The UK housing developers' five-star rating: fact or fiction?

Purpose - The purpose of the paper is to explore how the data collected by the NHBC is used in practice to improve the service provided to the customers, the transition of any changes into practice and the overall management of the customer satisfaction process by the builder. Design/methodology/approach – A Qualitative approach to the research was adopted and the findings from the interviews provide an indication of the views from a range of private house builders relating to the areas of customer satisfaction and the ratings provided through industry based questionnaires. Findings – This paper has uncovered the views and opinions of private house builders relating to customer satisfaction and five star ratings. The findings provide evidence that the house building industry is not fully engaged with the HBF five star related concept and that they provide a differing level of service in relation to customer satisfaction. Research Implications - The research concluded that the customer can be manipulated by the builders in some cases causing a bias in the market; on the whole the customer satisfaction surveys and star rating are simply seen as a marketing tool, used by the builders marketing department as a sign of quality and a way to promote the company. Practical Implications - This paper is of interest to private house builders and the wider construction industry and will aid their understanding of customer satisfaction and quality related ratings applied by industry bodies. Originality/value – The findings within this paper provide an overview of the opinions of house builders relating to customer satisfaction and five star ratings using interview-based data obtained from private house building operatives

The Impact of Gamma Radiation on Sediment Microbial Processes

Microbial communities have the potential to control the biogeochemical fate of some radionuclides in contaminated land scenarios or in the vicinity of a geological repository for radioactive waste. However, there have been few studies of ionizing radiation effects on microbial communities in sediment systems. Here, acetate and lactate amended sediment microcosms irradiated with gamma radiation at 0.5 or 30 Gy h(−1) for 8 weeks all displayed NO(3)(−) and Fe(III) reduction, although the rate of Fe(III) reduction was decreased in 30-Gy h(−1) treatments. These systems were dominated by fermentation processes. Pyrosequencing indicated that the 30-Gy h(−1) treatment resulted in a community dominated by two Clostridial species. In systems containing no added electron donor, irradiation at either dose rate did not restrict NO(3)(−), Fe(III), or SO(4)(2−) reduction. Rather, Fe(III) reduction was stimulated in the 0.5-Gy h(−1)-treated systems. In irradiated systems, there was a relative increase in the proportion of bacteria capable of Fe(III) reduction, with Geothrix fermentans and Geobacter sp. identified in the 0.5-Gy h(−1) and 30-Gy h(−1) treatments, respectively. These results indicate that biogeochemical processes will likely not be restricted by dose rates in such environments, and electron accepting processes may even be stimulated by radiation

Treatment of Alkaline Cr(VI)-Contaminated Leachate with an Alkaliphilic Metal-Reducing Bacterium

Chromium in its toxic Cr(VI) valence state is a common contaminant particularly associated with alkaline environments. A well-publicized case of this occurred in Glasgow, United Kingdom, where poorly controlled disposal of a cementitious industrial by-product, chromite ore processing residue (COPR), has resulted in extensive contamination by Cr(VI)-contaminated alkaline leachates. In the search for viable bioremediation treatments for Cr(VI), a variety of bacteria that are capable of reduction of the toxic and highly soluble Cr(VI) to the relatively nontoxic and less mobile Cr(III) oxidation state, predominantly under circumneutral pH conditions, have been isolated. Recently, however, alkaliphilic bacteria that have the potential to reduce Cr(VI) under alkaline conditions have been identified. This study focuses on the application of a metal-reducing bacterium to the remediation of alkaline Cr(VI)-contaminated leachates from COPR. This bacterium, belonging to the Halomonas genus, was found to exhibit growth concomitant to Cr(VI) reduction under alkaline conditions (pH 10). Bacterial cells were able to rapidly remove high concentrations of aqueous Cr(VI) (2.5 mM) under anaerobic conditions, up to a starting pH of 11. Cr(VI) reduction rates were controlled by pH, with slower removal observed at pH 11, compared to pH 10, while no removal was observed at pH 12. The reduction of aqueous Cr(VI) resulted in the precipitation of Cr(III) biominerals, which were characterized using transmission electron microscopy and energy-dispersive X-ray analysis (TEM-EDX) and X-ray photoelectron spectroscopy (XPS). The effectiveness of this haloalkaliphilic bacterium for Cr(VI) reduction at high pH suggests potential for its use as an in situ treatment of COPR and other alkaline Cr(VI)-contaminated environments

