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Hexafluoropropylene oxide-dimer acid (HFPO-DA) is one of the emerging replacements for the “forever” carcinogenic and toxic long-chain PFAS. HFPO-DA is a polymerization aid used for manufacturing fluoropolymers, whose global distribution and undetermined toxic properties are a concern regarding human and ecological health. To assess embryotoxic potential, zebrafish embryos were exposed to HFPO-DA at concentrations of 0.5–20,000 mg/L at 24-, 48-, and 72-h post-fertilization (hpf). Heart rate increased significantly in embryos exposed to 2 mg/L and 10 mg/L HFPO-DA across all time points. Spinal deformities and edema phenotypes were evident among embryos exposed to 1000–16,000 mg/L HFPO-DA at 72 hpf. A median lethal concentration (LC50) was derived as 7651 mg/L at 72 hpf. Shallow RNA sequencing analysis of 9465 transcripts identified 38 consistently differentially expressed genes at 0.5 mg/L, 1 mg/L, 2 mg/L, and 10 mg/L HFPO-DA exposures. Notably, seven downregulated genes were associated with visual response, and seven upregulated genes were expressed in or regulated the cardiovascular system. This study identifies biological targets and molecular pathways affected during animal development by an emerging, potentially problematic, and ubiquitous industrial chemical.

In this study, density plume visualizations and statistical comparisons were made of enterococci bacteria (the main marine recreational microbial water quality indicator) densities, both before and after the upgrade of the discharge from the South Bay Ocean Outfall (SBOO) to secondary treatment level, so that the effect of this upgrade on ocean microbial water quality could be assessed. During the dry weather (bathing) season, reduction in enterococci densities was rather limited with only 2 shore stations and one kelp station showing significant reductions, and none showing increased compliance frequency. During the wet weather season, although the signature of land-based sources of bacterial pollution were evident, a majority of both shore (7 of the 11 stations) and kelp (4 of the 7 stations) stations showed statistically significant (p ≤ 0.05) reductions enterococci densities pointing to the role of the upgrade to secondary treatment in improving microbial water quality.

Brian Pecson and Daniel Gerrity present an Editorial Perspective which focuses on the impact of SARS-CoV-2 on the water industry.

Smoked cigarettes are the most prevalent form of litter worldwide, often finding their way into oceans and inland waterways. Cigarette smoke contains more than 4000 individual chemicals, some of them carcinogenic or otherwise toxic. We examined the cytotoxicity, genotoxicity, aryl hydrocarbon receptor (AhR), estrogen receptor (ER), and p53 response pathways of smoked cigarette leachate in vitro. Both seawater and freshwater leachates of smoked cigarettes were tested. Cytotoxicity and genotoxicity were negligible at 100 smoked cigarettes/L, while statistically significant AhR, ER, and p53 responses were observed in the extracts of both leachates, suggesting a potential risk to human health through exposure to cigarette litter in the environment. To identify responsible chemicals for the AhR response, an effect directed analysis approach was coupled with nontargeted chemical analysis based on comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC × GC/TOF-MS). Eleve...

An assessment of human health risks posed by municipal wastewater treatment using constructed wetlands involves delineating pathogen content of inflowing water, degree of removal/inactivation of pathogens in wetland environments, and level of exposure of receptor (human) population to treated wastewaters. Four groups of pathogens (viruses, bacteria, protozoa, and worms) may cause human waterborne diseases. Since most excreta-related diseases in North America are caused by bacteria and viruses, this chapter focuses on use of constructed wetlands to reduce human health risks associated with these two groups. Important environmental stresses on viruses in a wetlands wastewater treatment process include temperature, pH, suspended solids, sunlight, redox potential, and microbial degradation. Constructed wetlands can make important contributions as wastewater treatment systems not only through their ability to reduce bacteria and virus levels but also due to their ability to remove suspended solids and ammonia, both of which interfere with efficient disinfection.

Wetland ecosystems have the ability to remove aquatic pollutants through a variety of physical, chemical, and biological processes occurring in the soil-water matrix and in the plant rhizosphere. This chapter presents design and operational data on the use of artificial wetlands for performing secondary treatment of primary municipal wastewaters. It describes the mechanisms by which these artificial wetlands may also remove nitrogen and total coliform bacteria from inflowing wastewaters. The artificial wetland bed used for testing of secondary wastewater treatment capability consisted of a plastic-lined excavation containing emergent vegetation growing in gravel. Ability of artificial wetlands to perform integrated wastewater treatment by removing bacterial indicators as well as BOD5, suspended solids, and nitrogen makes them an attractive alternative for meeting treatment needs of small to medium-sized communities. Where land is available, these artificial wetlands offer a simple process design, low O&M expense, and wildlife enhancement value, and represent an innovative solution to cost-effective wastewater treatment.

Levels of amphetamine, methamphetamine, cocaine, and benzoylecgonine (BE), the metabolite of cocaine, were quantitated by solid phase extraction and liquid chromatography with tandem mass spectrometry (LC/MS/MS) in Forester Creek in San Diego County, CA, and in raw wastewater from the region’s sewage treatment plant. Drug residues in these surface waters were detected with 100% frequency. Mean concentrations were 0.022 ± 0.016, 0.450 ± 0.398, 0.024 ± 0.014, and 0.019 ± 0.012 μg/L for amphetamine, methamphetamine, BE, and cocaine respectively. Nonparametric testing by Spearman rank correlation showed significant (p

