Bioanalytical characterisation of multiple endocrine- and dioxin-like activities in sediments from reference and impacted small rivers

A comprehensive evaluation of organic contamination was performed in sediments sampled in two reference and three impacted small streams where endocrine disruptive (ED) effects in fish have been evidenced. The approach combined quantitative chemical analyses of more than 50 ED chemicals (EDCs) and a battery of in vitro bioassays allowing the quantification of receptor-mediated activities, namely estrogen (ER), androgen (AR), dioxin (AhR) and pregnane X (PXR) receptors. At the most impacted sites, chemical analyses showed the presence of natural estrogens, organochlorine pesticides, parabens, polycyclic aromatic hydrocarbons (16 PAHs), bisphenol A and alkylphenols, while synthetic steroids, myco-estrogens and phyto-estrogens were not detected. Determination of toxic-equivalent amounts showed that 28-96% of estrogenic activities in bioassays (0.2-6.3 ng/g 17β-estradiol equivalents) were explained by 17β-estradiol and estrone. PAHs were major contributors (20-60%) to the total dioxin-like activities. Interestingly, high PXR and (anti)AR activities were detected; however, the targeted analysed compounds could not explain the measured biological activities. This study highlighted the presence of multiple organic EDCs in French river sediments subjected to mixed diffuse pollution, and argues for the need to further identify AR and PXR active compounds in the aquatic environment.     

Evaluation of food chain transfer of the antibiotic oxytetracycline and human risk assessment

There has been recent concern regarding the possibility of antibiotics entering the aquatic food chain and impacting human consumers. This work reports experimental results of the bioconcentration of the antibiotic oxytetracycline (OTC) by the Asian watermeal plant (Wolffia globosa Hartog & Plas) and bioaccumulation of OTC in watermeal and water by the seven-striped carp (Probarbus jullieni). They show, for the first time, the extent to which OTC is able to transfer from water to plant to fish and enter the food chain. The mean bioconcentration factor (dry weight basis) with watermeal was 1.28 × 10³ L kg^−1. Separate experiments were undertaken to characterize accumulation of OTC by carp from water and watermeal. These showed the latter pathway to be dominant under the conditions employed. The bioconcentration and biomagnification factors for these processes were 1.75 L kg^−1 and 2 × 10^−4 kg g^−1 respectively. Using an aqueous concentration range of 0.34–3.0 μg L^−1, hazard quotients for human consumption of contaminated fish of 1.3 × 10^−2 to 1.15 × 10^−1 were derived.     

Regulatory attitudes and environmental innovation in a model combining internal and external R&D

The extent to which environmental regulatory institutions are either ‘green’ or ‘brown’ impacts not just the intensity of regulation at any moment, but also the incentives for the development of new pollution-control technologies. We set up a strategic model of R&D in which a polluter can deploy technologies developed in-house, or license technologies developed by specialist outsiders (an ‘eco-industry’). Polluters exert R&D effort and may even develop redundant technologies to improve the terms on which they procure technology from outside. We find that, while regulatory bias has an ambiguous impact on the best-available technology, strategic delegation to systematically biased regulators can improve social welfare.     

Simulation studies of ammonia removal from water in a membrane contactor under liquid–liquid extraction mode

Simulation studies were carried out, in an unsteady state, for the removal of ammonia from water via a membrane contactor. The contactor had an aqueous solution of NH₃ in the lumen and sulphuric acid in the shell side. The model equations were developed considering radial and axial diffusion and convection in the lumen. The partial differential equations were converted by the finite difference technique into a series of stiff ordinary differential equations w.r.t. time and solved using MATLAB. Excellent agreement was observed between the simulation results and experimental data (from the literature) for a contactor of 75 fibres. Excellent agreement was also observed between the simulation results and laboratory-generated data from a contactor containing 10,200 fibres. Our model is more suitable than the plug-flow model for designing the operation of the membrane contactor. The plug-flow model over-predicts the fractional removal of ammonia and was observed to be limited when designing longer contactors.     

