Potential use of organic waste substances as an ecological technique to reduce pesticide ground water contamination

The heavy use of pesticides in agriculture has meant that the fate due to their movement after their application continue to be a real problem for the environment. In this work, a viable eco-remediation technique based on the use of natural organic substances (NOS) that characterize the Mediterranean region is proposed to demonstrate the efficiency of endosulfan sulphate removal from water. Experimental results showed that the pH of pesticide solutions and temperature negatively affect the adsorption process. According to adsorption kinetic data, 5 h were considered as the equilibrium time for realizing adsorption isotherm. The Freundlich isotherm model describes better the adsorption process of endosulfan sulphate on NOS tested. The Freundlich constant K_f depended mainly on the nature of each adsorbent and ranged from 5.56 for straw to 13.54 for date stones. The adsorption tests gave very satisfying results and point to the possible application of these supports as an ecological remediation technique to reduce pesticide contamination of aquatic ecosystems.     

有机硅涂层表面能对海生物附着的影响

随着海洋生态环境保护和防止海洋生物污损的要求,人们试图用具有特殊表面性能的涂层取代有毒涂层来减弱或消除海生物的附着。本文通过对含有机硅防污涂层表面能的测量计算,探讨了涂层表面能各分量对附着生物的影响。实验结果表明,在表面能低色散分量的含有机硅涂层上,随涂层与水的相互作用力分量减小,绿藻和玻璃海鞘的污损增加。     

Excitation-emission matrix fluorescence and parallel factor analyses of the effects of N and P nutrients on the extracellular polymeric substances of Microcystis aeruginosa

Extracellular polymeric substances (EPS) secreted by phytoplankton can induce bloom formation, and nutrients are considered the key factors that cause algal blooms outbreak. Thus, understanding the characteristics of EPS from blooming Microcystis under the influence of nitrogen (N) and phosphorus (P) is important. In this study, the effects of nitrogen (N) and phosphorus (P) nutrients on EPS released by Microcystis aeruginosa in Lake Taihu were examined in pure cultures. The characteristics of Microcystis EPS were evaluated by excitation-emission matrix (EEM) fluorescence spectroscopy with parallel factor analysis (PARAFAC). Results indicated that the fluorescent characterization of EPS was affected more by N than by P. Low N concentration can stimulate cells to secrete large amounts of tyrosine-like substances directly into the culture medium, thus suggesting that Microcystis features a mechanism for adapting to low N conditions. Total fluorescent intensities in the EPS were significantly related to cell biomass. All fluorescent substances in the bound EPS fraction were positively and significantly correlated with Microcystis growth. As for the soluble EPS fraction, the humic-like and tryptophan-like substances were both significantly related to cell biomass, whereas only the tyrosine-like substances were significantly related to cell biomass under low N supply. PARAFAC analysis of the EEM spectra showed that N greatly affected the exudation of tyrosine-like substances and redistribution of the EPS fractions. Thus, protein-like fluorophore could be used as a potential indicator to evaluate the nutritional status of cyanobacteria during cyanobacterial blooms in Lake Taihu.     

江苏高宝邵伯湖表层水体典型精神类药物及其代谢产物的污染水平、分布特征及风险评估

为探究典型精神类药物及其代谢产物在高宝邵伯湖——宝应湖、高邮湖和邵伯湖表层水体的污染水平、分布特征及生态风险,利用超高效液相色谱-串联质谱法,对研究区域18个采样点位表层水体中3类（抗抑郁药物、抗癫痫药物和抗精神病药物）21种精神类药物及其代谢产物的浓度水平进行检测分析.结果表明,除奥卡西平外,其余20种典型精神类药物及代谢产物均有不同程度地检出,检出率范围为22.2%～100%,总检出浓度范围为1.4～224.5 ng/L.其中抗精神病药物利培酮检出浓度最高,浓度范围为0.1～64.1 ng/L.不同采样点精神类药物及其代谢产物的浓度存在空间差异,呈现邵伯湖和高邮湖南部浓度较高,高邮湖北部和宝应湖浓度较低的趋势.由聚类分析可知,点位S1、S7单独形成聚类,浓度分别为175.7和102.9 ng/L.对精神类药物及其代谢产物的来源分析发现,污水处理厂、生活污水和农业废水排放可能是高宝邵伯湖地表水中精神类药物及其代谢产物的主要来源.采用风险商值法（risk quotient,RQ）进行生态风险评估,结果表明高宝邵伯湖表层水体中卡马西平和环氧卡马西平对水生生物具有高风险（RQ>1）.精神类药物及其代谢产物在环境中持续性赋存的风险需引起重视.     

Characterization and antifouling activity analysis of extracellular polymeric substances produced by an epibiotic bacterial strain Kocuria flava associated with the green macroalga Ulva lactuca

Extracellular polymeric substances(EPS) are present externally to the microorganisms and play an important role in attachment and biofilm formation. These polymers possess antibacterial and antifouling activities. In this study, the antifouling activity of EPS produced by an epibiotic bacterium associated with macroalga Ulva lactuca was assessed against fouling bacteria and barnacle larvae. Results indicate that the EPS isolated from the epibiotic bacterium inhibits the biofilm formation of the bacteria without much antibacterial activity. Also, the EPS reduced the settlement of barnacle larvae on the hard substrate under laboratory conditions. The epibiotic bacterium was identified as Kocuria flava based on 16 S rRNA gene sequencing. The EPS was further analysed using Fourier transform infrared(FT-IR), nuclear magnetic resonance(NMR) and X-ray diffraction(XRD) to understand the biochemical composition. NMR analysis revealed the presence of polysaccharides, proteins, acetyl amine and succinyl groups. Scanning electron microscope analysis indicated that the EPS consisted of aggregated and irregular sphere-shaped particles.     

