66 resultados para unregulated pollutants
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We used polyurethane foam units (PFUs) to collect persistent organic pollutants (POPs) from four sites in Baiyangdian Lake in July 2003. Following extraction from the PFUs, relative concentrations of seven organochlorine pesticides (OCPs) and ten polychlorinated biphenyls (PCBs) were determined by gas chromatography. OCPs and PCBs were detected in the microbial communities from all the four sampling stations. In terms of the total concentration of POPs (OCPs+ PCBs), two river estuary stations had more POP (18.45 mu g/L and 9.77 mu g/L) than the two mid-lake stations (4.75 mu g/L and 5.21 mu g/L), indicating that Baiyangdian Lake was significantly impacted by inflow from the Fu River and Baigou River.
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Numerous environmental pollutants have been detected for estrogenic activity by interacting with the estrogen receptor, but little information is available about their interactions with the progesterone receptor. In this study, emission samples generated by fossil fuel combustion (FFC) and air particulate material (APM) collected from an urban location near a traffic line in a big city of China were evaluated to interact with the human progesterone receptor (hPR) signaling pathway by examining their ability to interact with the activity of hPR expressed in yeast. The results showed that the soot of a petroleum-fired vehicle possessed the most potent anti-progesteronic activity, that of coal-fired stove and diesel fired agrimotor emissions took the second place, and soot samples of coal-fired heating work and electric power station had lesser progesterone inhibition activity. The anti-progesteronic activity of APM was between that of soot from petroleum-fired vehicle and soot from coal-fired establishments and diesel fired agrimotor. Since there was no other large pollution source near the APM sampling sites, the endocrine disrupters were most likely from vehicle emissions, tire attrition and house heating sources. The correlation analysis showed that a strong relationship existed between estrogenic activity and anti-progesteronic activity in emissions of fossil fuel combustion. The discoveries that some environmental pollutants with estrogenic activity can also inhibit OR activity indicate that further studies are required to investigate potential mechanisms for the reported estrogenic activities of these pollutants. (c) 2005 Elsevier B.V. All rights reserved.
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Hydroxylated polychlorinated biphenyls (OH-PCBs a group of main active metabolites of polychlorinated biphenyl (PCBs) which are typical persistent organic pollutants (Pops) I have been identified in wild animals and human. The endocrine disruption of OH-PCBs has been drawn great attention due to the similarity of their chemical structures to the natural estrogens and thyroid hormones. The metabolic pathways of PCBs, the levels of OHPCBs in organism, the endocrine disruption and other adverse effects of OH-PCBs are reviewed. The further investigation of OH-PCBs will not only reveal the toxicological mechanism of PCBs, but also can lay scientific basis for setting up the risk assessment of POPs contamination and early-warning system in China.
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Exposure to indoor air pollution (IAP) from the combustion of biomass fuels is an important cause of morbidity and mortality in developing countries. In the work discussed in this paper we evaluated the endocrine activity of soot particles from biomass fuels by using yeast bioassay. These pollutants could have beta-galactosidase activity with a relative potency (RP) about 10(-7)-10(-9) that of estradiol. Soot particles from wood and straw combustion only partially induced beta-galactosidase activity whereas others produced fully inductive activity in the yeast assay system. These pollutants did not have estrogen antagonist and progesterone agonist activity within the defined concentration range. However, these pollutants require 2-4 orders of magnitude higher IC50 to inhibit the activity of progesterone in a similar dose-response manner to mifepristone. We therefore propose that the endocrine activity of some environmental pollutants may be because of inhibition of the progesterone receptor (hPR). GC-MS results showed that substituted polycyclic aromatic hydrocarbon (PAH) compounds, substituted phenolic compounds and derivatives, aromatic carbonyl compounds, and phytosteroids in these soot particles may be mimicking endogenous hormones.
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The potential endocrine disrupting effects and other toxicity effects on aquatic biota resulted from food uptake was simulated by feeding the laboratory cultured rare minnow(Gobiocypris rarus) with field collected Limnodrilus sp. The results indicated that the food chain processes affected significantly the growth, slightly reduced gonadosomatic indices, and elevated hepatosomatic indices. There was an obvious vitellogenin(VTG) induction, which generally only occurred in mature female, in the serum of juvenile rare minnow and mature male when fed with Limnodrilus sp. In addition, the rare minnow feeding on Limnodrilus sp. had significantly high renal indices, it meant obvious renal hyperplasia. The present work suggested that. Limnodrilus sp. from field water may contain toxic pollutants and could lead to endocrine disruption effects to the predators. It was concluded that endocrine disruptors may not only be assimilated through water, but also be bioconcentrated through food web. The results also suggested the importance of food selection in conducting the study of endocrine disruption effects using sensitive species.