Fluorescence spectroscopy has been increasingly used to detect sewage and other anthropogenic contaminants in surface waters. Despite progress in successfully detecting bacterial and sewage inputs to rivers over diverse spatial scales, the use of fluorescence-based in-situ sensors to track contaminant inputs during storm events and to discern bacterial contamination from background natural organic matter (NOM) fluorescence have received less attention. A portable, submersible fluorometer equipped with tryptophan (TRP)-like and humic-like fluorescence sensors was used to track inputs of untreated wastewater added to natural creek water in a laboratory sewage spill simulation. Significant, positive correlations were observed between TRP fluorescence, the TRP:humic ratio, percent wastewater, and Escherichia coli concentrations, indicating that both the TRP sensor and the TRP:humic ratio tracked wastewater inputs against the background creek water DOM fluorescence. The portable fluorometer was subsequently deployed in an urban creek during a storm in 2018. The peak in TRP fluorescence was found to increase with the rising limb of the hydrograph and followed similar temporal dynamics to that of caffeine and fecal indicator bacteria, which are chemical and biological markers of potential fecal pollution. Results from this study demonstrate that tracking of TRP fluorescence intensity and TRP:humic ratios, with turbidity correction of sensor outputs, may be an appropriate warning tool for rapid monitoring of sewage or other bacterial inputs to aquatic environments.

Multiple stressors like alterations of water quality, hydrology and hydromorphology impact riverine ecosystems. To counteract its consequences, restoration measures are required, e.g. demanded by the EU Water Framework Directive. However, small-scale hydromorphological restoration measures often show little success. Besides overriding stressors, recolonization potential and insufficient time for development are often discussed as reasons for this lack of success. Over a period of 17 years a hydromorphological restoration measure in a German lowland stream reach was evaluated, excluding most of these confounding factors. The restoration measure was left to its self-dynamic development, i.e. there was no further intervention by water management, apart from some large wood installations after 8 years. In the accompanying studies, changes in hydromorphology and the organism groups’ macroinvertebrates (including both structural and functional diversities), fish and macrophytes were investigated. We proved a rapid and stable enhancement of ecological functions as indicated by a diverse and resilient macroinvertebrate biocoenosis. Both taxonomic and functional richness of macroinvertebrates significantly increased, but varied over time. Since the restoration measure allowed self-dynamic development, a taxonomic and functional endpoint was not achieved even after 17 years, even though near-reference conditions were attained after only 4 years. Deficits in fish communities were most probably due to their low recolonization potential. Our results underscore that small scale hydromorphological restoration can be successful if overriding stressors are absent. Furthermore, we proved the importance of self-dynamics in restoration measures, allowing hydromorphological and biological development.

Smoked cigarettes are the most prevalent form of litter worldwide, often finding their way into oceans and inland waterways. Cigarette smoke contains more than 4000 individual chemicals, some of them carcinogenic or otherwise toxic. We examined the cytotoxicity, genotoxicity, aryl hydrocarbon receptor (AhR), estrogen receptor (ER), and p53 response pathways of smoked cigarette leachate

In 2008 the “Forester Creek Improvement Project“ was completed near the mouth of Forester Creek, Santee, CA, along a 2-km section historically subject to flooding. With a cost of $36 million (US), the project’s goals were to: 1) improve water quality; 2) improve physical habitat and biodiversity; and 3) improve flood control. We evaluated if the project met these goals for water quality, physical habitat, and biodiversity. We evaluated the project’s monitoring data, conducted post-project monitoring, and analyzed data from other independent sources to assess goal attainment. The project’s required monitoring was insufficient to determine if any goals were met. Our own results found partial success, with only pH and water temperatures improved from pre-project conditions. No improvement was found for total dissolved solids or fecal coliform, for which the creek is impaired, and sediments contained toxic concentrations of urban-use pesticides. While the project’s monitoring was insufficient to document goal attainment, the project’s formal goals were largely infeasible due to degraded upstream conditions. The project should be considered a partial success in that riparian habitat has improved compared to the erosive and invasive species dominated pre-project condition and the original proposal by the City of Santee to line the creek with concrete. Forester Creek’s poor water quality, physical habitat, and biodiversity are driven by flow modification and pollution associated with urban development upstream, which must be addressed at the watershed scale and outside of the stream channel.

A 16S rRNA gene multiplex 454 pyrosequencing approach was used to characterize the structure of the bacterial community in subsurface flow constructed wetlands planted with Typha angustifolia and unplanted wetland mesocosms receiving ibuprofen-enriched wastewater at a concentration of 250 μg L −1 . The removal efficiency of ibuprofen (IBP) in the planted beds (78.5%) was significantly higher than that in the unplanted beds (57.9%) ( P ≤ 0.05). The presence of ibuprofen significantly ( P ≤ 0.05) reduced the diversity of the bacterial community. In total, 20 phyla comprising 265 genera were identified. The most predominant phyla were Firmicutes (27.6%), Actinobacteria (26.0%) and Proteobacteria (24.9%), making up 57–95% of the 16S rDNA sequences. Other dominating phyla in wetland soils were Chloroflexi (7.3%), Bacteroidetes (2.7%), Synergistetes (2.1%), and Acidobacteria (2.0%). A distinct profile of bacterial community in the wetland mesocosms was observed after IBP enrichment. IBP-enrichment enhanced the relative abundance of Actinobacteria, Bacilli and γ-Proteobacteria at class level. The efficient ibuprofen removal observed in this study suggested that the IBP-enriched wetland systems may have selected a restricted group of bacteria that was able to survive best in the disturbed condition and participate in the IBP biodegradation. Our findings also indicated that the presence of macrophytes may have a vital impact on the microbial community and planted wetlands may be more robust and buffered against significant shifts in microbial composition in response to IBP-disturbance.

