• Energy Research
• 2021-2025close
• 6. Clean water close
• AU close

With the acceleration of urbanization, the production of urban sludge is increasing rapidly. To minimize resource input and waste output, it is crucial to execute analyses of environmental impact and assessments of sustainability on different technical strategies involving sludge disposal based on Life Cycle Assessment (LCA), which is a great potential mean of environmental management adopted internationally in the 21st century. This review aims to compare the environmental sustainability of existing sludge management schemes with a purpose of nutrient recovery and energy saving, respectively, and also to include the substitution benefits of alternative sludge products. Simultaneously, LCA research regarding the emerging sludge management technologies and sludge recycling (cement, adsorbent, bricks) is analyzed. Additionally, the key aspects of the LCA process are worth noting in the context of the current limitations reviewed here. It is worth emphasizing that no technical remediation method can reduce all environmental damage simultaneously, and these schemes are typically more applicable to the assumed local conditions. Future LCA research should pay more attention to the toxic effects of different sludge treatment methods, evaluate the technical ways of adding pretreatment technology to the 'front end' of the sludge treatment process, and further explore how to markedly reduce environmental damage in order to maximize energy and nutrient recovery from the LCA perspective.

Pasture dieback (PD) is a grassland deteriorating syndrome resulting in grass loss and weed expansion in Australian pastures, with current estimates indicating that over four million hectares are affected. PD creates financial losses to the industry by reducing animal carrying capacity and producing poor-quality feed, resulting in diminished productivity. After more than a decade since PD first appeared in Australia, the causes and effective treatments are still unknown. Suggested causes include soil microbiota dysbiosis, pathogens, insects, climate change and overuse of chemical fertilisers. Sea minerals have been suggested as capable of improving plants’ yield, quality, taste, and nutritional value, but were never brought into conventional practice as an alternative to chemical fertilisers. Here, we investigated the capacity of sea minerals to improve grass health and yield of PD-affected soil. The replicate plots were treated with water or with 4 mL/m2 of commercially available sea mineral product to investigate the soil chemistry profile, plant morphometrics, pasture productivity, soil microbiota profile, and microbiota-nutrient interactions. Sea mineral application significantly increased total dry matter 20 weeks after a single application, translating to an additional 967 kg/ha; this benefit was still present at 498 kg/ha eleven months post a single application. Sea mineral application improved soil microbiota by boosting beneficial taxa while reducing genera associated with arid and toxic soils. Additionally, sea mineral application increased the number of grassroots up to eleven months post a single application. Our data suggest the benefits of sea mineral application to damaged, unproductive or exhausted soils could be further explored as a natural, affordable, and non-toxic alternative to chemical fertilisers.

Abstract The last decade has seen a worldwide increase in the use of alternative energy sources, especially renewable energy (RE), including its application in desalination. In the past many experimental and pilot investigations were presented which allowed the costs and effectiveness of such integrated solutions to be estimated. The present review describes experience related to the use of solar thermal technologies (solar collector and concentrated solar power technologies), solar electricity (photovoltaic and concentrator photovoltaics), wind, hydroelectric (hydropower, tidal, wave and ocean thermal energy), biomass and geothermal energy (power and thermal) as well as hybrid systems. The costs relating to energy and desalinated water production are investigated in the case of various technological processes used in desalination. The main directions for development of the RE systems investigated are discussed and their advantages and disadvantages are assessed. Such a comprehensive review showed that the expansion of the effective use of RE sources is still hampered by several techno-economic aspects. The paper focuses on the main concerns of the need to optimise energy processes, especially by creating more energy-efficient and economically effective solutions, energy storage, energy recovery and the expansion of off-grid systems. As a result of the analysis it was concluded that, despite some disadvantages, the combining of RE with desalination processes requires further intensive research and demonstration units for longer term performance. Regulations to develop less energy-intensive desalination technologies are also still needed.

