Estrogenic and dioxin-like compounds in sediment from Zierikzee harbour identified with CALUX assay-directed fractionation combined with one and two dimensional gas chromatography analyses

The identity of compounds responsible for estrogenic and dioxin-like activities in sediment from the harbour of the small town Zierikzee in Zeeland, The Netherlands, was investigated using a bioassay directed fractionation approach with the in vitro estrogen and dioxin responsive reporter gene assays ER- and DR-CALUX. For identification of compounds exhibiting activity in the bioassays, either one or two-dimensional GC in combination with quadrupole (MSD), ion trap (ITD) or time-of-flight mass spectrometric detection (ToF-MS) was used, depending on the biological and chemical characteristics and the complexity of the fractions. The natural estrogenic hormone 17-β-estradiol and its metabolite estrone were identified with GC–ITD as the main contributors to the estrogenic activity. After successive rounds of fractionation, the dioxin-like activity could be explained by the presence of various polycyclic aromatic hydrocarbons identified with GC–MSD and two-dimensional comprehensive GC × GC–ToF-MS. Some estrogenic activity of a relatively non-polar nature remained unidentified.     

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.     

活性污泥数学模型(ASM1)入流组分测定及应用

阐述了活性污泥 1号模型 (ASM1)入流中 7个含碳有机物、4个含氮物质、碱度等四大类 13种组分的分析方法 ,并用这些方法测定了西安市北石桥、电子村两个排放口的城市污水水质。实验结果表明快速可生物降解有机物 (SS)采用间歇实验法、慢速可生物降解有机物 (XS)采用测定BOD5间接计算法既操作简单又准确可靠 ,能为利用活性污泥 1号模型进行污水处理厂的设计、模拟及管理提供入流组分分析依据     

沉积物中磷形态与湖泊富营养化的关系

应用乙二胺四乙酸法对长江中下游太湖、巢湖和龙感湖等3个湖泊表层沉积物中磷的形态进行连续提取和测定.结果发现,在表层沉积物中,3个湖泊钙磷的百分含量比较接近,占总磷的30%左右,太湖和巢湖铁磷的百分含量显著高于龙感湖,而龙感湖有机磷的相对含量较高,可达40%~50%.这3个湖泊沉积物中有机磷形态差别十分明显,其中太湖沉积物中的有机磷主要以酸可提取有机磷形式存在,巢湖沉积物中酸可提取有机磷约占总有机磷的一半,而龙感湖的有机磷大部分与腐殖酸结合.沉积物中酸可提取有机磷的释放可能又是一个导致湖泊富营养化的重要过程.     

非传统稳定同位素锶(δ~(88/86)Sr)的地球化学研究进展

锶有4个稳定同位素:84Sr、86Sr、87Sr和88Sr。但其中的非传统稳定同位素(δ88/86Sr)成为近年来国际同位素地球化学领域的研究热点。本文根据国际众多学者的研究,阐述了大多数实验室新近采用双稀释剂和TIMS方法来获得高精度δ88/86Sr数据的原理,并综述自然界δ88/86Sr变化,列出一些影响锶同位素分馏的因素。综合讨论其在地质方面的应用:(1)根据冷水珊瑚稳定锶同位素重建古海洋温度;(2)联立87Sr/86Sr和δ88/86Sr来研究海洋中锶的地球化学循环;(3)利用骨骼中的锶稳定同位素研究古营养学。     

重金属在猪粪堆肥过程中的化学变化

运用DTPA浸提、化学分级提取、透析及G-75凝胶色谱分离等方法研究不同堆肥工艺及不同原料对猪粪混合堆肥重金属化学形态的影响及其机理.结果表明,堆肥后,树叶+翻DTPA-Cu、DTPA-Zn、DTPA-Pb浓度占其金属总浓度比例的减少量分别为3.36%、8.63%和4.68%,木糠+通翻分别为3.35%、7.45%和4.36%,均显著大于木糠+翻;树叶+翻有机态Cu的增加量为4.49%,木糠+通翻残渣态Zn的增加量为8.42%,均显著大于木糠+翻;木糠+翻及树叶+翻两处理<8000Da组分Zn增加,>25000Da组分Zn减少,而木糠+通翻的变化正好相反;Cu更易与大分子腐殖质组分结合,而且结合较紧密;Zn更易与小分子腐殖质组分结合,但结合不紧密.总的来说,加入树叶或采用强制通风结合翻堆的通风方式有助于降低猪粪堆肥的重金属活性.     