Urban stormwater runoff is both a significant pollution source and a potentially valuable resource. This study compares stormwater management in two cities: Singapore and Berlin, Germany. In comparing the strategies for stormwater management, we illustrate how differences in geography (e.g., land and water availability), urban infrastructure, regulatory regimes, legislation and intensives between the two cities have led to different solutions for stormwater management. Singapore, faced with a serious issue of water scarcity, has placed an increasing emphasis on stormwater management through developing a comprehensive network of drains and canals, mainly with the aim of controlling flooding and potable water supply. In contrast, in Berlin, concerns for the protection of surface water quality and non-potable water supply in the urban areas have resulted in a shift in management goals towards a low impact solution based on source control. The cost analysis indicated that the decentralized rainwater h...

Three horizontal subsurface flow constructed wetlands and three sand filters (without plants) were set up at the campus of Nanyang Technological University, Singapore. Eight pharmaceuticals including carbamazepine, naproxen, diclofenac, ibuprofen, caffeine, ketoprofen, salicylic acid, and clofibric acid were enriched in the wetland inflow. Three factors, namely, with/without the presence of vegetation, operational modes (batch and continuous), and hydraulic residence time were investigated by a polynomial regression model with analysis of variance, including factorial design, to find the relationships between contaminant removal and the affecting factors, as well as to determine the dominant variables and how each of them interact for each parameter. The objective of this study was to compare the removal efficiencies of selected pharmaceuticals under different wetland retention times, planted versus unplanted modes, and feeding strategies.

The rapid development of nanotechnology will inevitably result in an increasing release of engineered nanoparticles (NPs) to wastewaters. In this study we investigated the fate and toxicity of ZnO NPs in aquatic plant mesocosms, as well as the potential for root accumulation and root-to-shoot translocation of these Zn NPs in the wetland plant Schoenoplectus tabernaemontani exposed to ZnO NPs. The growth of S. tabernaemontani in these hydroponic mesocosms was significantly inhibited by ZnO NPs (1000 mg L(-1)) compared to a control. Levels of Zn in the plant roots for the ZnO NP treatment ranged from 402 to 36513 μg g(-1), while values ranged from 256 to 9429 μg g(-)(1) (dry weight) for Zn(2+) treatment, implying that the uptake of Zn from ZnO NPs was substantially greater than that for Zn(2+). The root uptake (of the initial mass of Zn in the solution) for ZnO NP treatment ranged from 8.6% to 43.5%, while for Zn(2+) treatment they were 1.66% to 17.44%. The low values of the translocation factor for both ZnO NP (0.001-0.05) and Zn(2+) (0.05-0.27) treatments implied that the potential for translocation of Zn NPs from roots to shoots was limited. ZnO NP distribution in the root tissues of S. tabernaemontani was confirmed by scanning electron microscopy (SEM). Transmission electron microscopy (TEM) demonstrated that ZnO NPs could pass through plant cell walls, and were present within the plant cells of S. tabernaemontani.

One of the United Nations Millennium Development Goals is to reduce the global proportion of people who do not have access to safe drinking water. In the past, the typical strategy to reach this goal has been the use of investment-intensive centralized infrastructure development for water supplies. However, there is increasing evidence suggesting that improving water quality at the source does not guarantee safe water at point-of-use. This study examined water quality, waterborne disease incidence and water system use over time in two small rural indigenous communities of Baja California, Mexico, before and after drinking-water infrastructure improvements. Community Promotoras collected data on the incidence of gastrointestinal illness through face-to-face surveys. Concurrently, water samples from the old and new water sources and household water storage containers were analyzed for fecal coliforms. Although source water quality was significantly improved in both communities (p < 0.05), neither community had a significant decrease in the level of contaminated drinking water sampled at the household level. No significant decrease in gastrointestinal illness was found after the improvements to the source water supply. These results indicate that point-of-use contamination and acceptance of the new sources may be a critical point for intervention when attempting to assure access to safe water, especially in rural communities.

Rapid growth in production and use of nanoparticles (NPs) will inevitably result in the introduction of NPs deliberately or unintentionally into industrial and urban wastewater streams. Efficient removal of NPs from wastewater is particularly important in view of increasing concerns over potential ecotoxicity and hazards of NP exposure to humans and the environment over the long term. For the first time, we report the fate of copper oxide (CuO) NPs and cadmium sulphide/zinc sulphide (CdS/ZnS) quantum dots (QDs) in aquatic mesocosms planted with Schoenoplectus tabernaemontani . S. tabernaemontani was more sensitive to toxic effects of CdS QDs than CuO NPs and the reduction in plant biomass was significant ( p −1 after exposure period of 21 d. Levels of Cu 2+ under CuO NP treatment in the root ranged from 14 μg g −1 (0.5 mg L −1 treatment) to 4,057 μg g −1 (50 mg L −1 treatment), while the values for Cd 2+ under CdS QDs treatment were 9 to 1518 μg g −1 , respectively. Root uptake percentage (of the total initial NP mass) for CuO NP treatment ranged from 40.6 to 68.4%, while the values were 8.7 to 21.3% for CdS QDs. The low value ( S. tabernaemontani roots. To our knowledge, this is the first evidence of NP uptake and accumulation by the higher aquatic plant S. tabernaemontani. These findings provide impetus for future investigation on NP behaviour and removal, as well as the complex interaction between NPs and plants in aquatic plant-based treatment systems.

