Methanogenic community development in anaerobic granular bioreactors treating trichloroethylene (TCE)-contaminated wastewater at 37 °C and 15 °C

Four expanded granular sludge bed (EGSB) bioreactors were seeded with a mesophilically-grown granular sludge and operated in duplicate for mesophilic (37 °C; R1 & R2) and low- (15°; R3 & R4) temperature treatment of a synthetic volatile fatty acid (VFA) based wastewater (3 kg COD m⁻³ d⁻¹) with one of each pair (R1 & R3) supplemented with increasing concentrations of trichloroethylene (TCE; 10, 20, 40, 60 mg l⁻¹) and one acting as a control. Bioreactor performance was evaluated by % COD removal efficiency and % biogas methane (CH₄) content. Quantitative Polymerase Chain Reaction (qPCR) was used to investigate the methanogenic community composition and dynamics in the bioreactors during the trial, while specific methanogenic activity (SMA) and toxicity assays were utilized to investigate the activity and TCE/dichloroethylene (DCE) toxicity thresholds of key trophic groups, respectively. At both 37 °C and 15 °C, TCE levels of 60 mg l⁻¹ resulted in the decline of % COD removal efficiencies to 29% (Day 235) and 37% (Day 238), respectively, and in % biogas CH₄ to 54% (Day 235) and 5% (Day 238), respectively. Despite the inhibitory effect of TCE on the anaerobic digestion process, the main drivers influencing methanogenic community development, as determined by qPCR and Non-metric multidimensional scaling analysis, were (i) wastewater composition and (ii) operating temperature. At the apical TCE concentration both SMA and qPCR of methanogenic archaea suggested that acetoclastic methanogens were somewhat inhibited by the presence of TCE and/or its degradation derivatives, while competition by dechlorinating organisms may have limited the availability of H₂ for hydrogenotrophic methanogenesis. In addition, there appeared to be an inverse correlation between SMA levels and TCE tolerance, a finding that was supported by the analysis of the inhibitory effect of TCE on two additional biomass sources. The results indicate that low-temperature anaerobic digestion is a feasible approach for the treatment of TCE-containing wastewater.     

Effects of ferric iron on the anaerobic treatment and microbial biodiversity in a coupled microbial electrolysis cell (MEC) – Anaerobic reactor

Adding Fe(III) into a MEC – anaerobic reactor enhanced the degradation of organic matters. To clarify the respective effects of combining Fe(III) dosage and a MEC and Fe(III) dosage only on strengthening anaerobic digestion, three anaerobic reactors were operated in parallel: a MEC – anaerobic reactor with dosing Fe(OH)₃ (R1), an anaerobic reactor with dosing Fe(OH)₃ (R2) and a common anaerobic reactor (R3). With increasing influent COD from 1500 to 4000 mg/L, the COD removal in R1 was maintained at 88.3% under a voltage of 0.8 V, which was higher than that in reactor R2 and R3. When the power was cut off, the COD removal in R1 decreased by 5.9%. The addition of Fe(OH)₃ enhanced both anaerobic digestion and anodic oxidation, resulting in the effective mineralization of volatile fatty acids (VFAs). The reduced Fe(II) combined with electric field resulted more extracellular polymeric substances (EPS) production. Quantitative real – time PCR showed a higher abundance of bacteria in the anodic biofilm and R1. Pyrosequencing and denaturing gradient gel electrophoresis (DGGE) analysis revealed that the dominant bacteria and archaea communities were richer and more abundant in the anode biofilm and R1.     

Productivity growth of wastewater treatment plants – accounting for environmental impacts: a Malmquist-Luenberger index approach

As the number of wastewater treatment plants (WWTPs) has increased, the economic considerations associated with their management have become more relevant. Measuring the productivity of WWTPs allows the best practice to be identified and resource use to be optimized. Previous studies assessing the productivity change of WWTPs have ignored undesirable outputs; thus, wastewater treatment was considered to be free of environmental impacts. To overcome this limitation and for the first time, we assessed the productivity growth of a sample of Spanish WWTPs, while also accounting for the emission of greenhouse gases and sludge production. The Malmquist-Luenberger productivity index (MLPI) and its components, the efficiency and technological changes, were estimated. To explore the role of environmental impacts in the measurement of the productivity growth of WWTPs, the MLPI was contrasted with the conventional measurement of productivity change: namely, the Malmquist productivity index (MPI). The omission of undesirable outputs led to an underestimation of the productivity growth, with statistically significant differences between the MLPI and MPI results. The comparison of the MPI and MLPI illustrated that WWTP operators and water agencies have internalized some good environmental practices into their production process costs.     

