粒度曲线和全球LR04深海氧同位素曲线对比,构建了岩心序列的年代标尺,利用粒度、磁化率等指标探讨风尘-湖相沉积对风力和水动力的不同响应.对粒度测试结果采用威布尔分布(Weibull-distribution)拟合方法,提取了4个粒度组分指示不同沉积相及变化,结果表明:(1)西安凹陷鄠邑地区在末次间冰期结束时发生了一次沉积相变,由湖泊沉积转向风成沉积;(2)尽管沉积相发生变化,粒度指标对沉积环境变化响应仍然敏感,与黄土和石笋记录可良好对比,揭示出末次间冰期以来渭河盆地沉积环境的显著变化.     

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.     

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.     

Simultaneous removal of ammonium and phosphate by zeolite synthesized from coal fly ash as influenced by acid treatment

Zeolite synthesized from fly ash （ZFA） without modification is not efficient for the purification of NH4＋ and phosphate at low concentrations that occur in real effluents, despite the high potential removal capacity. To develop an effective technique to enhance the removal efficiency of ammonium and phosphate at low concentrations, ZFA was modified with acid treatment and the simultaneous removal of ammonium and phosphate in a wide range of concentration was investigated. It was seen that when compared with untreated ZFA, only the treatment by 0.01 mol/L of H2SO4 significantly improved the removal efficiency of ammonium at low initial concentrations. The behavior was well explained by the pH effect. Treatment by more concentrated H2SO4 led to the deterioration of the ZFA structure and a decrease in the cation exchange capacity. Treatment by 0.01 mol/L H2SO4 improved the removal efficiency of phosphate by ZFA at all initial P concentrations, while the treatment by concentrated H2SO4 （≥0.9 mol/L） resulted in a limited maximum phosphate immobilization capacity （PIC）. It was concluded that through a previous mild acid treatment （e.g. 0.01 mol/L of H2SO4）, ZFA can be used in the simultaneous removal of NH4＋ and P at low concentrations simulating real effluent.