Owing to its rapid advancement in nanotechnology, latest publications (recent 5 years) related to zinc oxide (ZnO) in various aspects and applications have been reviewed. Trend has shifted to the innovation of pristine ZnO nanostructures functionalized with elemental dopants and heterojunction to improve the photoactivities on micropollutant degradation and heavy metals removal as well as the antibacterial effect towards microorganisms. The fundamentals of improved photoactivities (i.e., low recombination rate of charge carrier and effective charge transfer) and enhanced antibacterial properties (i.e., dissolution of ions and generation of reactive oxygen species) are accentuated. Subsequently, a detailed examination is undertaken to elucidate the key impacts of ZnO on actual wastewater treatment systems. This review concludes with a consolidated overview on the recent advances of ZnO for environmental wastewater decontamination and the future prospects on tailoring ZnO based on their photocatalytic and antibacterial properties to match various expectations from practical applications while minimising the adverse impacts on surrounding environment. Keywords antimicrobial effect , bactericidal mechanism , photocatalysis , ZnO nanostructures , ZnO photocatalysts

Three strains isolated by geosmin enrichment from a sand filter in an Australian drinking water treatment works were genome sequenced to identify their taxonomic placement, and a bench-scale batch experiment confirmed their geosmin-degrading capability. Using the average nucleotide identity based on the MUMmer algorithm (ANIm), pairwise digital DNA-DNA hybridization (dDDH), and phylogenomic analyses, the strains were identified as Sphingopyxis species.

Circular economy is among the most influential concepts relating to the realization of Agenda 2030 and the Sustainable Development Goals. Advocates of the circular economy promote its potential to achieve a decoupling of growth from material consumption. Academic critiques describe the circular economy concept as poorly defined and insufficiently concerned with other problems associated with consumerism, globalization, and inequality. South Australia has built a reputation as a first mover in waste management regulations and has recently positioned itself as a leader in the transition to the circular economy. However, the Asia-Pacific region contains a wide variety of socioeconomic, geographic, and climatic conditions that impact waste generation, resource recovery, and circular economy potentials. There are questions about the appropriateness of transferring waste strategy and technologies to different settings. Therefore, this paper explores the basis of South Australia’s leadership credentials and discusses its potential influence over the region. This research is based on an analysis of policy documents produced by the South Australian Government. This study found that while multiple South Australian policy documents highlight a desire to lead in circular economy transition, South Australia’s leadership reputation had been built prior to its adoption of circular economy ideology. The South Australian Waste Strategy 2020–2025 projects a vision of circular futures aligned to circular modernism and planned circularity. The paper concludes that any transfer of waste strategy should occur with sensitivity to existing waste management systems including the informal sector. Asia-Pacific countries, including Australia, should consider decentralized, low-tech circular economy projects to help to achieve the Sustainable Development Goals.

A water utility requires myriads of data for effective decision-making. As the sources and ranges of data are becoming increasingly complex, the use of a metadata framework can play a significant role in effective data management. Using case study method, this research analyzed data needs of a water supply system in a small town in South Australia and designed a demo portal of a metadata framework. As part of the case study, the project team undertook a broad investigative approach using focus group (interviews), observation, exploration of potential data sources, identification of knowledge leaders and information technology systems. The metadata framework comprised two separate but interconnected metadata groups, (1) metadata elements to describe the metadata source and (2) metadata elements to describe the datasets held in each data source. The metadata framework was populated to describe data sources and data held in each of the sources. The data catalogue created by this process showed that it was accomplishable and appropriate to describe data sources and datasets via a metadata framework.

Traditional water quality–based processes of assessment using grab samples are simple to implement but far too retrospective and intermediate to adequately deal with water quality change situation. This case study demonstrated a customised software package using a web-based prototype portal with data integration, visualisation, prediction, and anomaly detection functions for complex real-time field monitoring data sets as a visualisation and decision support tool for treatment plant operators. The prototype was developed to analyse two-dimensional data obtained from a spectrophotometer (absorbance against wavelength) and data integrated from other sources (such as rainfall and temperature). It supports normal functions of time series data visualisation, such as, raw data plotting, zooming, smoothing, Boolean band etc. More importantly, it is specialised in supporting real-time monitoring of data quality, time series data comparison, anomaly detection, and future value prediction. The application of the prototype revealed that if this was placed in an operational environment, it has the potential to inform better operational decision by early detection of changes in water quality and impacts on the treatment process. This work demonstrated the potential usefulness of such real-time display and visualisation of online water quality data and the feasibility for prediction tools to provide an early warning system for process upsets.