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Goal, Scope and Background. In some cases, soil, water and food are heavily polluted by heavy metals in China. To use plants to remediate heavy metal pollution would be an effective technique in pollution control. The accumulation of heavy metals in plants and the role of plants in removing pollutants should be understood in order to implement phytoremediation, which makes use of plants to extract, transfer and stabilize heavy metals from soil and water. Methods. The information has been compiled from Chinese publications stemming mostly from the last decade, to show the research results on heavy metals in plants and the role of plants in controlling heavy metal pollution, and to provide a general outlook of phytoremediation in China. Related references from scientific journals and university journals are searched and summarized in sections concerning the accumulation of heavy metals in plants, plants for heavy metal purification and phytoremediation techniques. Results and Discussion. Plants can take up heavy metals by their roots, or even via their stems and leaves, and accumulate them in their organs. Plants take up elements selectively. Accumulation and distribution of heavy metals in the plant depends on the plant species, element species, chemical and bioavailiability, redox, pH, cation exchange capacity, dissolved oxygen, temperature and secretion of roots. Plants are employed in the decontamination of heavy metals from polluted water and have demonstrated high performances in treating mineral tailing water and industrial effluents. The purification capacity of heavy metals by plants are affected by several factors, such as the concentration of the heavy metals, species of elements, plant species, exposure duration, temperature and pH. Conclusions. Phytoremediation, which makes use of vegetation to remove, detoxify, or stabilize persistent pollutants, is a green and environmentally-friendly tool for cleaning polluted soil and water. The advantage of high biomass productive and easy disposal makes plants most useful to remediate heavy metals on site. Recommendations and Outlook. Based on knowledge of the heavy metal accumulation in plants, it is possible to select those species of crops and pasturage herbs, which accumulate fewer heavy metals, for food cultivation and fodder for animals; and to select those hyperaccumulation species for extracting heavy metals from soil and water. Studies on the mechanisms and application of hyperaccumulation are necessary in China for developing phytoremediation.
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Goal, Scope and Background. Heavy metal is among one of the pollutants, which cause severe threats to humans and the environment in China. The aim of the present review is to make information on the source of heavy metal pollution, distribution of heavy metals in the environment, and measures of pollution control accessible internationally, which are mostly published in Chinese. Methods. Information from scientific journals, university journals and governmental releases are compiled focusing mainly on Cd, Cu, Pb and Zn. Partly Al, As, Cr, Fe, Hg, Mn and Ni are included also in part as well. Results and Discussion. In soil, the average contents of Cd, Cu, Pb and Zn are 0.097, 22.6, 26.0 and 74.2 mg/kg, respectively. In the water of. the Yangtze River Basin, the concentrations of Cd, Cu, Pb and Zn are 0.080, 7.91, 15.7 and 18.7 pg/L, respectively. In reference to human activities, the heavy metal pollution comes from three sources: industrial emission, wastewater and solid waste. The environment such as soil, water and air were polluted by heavy metals in some cases. The contents of Cd, Cu, Pb and Zn even reach 3.16, 99.3, 84.1 and 147 mg/kg, respectively, in the soils of a wastewater irrigation zone. These contaminants pollute drinking water and food, and threaten human health. Some diseases resulting from pollution of geological and environmental origin, were observed with long-term and non-reversible effects. Conclusions. In China, the geological background level of heavy metal is low, but with the activity of humans, soil, water, air, and plants are polluted by heavy metals in some cases and even affect human health through the food chain. Recommendations and Outlook. To remediate and improve environmental quality is a long strategy for the polluted area to keep humans and animals healthy. Phytoremediation would be an effective technique to remediate the heavy metal pollutions.
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The feasibility of an inexpensive wastewater treatment system is evaluated in this study. An integrated biological pond system was operated for more than 3 years to purify the wastewater from a medium-sized city, Central China. The experiment was conducted in 3 phases with different treatment combinations for testing their purification efficiencies. The pond system was divided into 3 functional regions: influent purification, effluent upgrading and multi-utilization. These regions were further divided into several zones and subzones. Various kinds of aquatic organisms, including macrophytes, algae, microorganisms and zooplankton, were effectively cooperating in the wastewater treatment in this system. The system attained high reductions of BOD5, COD, TSS, TN, TP and other pollutants. The purification efficiencies of this system were higher than those of most traditional oxidation ponds or ordinary macrophyte ponds. The mutagenic effect and numbers of bacteria and viruses declined significantly during the process of purification. After the wastewater flowed through the upgrading zone, the concentrations of pollutants and algae evidently decreased. Plant harvesting did not yield dramatic effects on reductions of the main pollutants, though it did significantly affect the biomass productivity of the macrophytes. The effluent from this system could be utilized in irrigation and aquaculture. Some aquatic products were harvested from this system and some biomass was utilized for food, fertilizer, fodder and some other uses. The wastewater was reclaimed for various purposes.