Financially sustainable management strategies for urban wastewater collection infrastructure – development of a system dynamics model

Causal loop diagrams are developed for wastewater collection networks to identify complex interactions and feedback loops among physical, financial, and social sectors. Causal loop diagrams are then incorporated into a novel system dynamics based decision support tool that can be used for financially sustainable management of wastewater collection networks. Data requirements to develop the decision support tool are discussed along with how can the decision support tool be used to manage a utility.The presented causal loop diagram is the first known attempt to lay out the interrelationships among system components using a formal technique. The causal loop diagram establishes the existence of several interacting feedback loops and demonstrates that the management of wastewater collection networks constitutes a complex dynamic system for which traditional management tools are deemed inadequate. The use of causal loop diagrams can be useful to mitigate effects of the silo-based organizational culture prevalent in many water utilities.The system dynamics model is the first known decision support tool to quantitatively simulate the influence of interrelationships and feedback loops in wastewater collection network management. The model is a mathematical representation of the causal loop diagram to capture cost drivers and revenues sources in the system. It also includes a set of policy levers which allows formulation of various financing and rehabilitation strategies. The model can be used to develop short- and long-term management plans. The impact of financing and rehabilitation strategies on system performance can be simulated and evaluated in terms of financial and service level metrics. The decision support tool can also be used by utilities to ensure essential data is collected and flows within organizational units.     

“SOLVENT”: development of a reversible solar-screen glazing system

Preliminary experiments with a novel glazing system developed at the Desert Architecture and Urban Planning Unit of Ben-Gurion University of the Negev in Israel indicated that it may provide improved visual and thermal performance in buildings with large glazed areas located in sunny regions, regardless of orientation. In winter, it reduces glare, local over-heating and damage to furnishings caused by exposure to direct solar radiation, with only a small reduction in solar space heating. In summer, it reduces the penetration of unwanted radiation without obstructing the view through the window, to an extent that may render external shading devices unnecessary. The SOLVENT project was contracted to complete the development of the glazing system, which is based on the concept of converting short-wave solar radiation to convective heat and long wave radiation. The glazing system was modeled and evaluated experimentally; a suitable frame was developed for it; and a design tool required for its application was developed. The current paper reports on physical modeling and experimental evaluation of the glazing system.     

Ozonation of secondary treated wastewater reduces ecotoxicity to Gammarus fossarum (Crustacea; Amphipoda): are loads of (micro)pollutants responsible?

Ozone application is an effective tool to reduce loads of (micro)pollutants in wastewater, however, its ecotoxicological implications are largely unknown. Therefore, the feeding rates of a leaf-shredding invertebrate (Gammarus fossarum) exposed to secondary (=non-ozone) or ozone treated wastewater were investigated to assess potential ecotoxicological effects. Two repetitive experiments resulted in significantly higher feeding rates for gammarids exposed to ozone compared to non-ozone treated wastewater sampled from a treatment plant equipped with a full-scale ozonation. A further experiment confirmed these results also for wastewater from the same treatment plant, when ozonation was conducted at the lab-scale. However, the deviations in dissolved organic carbon profiles of ozone and non-ozone wastewater did not seem to be the driving factor for the effects observed. Two additional experiments displayed on the one hand a higher feeding rate of G. fossarum if exposed to ten-fold enriched eluates from solid phase extraction cartridges loaded with ozone compared to non-ozone treated wastewater. On the other hand, the mean feeding rate of gammarids exposed to non-ozone treated wastewater, which contained hardly any (micro)pollutants (i.e. pharmaceuticals), was at the same level as wastewater from the same source additionally treated with ozone. These results suggest that not an alteration in the organic matrix but a reduction in the load of micropollutants most likely triggered the effects in the bioassay applied. Hence, the feeding rate of G. fossarum appears to be a well-suited bioassay to indicate alterations in ecotoxicological properties of wastewater due to the application of advanced oxidation processes like ozonation.     

Analysing the influence of operating conditions on the performance of algal–bacterial granular sludge processes for wastewater treatment: A review

This article discussed the effect of the main operating parameter involved in the operation of algal–bacterial granular sludge (ABGS) systems as promising biological processes for wastewater treatment. The focus was on the operational ranges reported in the literature capable of achieving better granule properties, good stability and high removal capacities. This review identified that hydraulic retention time (HRT), light intensity (LI) and light/dark periods were the most influential operating factors on the formation, stability, settleability and organic pollutant removal efficiency of ABGS. The discussion argued that ABGS systems enhance industrial and domestic wastewater treatment due to additional advantages that provide the symbiotic interactions to process performance, maintaining lesser operating costs concerning aerobic granular sludges (AGS) and microalgae consortia. This review will improve the understanding of the operation of ABGS systems and thus further expand possible operating combinations that help to enhance microbial interactions, microalgae growth and external aeration self-sufficiency in further research with a focus on its scaling up.     