Enzyme-induced carbonate precipitation (EICP) is a relatively new bio-cementation technique for ground improvement. In EICP, calcium carbonate (CaCO3) precipitation occurs via urea hydrolysis catalysed by the urease enzyme sourced from plants. EICP offers significant potential for innovative and sustainable engineering applications, including strengthening of soils, remediation of contaminants, enhancement of oil recovery through bio-plugging and other in situ field applications. Given the numerous potential applications of EICP, theoretical understanding of the rate and quantity of CaCO3 precipitation via the ureolytic chemical reaction is vital for optimising the process. For instance, in a typical EICP process, the rate and quantity of CaCO3 precipitation can depend significantly on the concentration, activity and kinetic properties of the enzyme used along with the reaction environment such as pH and temperature. This paper reviews the research and development of enzyme-catalysed reactions and its applications for enhancing CaCO3 precipitation in EICP. The paper also presents the assessment and estimation of kinetic parameters, such as the maximal reaction velocity (Vmax) and the Michaelis constant (Km), that are associated with applications in civil and geotechnical engineering. Various models for evaluating the kinetic reactions in EICP are presented and discussed, taking into account the influence of pH, temperature and inhibitors. It is shown that a good understanding of the kinetic properties of the urease enzyme can be useful in the development, optimisation and prediction of the rate of CaCO3 precipitation in EICP.

Stormwater runoff contains a myriad of pollutants, including faecal microbes, and can pose a threat to urban water supplies, impacting both economic development and public health. Therefore, it is a necessity to implement a real-time hazard detection system that can collect a substantial amount of data, assisting water authorities to develop preventive strategies to ensure the control of hazards entering drinking water sources. An on-line UV-Vis spectrophotometer was applied in the field to collect real-time continuous data for various water quality parameters (nitrate, DOC, turbidity and total suspended solids) during three storm events in Mannum, Adelaide, Australia. This study demonstrated that the trends for on-line and comparative laboratory-analysed samples were complimentary through the events. Nitrate and DOC showed a negative correlation with water level, while turbidity and total suspended solids indicated a positive correlation with water level during the high rainfall intensity. The correlations among nitrate, DOC, turbidity, total suspended solids and water level are the opposite during low rainfall intensity. Nitrate, one of the main pollutants in stormwater, was investigated and used as a surrogate parameter for microbial detection. However, the microbiological data (Escherichia coli) from captured storm events showed poor correlations to nitrate and other typical on-line parameters in this study. This is possibly explained by the nature of the stormwater catchment outside of rain events, where the sources of bacteria and nutrients may be physically separated until mixed during surface runoff as a result of rainfall. In addition, the poor correlations among the microbiological data and on-line parameters could be due to the different sources of bacteria and nutrients that were transported to the stormwater drain where sampling and measurement were conducted.

Biosolids produced at wastewater treatment facilities are extensively used in agricultural land and degraded mine sites to improve soil health and soil organic carbon (SOC) stocks. Many studies have reported increases in SOC due to application of biosolids to such sites. However, lack of a comprehensive quantification on overall trends and changes of magnitude in SOC remains. Here, we performed a meta-analysis to identify drivers with a relationship with SOC stocks. A meta-regression of 297 treatments found four variables with a relationship with SOC stocks: cumulative biosolids carbon (C) input rate, time after application, soil depth and type of biosolids. The cumulative biosolids C input rate was the most influencing driver. The highest mean difference for SOC% of 3.3 was observed at 0-15 cm soil depth for a cumulative C input of 100 Mg ha(-1) at one year after biosolids application. Although years after biosolids application demonstrated a negative relationship with SOC stocks, mineralization of C in biosolids-applied soils is slow, as indicated with the SOC% decrease from 4.6 to 2.8 at 0-15 cm soil depth over five years of 100 Mg ha(-1) biosolids C input. Soil depth illustrated a strong negative effect with SOC stocks decreasing by 2.7% at 0-15 cm soil depth at a cumulative biosolids C input of 100 Mg ha(-1) over a year. Overall, our model estimated an effect of 2.8 SOC% change, indicating the application of biosolids as a viable strategy for soil C sequestration on a global scale.

