Using legitimacy dialogues to explore responses to flooding issues in a UK catchment

A growing awareness of the potential impacts of climate change has led to the consideration of a variety of future outcomes by water supply companies, regulators and local authorities within England and Wales. These strategies recognise the possibility of episodes of flooding within catchments, with the Environment Agency's fourth Periodic Review requiring water companies to explore future demand and supply scenarios up to 2030. However, there is a gap in the literature concerning how those tasked to implement water policy, and those subject to it, view these change scenarios. This paper outlines a study undertaken within the River Nene catchment, exploring how water resource governance bodies and water users respond to flooding issues. In particular, the research focuses on the twin concepts of legitimacy and dialogue as a means to assess the boundaries of stakeholder engagement with these strategic change scenarios.     

Anthropogenic tracers, endocrine disrupting chemicals, and endocrine disruption in Minnesota lakes

Concentrations of endocrine disrupting chemicals and endocrine disruption in fish were determined in 11 lakes across Minnesota that represent a range of trophic conditions and land uses (urban, agricultural, residential, and forested) and in which wastewater treatment plant discharges were absent. Water, sediment, and passive polar organic integrative samplers (POCIS) were analyzed for steroidal hormones, alkylphenols, bisphenol A, and other organic and inorganic molecular tracers to evaluate potential non-point source inputs into the lakes. Resident fish from the lakes were collected, and caged male fathead minnows were deployed to evaluate endocrine disruption, as indicated by the biological endpoints of plasma vitellogenin and gonadal histology. Endocrine disrupting chemicals, including bisphenol A, 17β-estradiol, estrone, and 4-nonylphenol were detected in 90% of the lakes at part per trillion concentrations. Endocrine disruption was observed in caged fathead minnows and resident fish in 90% of the lakes. The widespread but variable occurrence of anthropogenic chemicals in the lakes and endocrine disruption in fish indicates that potential sources are diverse, not limited to wastewater treatment plant discharges, and not entirely predictable based on trophic status and land use.     

Deconstructing public participation in the Water Framework Directive: implementation and compliance with the letter or with the spirit of the law?

This article offers a fresh reading of the Water Framework Directive (WFD) and of the Common Implementation Strategy guidance document number 8 on public participation (PP) aimed at identifying the conditions required for successful implementation. We propose that a central barrier to implementing Article 14 is that Integrated Water Resources Management (IWRM) problems are complex in character and that participation is a wicked process in practice. This article highlights some ambiguous interpretations of the WFD comparing and contrasting the ‘letter of the law’ and its ‘spirit’, based on a critical review of the nature of PP, who it concerns and when it takes place. First we articulate a complex system interpretation of IWRM in the context of the WFD. Second, we explain the difficulty to define blueprint for PP in IWRM. Finally, we present five interpretative challenging readings in order to highlight tensions between the ‘spirit’ and the ‘letter’ of the WFD.     

Determination of copper speciation in highway stormwater runoff using competitive ligand exchange - Adsorptive cathodic stripping voltammetry

Low concentrations of dissolved copper have been shown to adversely affect the olfactory system of salmonid species, impairing their ability to avoid predators and likely increasing mortality. These studies have resulted in increased regulatory scrutiny of stormwater discharges to surface waters inhabited by threatened and endangered salmonid species. Because it is primarily the free ionic (Cu²⁺) and weakly complexed forms of copper that are bioavailable, it is critical to understand the speciation of copper in stormwater. This paper reports on the characterization of copper binding ligands and copper speciation in composite samples of highway stormwater runoff collected at four sites in Oregon, USA using competitive ligand exchange - adsorptive cathodic stripping voltammetry (CLE-ACSV). Although the concentration and strength of copper binding ligands in stormwater varied considerable between sites and storms, the vast majority (>99.9%) of the total dissolved copper in composite samples was complexed by organic ligands in stormwater. Although total dissolved copper concentrations range from 2 to 20 μg/L, the analytically determined free ionic copper concentrations did not exceed 10⁻¹⁰ M (6.3 ng/L) in any of the fully characterized samples, suggesting that much of the copper in highway stormwater is not bioavailable. Analytically determined free ionic copper concentrations were compared with those predicted by a readily available chemical equilibrium models and found to be in reasonable agreement.     

Impact of placement of portable air cleaning devices in multizone residential environments

An advantage of portable air cleaners is that they can be positioned in different parts of a building and used where air cleaning is needed. This makes them a popular choice for use in residential buildings. In typical indoor particle modeling efforts, perfect air mixing and uniform contaminant concentration distribution are assumed. However, nonuniform spatial concentrations of particles are more reflective of most environments. Using experiments to validate computational fluid dynamic and particle tracking models and applying these models in numerical based parametric analysis, this paper analyzes the overall contaminant removal in a multi-room residential building. Simulations varied (1) particle size (0.74, 3.4 and 10 μm), (2) clean air delivery rate (CADR) of the air cleaner (50 m³/h and 500 m³/h), and (3) position of portable air cleaner in different rooms. The results show very large variation of the overall particle removal for different positions of portable cleaning device. In extreme cases, the effective positioning of cleaning device can result in a factor of 2.5 change in overall particle removal and, consequently, strongly affect occupant exposure to particles.     

Hot-dip galvanizing of cold-formed steel hollow sections: a state-of-the-art review

A good understanding of the effects of galvanizing on the short- and long-term behaviours of steel components is essential for structural design. This review paper is motivated by a series of recent reports on cracking in galvanized cold-formed tubular steel structures and the limitations of current steel product standards and steel design specifications in this field. The steel-related and galvanizing-related factors, different pre-galvanizing countermeasures for brittle cracking and the available technical documents are summarized. An extensive bibliography is provided as a basis for future research and development in this field.     