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The purpose of this article is to examine the methods and equipment for abating waste gases and water produced during the manufacture of semiconductor materials and devices. Three separating methods and equipment are used to control three different groups of electronic wastes. The first group includes arsine and phosphine emitted during the processes of semiconductor materials manufacture. The abatement procedure for this group of pollutants consists of adding iodates, cupric and manganese salts to a multiple shower tower (MST) structure. The second group includes pollutants containing arsenic, phosphorus, HF, HCl, NO2, and SO3 emitted during the manufacture of semiconductor materials and devices. The abatement procedure involves mixing oxidants and bases in an oval column with a separator in the middle. The third group consists of the ions of As, P and heavy metals contained in the waste water. The abatement procedure includes adding CaCO3 and ferric salts in a flocculation-sedimentation compact device equipment. Test results showed that all waste gases and water after the abatement procedures presented in this article passed the discharge standards set by the State Environmental Protection Administration of China.
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Processing networks are a variant of the standard linear programming network model which are especially useful for optimizing industrial energy/environment systems. Modelling advantages include an intuitive diagrammatic representation and the ability to incorporate all forms of energy and pollutants in a single integrated linear network model. Added advantages include increased speed of solution and algorithms supporting formulation. The paper explores their use in modelling the energy and pollution control systems in large industrial plants. The pollution control options in an ethylene production plant are analyzed as an example. PROFLOW, a computer tool for the formulation, analysis, and solution of processing network models, is introduced.
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TiO2 sol-gels with various Ag/TiO2 molar ratios from 0 to 0.9% were used to fabricate silver-modified nano-structured TiO2 thin films using a layer-by-layer dip-coating (LLDC) technique. This technique allows obtaining TiO2 nano-structured thin films with a silver hierarchical configuration. The coating of pure TiO2 sol-gel and Ag-modified sol-gel was marked as T and A, respectively. According to the coating order and the nature of the TiO2 sol-gel, four types of the TiO2 thin films were constructed, and marked as AT (bottom layer was Ag modified, surface layer was pure TiO,), TA (bottom layer was pure TiO,, surface layer was Ag modified), TT (pure TiO, thin film) and AA (TiO, thin film was uniformly Ag modified). These thin films were characterized by means of linear sweep voltammetry (LSV), X-ray diffraction (XRD), scanning electron microscopy (SEM), electrochemical impedance spectroscopy and transient photocurrent (I-ph). LSV confirmed the existence of Ago state in the TiO, thin film. SEM and XRD experiments indicated that the sizes of the TiO,, nanoparticles of the resulting films were in the order of TT > AT > TA > AA, suggesting the gradient Ag distribution in the films. The SEM and XRD results also confirmed that Ag had an inhibition effect on the size growth of anatase nanoparticles. Photocatalytic activities of the resulting thin films were also evaluated in the photocatalytic degradation process of methyl orange. The preliminary results demonstrated the sequence of the photocatalytic activity of the resulting films was AT > TA > AA > TT. This suggested that the silver hierarchical configuration can be used to improve the photocatalytic activity of TiO2 thin film.