Inadequate access to clean water and sanitation has become one of the most pervasive problems afflicting people throughout the developing world. Replication of centralized water-, energy- and cost-intensive technologies has proved ineffective in resolving the complex water-related problems resulting from rapid urbanization in the developing countries. Instead constructed wetlands (CWs) have emerged and become a viable option for wastewater treatment, and are currently being recognized as attractive alternatives to conventional wastewater treatment methods. The primary objective of this review is to present a comprehensive overview of the diverse range of practice, applications and researches of CW systems for removing various contaminants from wastewater in developing countries, placing them in the overall context of the need for low-cost and sustainable wastewater treatment systems. Emphasis of this review is placed on the treatment performance of various types of CWs including: (i) free water surface flow CW; (ii) subsurface flow CW; (iii) hybrid systems; and, (iv) floating treatment wetland. The impacts of different wetland design and pertinent operational variables (e.g., hydraulic loading rate, vegetation species, physical configurations, and seasonal variation) on contaminant removal in CW systems are also summarized and highlighted. Finally, the cost and land requirements for CW systems are critically evaluated.

Pharmaceuticals and personal care products (PPCPs) in the aquatic environment are regarded as emerging contaminants and have attracted increasing concern. The use of aquatic plant-based systems such as constructed wetlands (CWs) for treatment of conventional pollutants has been well documented. However, available research studies on aquatic plant-based systems for PPCP removal are still limited. The removal of PPCPs in CWs often involves a diverse and complex set of physical, chemical and biological processes, which can be affected by the design and operational parameters selected for treatment. This review summarizes the PPCP removal performance in different aquatic plant-based systems. We also review the recent progress made towards a better understanding of the various mechanisms and pathways of PPCP attenuation during such phytoremediation. Additionally, the effect of key CW design characteristics and their interaction with the physico-chemical parameters that may influence the removal of PPCPs in functioning aquatic plant-based systems is discussed.

In this study, six mesocosms, including three subsurface flow constructed wetlands (SSF CWs) and three sand filters (without plants) were set up at the campus of Nanyang Technological University, Singapore. The objective of this study was to compare the removal efficiencies of chemical oxygen demand (COD), nitrogen (N) and total phosphorus (TP) under batch and continuous operational modes. Three factors, namely, with/without the presence of vegetation, operational modes (batch and continuous) and hydraulic residence time were investigated by two statistical models including factorial design and its rationale analysis and a quadratic polynomial regression model with ANOVA, to find the relationships between the contaminant removal efficiencies and the affecting factors, as well as to determine the dominant variables and how each of them interact for each parameter.

Uptake, accumulation and translocation of caffeine by Scirpus validus grown in hydroponic condition were investigated. The plants were cultivated in Hoagland's nutrient solution spiked with caffeine at concentrations of 0.5-2.0 mg L(-1). The effect of photodegradation on caffeine elimination was determined in dark controls and proved to be negligible. Removal of caffeine in mesocosms without plants showed however that biodegradation could account for about 15-19% of the caffeine lost from solutions after 3 and 7 d. Plant uptake played a significant role in caffeine elimination. Caffeine was detected in both roots and shoots of S. validus. Root concentrations of caffeine were 0.1-6.1 μg g(-1), while the concentrations for shoots were 6.4-13.7 μg g(-1). A significant (p0.05) positive correlation between the concentration in the root and the initial concentrations in the nutrient solution was observed. The bioaccumulation factors (BAFs) of caffeine for roots ranged from 0.2 to 3.1, while BAFs for shoots ranged from 3.2 to 16.9. Translocation from roots to shoots was the major pathway of shoot accumulation. The fraction of caffeine in the roots as a percentage of the total caffeine mass in solution was limited to 0.2-4.4% throughout the whole experiment, while shoot uptake percentage ranged from 12% to 25% for caffeine at the initial concentration of 2.0 mg L(-1) to 50-62% for caffeine at the initial concentration of 0.5 mg L(-1). However, a marked decrease in the concentration of caffeine in the shoots between d-14 and d-21 suggests that caffeine may have been catabolized in the plant tissues subsequent to plant uptake and translocation.

Pharmaceutical compounds are now considered as emerging contaminants of environmental concern. The overall objective of this study was to evaluate the uptake and translocation of clofibric acid (CA) by the macrophyte Scirpus validus growing hydroponically. A set of the three replicates was established for each exposure time and for each CA concentration. Plants were grown in 4 L vessels (four plants per vessel corresponding to the three exposure period studies, i.e., 7, 14, 18, and 21 days) which contained an aerated modified Hoagland nutrient solution that was spiked with CA at concentrations of 0.5, 1.0, and 2.0 mg L(-1). At each exposure period, CA concentration was measured in the nutrient solutions. A sea sand disruption method was employed for the extraction of CA from plant tissues. The determination of the pharmaceutical concentration was carried out using solid phase extraction (SPE) followed by chromatographic analysis. The quantification of CA concentrations in both nutrient solutions (after SPE) and plant tissues (after extraction) was conducted by chromatographic analysis. CA concentrations of 5.4-26.8 μg g(-1) (fresh weight) were detected in the roots and 7.2-34.6 μg g(-1) (fresh weight) in the shoots after 21 days. Mass balance calculations showed that S. validus uptake alone accounted for a significant contribution (6-13% for the roots and 22-49% for the shoots) of the total loss of CA. The bioaccumulation factors (BAFs) based on fresh weight for the roots ranged from 6.6 to 23.2, while values for the shoots ranged from 9.5 to 32.1. All the BAFs for the shoots were greater than those in the roots, implying that CA has greater tendency to be translocated to the shoots, rather than the roots of S. validus. All the shoot-to-root concentration ratios were more than 1, denoting that the shoots of S. validus do preferentially accumulate CA. We demonstrated that CA can be actively taken up, subsequently translocated and accumulated by aboveground tissues of S. validus. Since S. validus could account for the removal of 28-62% of the total mass loss of CA from the system, such phytoremediation technology has great potential for the removal of pharmaceuticals such as CA from inflowing waters.