Tubulovesicular structures: what are they really?

The tubulovesicular structures (TVS) are the only structures unique at the level of thin-section electron microscopy for all TSEs so far examined. They were first described in NIH Swiss mice infected intracerebrally with the "Chandler" strain of scrapie by David-Ferreira et al. in 1968 [Proc. Soc. Exp. Biol. Med. 127:313-320]. TVS were described as "particles and rods ranging in diameter from 320 to 360 A(o)." The exact topology of TVS is not entirely clear. In most published electron micrographs, TVS appeared as spheres measuring between 20 and 40 nm in diameter. The number of neuritic processes containing TVS increases through the incubation period and has been shown to correlate with the incubation period and titre of infectivity in three longitudinal disease studies of scrapie and CJD. These studies, therefore, suggest that TVS may represent a primary pathogenetic event rather than a pathological product of disease. The predominant theory of the scrapie agent is now the "prion hypothesis" and its derivatives, which implies that a conformationally altered abnormal isoform (PrP(Sc) or PrP*) of a normal cellular membrane glycoprotein (PrP(c)) is the agent and its accumulation merely mimicks replication. If an abnormal fraction of PrP is indeed the infectious agent, (although it is no longer suggested in some quarters that protease resistant fraction of PrP(Sc) is the agent). The absence of stainable PrP in TVS, however, would indicate that they are not the ultrastructural correlate of the agent. However, TVS appear to be specific and unique to the TSEs, appearing before the earliest pathological changes and increasing in line with incubation period or titre. The very existence of TVS and their correlation with infectivity, therefore, urgently needs an explanation.     

STS滤池组合工艺处理污水的中试研究

针对浙江北部某污水处理项目,开展了淹没式前置反硝化滤2／淹没式好氧滤池／后置深床反硝化滤池处理城市污水的脱氮除磷中试研究。经过5个月的运行结果表明,在进水污染物浓度高、水质波动大的情况下,系统的出水水质仍达到了GB18918--2002标准的一级A排放标准,使BOD5、NH4^＋-N、TN分别从200、82．5、82．5mg／L左右降到1．9、2．3、11．1mg／L,在出水中未检测到SS,TP可通过在深床反硝化滤池的进水中投加絮凝剂而去除。中试数据已用于浙江北部某污水处理项目的工程设计,并于2008年8月通水运行。     

Biofiltration for removal of BOM and residual ammonia following control of bromate formation

Nitrification was developed within a biological filter to simultaneously remove biodegradable organic matter (BOM) and residual ammonia added to control bromate formation during the ozonation of drinking water. Testing was performed at pilot-scale using three filters containing sand and anthracite filter media. BOM formed during ozonation (e.g., assimilable organic carbon (396-572 microg/L), formaldehyde (11-20 microg/L), and oxalate (83-145 microg/L)) was up to 70% removed through biofiltration. Dechlorinated backwash water was required to develop the nitrifying bacteria needed to convert the residual ammonia (0.1-0.5 mg/L NH(3)-N) to nitrite and then to nitrate. Chlorinated backwash water resulted in biofiltration without nitrification. Deep-bed filtration (empty-bed contact time (EBCT) = 8.3 min) did not enhance the development of nitrification when compared with shallow-bed filtration (EBCT = 3.2 min). Variable filtration rates between 4.8 and 14.6 m/h (2 and 6 gpm/sf) had minimal impact on BOM removal. However, conversion of ammonia to nitrite was reduced by 60% when increasing the filtration rate from 4.8 to 14.6 m/h. The results provide drinking water utilities practicing ozonation with a cost-effective alternative to remove the residual ammonia added for bromate control.     

Estimating the primary etiologic agents in recreational freshwaters impacted by human sources of faecal contamination

Epidemiology studies of recreational waters have demonstrated that swimmers exposed to faecally-contaminated recreational waters are at risk of excess gastrointestinal illness. Epidemiology studies provide valuable information on the nature and extent of health effects, the magnitude of risks, and how these risks are modified or associated with levels of faecal contamination and other measures of pollution. However, such studies have not provided information about the specific microbial agents that are responsible for the observed illnesses in swimmers. The objective of this work was to understand more fully the reported epidemiologic results from studies conducted on the Great Lakes in the US during 2003 and 2004 by identifying pathogens that could have caused the observed illnesses in those studies. We used a Quantitative Microbial Risk Assessment (QMRA) approach to estimate the likelihood of pathogen-induced adverse health effects. The reference pathogens used for this analysis were Norovirus, rotavirus, adenovirus, Cryptosporidium spp., Giardia lamblia, Campylobacter jejuni, Salmonella enterica, and Escherichia coli O157:H7. Two QMRA-based approaches were used to estimate the pathogen combinations that would be consistent with observed illness rates: in the first, swimming-associated gastrointestinal (GI) illnesses were assumed to occur in the same proportion as known illnesses in the US due to all non-foodborne sources, and in the second, pathogens were assumed to occur in the recreational waters in the same proportion as they occur in disinfected secondary effluent. The results indicate that human enteric viruses and in particular, Norovirus could have caused the vast majority of the observed swimming-associated GI illnesses during the 2003/2004 water epidemiology studies. Evaluation of the time-to-onset of illness strongly supports the principal finding and sensitivity analyses support the overall trends of the analyses even given their substantial uncertainties.