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Odor emissions from biosolids limit opportunities for their beneficial reuse by land application. Odorous emissions are affected by the operation of stabilization processes via methods such as anaerobic digestion, aerobic digestion, alkaline treatment, thermal drying, or composting. Commonly used sampling and measurement methods for assessing odor emissions were identified and key odorants reported for biosolids produced using different stabilization methods. Generally, dominant odorants from biosolids were volatile sulfur compounds; however other odorants such as trimethylamine, ammonia, indole, p-cresol and pinene may also be sensorially important in different types of stabilized biosolids. Therefore, initial studies should target a range of odorants potentially emitted at different sites. The use of sensory analysis, which was limited in many studies, coupled with analytical methods can be effectively used to characterize nuisance emissions. The processing of the biosolids both before and after stabilization was shown in many studies to affect the resultant biosolids odorous emissions. These findings suggest that not only should the operational performance of biosolids processing before, during and after stabilization should be reported but that the biosolids management systems should consider the whole biosolids processing train, rather than just the operation of the chosen stabilization method. [ABSTRACT FROM AUTHOR]

With the wave of digitisation sweeping through the higher education sector, end-of-life outcomes for decommissioned computers will pose a serious sustainability challenge for higher education institutions. This challenge presents an opportunity for universities to implement and demonstrate best practice in sustainability; in this case, computer re-use schemes. The paper addresses the practical realisation of sustainability innovation in a social and institutional context via an examination of the first computer re-use scheme implemented within an Australian university. It also contributes a unique, institutional and social perspective to the study of a sustainability innovation, computer re-use schemes. The key factors that contributed to the successful implementation of the Scheme are derived and presented as a social and institutional model for implementing sustainability initiatives. A summary of the model is presented in the graphical abstract. Given the complex organisational structure of universities, these learnings can be relevant to a wide range of institutions and the implementation of other sustainability initiatives. Image 1 • A social and institutional model for sustainability innovation is presented. • Student leadership and initiative was the catalyst for the re-use scheme. • A common language and stated objective for sustainability and social impact supported the scheme. • Partnerships led to new organisational and delivery set-ups for sustainability innovation. [ABSTRACT FROM AUTHOR]

The composition of wastewater in sewer catchments is known to affect the performance of wastewater treatment plants (WWTPs). However, there is limited knowledge as to how catchment characteristics, such as types of catchment industries, impact odour emissions from downstream sludge processing and biosolids management. Odorous emissions from biosolids processing at WWTPs can represent a significant community impact when the local population is exposed to odours. The main odorants emitted from biosolids are volatile sulfur compounds (VSCs), however, volatile organic compounds (VOCs) in emissions may also be perceptable after the removal of VSCs in odour abatement systems. Types of compounds present in emissions throughout biosolids processing at five WWTPs of varying sizes and levels of treatment (primary only and primary and secondary) were analysed. The ratio of total VSCs to VOCs in emissions, and the sensorial importance of each class varied between the sites. As a number of the VOCs in emissions were of industrial origin, this variation is likely dependent on industrial flows into the upstream sewer catchment. The impact of different emission compositions on both activated carbon and biologically based odour abatement systems were discussed. [ABSTRACT FROM AUTHOR]

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 (E10 1–10% 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. Image 1 • The environmental impacts of corn planting was allocated to corn, stalk and corncob. • Exergy allocation was applied. • E10 was 6% and E85 was 64–70% lower of FDP than gasoline. • E10 was 1–10% lower and E85 was 5–113% lower of GWP than gasoline. • E10 and E85 performed inferior ODP, AP and EP than gasoline. [ABSTRACT FROM AUTHOR]

