Cooperative Research Center for Water Sensitive Cities

Cooperative, Australia

Cooperative Research Center for Water Sensitive Cities

Cooperative, Australia
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Coutts A.M.,Monash University | Coutts A.M.,Cooperative Research Center for Water Sensitive Cities | Daly E.,Monash University | Daly E.,Cooperative Research Center for Water Sensitive Cities | And 4 more authors.
Building and Environment | Year: 2013

As cities continue to grow and develop under climate change, identifying and assessing practical approaches to mitigate high urban temperatures is critical to help provide thermally comfortable, attractive and sustainable urban environments. Green and cool roofs are commonly reported to provide urban heat mitigation potential; however, their performance is highly dependent upon their design, particularly green roofs that vary in substrate depth, vegetation species, and watering regime. This study compares the insulating properties, the radiation budget and surface energy balance of four experimental rooftops, including a green roof (extensive green roof planted with Sedum) and a cool roof (uninsulated rooftop coated with white elastomeric paint), over the summer of 2011-12 in Melbourne, Australia. For the roof treatments explored here, results suggest that cool roofs, combined with insulation, provide the greatest overall benefit in terms of urban heat mitigation and energy transfer into buildings. The high albedo of the cool roof substantially reduced net radiation, leaving less energy available at the surface for sensible heating during the day. Under warm and sunny conditions, when soil moisture was limited, evapotranspiration from the green roof was low, leading to high sensible heat fluxes during the day. Irrigation improved the performance of the green roof by increasing evapotranspiration. Daytime Bowen ratios decreased from above four during dry conditions, to less than one after irrigation, yet sensible heat fluxes were still higher than for the cool roof. These results demonstrate that rooftops must be designed accordingly to target specific performance objectives, such as heat mitigation. © 2013 Elsevier Ltd.

Ferguson B.C.,Monash University | Ferguson B.C.,Cooperative Research Center for Water Sensitive Cities | Brown R.R.,Monash University | Brown R.R.,Cooperative Research Center for Water Sensitive Cities | And 4 more authors.
Water Research | Year: 2013

There is widespread international acceptance that climate change, demographic shifts and resource limitations impact on the performance of water servicing in cities. In response to these challenges, many scholars propose that a fundamental move away from traditional centralised infrastructure towards more integrated water management is required. However, there is limited practical or scholarly understanding of how to enable this change in practice and few modern cities have done so successfully. This paper addresses this gap by analysing empirical evidence of Melbourne's recent experience in shifting towards a hybrid of centralised and decentralised infrastructure to draw lessons about the institutional context that enabled this shift. The research was based on a qualitative single-case study, involving interviews and envisioning workshops with urban water practitioners who have been directly involved in Melbourne's water system changes. It was found that significant changes occurred in the cultural-cognitive, normative and regulative dimensions of Melbourne's water system. These included a shift in cultural beliefs for the water profession, new knowledge through evidence and learning, additional water servicing goals and priorities, political leadership, community pressure, better coordinated governance arrangements and strong market mechanisms. The paper synthesises lessons from the case study that, with further development, could form the basis of prescriptive guidance for enabling the shift to new modes of water servicing to support more liveable, sustainable and resilient outcomes for future cities. © 2013 Elsevier Ltd.

Dobbie M.F.,Monash University | Dobbie M.F.,Cooperative Research Center for Water Sensitive Cities | Brown R.R.,Cooperative Research Center for Water Sensitive Cities | Brown R.R.,Monash Sustainability Institute | And 2 more authors.
Environmental Science and Policy | Year: 2016

In the water sensitive city, a hybrid mix of centralised and decentralised water systems and sources will operate at a range of scales to provide sustainable fit-for-purpose water services that will safeguard environmental quality, intergenerational equity and landscape amenity. Governance of these systems is likely to differ from the traditional arrangement, involving multiple stakeholders who must work together to manage risk. Trust will be essential to effective governance. This study explored attitudes of Australian urban water practitioners towards ownership and management of different water systems that might comprise the water sensitive city, including who they would trust to manage the associated risk. Results support the status quo, in which risk management responsibilities lie with state and local government or corporatised water utilities. Although practitioners support ownership and management of lot-scale water systems by homeowners, they trust them only to manage the risks associated with rainwater tanks. These results can be interpreted as risk perceptions, which are influenced by trust and knowledge. Implementation of decentralised water systems should be accompanied by governance arrangements that include strategies to enhance trust between stakeholders and to facilitate the co-production of knowledge to inform shared decision-making. © 2015 Elsevier Ltd.