伪装遮障材料耐老化性能与机理分析

目的 研究伪装遮障材料在实用期的老化机理,获悉伪装遮障材料失效的主要环境因素。方法 通过分析伪装遮障材料在自然环境和实验室单因素环境中的性能变化,得出影响伪装遮障材料老化失效的主要因素。采用扫描电子显微镜、红外光谱仪、X射线光电子能谱仪表征材料的微观形貌、化学结构和化学成分变化,解释伪装遮障材料的老化机理。结果 获得了在不同自然环境、实验室单因素环境下,伪装遮障材料颜色外观和力学性能的变化规律,得到了伪装遮障材料在老化过程中发生的微观形貌、化学结构和化学成分变化。结论 伪装遮障材料在西双版纳自然环境下的老化程度最大,在济南自然环境下的老化程度最小。光照是导致伪装遮障材料颜色外观及力学性能降低的主要因素。老化过程中,主要是材料表面的聚氨酯发生老化、脱落,导致材料的力学性能下降。伪装遮障材料破坏时,纤维有2种失效形式,一种是纤维脱黏、直接断裂;另一种是纤维脱黏,拔出,或者拔出过程中断裂。     

我国重金属防治与土壤修复行业2013年发展综述

综述了2013年我国重金属防治与土壤修复行业的发展环境、行业的技术发展进展,分析了我国重金属防治与土壤修复的市场规模和市场潜力,针对行业发展中存在的主要问题,提出了解决对策和建议,并对行业的发展进行了展望。     

Monitoring the formation of trihalomethanes in the effluents from a shrimp hatchery

Formation of trihalomethanes (THM) was monitored at the Laboratório de Camarões Marinhos (LCM) from the Universidade Federal de Santa Catarina. THM could be present because chlorinated effluents from disinfection are discharged from the different hatchery rooms. THM quantification was done through an analytical methodology using Purge&;Trap coupled with a gas chromatograph equipped with an electron capture detector. Relative standard deviation (RSD), limit of detection (LOD) and limit of quantification (LOQ) for the methodology corresponded to the ranges of 8–17%; 0.01–0.03 μg L^?1 and 0.03–0.08 μg L^?1, respectively. Linear working range was of 0.1–8.0 μg L^?1 for all compounds. Enrichment and recovery method was applied to evaluate possible matrix effects and the results varied from 71.2% to 107.9%. LCM was monitored between August and December, 2004. This study showed that THM did not increase with the increase in postlarvae production and also that the aquatic life and the surrounding environment were not affected.     

How and why is Aquatic Quality Changing at Nahanni National Park Reserve, nwt, Canada?

Nahanni National Park Reserve is located at southwestern NWT-Yukon border. One of the first UNESCO World Heritage sites, Nahanni lies within Taiga Cordillera and Taiga Shield Ecozones. Base and precious metal mining occurred upstream of Nahanni prior to park establishment. Nahanni waters, sediments, fish, and caribou have naturally elevated metals levels. Baseline water, sediment and fish tissue quality data were collected and analyzed throughout Nahanni during 1988–91 and 1992–97. These two programs characterized how aquatic quality variables are naturally varying in space and time, affected by geology, stream flow, seasonality, and extreme meteorological and geological events. Possible anthropogenic causes of aquatic quality change were examined. Measured values were compared to existing Guidelines and site-specific objectives were established.     

新体制下装备环境适应性试验鉴定的思考

通过分析现行装备环境工程工作与新体制下试验鉴定要求的差距,归纳提出了新体制下装备环境适应性试验鉴定的总体解决思路,明确了全寿命周期装备环境适应性工作项目剪裁方法,以及完整的装备试验鉴定工作项目集,给出了装备环境适应性要求确定原则,以及各阶段、各层级产品环境适应性要求集,为装备面向实战、全过程、全层级、全指标的环境适应性试验鉴定提供了指导。