A 454 high-throughput pyrosequencing approach was used to characterize the structures of microbial communities in wetland mesocosms receiving caffeine-enriched wastewater at a concentration of 250 μg L(-1). The removal efficiencies of caffeine in the planted beds (93.0 %) were significantly (p

Determining the fate of emerging organic contaminants in an aquatic ecosystem is important for developing constructed wetlands (CWs) treatment technology. Experiments were carried out in subsurface flow CWs in Singapore to evaluate the fate and transport of eight pharmaceutical compounds. The CW system included three parallel horizontal subsurface flow CWs and three parallel unplanted beds fed continuously with synthetic wastewater at different hydraulic retention times (HRTs). The findings of the tests at 2–6 d HRTs showed that the pharmaceuticals could be categorized as (i) efficiently removed compounds with removal higher than 85% (ketoprofen and salicylic acid); (ii) moderately removed compounds with removal efficiencies between 50% and 85% (naproxen, ibuprofen and caffeine); and (iii) poorly removed compounds with efficiency rate lower than 50% (carbamazepine, diclofenac, and clofibric acid). Except for carbamazepine and salicylic acid, removal efficiencies of the selected pharmaceuticals showed significant (p < 0.05) enhancement in planted beds as compared to the unplanted beds. Removal of caffeine, ketoprofen and clofibric acid were found to follow first order decay kinetics with decay constants higher in the planted beds than the unplanted beds. Correlations between pharmaceutical removal efficiencies and log Kow were not significant (p > 0.05), implying that their removal is not well related to the compound’s hydrophobicity.

Unplanned urban population growth in developing countries such as Sri Lanka exert pressures on the sectors of water supply, sewage disposal, waste management, and surface drainage in the cities as well as their surrounding areas. The Mid-canal is considered the most polluted surface water body in the Kandy district of Sri Lanka and contributes significantly to pollution of the Mahaweli River. Health problems in the nearby population may well be associated with environmental degradation and related to deteriorated water quality. The overall objectives of this study were to identify the socio-economic status of the community settled along the Meda Ela banks, and to examine the current water quality status of the Meda Ela and possible impacts of the nearby residents on water quality. Additionally, we propose remedial measures concerning wastewater and solid waste disposal to improve environmental conditions in this area.

Large-scale restoration of streams and rivers is a mandatory prerequisite for the implementation of the European Water Framework Directive (WFD) to reach good ecological status of water bodies. This contribution analyzes the success of the largest river restoration in Germany at the Upper Main. Sections with a length of more than 18 km were restored between 1990 and 2008, including re-connection of former oxbow-lakes, multiple-channelling, and establishment of wide riparian buffer zones. Measuring the success of restoration by means of a multimetric assessment system, we found a clear success of restoration indicated by the status of hydromorphology and by the biological parameters, including macroinvertebrates, fishes, and macrophytes. Unlike non-restored reaches, the restored reaches attained a good ecological status. As such, the restoration of the Upper Main is shown to be a pilot project for the implementation of the WFD on a large scale.

The ability of tropical horizontal subsurface constructed wetlands (HSSF CWs) planted with Typha angustifolia to remove four widely used pharmaceutical compounds (carbamazepine, declofenac, ibuprofen and naproxen) at the relatively short hydraulic residence time of 2–4 days was documented. For both ibuprofen and naproxen, pharmaceutical compounds with low Dow values, the planted beds showed significant (p 0.05) in their removal efficiencies between planted as compared to unplanted beds. No statistical significant differences (p > 0.05) were observed for the removal efficiencies of any of the pharmaceuticals tested for the 2-day HRT as compared to that corresponding to 4-day HRT. The rather efficient removal shown by the wetlands in this study (with HRTs of 2–4 days), indicates that such a CW system may be more practically used (with less land requirements) in tropical regions for removing conventional pollutants and certain pharmaceutical compounds from wastewater effluents.

Background Cigarette butts are the most common form of litter, as an estimated 4.5 trillion cigarette butts are thrown away every year worldwide. Many chemical products are used during the course of growing tobacco and manufacturing cigarettes, the residues of which may be found in cigarettes prepared for consumption. Additionally, over 4000 chemicals may also be introduced to the environment via cigarette particulate matter (tar) and mainstream smoke. Methods Using US Environmental Protection Agency standard acute fish bioassays, cigarette butt-derived leachate was analysed for aquatic toxicity. Survival was the single endpoint and data were analysed using Comprehensive Environmental Toxicity Information System to identify the LC50 of cigarette butt leachate to fish. Results The LC50 for leachate from smoked cigarette butts (smoked filter + tobacco) was approximately one cigarette butt/l for both the marine topsmelt (Atherinops affinis) and the freshwater fathead minnow (Pimephales promelas). Leachate from smoked cigarette filters (no tobacco), was less toxic, with LC50 values of 1.8 and 4.3 cigarette butts/l, respectively for both fish species. Unsmoked cigarette filters (no tobacco) were also found to be toxic, with LC50 values of 5.1 and 13.5 cigarette butts/l, respectively, for both fish species. Conclusion Toxicity of cigarette butt leachate was found to increase from unsmoked cigarette filters (no tobacco) to smoked cigarette filters (no tobacco) to smoked cigarette butts (smoked filter + tobacco). This study represents the first in the literature to investigate and affirm the toxicity of cigarette butts to fish, and will assist in assessing the potential ecological risks of cigarette butts to the aquatic environment.