Abstract Stormwater runoff contains a myriad of pollutants, including faecal microbes, and can pose a threat to urban water supplies, impacting both economic development and public health. Therefore, it is a necessity to implement a real-time hazard detection system that can collect a substantial amount of data, assisting water authorities to develop preventive strategies to ensure the control of hazards entering drinking water sources. An on-line UV-Vis spectrophotometer was applied in the field to collect real-time continuous data for various water quality parameters (nitrate, DOC, turbidity and total suspended solids) during three storm events in Mannum, Adelaide, Australia. This study demonstrated that the trends for on-line and comparative laboratory analysed samples were complimentary through the events. Nitrate and DOC showed a negative correlation with water level while turbidity and total suspended solids indicated a positive correlation with water level during the high rainfall intensity. The correlations among nitrate, DOC, turbidity, total suspended solids, and water level are the opposite during the low rainfall intensity. Nitrate, one of the main pollutants in stormwater, was investigated and used as a surrogate parameter for microbial detection. However, the microbiological data (E.coli) from captured storm events showed poor correlations to nitrate and other typical on-line parameters in this study, possibly explained by the nature of the stormwater catchment outside of rain events, where the sources of bacteria and nutrients may be physically separate until mixed during surface runoff as a result of rainfall. In addition, the poor correlations among the microbiological data and on-line parameters can be due to the different sources of bacteria and nutrients that end up into the stormwater drain.

Acid mine drainage (AMD) presents severe ecological pollution challenges because of its extreme acidity and sulphate and toxic metal contents. The bacterial separation of metals by sulphate reducing bacteria (SRB) and diffusion dialysis (DD) are considered as the most efficient techniques for the treatment/valorisation of AMD owing to their low energy consumption and waste effluents. However, the performance of SRB or DD standalone technologies still face several challenges. The integration strategy of these techniques can lead to an improved treatment/valorisation process, with the AMD components recovered and converted into value-added marketable products. These products can financially reduce the total costs of the AMD treatment. In the current review, both approaches, representing the biotic and abiotic methods, are compared in terms of their mechanisms, challenges and efficiencies. In addition, critical evaluations of the feasibility of both methods along with the potential of their integrated processes are discussed and future strategies proposed.

There is a growing research interest in exploring the self-photorechargeability of photoanodes, which enables photoelectrochemical (PEC) water oxidation even under non-irradiated conditions. The main aim of this study was to develop a facile synthesis of molybdenum trioxide (MoO3) photoanode displaying self-photorechargeability using an aerosol-assisted chemical vapour deposition (AA-CVD) method. A systematic optimisation of the key synthesis parameters of AA-CVD method, namely: (1) ultrasonication time of precursor solution, and (2) annealing temperature was carried out in order to understand the best trade-off between photocurrent density (illuminated conditions) and charge density (non-illuminated conditions). Field emission-scanning electron microscopy images showed that the MoO3 photoanodes synthesized via AA-CVD method exhibited a 3D plate-like crystalline structure that gave a large voltammogram area, indicating that the MoO3 photoanodes possessed high charge storage capacity for photogenerated electrons. PEC measurements showed that the optimised MoO3 photoanode obtained during an ultrasonication time of 25 min and at the annealing temperature of 500 °C achieved a photocurrent density of 1.47 μA/cm2 at 1.0 V vs Pt electrode. A significantly prolonged on-off illumination cycle (i.e. 1000 s) showed a significant storage capacity of photogenerated electrons within the 3D plate-like MoO3 crystalline structure was discharged during the non-irradiated conditions, and a charge density of 0.35 mC/cm2.

After the implementation of a biofuel target in 2017, China, the second largest consumer of oil in the world, accelerated the development of lignocellulosic biomass technology to produce ethanol and minimized food security risks commonly associated with first generation biofuel production. In this study, Life Cycle Assessment (LCA) is used to investigate three new lignocellulosic biomass refinery systems based on corncob which co-produce ethanol with chemicals and energy. The bioethanol is used in E10 and E85 biofuel mixes and these are compared with a fossil gasoline reference system. Using 1 km distance driven by a compact size flexible fuel passenger vehicle as the functional unit and a exergy allocation approach to the raw material inputs and to the co-products in the simulated multifunctional biorefinery processes, the results indicate that regardless of the configuration of the ethanol-biorefinery, ethanol-blended fuels performed better than gasoline in terms of fossil fuels depletion (E10 6% lower; E85 64-70% lower), global warming potential (E101-10% lower; E85 5-113% lower) and human toxicity potential (E10 6-7% lower; E85 72-75% lower), but worst in terms of ozone layer depletion (E10 4.5-6.8 times higher; E85 51.9-78.2 times higher), acidification (E10 30-50% higher; E85 3.3-5.5 times higher) and eutrophication potential (E10 5.2-7.0 times higher; E85 42.4-64.0 times higher) than gasoline. (C) 2019 Elsevier Ltd. All rights reserved.