Danish low‐rise housing co‐operatives (bofsellesskaber) as an example of a local community organization

This article gives a brief survey of the recent discussion among research workers in Scandinavia on the role of local communities today and in the future. Three different kinds of local community development are defined as the transferring of tasks to local community organizations from respectively the market economy, the public sector and the family. The Danish low‐rise housing co‐operative—called “bofællesskaber"—can be seen as a kind of a small local community organization in a housing area. These co‐operatives differ from other kinds of housing collectives by their size and by being based on co‐operation between nuclear families. The experience of bofællesskaber in connection with the discussion on local community development is that for different reasons they are difficult to establish, but after the establishment phase function well. How well they function, though, depends upon to what extent they succeed in establishing common tasks and activities that serve the fundamental material and social needs of the occupants in the housing areas.     

Membrane bioreactors for municipal wastewater treatment - a viable option to reduce the amount of polar pollutants discharged into surface waters?

The potential of a lab-scale membrane bioreactor (MBR) to remove polar pollutants from municipal wastewater was studied for industrial and household chemicals over a period of 22 months parallel to a conventional activated sludge (CAS) treatment. For half of the compounds, such as benzotriazole, 5-tolyltriazole (5-TTri), benzothiazole-2-sulfonate and 1,6-naphthalene disulfonate (1,6-NDSA), removal by MBR was significantly better than in CAS, while no improvement was recorded for the other half (1,5-NDSA, 1,3-NDSA, 4-TTri and naphthalene-1-sulfonate). The influence of operational conditions on trace pollutant removal by MBR was studied but no significant effects were found for variation of hydraulic retention time (7h-14h) and sludge retention time (26d-102d), suggesting that the lowest values selected have already been high enough for good removal. It is shown that the seemingly inconsistent results reported here and in previous studies regarding the comparison of trace pollutant removal in MBR and CAS are highly consistent. MBR is neither superior for well degradable compounds that are already extensively degraded in CAS treatment nor for recalcitrant compounds that are not amenable to biodegradation. For most compounds of intermediate removal in CAS treatment (15-80%), among them pharmaceuticals, personal care products and industrial chemicals, the MBR is clearly superior and reduces the effluent concentration by 20-50%. Despite of this clear benefit of MBR, the effect is not pronounced enough to serve as a sole argument for employing MBR in municipal wastewater treatment.     

Ozonation: a tool for removal of pharmaceuticals,contrast media and musk fragrances from wastewater?

A pilot plant for ozonation and UV-disinfection received effluent from a German municipal sewage treatment plant (STP) to test the removal of pharmaceuticals, iodinated X-ray contrast media (ICM) and musk fragrances from municipal wastewater. In the original STP effluent, 5 antibiotics (0.34-0.63 microgl(-1)), 5 betablockers (0.18-1.7 microgl(-1)), 4 antiphlogistics (0.10-1.3 microgl(-1)), 2 lipid regulator metabolites (0.12-0.13 microgl(-1)), the antiepileptic drug carbamazepine (2.1 microgl(-1)), 4 ICM (1.1-5.2 microgl(-1)), the natural estrogen estrone (0.015 microgl(-1)) and 2 musk fragrances (0.1-0.73 microgl(-1)) were detected by LC-electrospray tandem MS and/or GC/MS/MS. ICM, derived from radiological examinations, were present with the highest concentrations (diatrizoate: 5.7 microgl(-1), iopromide: 5.2 microgl(-1)). By applying 10-15 mgl(-1) ozone (contact time: 18 min), all the pharmaceuticals investigated as well as musk fragrances (HHCB, AHTN) and estrone were no longer detected. However, ICM (diatrizoate, iopamidol, iopromide and iomeprol) were still detected in appreciable concentrations. Even with a 15 mgl(-1) ozone dose, the ionic diatrizoate only exhibited removal efficiencies of not higher than 14%, while the non-ionic ICM were removed to a degree of higher than 80%. Advanced oxidation processes (O(3)/UV-low pressure mercury arc, O(3)/H(2)O(2)), which were non-optimized for wastewater treatment, did not lead significantly to a higher removal efficiency for the ICM than ozone alone.     

数据中心研究(7):自然冷却

自然冷却是降低数据中心能耗行之有效的方法之一。给出了国内自然冷却的气象条件,以及规范和标准对数据中心热环境的限制。介绍了目前国内外数据中心现行的自然冷却技术的特点和适用范围,分析了应用过程中存在的主要问题。指出了数据中心自然冷却仍然是一项值得深入研究和实践的技术。     

New Europe: place(s) without a sense of place?

