Pharmaceuticals and personal care products (PPCPs) are contaminants of emerging concern that are increasing in use and have demonstrated negative effects on aquatic organisms. There is a growing body of literature reporting the effects of PPCPs on freshwater organisms, but studies on the effects of PPCPs to marine and estuarine organisms are limited. Among effect studies, the vast majority examines subcellular or cellular effects, with far fewer studies examining organismal- and community-level effects. We reviewed the current published literature on marine and estuarine algae, invertebrates, fish, and mammals exposed to PPCPs, in order to expand upon current reviews. This paper builds on previous reviews of PPCP contamination in marine environments, filling prior literature gaps and adding consideration of ecosystem function and level of knowledge across marine habitat types. Finally, we reviewed and compiled data gaps suggested by current researchers and reviewers and propose a multi-level model to expand the focus of current PPCP research beyond laboratory studies. This model includes examination of direct ecological effects including food web and disease dynamics, biodiversity, community composition, and other ecosystem-level indicators of contaminant-driven change. 相似文献
A case study of landfill liquids addition using small diameter (5 cm) vertical wells is reported. More than 25,000 m3 of leachate was added via 134 vertical wells installed 3 m, 12 m, and 18 m deep over five years in a landfill in Florida, US. Liquids addition performance (flow rate per unit screen length per unit liquid head) ranged from 5.6 × 10?8 to 3.6 × 10?6 m3 s?1 per m screen length per m liquid head. The estimated radial hydraulic conductivity ranged from 3.5 × 10?6 to 4.2 × 10?4 m s?1. The extent of lateral moisture movement ranged from 8 to 10 m based on the responses of moisture sensors installed around vertical well clusters, and surface seeps were found to limit the achievable liquids addition rates, despite the use of concrete collars under a pressurized liquids addition scenario. The average moisture content before (51 samples) and after (272 samples) the recirculation experiments were 23% (wet weight basis) and 45% (wet weight basis), respectively, and biochemical methane potential measurements of excavated waste indicated significant (p < 0.025) decomposition. 相似文献
Since 2005, a dramatic decline of the Arctic sea-ice extent is observed which results in an increase of shipping activities. Even though this provides commercial and social development opportunities, the resulting environmental impacts need to be investigated and monitored. In order to understand the impact of shipping in arctic areas, the method described in this paper determines the travel time, fuel consumption and resulting exhaust emissions of ships navigating in arctic waters. The investigated case studies are considering ship particulars as well as environmental conditions with special focus on ice scenarios. Travel time, fuel consumption and exhaust gas emission were investigated for three different vessels, using different passages of the Northern Sea Route (NSR) in different seasons of years 1960, 2000 and 2040. The presented results show the sensitivity of vessel performance and amount of exhaust emissions to optimize arctic traffic with respect to efficiency, safety and environmental impact. 相似文献
There is actually increasing concern about the accumulation of antibiotics, such as tetracycline, in soil and water bodies. There is therefore a need for efficient methods to degrade antibiotics and thus clean waters. Here we tested the degradation of tetracycline using the heterogeneous electro-Fenton-pyrite method and compared the results with the conventional electro-Fenton method. The reaction was performed with a boron-doped diamond or Pt anode and carbon-felt cathode allowing electrogeneration of H2O2 from O2 reduction. Results show an increasing tetracycline mineralization using the following methods: anodic oxidation with electrogenerated H2O2, electro-Fenton and then electro-Fenton-pyrite using boron-doped diamond. Ion-exclusion HPLC revealed the complete removal of malic malonic, succinic, acetic, oxalic and oxamic acids. Nitrogen present in tetracycline was mainly mineralized in NH4+. The higher efficiency of electro-Fenton-pyrite is explained by self-regulation of soluble Fe2+ and pH to 3.0 from pyrite catalyst favoring larger ·OH generation from Fenton’s reaction. 相似文献
This paper presents comprehensive 3D numerical investigations on depositions of particles flowing through a horizontal pipe
loop consisting of four bends. The multiphase mixture model available in FLUENT 6.2 was used in this study. In this numerical
simulation, five different particle sizes have been used as secondary phases to calculate real multiphase effect in which
inter-particle interaction has been considered. The deposition of particles along the periphery of the pipe wall was investigated
as a function of particle size and fluid velocity. The simulations showed that near the upstream of the bends, maximum particle
concentration occurred at the bottom of the pipe. However, downstream the bends, the maximum particle concentration occurred
at an angle of 60° from the bottom. The larger particles clearly showed deposition near the bottom wall except downstream.