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土壤养分、污染物的生物有效性与其固液相分配规律密切相关。本研究通过室内模拟试验,设置不同的水、热、肥条件和培养时间序列,采用高速离心法对红壤、黑土、潮土、黑垆土、塿土5种典型土壤的磷素固液相分配规律及其影响因素进行了探讨。结果表明,质地不同土壤磷素固液相分配系数(Kd)值差别很大,整体变化趋势是红壤>黑垆土>塿土>黑土>潮土。不同培养条件下土壤磷素固液相分配系数(Kd)值变化特征表现出随着培养时间延长,土壤磷素Kd值增大,土壤磷素生物有效性逐渐降低。水吸力、浓度与之相反,随着水吸力的增加土壤磷素Kd值变小,随着施入磷素浓度的增加而Kd值降低。在整个温度梯度中,当温度处于20 ̄25℃左右时,土壤磷素Kd值达到最小值,液相磷素含量相对增多,养分有效性增强。
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本论文采用第三代超分子受体化合物——磺化硫杂杯芳烃(简称TCAS)作为活性组分,将其加载到树脂载体上,制成一种新型的TCAS吸附树脂。借助红外光谱、紫外光谱、核磁共振和电喷雾质谱等检测分析手段对TCAS吸附树脂及其制备的中间产物进行表征。采用静态批试验方法研究发现TCAS吸附树脂对重金属和卤代烃类有机物都有较好的吸附去除效果,其对Pb2+、Cd2+、Cu2+和Zn2+四种重金属的吸附容量分别达到26.32mg•g-1、18.12mg•g-1、12.24mg•g-1和6.85mg•g-1;对二氯甲烷、三氯甲烷、四氯化碳、三氯乙烯四种卤代烃的吸附容量分别为9.23 mg•g-1、7.92 mg•g-1、6.73 mg•g-1和4.34 mg•g-1。并发现温度、树脂用量和溶液pH值等因素能影响TCAS吸附树脂的吸附去除效果。同时研究了TCAS吸附树脂对污染物的吸附优先性规律、动力学规律和热力学规律。采用化学计量学分析TCAS络合重金属的紫外光谱,获得了TCAS-重金属络合物的纯紫外光谱,以及TCAS、TCAS-重金属络合物随重金属浓度变化的分布曲线,并最终解析得到TCAS与Cu、Zn、Cd和Pb的络合常数(lgβ)分别为9.79、8.72、6.87和5.00。通过多次吸附试验,考察了TCAS吸附树脂回收循环利用的可行性,发现TCAS吸附树脂可进行多次循环回收再利用。
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人工合成麝香作为一种新型污染物,其生态行为及生态效应已经越来越受到关注。城市土-水界面污染流是除农业面源污染以外第二大面源污染,其成分复杂,采用常规的理化监测方法很难对其生态安全性加以评价。本研究在水生生态毒理实验基础之上,利用城市标识污染物-重金属镉(Cd)、铅(Pb)、佳乐麝香(HHCB)和城市土壤模拟城市土-水界面污染流,并以斑马鱼、草鱼为对象,以超氧化物岐化酶(SOD),过氧化物酶(POD),过氧化氢酶(CAT),丙二醛(MDA),可溶性蛋白(SP)为生物标志物,对其急性和亚急性生态毒理过程进行模拟研究,并通过对联合毒性实验的开展,系统研究了Cd、Pb和HHCB的单一与联合毒性效应、机理和过程。主要结论如下: HHCB和Cd均为中等毒性污染物,Cd和HHCB对斑马鱼的96h-LC50值分别为30.33和4.45 mg/L;在HHCB和Cd的等毒性复合急性实验中,联合作用类型随暴露时间的延长从联合变为拮抗,HHCB是复合污染中的主要污染物。 对水体中总浓度0.95-15.16 mg/L 的Cd和0.14-2.22mg/L的HHCB7天急性毒性机理实验显示,暴露于单一Cd污染斑马鱼体内抗氧化酶活性升高,暴露4天后,其体内MDA含量升高;而在HHCB胁迫2-4天后抗氧化酶活性和MDA含量均降低;联合作用中Cd在暴露的前1-4天对抗氧化酶的变化起主要作用,而之后HHCB开始起主导作用;斑马鱼急性胁迫下,抗氧化系统的诱导是斑马鱼对Cd胁迫的最初反应之一,而对于受HHCB胁迫的斑马鱼,蛋白含量的降低相对于抗氧化系统来说是斑马鱼受到损害的更重要原因。 对水体中总浓度0.005-0.05mg/L的Cd、0.5-4mg/L的Pb和0.01-0.2mg/L的HHCB对草鱼不同器官的14天亚急性毒性机理研究显示:肝脏受污染物的毒性作用最为显著,体内生物标志物也最为敏感;在Cd和Pb胁迫下,肝脏和肾脏内抗氧化酶随浓度的升高被显著抑制,而HHCB对各器官SOD和CAT活性产生诱导作用; MDA在重金属胁迫下其含量变化均不明显,SP含量轻微降低,而在HHCB胁迫下却分别呈现显著的升高和降低的趋势,所以MDA和SP含量可以作为检测HHCB的生物标志物;复合作用下HHCB的加入能使草鱼各器官中抗氧化酶的活性有所升高, MDA含量显著大幅度升高,SP含量显著大幅度降低,HHCB和Cd表现出很强的协同作用,而且HHCB在复合污染中起主导作用。