Multi-storey residential buildings and occupant’s behaviour during fire evacuation in the UK: Factors relevant to the development of evacuation strategies

Purpose – The paper aims to investigate human behaviour during fire evacuations in multistorey residential buildings through a focus on the challenges and obstacles that occupants face. Any variations in response behaviours that are relevant to the evacuation strategies/plans in the UK context of occupancy typical of multi-storey buildings in large cities. Design/methodology/approach – A literature review was conducted to identify the factors occupants face and also the decision-making of occupants regarding methods of egress. A mixed research method was adopted using interviews and a questionnaire survey. The findings from the interviews and survey are benchmarked against the information gathered from the literature review. Findings – The paper identifies various challenges that occupants face when evacuating a multi-storey residential building. In terms of the decision-making process, the research results evidence that occupants could be given more information on the evacuation procedures within their specific building. The paper also finds that occupants remain reluctant to use a lift during evacuation in fire event, irrespective of any signage clearly stating that is appropriate to do so in the context of modern lift technology. Originality/Value – This paper contributes to the body of knowledge available on the evacuation of multi-storey buildings located in large cities within the UK, outlining potential areas for future research, focused on providing an insight of the behavioural decisions made by the occupants make when evacuating a building in the event of a fire

454 pyrosequencing assessment of biodegradative bacteria from thermal hydrolysis processes

Anaerobic treatment process is a cost-effective method for treating organic wastes, since the biogas formed can be used for heat/electricity production and the digester residues can be recycled for other applications. An innovative use of the digestate could be as biodegradative and methanogenic inoculum for the stimulation of methane production in gas-producing or depleted wells. The microbial communities involved in the biodegradation of petrochemical waste are similar to the indigenous microorganisms typically found in unconventional basins. These communities also follow the same cascade of reactions: from the initial breakdown of complex molecules to the production of intermediate compounds used by methanogens. This study carried out a culture-independent assessment of the bacterial community composition of a digestate from the Bran Sands Advanced Digestion Facility (Middleborough, UK) and compared the results with the microbial populations found in unconventional gas basins. The 454 pyrosequencing analyses revealed a bacterial community dominated by Thermotogae, Bacteroidia, Clostridia and Synergistia, which are typically found in unconventional gas systems. The classification of nucleotide sequence reads and assembled contigs revealed a genetic profile characteristic for an anaerobic microbial consortium running fermentative metabolic pathways. The assignment of numerous sequences was related to hydrocarbon decomposition and digestion of cellulosic material, which indicates that the bacterial community is engaged in hydrolysis of plant-derived material. The bacterial community composition suggest that the effluent of the digester can be used as a biodegradative inoculum for the stimulation of methane generation in unconventional wells, where events of microbial methanogenesis have been previously observed

Biogenic methane in shale gas and coal bed methane : a review of current knowledge and gaps

Biogenic CH4 generation has been observed in many shallow, low temperature shale gas basins and coal seams. The depletion of conventional resources and the increasing demand of natural gas for human consumption have spurred the development of so-called unconventional gas resources such as shale gas (SG) and coal-bed methane (CBM). Such unconventional systems represent the opportunity for the stimulation of biogenic CH4 generation. Biogenic CH4 in shale and coal is produced by anaerobic biodegradation of organic matter (OM): methanogenic Archaea represent only the final step of biogenic CH4 generation. Several communities of microorganisms are involved in the initial breakdown of complex geopolymers and the production of intermediate compounds used by methanogens. There are several key knowledge gaps on biogenic CH4 production in unconventional gas systems, such as the exact fraction of bioavailable OM, the microbial communities involved and how they can be stimulated to enhance microbial methanogenesis. Progress on biodegradation studies, isotopic signatures, as well as DNA analyses and proteomics could help unravel interactions within the syntrophic community involved in the methanogenic biodegradation of OM. Questions also remain regarding the environmental impact of unconventional gas production, such as water quality and the mobility of toxic metals and radionuclides. The answers to these questions might have implications for both recovery practices and a sustainable development of unconventional resources. This review summarises the current knowledge regarding biogenic CH4 in SG and CBM: from the nature of the rocks to the producing microbial community and the indicators of biogenic CH4, illustrating how these two environments show remarkably similar opportunities for the stimulation of biogenic CH4 generation

Microbial impacts on 99mTc migration through sandstone under highly alkaline conditions relevant to radioactive waste disposal