This review presents an assessment of international wastewater treatment plant (WWTP) energy benchmarking studies and provides for the first time a detailed historical evolution of seminal European benchmarking methodology for the international water sector. We commence by comparing international applications of energy performance assessment and how the different methods have been applied and have evolved. More specifically, we investigate how international studies have measured WWTP energy performance and what are the different views in relation to energy performance reference value, whether the energy consumption should be related to the number of people connected, the applied load, treated wastewater volume, and the advantages and disadvantages of different approaches. International literature sources were identified using targeted keyword searches using Google Scholar in order to capture a broad range of scholarly and technical works. The review then follows with a detailed account of the origin and development of the seminal (German) energy benchmarking methodologies, delivered here for the first time and opening up previously inaccessible literature to an international audience. The review finds that despite its long-term use, disagreement remains regarding the most suitable energy benchmarking performance metrics and there is currently no internationally agreed approach to assess the energy performance of a WWTP. It further highlights that the European approach to energy benchmarking demonstrates that methodical optimisation of WWTPs and application of identified energy-saving measures, presents great opportunities to deliver achievable, environmentally and economically favourable change to water industry practice. Nevertheless, site-specific factors such as differing discharge conditions, topographical boundary conditions, wastewater volume and composition need to be considered when adapting and applying energy benchmarking methodologies elsewhere, and these factors should be taken into consideration by wastewater practitioners during energy benchmarking assessments.

Our study was focused on whether the optimization of nutrition at various growth stages of Pinus radiate D. Don plantation was an important factor to increase its merchantable wood volume yield in Silviculture. The present study site is located within the ‘Green Triangle’ bordering the Australian states of South Australia and Victoria. A total of 24 sampling sub-plots, averaged to 12 super plots, were established in both the sites, and all the plots, except one set aside as 'controlled plot' in each site, were treated with 5 types of coated and un-coated urea fertilizers. The data on tree-height and diameter at breast height over bark (DBHOB) of all the standing trees were measured and recorded. A five-year sampling data from the 24 sub-plots consisting of two sites, namely Picks (Site 'A') and Hollands Lane (Site 'B') in post thinned condition were analysed. The specific target was to evaluate a productivity response in terms of merchantable volumes based on fertilizer types. The statistical analysis employing ANOVA, t-test, a neural network model, decision tree and box-plot model based on fertilizer treatment determined that Di-Ammonium Phosphate Entec Urea (DAPEU) fertilizer was found to be more effective in increasing productivity. As such, the merchantable wood volume increments measured after four years of application of DAPEU were found to be 48.61 m3 ha-1 at Site 'A' and 41.97 m3 ha-1 at Site 'B', higher than the 46.71 m3 ha-1 at Site 'A' and 39.79 m3 ha-1 at Site 'B' with 'control' treatment. Hence, the application of DAPEAU was found to be effective as compared to the 'control' treatment in silviculture to increase the merchantable wood volume.

Drugs of addiction, have been recognized as potential contaminants of concern to the environment. Effluent wastewater discharge is a major source of contamination to aquatic receiving environments. A year-long monitoring program was undertaken in Australia to characterise the fate of four emerging drugs of addiction: methamphetamine; MDMA; pharmaceutical opioids: codeine and morphine and a metabolite: benzoylecgonine in four wastewater treatment plants operating with different secondary treatment technologies: conventional activated sludge (CAS), membrane bioreactors (MBR), integrated fixed-film AS (IFAS) and sequencing batch reactor (SBR). The effect of subsequent tertiary treatment (coagulation/flocculation) on the removal efficiency was also assessed. Drugs were detected in influent and effluent samples (mean concentration ranged from 43-4777 and 17-1721 ng/L, respectively). Treated effluents had noticeably lower levels compared to raw influents. Removal efficiency of compounds depended on the secondary treatment employed, with IFAS and MBR performing the best with significant removal of compounds (approximate to 90%) followed by CAS (54-96%) and lastly SBR (42-83%). Despite the low levels of drugs measured after the secondary treatment, near complete removal after tertiary treatment (approximate to 99%) was recorded, which demonstrated the effectiveness of using the coagulation/flocculation process as an effective step for enhancing the removal efficiency. The levels of drugs were at a low level in the effluents released into the environment and used for recycling and all posed a low environmental risk in urban water courses based on the risk assessment. The information given here provides new and useful information to the water industry and regulators on the efficiency of drug removal in a range of wastewater treatment configurations. Crown Copyright (C) 2019 Published by Elsevier B.V. All rights reserved.