As expected, the smaller particles showed less tendency of deposition and lesser at higher velocity. This numerical investigation
showed qualitative agreement with the experiments conducted by Commonwealth Scientific and Industrial Research Organisation,
Melbourne team for similar conditions. 相似文献
Alum (aluminum sulfate) is the currently preferred chemical amendment for phosphorus (P) treatment in poultry litter (PL).
Aluminum-based drinking-water treatment residuals (Al-WTRs) are the waste by-product of the drinking-water treatment process
and have been effectively used to remove P from aqueous solutions, but their effectiveness in PL water extracts has not been
studied in detail. Elevated cost associated with alum could be minimized by using the equally effective WTRs to remove soluble
P from PL, and they can be obtained at a minimal cost from drinking-water treatment plants. 相似文献
Monitoring of body burden of toxic elements is usually based on analysis of concentration of particular elements in blood, urine and/or hair. Analysis of these matrices, however, predominantly reflects short- or medium-term exposure to trace elements or pollutants. In this work, urinary stones were investigated as a matrix for monitoring long-term exposure to toxic and essential elements. A total of 431 samples of urinary calculi were subjected to mineralogical and elemental analysis by infrared spectroscopy and inductively coupled plasma mass spectrometry. The effect of mineralogical composition of the stones and other parameters such as sex, age and geographical location on contents of trace and minor elements is presented. Our results demonstrate the applicability of such approach and confirm that the analysis of urinary calculi can be helpful in providing complementary information on human exposure to trace metals and their excretion. Analysis of whewellite stones (calcium oxalate monohydrate) with content of phosphorus <0.6 % has been proved to be a promising tool for biomonitoring of trace and minor elements.
The classical use of synthetic dyes is causing issues of environmental pollution and heath risk. As a consequence natural dyes are gaining interest, but the use of natural dyes still includes toxic reagents such as metals as mordants and acids to enhance color and yield. Therefore, we designed a new chitosan-polypropylene imine dendrimer hybrid at 0–2000 mg/L to treat wool before dyeing with cochineal. We compared dye exhaustion, color depth, color characteristics, and color fastness of the new process with dyed pristine and metal mordanted wool. Results show that wool pretreatment improved dye exhaustion from 48 to 88 %, shifted saturation point toward lower dye concentration from 3000 to 1000 mg/L, and improved color depth from 13.68 for pristine wool and 15.17 for metal mordanted wool to 23.89 for the new process. 相似文献
International environmental agreements (IEAs) can coordinate abatement of transboundary pollutants. This paper investigates
how heterogeneous countries facing a stock pollutant might structure such an agreement. In particular, we examine how an IEA
might be implemented with a set of monetary transfers. The focus is on transfers that are time invariant, linear in emissions,
and consistent with budget balance. There is a range of such schemes that would induce efficient emissions. We provide a simple
and intuitive characterization of these penalties and describe how specific proposals might be chosen in order to facilitate
compliance and implementation. Our proposals are illustrated with a simple example. We show that heterogeneity reduces the
scope for penalty schemes to jointly satisfy desirable properties. 相似文献
The objective of this study was to survey the cation and anion contents of geothermal waters to gather fundamental information
on geographical variations. Sixteen sites in hot spring areas on the island of Kyushu in Japan were studied. The study focused
on the arsenic content of the samples. Very high arsenic concentrations (more than 0.1 mg/l) were detected in most of the
geothermal waters sampled. High contents of boron and fluoride (more than 1.0 mg/l) were also detected in some samples. Arsenic
removal was performed on a laboratory scale using columns packed with a magnetite-type adsorbent. The reduction of arsenic
contamination to a concentration of less than 0.01 mg/l could be achieved in the early stages of adsorption (bed volume = 200). 相似文献