AbstractThis assessment by the Environmental Effects Assessment Panel (EEAP) of the United Nations Environment Programme (UNEP) provides the latest scientific update since our most recent comprehensive assessment (Photochemical and Photobiological Sciences, 2019, 18, 595–828). The interactive effects between the stratospheric ozone layer, solar ultraviolet (UV) radiation, and climate change are presented within the framework of the Montreal Protocol and the United Nations Sustainable Development Goals. We address how these global environmental changes affect the atmosphere and air quality; human health; terrestrial and aquatic ecosystems; biogeochemical cycles; and materials used in outdoor construction, solar energy technologies, and fabrics. In many cases, there is a growing influence from changes in seasonality and extreme events due to climate change. Additionally, we assess the transmission and environmental effects of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is responsible for the COVID-19 pandemic, in the context of linkages with solar UV radiation and the Montreal Protocol.

The extensive use of dyes in numerous industries results in massive dye discharge in the wastewater, which is a major cause of water pollution. Globally, the consumption of dyes is near seven hundred thousand tons across different sectors, of which around 10–15% goes into the wastewater. Among the dye kinds, anionic dyes make up the main proportion, having a 32–90% share in the wastewater. Different plant-derived wastes, which are sustainable given their natural abundance, effectiveness, and low cost, are frequently proposed for dye separation. However, these adsorbents are inherently more suitable for cationic dyes than anionic dyes. In recent years, the modification of these wastes has been progressively considered to suit them to anionic dye removal. These modifications involve mechanical, thermal, or chemical treatments, or combinations. These attempts propose two-way benefits, as one abundant waste is being used to cure another severe problem, and eventually both could be diminished. This review has a key focus on the evaluation of plant-derived adsorbents and their modifications, and particularly for anionic dye adsorption. Overall, the mechanism of adsorption and the suitability of the current methods are discussed, and their future potential is explored.

AbstractAs the impacts of climate change and water demands from irrigation continue to increase in the Murray–Darling Basin, water for the environment is becoming more scarce and the ecological conditions of many wetlands is poor. With water scarcity, conservation triage is becoming an increasingly relevant management option for environmental watering of wetlands. However, triage is controversial; being considered contrary to current conservation objectives and practices. We assessed environmental watering at two Ramsar wetlands, Macquarie Marshes and Gunbower Forest, based on international environmental treaty obligations and domestic policy settings, changes to flow regimes, wetland condition and current management. Triage decision making was found to be in tacit use at Macquarie Marshes, based on ‘rules of thumb’ and experiential ecohydrological knowledge, whereas formal environmental watering planning formed the basis for triage decision making at Gunbower Forest. We developed a framework for conservation triage of wetlands in the Murray–Darling Basin to stimulate change in the decision context for wetland conservation and adaptation under climate change. Conservation triage entails reframing of relationships between people and nature and values, rules and knowledge used by stakeholders. Because water is the medium by which wetland conservation outcomes eventuate, trade-offs between competing water uses can be realised with the triage framework.

Blast Furnace Slag (BFS) is a by-product of the iron ore processing industry with potential to be used in different industrial applications. In this research, BFS was used to examine its ability for dye removal from wastewater. The efficiency of two types of BFS samples for removal of cationic methylene blue (MB) and acidic methyl orange (MO) dyes was investigated and results found that the optimal conditions for treatment of wastewater were 80 g/L of adsorbent dose and 1 h of treatment time for both dyes. BFS was found to be more effective for removal of the acidic MO dye than the cationic MB dye. Under shorter residence times, the results showed reverse trends with BFS samples removing higher concentrations of MB than MO. The BFS chemistry had additional impacts on the efficiency of dye removal. Higher basicity of BFS had lower dye removal ability for adsorption of acidic dye when applied at smaller concentrations, while for cationic dye when applied at higher concentrations. The results showed that BFS has potential role for pre-treatment of industrial wastewater contaminated with dyes and may contribute to reduced use of more expensive adsorbents, such as activated carbons.