Zhang K.,Monash University | Zhang K.,Cooperative Research Center for Water Sensitive Cities | Randelovic A.,University of Belgrade | Page D.,CSIRO | And 4 more authors.
Ecological Engineering | Year: 2014

Stormwater harvesting is becoming a popular alternative water resource in water stressed regions. Stormwater biofilters have been recognized as being among the most promising pre-treatment technologies. In this study, a series of challenge tests were conducted as part of a validation framework of stormwater biofilters for selected micropollutants. Two biofilter configurations were studied: a configuration with loamy sand and no submerged zone (LS-noSZ) and another configuration that uses sand and a submerged zone (S-SZ). Biofilter challenge conditions were: (i) treatment volume set at 95th percentile of all treated events and (ii) the maximum and minimum durations of dry period between two events, both based on hydrology simulations using 30 years rainfall data for Melbourne. The hydraulic performance of S-SZ was stable and not affected by either prolonged wet or dry periods, while the outflow rate of LS-noSZ was largely reduced during prolonged wet periods. Biofilters had a removal efficiency of >80% for total petroleum hydrocarbons (TPHs), glyphosate, dibutyl phthalate (DBP), bis-(2-ethylhexyl) phthalate (DEHP), pyrene and naphthalene loads by both configurations under the most challenge conditions; the removal of pentachlorophenol (PCP) and phenol loads was >80% in LS-noSZ and 50-80% in S-SZ, while chloroform had load removal rates between 20% and 50%. Biofilters were less effective in removing atrazine and simazine with load removal 20-50% in LS-noSZ and <20% in S-SZ. Prolonged dry periods benefited the removal of micropollutants while very short dry periods adversely affected micropollutants removal. The study contributes to the development of the overall framework for validation of stormwater biofilters, which is required if these systems are to be applied in stormwater treatment systems for higher end water uses such as drinking water. © 2014 Elsevier B.V.

Li Y.L.,Monash University | Li Y.L.,Cooperative Research Center for Water Sensitive Cities | Deletic A.,Monash University | Deletic A.,Cooperative Research Center for Water Sensitive Cities | And 2 more authors.
Journal of Hazardous Materials | Year: 2014

Stormwater filters featuring traditional sand filter media cannot reliably treat indicator bacteria for stormwater harvesting. In this work, copper-modified zeolite and granular activated carbon (GAC) were prepared through Cu2+ impregnation and in situ Cu(OH)2 precipitation. Their antibacterial properties and stability in natural stormwater were studied in gravity-fed columns for 24 weeks, under typical stormwater operational conditions. 11 types of other filter media, prepared using zinc, iron, titanium and quaternary ammonium salts as antibacterial agents, were tested in parallel by way of comparison. Cu2+-immobilised zeolite and Cu(OH)2-coated GAC yielded an estimated 2-log reduction of E. coli within 40min with the presence of other native microbial communities in natural stormwater. Even at high flow velocity (effective contact time of 4.5min), both media demonstrated 0.8 log removal. Both media and Cu2+-treated GAC showed effective inactivation of the removed E. coli during dry periods. Copper leaching from Cu(OH)2-coated GAC was found to be below the NHMRC specified drinking water standard, while that from Cu2+-immobilised zeolite varied with the salinity in stormwater. These findings could provide useful information for further development of passive stormwater harvesting systems. © 2014 Elsevier B.V.

Utz R.M.,Chatham University | Hopkins K.G.,National United University | Beesley L.,University of Western Australia | Beesley L.,Cooperative Research Center for Water Sensitive Cities | And 5 more authors.
Freshwater Science | Year: 2016

Urbanization substantially changes the physicochemical and biological characteristics of streams. The trajectory of negative effect is broadly similar around the world, but the nature and magnitude of ecological responses to urban growth differ among locations. Some heterogeneity in response arises from differences in the level of urban development and attributes of urban water management. However, the heterogeneity also may arise from variation in hydrologic, biological, and physicochemical templates that shaped stream ecosystems before urban development. We present a framework to develop hypotheses that predict how natural watershed and channel attributes in the pre-urban-development state may confer ecological resistance to urbanization. We present 6 testable hypotheses that explore the expression of such attributes under our framework: 1) greater water storage capacity mitigates hydrologic regime shifts, 2) coarse substrates and a balance between erosive forces and sediment supply buffer morphological changes, 3) naturally high ionic concentrations and pH pre-adapt biota to waterquality stress, 4) metapopulation connectivity results in retention of species richness, 5) high functional redundancy buffers trophic function from species loss, and 6) landuse history mutes or reverses the expected trajectory of eutrophication. Data from past comparative analyses support these hypotheses, but rigorous testing will require targeted investigations that account for confounDing or interacting factors, such as diversity in urban infrastructure attributes. Improved understanDing of the susceptibility or resistance of stream ecosystems could substantially strengthen conservation, management, and monitoring efforts in urban streams. We hope that these preliminary, conceptual hypotheses will encourage others to explore these ideas further and generate additional explanations for the heterogeneity observed in urban streams. © 2016 by The Society for Freshwater Science.