地表环境氮循环过程中微生物作用及同位素分馏研究综述

综述了氮循环过程中的微生物作用及其研究进展 ,阐述了生物固氮、微生物吸收同化、有机氮素矿化、硝化和反硝化的反应机理及反应过程中的同位素分馏 ,提出了微生物驱动氮循环的简要模型。微生物驱动的氮循环中不同过程有不同的同位素分馏特征 ,生物固氮、土壤有机氮矿化过程中分馏效应小 ,而吸收同化、硝化和反硝化过程中同位素分馏较大 ,利用各个过程不同的同位素分馏特征可示踪含氮物质的来源、转化和迁移等。     

Short-term prediction of the influent quantity time series of wastewater treatment plant based on a chaos neural network model

By predicting influent quantity, a wastewater treatment plant (WWTP) can be well controlled. The nonlinear dynamic characteristic of WWTP influent quantity time series was analyzed, with the assumption that the series was predictable. Based on this, a short-term forecasting chaos neural network model of WWTP influent quantity was built by phase space reconstruction. Reasonable forecasting results were achieved using this method. Translated from Acta Scientiae Circumstantiae, 2006, 26(3): 416–419 [译自: 环境科学学报]     

Fractionation of radionuclide species in the environment

Naturally occurring and artificially produced radionuclides in the environment may be present in different physico-chemical forms (i.e., radionuclide species) varying in size (nominal molecular mass), charge properties and valence, oxidation state, structure and morphology, density, degree of complexation, etc. Low molecular mass (LMM) species are believed to be mobile and potentially bioavailable, while high molecular mass (HMM) species such as colloids, polymers, pseudocolloids and particles are considered inert. Due to time-dependent transformation processes such as mobilisation of radionuclide species from solid phases or interactions of mobile and reactive radionuclide species with components in soils and sediments, the original distribution of radionuclides deposited in ecosystems will change over time. To assess the environmental impact from radionuclide contamination, information on radionuclide species deposited, interactions within affected ecosystems and the time-dependent distribution of radionuclide species influencing mobility and biological uptake is essential. The development of speciation techniques to characterize radionuclide species in waters, soils and sediments should therefore be essential for improving the prediction power of impact and risk assessment models. The present paper reviews available fractionation techniques which can be utilised for radionuclide speciation purposes.     

Survey of Levels of Phthalate Ester Plasticizers in a Sewage Lagoon Effluent and a Receiving Stream

In this study, samples from a sewage treatment lagoon and those from a receiving stream were analyzed for their phthalate esters content. Knowledge of the distribution of ubiquitous phthalate esters in the sewage lagoon and the receiving stream was necessary because of the reports of their subtle toxicity to aquatic biota and humans. Liquid–liquid extraction, Clean-up experiment and High Performance Liquid Chromatography (HPLC) were the methods employed for the quantitative determination of the Phthalates. A study of uncontaminated water was done to establish blank levels. The sewage lagoon and the receiving stream were grossly polluted as several phthalate ester plasticizers: DMP, DEP, DPhP, DBP, DEHP, DOP and DINP were found present at monthly mean levels of between 24.02 mg/L and 139.25 mg/L in the sewage treatment lagoon and 10.41 mg/L and 80.53 mg/L in the receiving stream. The results showed higher levels of phthalate esters in the sewage lagoon compared to the receiving stream. The sewage lagoon was identified as a pollution point source into the receiving stream. Levels of phthalates obtained from the receiving stream are much higher than the water criteria of 3 μg/L phthalates recommended by the United States Environmental Protection Agency (USEPA) for the protection of fish and other aquatic life in water and the Suggested No-Adverse Effect Levels (SNAEL) of 7.5–38.5 μg/L for drinking water. This should give cause for great environmental concern. Peoples’ health downstream is at stake and so is the ‘health’ of the ecosystem.