A comparative analysis of municipal solid waste management (MSWM) in Singapore and Berlin was carried out in order to identify its current status, and highlight the prevailing conditions of MSWM. An overview of the various aspects of MSWM in these two cities is provided, with emphasis on comparing the legal, technical, and managerial aspects of MSW. Collection systems and recycling practiced with respect to the involvement of the government and the private sector, are also presented. Over last two decades, the city of Berlin has made impressive progress with respect to its waste management. The amounts of waste have declined significantly, and at the same time the proportion that could be recovered and recycled has increased. In contrast, although Singapore's recycling rate has been increasing over the past few years, rapid economic and population growth as well as change in consumption patterns in this city-state has caused waste generation to continue to increase. Landfilling of MSW plays minor role in both cities, one due to geography (Singapore) and the other due to legislative prohibition (Berlin). Consequently, both in Singapore and Berlin, waste is increasingly being used as a valuable resource and great efforts have been made for the development of incineration technology and energy recovery, as well as climate protection.

Large-scale centralised wastewater treatment system has often prevailed in industrial countries, and has been regarded as a successful approach during the last century. However, transfer of this highly water-consuming system and so-called ‘end-of-pipe’ technology to developing countries, especially in fast-growing cities with scarce water resources, has been extremely limited. Decentralized water treatment is not a new technology and has been successfully implemented in many rural areas worldwide. However, there are few applications in urban areas. This study at Tianxiu Garden in Beijing, China, investigated the potential and feasibility of water management based on a decentralized approach, but modified for application of greywater recycling and rainwater harvesting in a densely populated semi-urban area. A high degree of drinking water substitution (more than 25%) could not be attained by rainwater harvesting. Recycling of treated greywater for toilet flushing was shown to be an efficient method for min...

Large-scale centralized wastewater treatment systems often prevail in industrial countries and have been regarded as a successful approach during the last century. However, to solve the multifold water-related problems in China with its rapid growth of urbanization and industrialization, complete replication of this centralized, cost- and energy-intensive technology has proved to be extremely limited in scope and success. As one of the most important applications of ecological engineering, constructed wetland (CW) systems for wastewater treatment can offer an optimal alternative and result in beneficial conservation of natural resources with low capital costs and energy consumption, as well as minimal operation and maintenance expenditures. CW technology is particularly suitable for rapidly growing small- and medium-size cities in China. This paper aims at examining the mechanisms of pollutant removal efficiency in these systems and investigating the merits, status and feasibility of using constructed wetland systems to treatment wastewater in China. Additionally, it investigates existing impediments to application and implementation of CWs in China, as well as challenges to future development.

The New River Wetlands Project is comprised of two constructed treatment wetland sites supplied with water from the New River and agricultural drainage water from the Imperial Valley in California. Bioaccumulation of selenium has created toxic conditions for wildlife in similar wetlands in other areas. Selenium levels in water (at wetland inflow and outflow), sediments, plants, invertebrates, and fish were analyzed for both wetland sites from 2006 to 2007. An average of 56% of the total mass of selenium in the inflow was removed at the Imperial site, and 70% was removed at the Brawley site. Most of the retained selenium (8 kg at the Imperial site and 2 kg at the Brawley site) was in the sediments. Less than 1% of the selenium accumulated in plant tissues. Mass balance calculations estimated that 17–61% of the selenium was lost through volatilization. After 6 years of operation of these wetlands, concentrations of selenium in fish and invertebrates were at or above threshold ranges for reproductive effects in birds and fish. Constructed wetlands are an efficient method for removing selenium from agricultural drainwater, although they need to be monitored over the long-term for potential risks posed by bioaccumulation of selenium.

In 2004, the organophosphorus pesticide, diazinon, was phased-out for all residential uses in the United States. The objective of this study was to determine the temporal trend of diazinon levels in the Chollas Creek, CA watershed since the phase-out of this pesticide. Stormwater samples from Chollas Creek were collected during seven storm events in 2006–2007. The median diazinon level for all samples was 0.13 µg/L. Statistical analysis using the Kruskal-Wallis test revealed no statistically significant (p=0.765) spatial difference among any of the sampling sites. Correlational analysis (using the Spearman's rho test) revealed that there was no significant association between antecedent dry days and median diazinon levels (p=0.383, rho=0.393). Additionally, no association between storm event precipitation (p=0.355, rho=−0.414), median storm event intensity (p=0.585, rho=−0.252), or annual cumulative precipitation (p=0.760, rho=0.143) was observed. Trend analysis of diazinon levels (1998–2005) sho...

A summary of all existing information gathered since 1980 on contaminants in bairdiella (Bairdiella icistia), orangemouth corvina (Cynoscion xanthulus), and sargo (Anisotremus davidsonii) living in the Salton Sea is presented. Comparisons are made with an earlier analysis of contaminants in tilapia (Oreochromis mossambicus x O. urolepis hornorum hybrid). Risks are assessed for humans and piscivorous birds consuming these fish and for the health of the fish populations themselves. Of the 17 trace elements, 42 organic pesticides and 48 polychlorinated biphenyls (PCBs) sampled in whole-body and fillet samples of fish collected from the Salton Sea, only arsenic (As), selenium (Se), total DDT (tDDT), and total PCBs (tPCBs) were determined to be of potential concern for the health of human consumers. Recent average concentrations of total As in fillet tissue are 1.3 μg g−1 wet weight (ww) for bairdiella and 1.2 μg g−1 ww for corvina and tilapia, respectively, with the inorganic As fraction representing...