The 10 new member states of Europe are united by no more than historic synchronicity - a single point of entry into the EU in May 2004. Guest-editor Valentina Croci introduces this title of AD by explaining both the circumstances that some of these countries share, particularly those of the ex-Soviet bloc, but also the very different conditions the nations grapple with as separate entities. Despite the many disparities between countries, she finds an underlying consistency in the concerns voiced by the local contributors, as the respect for individual national identities and a sense of place emerge as paramount. Copyright © 2006 John Wiley & Sons, Ltd.     

Quantifying stakeholders’ influence on energy efficiency of housing: development and application of a four-step methodology

Identifying stakeholders’ influence on project outcomes, prioritizing their importance and managing their interests accordingly is an effective strategy for maximizing benefits for organizations. Quantifying the influence of stakeholders on energy efficiency of housing allows for the development of an engagement plan that takes into consideration stakeholders’ diverse goals, needs, levels of expertise, knowledge, authority, connectivity and closeness to decision-making processes throughout the different stages of the housing procurement. We present a theoretical approach for quantifying the influence of stakeholders on the thermal performance of housing. The quantification methodology builds on a number of stakeholder management approaches and is applied to Australian case studies for reflection and sense making. The quantification of the degree of influence is calculated by combining the rankings of stakeholders in six attributes that affect their influence on a building’s energy efficiency outcomes. Quantifying human influence on buildings’ energy efficiency can help future researchers and housing industry stakeholders in integrating the human aspect with technological, technical, economic and regulatory aspects to optimize the performance outcomes of energy efficient housing.     

The determination of the “true” property boundary in planned development: a Coasian analysis

This interdisciplinary paper, informed by research and practices in neo-institutional economics, property law and land surveying, is an exploratory account of the boundary as (a) the ontological foundation of private property in land and boundary dispute resolution, and (b) as a pre-contractual condition of any Coasian exchange of rights for planned urban development and space-relevant innovations. Under conditions of positive transaction costs according to the third Coase Theorem, with the help of real-life examples, the paper explains the choice of using the courts, instead of the market, as a means of resolving disputes over land boundaries. It does so in terms of two land surveying and three economic reasons. The surveying reasons are historical and cartographical. The economics reasons relate to the price level of land, the transaction costs of enforcing dispute resolutions and the externalities of land boundary determination.     

Economic growth and development in Macau (1999–2016): The role of the booming gaming industry

In 2018, Macau will celebrate the 20th anniversary of its return to China. The past few years have witnessed brilliant economic achievements as well as a structural shift toward a gaming-industry dominated economy. Following so many years of rapid growth, it is essential to take stock of both the benefits and costs of gaming industry development. Accordingly, this paper analyzes the evolution of Macau's gaming industry between 1999 and 2016, and evaluates the industry's effects on local economic growth and urban development. As the paper shows, Macau has exhibited many of the symptoms typically associated with booming sectors in small economies, and has witnessed the similar effects widely experienced by western casino cities. However, Macau is also faced with some unique challenges, regarding its geographic location, size constraints, and political factors. These findings illustrate the difficulties that have accompanied Macau's economic achievements, but also call attention to opportunities in the next phase of Macau's development.     

An analysis of sustainable development and environmental protection in postcommunist countries: the case of croatia‐a view point

The paper analyses the origins, the definitions, and the implementation of sustainable development in the post‐communist countries of Central and Eastern Europe, using Croatia as an example. The overview of events in environmental concern world‐wide, in the last 25 years, shows that there is evidence of fast changes which have left the former communist countries behind. The major concern of the paper is the lack of an agreed upon definition and criteria on what sustainable development actually represents, and why it is still an odd subject in the Central and Eastern European region. Five recognition criteria described in the open literature are compared with the situation in the region. Using the examples of implementation of new UN Conventions, accepted at the UNCED Conference in Rio de Janeiro in 1992, the paper discusses the shortcomings and obstacles to current policies of sustainability.     

Large-scale public venue development and the application of Public–Private Partnerships (PPPs)

Large-scale venues for exhibitions and events are important public infrastructure. Developing venues have captured much of governments' attention due to the potential benefits the industry would bring to the community. However, venue development requires considerable capital and operating costs, unique standards of design and complicated operational issues. Public–Private Partnerships were introduced by governments as innovative delivery models to bring forward venue projects. This paper presents comparative case studies of two PPP venue projects in Hong Kong Special Administrative Region and New Zealand aiming to investigate key challenges for using PPPs in venue development and propose strategies to address the problems and assist future planning and organization for venue PPPs. The research shows that for a successful venue PPP, the following are critical features: (1) sound business case development; (2) streamlined financial arrangements; (3) robust tendering; (4) effective governance structure and partnership-based consortium; and (5) realistic risk allocation.