Lipopolysaccharides (LPS) are the major component of the outer membrane of all Gram-negative bacteria and some cyanobacteria and are released during growth and cell death. LPS pose a potential health risk in water, causing acute respiratory illnesses, inhalation fever, and gastrointestinal disorders. The need for rapid and accurate detection of LPS has become a major priority to facilitate more timely and efficacious intervention and, hence, avoid unsafe water distribution. In this context, a porous silicon membrane (pSiM)-based electrochemical biosensor was developed for direct and sensitive detection of LPS. pSiM, featuring arrays of nanochannels, was modified with polymyxin B (PmB), an antimicrobial peptide with strong affinity to LPS. Detection of LPS was based on measuring the changes in the diffusion through the nanochannels of an electroactive species added in solution, caused by the nanochannel blockage upon LPS binding to PmB. Results showed a limit of detection of 1.8 ng/mL, and a linear response up to 10,000 ng/mL spiked in buffer. Selectivity of the sensor toward potential interfering species in water supplies was also assessed. Sensor performance was then evaluated in water samples from a water treatment plant (WTP), and detection of LPS well below the levels encountered in episodes of water contamination and in humidifiers was demonstrated. The same platform was also tested for bacterial detection including Pseudomonas aeruginosa and Escherichia coli spiked in water samples from a WTP. Considering its performance characteristics, this platform represents a promising screening tool to identify the presence of LPS in water supplies and provide early warning of contamination events.

Emerging contaminants of concern have become a serious issue for the scientific community and society more broadly in recent years due to their increasingly widespread environmental distribution and largely unknown environmental and human health impacts. This study aimed to explore the use of fluorescence excitation-emission (F-EEM) spectroscopy as an alternative analytical method to evaluate the presence of key drugs of addiction (benzoylecgonine, methamphetamine, MDMA, codeine and morphine) in wastewater treatment plants. The chemicals of interest from wastewater were extracted by mixed-mode solid phase extraction and quantified using liquid chromatography tandem mass spectrometry. The same wastewater samples were also analysed by a fluorescence spectrophotometer for fluorescence spectra at wavelengths 280–600 nm (emission) and 200–600 nm (excitation). The study also investigated the relevance of different methods for interpreting F-EEM matrices data including parallel factor analysis (PARAFAC) modelling and fluorescence regional integration technique. PARAFAC identified four components, and among them, component C2, identified at the λex/λem = 275/340 nm wavelength associated with proteinaceous compounds most likely related to tryptophan amino acid, showed significant correlation with codeine removal. MDMA and morphine were not correlated to any of the fluorescence regions. The fluorescence regions related to aromatic protein-like fluorescence were correlated significantly with drug concentration and so may offer a suitable alternative approach for monitoring drugs including benzoylecgonine, methamphetamine and codeine.

In drinking water treatment, complete mineralization of organophosphorus pesticides (OPPs) by UV-based advanced oxidation processes (UV AOPs) is rarely achieved. The formation of intermediate oxidation byproducts would likely have some profound effects on toxicity of the reaction solutions. This study investigated the intermediate oxidation byproducts, transformation pathway and toxicity of malathion solutions during the treatment processes of UV alone, UV/H2O2, UV/TiO2 and UV/Fenton. The main intermediate oxidation byproducts were derived using ultra-performance liquid chromatography - electrospray - time-of-flight mass spectrometry. Thereby the transformation pathway for each of these treatment processes was proposed. The results indicate that in UV photolysis, the transformation pathway of malathion proceeded initially via cleavage of the phosphorus-sulfur bonds while in photocatalysis, the desulfurization from a PS bond to a PO bond was the primary degradation pathway. Interestingly, only in the UV/TiO2 process a small fraction of malathion was found decomposed via a demethylation reaction. At the same time, a toxicity assessment of the treated solutions was conducted by both luminescence inhibition of Vibrio fischeri and inhibition of acetylcholinesterase (AChE). It was found that after UV AOP treatment, the toxicity of the malathion aqueous solution increased sharply. In contrast, no increase in toxicity was observed for the malathion aqueous solution after UV alone treatment. This study demonstrates that the high removal efficiency achieved by OPPs does not imply that detoxification of the water solution has been achieved. On the contrary, the toxicity of the treated solutions by OPPs may be increased significantly depending on the selected treatment processes.