A summary of all existing information collected since 1980 on contaminants in tilapia from the Salton Sea is presented and risks to humans and fish-eating birds assessed. Of the 17 trace elements, 42 organic pesticides and 48 polychlorinated biphenyls (PCBs) analyzed in tilapia whole body and fillet samples, only selenium (Se), arsenic (As) and possibly dichlorodiphenyltrichloroethane (DDE) were found at levels high enough to be of concern for fish, birds or humans. Average current concentration of arsenic (As) was 0.7 µg g−1 wet weight (ww) in whole body samples and 1.2 µg g−1 ww in fillet samples, or 2.8 and 5.7 µg g−1 dry weight (dw), respectively. Inorganic As averaged 0.006 µg g−1 ww (0.03 µg g−1 dw) in fillet samples, which represented 0.3% of total As. By U.S. Environmental Protection Agency (U.S.EPA) guidelines, As levels in tilapia pose no threat of non-cancerous adverse health effects in children and adults. As is a known human carcinogen, however, and U.S.EPA cancer risk assessment procedures indicate that a weekly consumption of 540 g (19 oz) or more for 70 years would increase the upper bound cancer risk by 1 in 100,000 consumers exposed. Average current Se concentration was 2.2 µg g−1 ww in tilapia whole body samples and 1.9 µg g−1 ww in fillet (8.3 and 9 µg g−1 dw, respectively). Consumption of Se-contaminated tilapia was found to present no unacceptable risk for adverse health effects for adults consuming up to 1000 g (35 oz) of fillet per week even when additional intakes of Se from other food items were taken into account. Similarly, children weighing 30 kg or more could safely eat up to 430 g (15 oz) of tilapia fillet on a weekly basis. A health advisory issued by the State of California in 1986 recommended, on the basis of Se levels, that consumption of any fish from the Salton Sea be limited to 114 g (4 oz) every 2 weeks, but the rationale and calculations on which that advisory was based are unavailable. We suggest that the existing health advisory for Salton Sea tilapia be revised by the state in light of this new information and updated risk parameters for As and Se. Dichlorodiphenyltrichloroethane (DDE) was detected in all samples of tilapia, with current levels averaging 0.085 µg g−1 in whole tilapia and 0.032 µg g−1 in fillet ww. Compared to screening values proposed by the U.S. EPA, these concentrations are unlikely to cause non-cancerous health effects in anglers, but one might exceed a 1 × 10−5 increase in cancer risk by consuming more than 4 meals of tilapia per week. Similarly, polychlorinated biphenyls (PCBs) were detected in tilapia fillets at levels that may increase the cancer risk for those anglers also eating more than 4 meals of tilapia per week. These determinations are based, however, on DDE concentrations reported from a small sample size (n = 4), and on screening values recommended by U.S.EPA. The paucity of DDE and total DDT analyses carried out in recent times on the edible portion of Salton Sea tilapia warrants additional analyses in order to evaluate the need for issuance of a fish consumption advisory with regards to long term exposure to total DDT via consumption of Salton Sea fish. With regards to the potential impact on fish and piscivorous birds, we cannot conclude whether concentrations of As in tilapia could pose a threat to the fish and the birds feeding on them. Se concentrations, however, may be elevated enough to negatively affect fish health, and reproduction and immune systems of piscivorous birds, but definitive studies are lacking. Total DDT and PCB concentrations in whole tilapia are not elevated enough to have adverse effects on fish and piscivorous birds. Fish harvesting for fish meal production has been proposed for the Salton Sea. Based on whole fish dry weight values of 61% protein and 21% ash, and the determined contaminant levels, tilapia could yield a meal of reasonable quality for use in formulating poultry, livestock and aquaculture feeds.

In order to assess the microbial water quality of the lagoon canals of Venice, Italy and nearby beach on Lido island, a study was conducted using real-time RT-PCR to enumerate levels of hepatitis A virus (HAV) and enteroviruses in these marine waters over a 3-year period from 2003 to 2005. A total of 17 sites (9 lagoon canal and 8 beach sites) were assayed. For the canals of the Venice Lagoon, 78% were positive for both HAV and enteroviruses, with levels ranging from 75 to 730 and 3 to 1,614 genome copies/L, respectively. At Lido beach, HAV was never detected, but enteroviruses were detected in all Lido beach samples at levels ranging from 2 to 71 genome copies/L. There was a statistically significant correlation between thermotolerant coliform densities and HAV levels (p=0.0002), but the relationship between thermotolerant coliform densities and enterovirus levels was not significant (p>0.05). Despite the fact that enteroviruses were detected at low levels in the surfzone at Lido beach, the risk for enteroviral infection (calculated using the beta-Poisson model) for recreational exposure from swimming, was in the range of 1.9 x 10(-3) - 6.1 x 10(-2), yielding a disease risk at or below the level (5% for gastroenteritis) deemed acceptable by European Guide standards.

Macroinvertebrate organisms were sampled at four sites on Tecate Creek (U.S.–Mexico) and quantitatively evaluated using the SIGNAL-w (Stream Invertebrate Grade Number—Average Level-weighted) index. A morphological assessment of the stream structure was also carried out. Bioindication by SIGNAL reflected a very low water quality in the upper three sampled stream reaches, but with a significant improvement by the last site on the Rio Alamar, but only to a grade of critical to high pollution over a flowing distance of 29 km. Levels of BOD and ammonium-N at the Rio Alamar (Toll Bridge) site remained quite high, 56 mg/L and 48 mg/L, respectively. Metal levels also generally decreased as the water flowed downstream to the the Rio Alamar. Despite the fact that Tecate Creek has a quite natural morphological structure, solid inorganic surfaces and aquatic macrophytes (as settlement area) are mostly absent in Tecate Creek. This lack of stable habitats prevents the development of an effective biofilm which ...