On sediment pollution in selected german coastal waters of the Baltic Sea

In order to determine and assess their status sediments from the German coastal waters of the baltic sea were analyzed for structural parameters and for several groups of harmful substances. Regarding all groups of harmful substances, i.e. nutrients, heavy metals and organic toxicants the sediments of the eastern sections investigated (Strelasund, Peenestrom and Stettin Lagoon) are generally more polluted than the sediments of the other ones.The sediments of the examined sections of the Baltic coast compare with North Sea sediments by factors of between 0.05 and 4 with regard to heavy metals.Because of the variability of the concentration of harmful substances in the various coastal sections, it is imperative to make a differentiated assessment of the polluted sediments and to set district-related targets for the various sections of the Baltic coast.     

Comparison of the Complexation of Cu and Cd by Humic or Fulvic Acids and by Ligands Observed in Lake Waters

The complexation of Cu and Cd by ligands observed in filtered unfractionated lakewaters is compared to the complexation by humic and fulvic acids. Complexation parameters (conditional stability constants and ligand concentrations) of Suwannee River fulvic acids (FA), purified peat humic acids (HA) and of ligands in lakewater samples have been determined using the same methods (ligand-exchange and CSV (cathodic stripping voltammetry) or ASV (anodic stripping voltammetry)), and the same titration ranges of Cu, Cd and organic carbon concentrations. The performance of the used techniques is first evaluated in FA and HA suspensions, and gives comparable results with the literature values for the same materials, according to published models (5-site model, NICA model) and parameters. Model calculations using the WHAM model for FA and HA (Tipping, 1994) are also presented. The comparison of titrations of FA and HA with Cu and Cd with those of lakewater samples indicates that stronger ligands than FA and HA are present at low concentrations in the lakewaters. Specific strong ligands occur in particular in eutrophic lake waters, whereas in a lake with higher metal concentrations and low biological productivity the ligands more closely match the fulvic acid characteristics.     

Contaminants and habitat choice in the Baltic Sea: Behavioural experiments with the native species, Monoporeia affinis, and the invasive genus, Marenzelleria

The invasive polychaete genus, Marenzelleria and the native amphipod, Monoporeia affinis are food and habitat competitors in the Baltic Sea. Previous studies have shown that moderate densities of Marenzelleria can affect the behaviour of M. affinis. To examine the short-term interactive effects of interspecific habitat choice and environmental contaminants a series of habitat colonisation experiments were performed. The contaminants examined included harbor sediments and sediment spiked with the antifouling substances, Cu, Zn and Irgarol. Polychaetes and amphipods were exposed to contaminants in single-species and two-species experiments. In spiked-sediment experiments, M. affinis showed clear dose-dependent response. These experiments verified that behavioural response of M. affinis to different habitats is a sensitive method for testing toxicity under controlled conditions. In experiments with three different harbor sediments and reference sediment both species showed the lowest preference for the reference sediment. This sediment also had the lowest content of quality food, indicating that factors such as food quality and quantity may override the disturbing effects of contaminants in natural sediments. The presence of Marenzelleria spp. did not affect amphipod habitat choice, indicating no short-term effects, which implies that both species can co-exist provided sufficient food is available.     

Spectroscopic Characterization of Humic-Like Substances in Airborne Particulate Matter

In a standard reference air dust (NIST 1648 – urban particulate matter) as well as in airborne particulate matter collected in German urban and rural areas (Dortmund, Sauerland) 10% and more of the organic carbon can be attributed to macromolecular substances like humic and fulvic acids (HA, FA). Indirect evidence for the presence of humin was also obtained. HA and FA extracted from NIST 1648 and other urban and rural atmospheric particles using 0.1 m NaOH and isolated by ion-exchangers were characterized by their molecular-size distribution applying multistage ultrafiltration, their carbon content and their UV/VIS, Fourier-transformed infrared (FTIR) and nuclear magnetic resonance (¹H-NMR) spectra. Summarizing, the structural studies exhibit that these humic-like substances (HULIS) contained in air dust samples are small in their molecular size and rich in aliphatic and carbohydrate substructures compared to HA and FA from soils and aquatic systems.     

江西省相山铀矿田成矿模式探讨

本文在阐述相山矿田区域地质背景和成矿特征的基础上, 分析了成矿物质来源、成矿溶液来源及成矿物质迁移途径, 建立了相山矿田铀成矿模式。认为相山矿田铀成矿是受区域地质背景控制的特定时空域内的客观产物, 区域富铀地层是成矿的物质基础, 成矿溶液源自岩浆水和混入的雨水, 岩浆及期后热液是铀迁移的载体。铀成矿模式强调了火山岩成岩过程是成矿物质的富集过程, 火山岩浆期后成矿热液系统演化孕育了相山火山盆地50Ma的成矿过程, 流体降温、浓缩、混合等成矿机制的耦合, 促使了铀沉淀、成矿。