Quantifying the sensitivity of ephemeral streams to land disturbance activities in arid ecosystems at the watershed scale

Large areas of public lands administered by the Bureau of Land Management and located in arid regions of the southwestern United States are being considered for the development of utility-scale solar energy facilities. Land-disturbing activities in these desert, alluvium-filled valleys have the potential to adversely affect the hydrologic and ecologic functions of ephemeral streams. Regulation and management of ephemeral streams typically falls under a spectrum of federal, state, and local programs, but scientifically based guidelines for protecting ephemeral streams with respect to land-development activities are largely nonexistent. This study developed an assessment approach for quantifying the sensitivity to land disturbance of ephemeral stream reaches located in proposed solar energy zones (SEZs). The ephemeral stream assessment approach used publicly-available geospatial data on hydrology, topography, surficial geology, and soil characteristics, as well as high-resolution aerial imagery. These datasets were used to inform a professional judgment-based score index of potential land disturbance impacts on selected critical functions of ephemeral streams, including flow and sediment conveyance, ecological habitat value, and groundwater recharge. The total sensitivity scores (sum of scores for the critical stream functions of flow and sediment conveyance, ecological habitats, and groundwater recharge) were used to identify highly sensitive stream reaches to inform decisions on developable areas in SEZs. Total sensitivity scores typically reflected the scores of the individual stream functions; some exceptions pertain to groundwater recharge and ecological habitats. The primary limitations of this assessment approach were the lack of high-resolution identification of ephemeral stream channels in the existing National Hydrography Dataset, and the lack of mechanistic processes describing potential impacts on ephemeral stream functions at the watershed scale. The primary strength of this assessment approach is that it allows watershed-scale planning for low-impact development in arid ecosystems; the qualitative scoring of potential impacts can also be adjusted to accommodate new geospatial data, and to allow for expert and stakeholder input into decisions regarding the identification and potential avoidance of highly sensitive stream reaches.     

Different collector types for sampling deposition of polycyclic aromatic hydrocarbons--comparison of measurement results and their uncertainty

Different collector types, sample workup procedures and analysis methods to measure the deposition of polycyclic aromatic hydrocarbons (PAH) were tested and compared. Whilst sample workup and analysis methods did not influence the results of PAH deposition measurements, using different collector types changed the measured deposition rates of PAH significantly. The results obtained with a funnel-bottle collector showed the highest deposition rates and a low measurement uncertainty. The deposition rates obtained with the wet-only collectors were the lowest at industrial sites and under dry weather conditions. For the open-jar collectors the measurement uncertainty was high. Only at an industrial site with extremely high PAH deposition rates the results of open-jar collectors were comparable to those obtained with funnel-bottle collectors. Thus, if bulk deposition of PAH has to be measured, funnel-bottle combinations are proved to be the collectors of choice. These collectors were the only ones always fulfilling the requirements of European legislation.     

Cytotoxic effects of seven Tunisian hospital wastewaters on the proliferation of human breast cancer cell line MDA-231: correlation with their chemical characterization

Environmental Science and Pollution Research - Hospital wastewaters contain large amounts of pharmaceutical residues, which may eventually be discharged into the aquatic environment through...     

围场县农田典型药物和个人护理品污染特征与生态风险预评价

利用超声萃取-固相萃取-高效液相色谱/串联质谱(LC-MS/MS)技术,对围场县全县农田中5个大类(磺胺类、四环素类、氟喹诺酮类、大环内酯类以及其他类)25种典型药物和个人护理品(PPCPs)的污染水平进行了调查,并采用风险熵法对其进行生态风险预评价。结果表明:有23种目标PPCPs被检出,不同目标物检出率差异显著,检出含量范围为0.38~6.50μg·kg-1,单种污染物最高检出浓度为101.9μg·kg-1(磺胺甲恶唑)。以目标物划分,分别有7种和5种被检出物质达到生态高风险和中等风险水平;以采样区域划分,41个土壤点位中分别有17个和12个达到生态高风险和中等风险水平。畜用PPCPs是围场农田中PPCPs污染物的主要来源,兽药滥用、粪便自然堆沤等传统农耕模式有造成农田土壤中PPCPs累积的趋势,因此需严控PPCPs污染源头,并推进畜禽粪便安全的资源化利用,以减缓农田土壤中由于PPCPs污染带来的潜在生态风险,保障围场地区生态环境功能、农田环境质量以及农产品安全品质。     