Geological disposal of intermediate level radioactive waste in the UK is planned to involve the use of cementitious materials, facilitating the formation of an alkali-disturbed zone within the host rock. The biogeochemical processes that will occur in this environment, and the extent to which they will impact on radionuclide migration, are currently poorly understood. This study investigates the impact of biogeochemical processes on the mobility of the radionuclide technetium, in column experiments designed to be representative of aspects of the alkali-disturbed zone. Results indicate that microbial processes were capable of inhibiting 99mTc migration through columns, and X-ray radiography demonstrated that extensive physical changes had occurred to the material within columns where microbiological activity had been stimulated. The utilisation of organic acids under highly alkaline conditions, generating H2 and CO2, may represent a mechanism by which microbial processes may alter the hydraulic conductivity of a geological environment. Column sediments were dominated by obligately alkaliphilic H2-oxidising bacteria, suggesting that the enrichment of these bacteria may have occurred as a result of H2 generation during organic acid metabolism. The results from these experiments show that microorganisms are able to carry out a number of processes under highly alkaline conditions that could potentially impact on the properties of the host rock surrounding a geological disposal facility for intermediate level radioactive waste

Airborne Bacterial and Eukaryotic Community Structure across the United Kingdom Revealed by High-Throughput Sequencing

Primary biological aerosols often include allergenic and pathogenic microorganisms posing potential risks to human health. Moreover, there are airborne plant and animal pathogens that may have ecological and economic impact. In this study, we used high-throughput sequencing techniques (Illumina, MiSeq) targeting the 16S rRNA genes of bacteria and the 18S rRNA genes of eukaryotes, to characterize airborne primary biological aerosols. We used a filtration system on the UK Facility for Airborne Atmospheric Measurements (FAAM) research aircraft to sample a range of primary biological aerosols across southern England overflying surface measurement sites from Chilbolton to Weybourne. We identified 30 to 60 bacterial operational taxonomic units (OTUs) and 108 to 224 eukaryotic OTUs per sample. Moreover, 16S rRNA gene sequencing identified significant numbers of genera that have not been found in atmospheric samples previously or only been described in limited number of atmospheric field studies, which are rather old or published in local journals. This includes the genera Gordonia, Lautropia, and Psychroglaciecola. Some of the bacterial genera found in this study include potential human pathogens, for example, Gordonia, Sphingomonas, Chryseobacterium, Morganella, Fusobacterium, and Streptococcus. 18S rRNA gene sequencing showed Cladosporium to be the major genus in all of the samples, which is a well-known allergen and often found in the atmosphere. There were also genetic signatures of potentially allergenic taxa; for example, Pleosporales, Phoma, and Brassicales. Although there was no significant clustering of bacterial and eukaryotic communities depending on the sampling location, we found meteorological factors explaining significant variations in the community composition. The findings in this study support the application of DNA-based sequencing technologies for atmospheric science studies in combination with complementary spectroscopic and microscopic techniques for improved identification of primary biological aerosols

Retention of immobile Se(0) in flow-through aquifer column systems during bioreduction and oxic-remobilization

Selenium (Se) is a toxic contaminant with multiple anthropogenic sources, including Se-79 from nuclear fission. Se mobility in the geosphere is generally governed by its oxidation state, therefore understanding Se speciation under variable redox conditions is important for the safe management of Se contaminated sites. Here, we investigate Se behavior in sediment groundwater column systems. Experiments were conducted with environmentally relevant Se concentrations, using a range of groundwater compositions, and the impact of electron-donor (i.e., biostimulation) and groundwater sulfate addition was examined over a period of 170 days. X-Ray Absorption Spectroscopy and standard geochemical techniques were used to track changes in sediment associated Se concentration and speciation. Electron-donor amended systems with and without added sulfate retained up to 90% of added Se(VI)(aq), with sediment associated Se speciation dominated by trigonal Se(0) and possibly trace Se(-II); no Se colloid formation was observed. The remobilization potential of the sediment associated Se species was then tested in reoxidation and seawater intrusion perturbation experiments. In all treatments, sediment associated Se (i.e., trigonal Se(0)) was largely resistant to remobilization over the timescale of the experiments (170 days). However, in the perturbation experiments, less Se was remobilized from sulfidic sediments, suggesting that previous sulfate-reducing conditions may buffer Se against remobilization and migration.Peer reviewe