Sun J.,University of Queensland | Hu S.,University of Queensland | Sharma K.R.,University of Queensland | Sharma K.R.,Cooperative Research Center for Water Sensitive Cities | And 3 more authors.
Applied and Environmental Microbiology | Year: 2014

Simultaneous production of sulfide and methane by anaerobic sewer biofilms has recently been observed, suggesting that sulfate-reducing bacteria (SRB) and methanogenic archaea (MA), microorganisms known to compete for the same substrates, can coexist in this environment. This study investigated the community structures and activities of SRB and MA in anaerobic sewer biofilms (average thickness of 800 μm) using a combination of microelectrode measurements, molecular techniques, and mathematical modeling. It was seen that sulfide was mainly produced in the outer layer of the biofilm, between the depths of 0 and 300 μm, which is in good agreement with the distribution of SRB population as revealed by cryosection-fluorescence in situ hybridization (FISH). SRB had a higher relative abundance of 20% on the surface layer, which decreased gradually to below 3% at a depth of 400 μm. In contrast, MA mainly inhabited the inner layer of the biofilm. Their relative abundances increased from 10% to 75% at depths of 200 μm and 700 μm, respectively, from the biofilm surface layer. High-throughput pyrosequencing of 16S rRNA amplicons showed that SRB in the biofilm were mainly affiliated with five genera, Desulfobulbus, Desulfomicrobium, Desulfovibrio, Desulfatiferula, and Desulforegula, while about 90% of the MA population belonged to the genus Methanosaeta. The spatial organizations of SRB and MA revealed by pyrosequencing were consistent with the FISH results. A biofilm model was constructed to simulate the SRB and MA distributions in the anaerobic sewer biofilm. The good fit between model predictions and the experimental data indicate that the coexistence and spatial structure of SRB and MA in the biofilm resulted from the microbial types and their metabolic transformations and interactions with substrates. © 2014, American Society for Microbiology.

Cardell-Oliver R.,Cooperative Research Center for Water Sensitive Cities | Cardell-Oliver R.,University of Western Australia
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016

Conserving water is a critical problem and characterising how households in communities use water is a first step for reducing consumption. This paper introduces a method for discovering habits in smart water meter time series. Habits are household activities that recur in a predictable way, such as watering the garden at 6 am twice a week. Discovering habit patterns automatically is a challenging data mining task. Habit patterns are not only periodic, nor only seasonal, and they may not be frequent. Their recurrences are partial periodic patterns with a very large number of candidates. Further, the recurrences in real data are imperfect, making accurate matching of observations with proposed patterns difficult. The main contribution of this paper is an efficient, robust and accurate Habit Detection Algorithm (HDA) for discovering regular activities in smart meter time series with evaluation the performance of the algorithm and its ability to discover valuable insights from real-world data sets. © Springer International Publishing Switzerland 2016.

Jiang G.,University of Queensland | Sun J.,University of Queensland | Sun J.,Cooperative Research Center for Water Sensitive Cities | Sharma K.R.,University of Queensland | And 3 more authors.
Current Opinion in Biotechnology | Year: 2015

Sewers emit hydrogen sulfide and various volatile organic sulfur and carbon compounds, which require control and mitigation. In the last 5-10 years, extensive research was conducted to optimize existing sulfide abatement technologies based on newly developed in-depth understanding of the in-sewer processes. Recent advances have also led to low-cost novel solutions targeting sewer biofilms. Online control has been demonstrated to greatly reduce the chemical usage. Dynamic models for both the water, air and solid (concrete) phases have been developed and used for the planning and maintenance of sewer systems. Existing technologies primarily focused on 'hotspots' in sewers. Future research should aim to achieve network-wide corrosion and emission control and management of sewers as an integrated component of an urban water system. © 2015 Elsevier Ltd.

Hulsen T.,University of Queensland | Hulsen T.,Cooperative Research Center for Water Sensitive Cities | Batstone D.J.,University of Queensland | Batstone D.J.,Cooperative Research Center for Water Sensitive Cities | And 2 more authors.
Water Research | Year: 2014

The organics and nutrients in industrial and domestic wastewater are increasingly being regarded as a valuable resource for energy and nutrient recovery. Emerging concepts to redesign wastewater treatment as resource recovery systems include the use of different bacteria and algae to partition carbon and nutrients to the particulate phase through assimilation or bio-accumulation. This study evaluates the use of purple phototrophic bacteria (PPB) (also known as purple non-sulphur bacteria or PNSB) for such a biological concentration process through a series of batch tests. The key objectives are to (a) demonstrate consistent selection and enrichment of PPB using infrared light in a non-sterile medium, and (b) achieve effective partitioning of soluble organics, ammonium and phosphate into the PPB culture. PPB were successfully enriched from pre-settled domestic wastewater within 2-3 days and identified as members of the order Rhodobacterales. Under anaerobic conditions with infrared irradiation the enrichment culture was able to simultaneously remove COD (63±5%), NH4-N (99.6%-0.12±0.03mgNL-1) and PO4-P (88%-0.8±0.6mgPL-1) from primary settled domestic wastewater in 24h. In this experiment, acetate was added as an additional carbon source to demonstrate the maximal nitrogen and phosphorous elimination potential. Almost all the COD removed was assimilated into biomass rather than oxidised to CO2, with the total COD actually increasing during the batch experiments due to phototrophic synthesis. NH4-N and PO4-P were also assimilated by the biomass rather than removed through destructive oxidation or accumulation. The process offers the opportunity to concentrate organics and macronutrients from wastewater in one solids stream that can be anaerobically digested to generate energy and recover nutrients from the concentrated digestate. Technical challenges include the design of a continuous reactor system, as well as efficient delivery of electrons, either through light or chemical sources. © 2013 Elsevier Ltd.

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