Bringing diverse knowledge sources together--a meta-model for supporting integrated catchment management

Integrated catchment management (ICM), as promoted by recent legislation such as the European Water Framework Directive, presents difficult challenges to planners and decision-makers. To support decision-making in the face of high complexity and uncertainty, tools are required that can integrate the evidence base required to evaluate alternative management scenarios and promote communication and social learning. In this paper we present a pragmatic approach for developing an integrated decision-support tool, where the available sources of information are very diverse and a tight model coupling is not possible. In the first instance, a loosely coupled model is developed which includes numerical sub-models and knowledge-based sub-models. However, such a model is not easy for decision-makers and stakeholders to operate without modelling skills. Therefore, we derive from it a meta-model based on a Bayesian Network approach which is a decision-support tool tailored to the needs of the decision-makers and is fast and easy to operate. The meta-model can be derived at different levels of detail and complexity according to the requirements of the decision-makers. In our case, the meta-model was designed for high-level decision-makers to explore conflicts and synergies between management actions at the catchment scale. As prediction uncertainties are propagated and explicitly represented in the model outcomes, important knowledge gaps can be identified and an evidence base for robust decision-making is provided. The framework seeks to promote the development of modelling tools that can support ICM both by providing an integrated scientific evidence base and by facilitating communication and learning processes.     

Treatment process and toxicities assessment of wastewater issued from anaerobic digestion of household wastes

Modern society grapples with large amounts of household waste. The anaerobic digestion of this waste offers a promising source for energy-rich biogas production but generates high toxic effluents that require treatment before reuse or disposal into the environment. This study aimed to investigate three techniques, namely coagulation/flocculation, electro-coagulation, and activated sludge, in terms of efficiency in the treatment of these effluents. It also aimed to assess their toxicity effects on the germination and growth of durum wheat Triticum aestivum L. seeds before and after 6 days of treatment. Activated sludge was most efficient in reducing chemical oxygen demand, turbidity, and conductivity (95.7 %, 15.8 %, and 37.5 %, respectively). The effluent treated with this technique induced a marked delay in germination (low mean time of germination) and a significant reduction in the percentages of seed germination and root and leaf growths. It was also noted to strongly induce lipid peroxidation in roots and leaves, which presumably explained the germination/growth inhibition of the wheat seeds. The effluent also induced marked lipid peroxidation effects and strongly inhibited the activities of butyrylcholinesterase in mice bone marrows. The effluent shows a high ability to inhibit the growth of three microalgae; these endpoints are useful tools to biomonitor the physico-chemical quality of this wastewater. Overall, while no significant alterations were observed in terms of animal and vegetable toxicities when the effluent was treated by coagulation/flocculation, activated sludge treatment proved efficient in reducing the toxicities induced by the untreated effluents. The results indicate that the application of this technique is promising with regards to attaining efficient, eco-friendly, and cost-effective strategies for the management and treatment of household waste.     

Exploring Patterns of Seafood Provision Revealed in the Global Ocean Health Index

Sustainable provision of seafood from wild-capture fisheries and mariculture is a fundamental component of healthy marine ecosystems and a major component of the Ocean Health Index. Here we critically review the food provision model of the Ocean Health Index, and explore the implications of knowledge gaps, scale of analysis, choice of reference points, measures of sustainability, and quality of input data. Global patterns for fisheries are positively related to human development and latitude, whereas patterns for mariculture are most closely associated with economic importance of seafood. Sensitivity analyses show that scores are robust to several model assumptions, but highly sensitive to choice of reference points and, for fisheries, extent of time series available to estimate landings. We show how results for sustainable seafood may be interpreted and used, and we evaluate which modifications show the greatest potential for improvements.     