Abstract The application of aerobic granular sludge (AGS) technology has increased in popularity, largely due to the smaller physical footprint, enhanced biological nutrient removal performance and ability to perform with a more stable operation when compared to conventional activated sludge (CAS) systems. To date, the ability of AGS to remove microbial pathogens such as; Escherichia coli , Giardia , and Cryptosporidium has not been reported. This study compared the log 10 removal performance of commonly used pathogen surrogates (sulfite-reducing clostridia spores, f-RNA bacteriophage, E. coli and total coliforms) by AGS and CAS during the start-up phase, through to maturation. Results showed that AGS performed as well as CAS for the log 10 removal performance of all microbial surrogates, except for spores which were removed more effectively by AGS most likely due to greater adherence of spores to the AGS biomass compared to CAS mixed liquor. Results suggest that AGS is capable of meeting or exceeding CAS-equivalent health-based targets for pathogen removal in the context of water recycling as well as not adversely affecting the secondary effluent water quality (suspended solids, turbidity and particle size) in terms of ultraviolet light transmissivity (254 nm). These findings confirmed for the first time that the adoption of AGS operation would not adversely impact downstream tertiary disinfection processes from altered water quality, nor would it require further pathogen treatment interventions in addition to what is already required for CAS systems. Graphical abstract Image 1 Highlights • Microbial LRV validation of AGS was conducted during start-up and mature operation. • LRV was assessed for four indicators and compared to Conventional Activated Sludge. • Start-up of AGS did not reduce microbial indicator LRV performance. • AGS is able to meet or exceed CAS health-based targets for pathogen removal. • Effluent quality from AGS is unlikely to impact downstream disinfection processes. [ABSTRACT FROM AUTHOR]

The successful development of aerobic granular sludge (AGS) for secondary wastewater treatment has been linked to a dedicated anaerobic feeding phase, which enables key microbes such as polyphosphate- accumulating organisms (PAOs) and glycogen-accumulating organisms to gain a competitive advantage over floc-forming organisms. The application of AGS to treat high-saline sewage and its subsequent impacts onmicrobial ecology, however, are less well understood. In this study, the impacts of high-saline sewage on AGS development, performance and ecology were investigated using molecular microbiology methods. Two feeding strategies were compared at pilot scale: a full (100%) anaerobic feed; and a partial (33%) anaerobic feed. The results were compared to a neighbouring fullscale conventional activated sludge (CAS) system (100% aerobic). We observed that AGS developed under decreased anaerobic contact showed a comparable formation, stability and nitrogen removal performance to the 100% anaerobically fed system. Analysis of the microbial ecology showed that the altered anaerobic contact had minimal effect on the abundances of the functional nitrifying and denitrifying bacteria and Archaea; however, there were notable ecological differences when comparing different sized granules. In contrast to previous work, a large enrichment in PAOs in AGS was not observed in high-saline wastewater, which coincided with poor observed phosphate removal performance. Instead, AGS exhibited a substantial enrichment in sulfide-oxidising bacteria, which was complemented by elemental analysis that identified the presence of elemental sulfur precipitation. The potential role for these organisms in AGS treating high-saline wastewater is discussed. [ABSTRACT FROM AUTHOR]

Conventional activated sludge (CAS)-based wastewater treatment processes have the potential to emit high concentrations of nitrous oxide (N 2 O) during nitrification and denitrification, which can significantly impact the environmental performance and carbon footprint of wastewater treatment operations. While N 2 O emissions from CAS have been extensively studied, there is little knowledge of N 2 O emissions from aerobic granular sludge (AGS) which is now an increasingly popular secondary treatment alternative. The N 2 O emissions performance of AGS needs to be investigated to ensure that the positive benefits of AGS, such as increased capacity and stable nutrient removal, are not offset by higher emissions. This study quantified N 2 O emissions from a pilot-scale AGS reactor operated under a range of organic loading rates. A second CAS pilot plant was operated in parallel and under identical loading rates to allow for side-by-side comparison of N 2 O emissions from floc-based activated sludge. Under low loadings of <0.6 kg COD/m3/d the N 2 O emission factor from AGS and CAS were similar, at around 1.46 ± 0.1% g N 2 Oemitted/g ammonium loaded. A step increase in the organic loading rate increased N 2 O emissions from AGS more so than CAS which appeared to be attributed to the reactor feeding strategy that was required for AGS formation. The use of a separate anaerobic feeding phase which was followed by the aeration phase, resulted in extended periods of low dissolved oxygen (DO) concentrations combined with an initial high biomass ammonium loading rate, which favours N 2 O production and was exacerbated at higher organic loads. Conversely, the combined feeding plus aeration operation (aerobic feed) employed by the CAS system enabled a more even biomass ammonium loading rate and DO supply. This work has shown that while AGS has many operational benefits, the impacts that aeration profile, loading rate and feeding strategy have on N 2 O emissions must be considered. Unlabelled Image • At <0.6 kg COD/m3/d the N 2 O emission factor from AGS and CAS were similar. • Emissions were higher from AGS at loadings >0.6 kg COD/m3/d when compared to CAS. • Functional nitrifying bacterial groups showed no large changes between AGS and CAS. [ABSTRACT FROM AUTHOR]