Up until the present, canals and ditches in Europe have been used to drain and thus devastate fens (lowland moors). However, in many cases, their function can be changed from drainage to irrigation and re-wetting of previously drained areas. These systems of canals and ditches are characteristic elements of the historically developed cultural landscape. Therefore, management and development plans should be oriented towards their continual maintenance. Despite the density of canals and ditches in many regions of Germany, especially of Eastern Germany, there are only a few studies to evaluate these systems of waterways, and an integrated approach towards their assessment has been totally absent. Existing approaches for typology and assessment

Six years after re-connection of an oxbow lake from periodically to permanently connected to the main channel, the restoration success was assessed. This permanently connected oxbow lake was compared with the main channel of the Elbe River and with a periodically connected oxbow lake by means of comparisons of the aquatic macroinvertebrates, fish and aquatic macrophyte communities. The permanently connected oxbow was suited as important replacement habitat for riverine invertebrates, especially for clubtails (Odonata) and unionid mussels (Bivalvia). The periodically connected oxbow lake was colonized by typical species for shallow lakes. As expected, riverine species did not occur. Meanwhile, the invertebrate community in the main channel was poor and dominated by invasive species (Dikerogammarus villosus, Dreissena polymorpha). The results concerning fish showed a clear dominance of the rheophilic species spined loach (Cobitis taenia) in the permanently connected oxbow lake and of the indifferent species roach (Rutilus rutilus) and European perch (Perca fluviatilis) in the periodically connected oxbow lake. However, species number was highest in the main channel. For macrophytes, quantity, number of taxa and growth forms and diversity were lower in the permanently compared to the periodically connected oxbow lake. In conclusion, the re-connection of oxbow lakes to main channels can be an important measure for native species conservation, especially macroinvertebrates, and hence for the implementation of the Water Framework Directive.

Constructed wetlands (CWs) have been successfully used for treating various wastewaters for decades and have been identified as a sustainable wastewater management option for developing countries. With the goal of promoting sustainable engineered systems that support human well-being but are also compatible with sustaining natural (environmental) systems, the application of CWs has become more relevant. Such application is especially significant for developing countries with tropical climates, which are very conducive to higher biological activity and productivity, resulting in higher treatment efficiencies compared to those in temperate climates. This paper therefore highlights the practice, applications, and research of treatment wetlands under tropical and subtropical conditions since 2000. In the present review, removal of biochemical oxygen demand (BOD) and total suspended solid (TSS) was shown to be very efficient and consistent across all types of treatment wetlands. Hybrid systems appeared more efficient in the removal of total suspended solid (TSS) (91.3%), chemical oxygen demand (COD) (84.3%), and nitrogen (i.e., 80.7% for ammonium (NH)4-N, 80.8% for nitrate (NO)3-N, and 75.4% for total nitrogen (TN)) as compared to other wetland systems. Vertical subsurface flow (VSSF) CWs removed TSS (84.9%), BOD (87.6%), and nitrogen (i.e., 66.2% for NH4-N, 73.3% for NO3-N, and 53.3% for TN) more efficiently than horizontal subsurface flow (HSSF) CWs, while HSSF CWs (69.8%) showed better total phosphorus (TP) removal compared to VSSF CWs (60.1%). Floating treatment wetlands (FTWs) showed comparable removal efficiencies for BOD (70.7%), NH4-N (63.6%), and TP (44.8%) to free water surface (FWS) CW systems. Published version

In order to reduce the very high costs of sewage disposal in the new federal states of Germany, more decentralized purification systems need to be established. To attain higher surface water quality, and thereby the acceptance of such systems by governmental authorities, good removal rates for organic substances and also for nutrients (N, P) are necessary. Constructed wetlands for wastewater treatment (reed-bed systems) in Germany and in the USA have been used successfully. This study compares the purification performances of constructed horizontal flow wetlands (HFW) and vertical flow wetlands (VFW), including: (1) a small horizontal flow wetland (HFW); (2) a sloped HFW; (3) a larger HFW; (4) a stratified vertical flow wetland (VFW); and (5) an unstratified VFW. It is shown that both the horizontal flow and vertical flow systems can remove more than 90% of organic load and of total N and P, if there is an effective precleaning step, and if the specific treatment area is great enough (>50 m 2 /m 3 per d). HFWs have an advantage in long-term removal of P because it is bound to organic substances to a high degree. Decentral and semicentral natural treatment systems also save material (76%) and energy (83%) for their function compared with central technical systems.

This paper describes a geographic information system (GIS)-based, land use runoff model that estimates the annual mass emission of copper (Cu), lead (Pb), and zinc (Zn) from the binational Tijuana River watershed (TRW). This model estimates that the urbanized portion of the City of Tijuana, Mexico, accounted for 37 to 47 percent of the actual downstream loading of these metals to the Tijuana Estuary and coastal ocean. The fraction of loading contributed by open space was about the same (31-44%), although this land use comprised about 90 percent of the total watershed area. Modeled estimates of the annual mass emission of heavy metals are in reasonable agreement with actual measurements, particularly for zinc (within about 10%), thereby suggesting that GIS-based modeling may be useful for predicting nonpoint source pollutant loading in a variety of border development scenarios.

The US EPA's Integrated Exposure Uptake Biokinetic (IEUBK) Model is a physiologically-based, multicompartment model which simulates lead uptake, distribution within the body, and elimination in order to predict children's blood lead levels. This study used the IEUBK to quantify the relative importance of dietary lead exposure from ceramic bean pots (as opposed to other environmental sources including soil, water, air and indoor dust) in children from San Diego County, CA, the majority of whom had been identified (by actual measurements) to have elevated blood lead levels. The EUBK modeling suggested that dietary lead exposure from beans prepared in Mexican pottery may account for a major fraction of the blood lead burden in children (all of Hispanic ethnicity) whose families used such ceramic ware. The IEUBK model tended to be overpredictive of actual values for blood lead levels, but this was most probably due to uncertainties in the exposure variables in the risk assessment. The results of this model si...