金霉素在活性污泥上的吸附行为

通过批次实验考察了活性污泥对金霉素（chlortetracycline,CTC）的吸附特性,研究了包括吸附平衡时间、污泥浓度（MLSS）、温度以及pH值对吸附的影响。结果表明,CTC在活性污泥上的吸附是一个快速的过程,5 min可达到平衡吸附量的90%以上,6 h达到吸附平衡;CTC的总去除率随着MLSS浓度的增加而增大,而污泥单位吸附量却随之减少,当CTC初始浓度为500 μg/L,MLSS浓度从1 000 mg/L增至8 000 mg/L时,吸附平衡时CTC的总去除率从30.97%上升至60.42%,而污泥单位吸附量则从151 326.70 μg/kg下降至37 530.98 μg/kg;在10、20、30℃条件下,吸附较好地符合Freundlich等温吸附模型和线性分配吸附模型,K_d值依次为190.93、162.32和121.08 L/kg;热力学数据表明,CTC在污泥上的吸附为放热过程,低温有利于吸附的进行;当pH值介于3~11之间时,CTC在污泥上的吸附量随着pH值的增加而减少。     

Organic contamination of Italian and Tunisian culinary herbs and spices

Contaminants belonging to various classes, as polychlorobiphenyls, polycyclic aromatic hydrocarbons, organochlorine pesticides, organophosphorous pesticides, pyrethroid insecticides, fungicides, herbicides, synergists, carbamates, acaricides and insect growth regulators were simultaneously analysed by GC-MS/MS in 118 Italian and Tunisian culinary herbs and spices. The results obtained in Italian samples shown that laurel samples were the most contaminated with the presence of 15 residues on 140, whereas in rosemary (max value of 35?ng/g for cis-chlorfenyvinphos) and oregano (max value of 118.16?ng/g for ethion) some occasional residues can be observed, but always lower than the maximum residue levels; all the others samples shown no contamination. Among Tunisian samples, only rosemary contains a notably high content of pollutants exceeded the EU maximum residue limits (i.e., alachlor and phosalone with level of 359.2 and 43.3?ng/g, respectively), while oregano was determined to be free of contaminant residues. Considering the comparison among the different organic pollutants in Italian and Tunisian spices and herbs evaluated and the differences observed in this study a harmonization of regulation on contaminant residues in herbs and spices for human consumption should be needed, considering their increased use in diet and cooking.     

Presence of carbamazepine,naproxen, and ibuprofen in wastewater from northern Tunisia

We investigated the occurrence of three pharmaceutical residues in four wastewater treatment plants (WWTPs) from northern Tunisia. The selected compounds were carbamazepine, naproxen, and ibuprofen; they are among the most commonly prescribed and widely used pharmaceutical agents worldwide. Samples (200?mL) were pre-concentrated using the solid phase extraction (SPE) enrichment procedure and the analysis of the pharmaceuticals was performed with high-performance liquid chromatography (HPLC-UV). The overall procedure provided limits of detection (LOD) lower than 0.5 µg.L^?1and recoveries of 78–97%. For the carbamazepine compound, the mean concentrations were 60.58, 93.19, and 132 µg.L^?1 for the Bizerte, Jendouba, and Tunis WWTPs, respectively. This pharmaceutical was not detected in the Beja WWTPs. Naproxen and ibuprofens were not detected in the Jendouba WWTP but were found in the three other WWTPs with concentrations ranging from 2.94 to 36.17 µg.L^?1 and from 8.02 to 43.22 µg.L^?1, respectively. From the obtained data, it seems that these WWTPs are not able to eliminate this kind of micro-pollutants.