Application of maghemite nanoparticles as sorbents for the removal of Cu(II), Mn(II) and U(VI) ions from aqueous solution in acid mine drainage conditions.

The adsorptive removal of Cu(II), Mn(II) and U(VI) by maghemite nanoparticles (NPs) was investigated under acid mine drainage (AMD) conditions to assess NP potential for remediating AMD-contaminated water. The effects of time, NP and metal concentration, as well as manganese and sulphate ions were quantified at pH 3. Adsorption of all three ions was rapid, and equilibrium was attained in 5 min or less. 56 % of Cu, 53 % of Mn and 49 % of U were adsorbed. In addition, adsorption efficiencies were enhanced by >= 10 % in the presence of manganese and sulphate ions, although Cu sorption was reduced in 1: 2 Cu-to-Mn solutions. Adsorption also increased with pH: 86 % Cu, 62 % Mn and 77 % U were removed from solution at pH 9 and increasing initial metal concentrations. Increasing NP concentrations did not, however, always increase metal removal. Kinetics data were best described by a pseudo-second-order model, implying chemisorption, while isotherm data were better fitted by the Freundlich model. Metal removal by NPs was then tested in AMD-contaminated surface and ground water. Removal efficiencies of up to 46 % for Cu and 54 % for Mn in surface water and 8 % for Cu and 50 % for Mn in ground water were achieved, confirming that maghemite NPs can be applied for the removal of these ions from AMD-contaminated waters. Notably, whereas sulphates may increase adsorption efficiencies, high Mn concentrations in AMD will likely inhibit Cu sorption.SP201

PROTOCOL: Gender transformative approaches in agriculture for women's empowerment: a systematic review

Open Access Journal; Published online: 09 Jul 2022This is the protocol for a Campbell systematic review. The objective of this systematic review is to assess the effectiveness of interventions with gender transformative approach (GTA) components in improving women's empowerment in low- and middle-income countries, and to curate evidence on the mechanisms through which GTA works to improve women's empowerment in agriculture

A Delphi assessment of climate change risks in southern Africa in the 21st century

DATA AVAILABILITY : Data will be made available on request.Climate change is acknowledged as one of the greatest environmental and development challenges society faces. Many organisations are now encouraged to conduct assessments of the climate risks they will be exposed to over the next decades. The Global Change Institute (University of Witwatersrand, South Africa) conducted such an assessment for the southern Africa region, to identify some of the main clusters of climate-change related risks. A list of over fifty risks was scored and ranked using a modified-Delphi process; an iterative process of expert-driven risk identification and ranking that was informed from our collective experience and the literature. We focused on the likelihood and consequence in the mid-term (2041–2060) and scored each risk according to this time frame (risk score = [likelihood of event occurring] × [the impact of the event], moderated by the multiple lines of evidence available (Evidence confidence), and the expert rankings of the assessors (Scorer confidence)), using the assumption of the IPCC RCP8.5 climate scenario. The top quartile was organized into five clusters of risk: food insecurity; water shortages; failed energy transition; human heat stress; and risks to nature and the bioeconomy. This paper describes these risk clusters, explored through the lens of available literature, and analysed within the broader framework of the sustainable development goals (SDGs), and the individual and collective actions that can be taken to reduce or adapt to these risks. There are many technical solutions to these risks, but these typically are costly and only function up to a point where the risks become unmanageable. For solutions to be successful, a ‘systems view’ and the complex interlinkages between climate change and socio-economic development must be addressed. The interconnected and cross-sectoral nature of the climate risk domains certainly presents a challenge for governance; the success of some of the measures discussed in this paper depends on the existence of strong, well-resourced, well-coordinated and influential governance mechanisms and state institutions and focusing on investigating the many synergies that exist among solutions.The Carnegie Corporation of New York (Next Generation of African Scholars programme), awarded to the Global Change Institute, University of the Witwatersrand; the Jennifer Ward Oppenheimer Research Grant and the National Research Foundation (NRF) Global Change Social Science Research Programme.http://www.elsevier.com/locate/crmam2024Geography, Geoinformatics and MeteorologyZoology and EntomologySDG-13:Climate actio

Tap versus bottled water consumption: The influence of social norms, affect and image on consumer choice

What drives consumers to choose bottled water instead of tap water where the latter is safe, accessible, costs far less, and in spite of its environmental impacts? This research investigates the influence of hitherto unexplored psychological drivers in an attempt to generate a more holistic understanding of the phenomenon, and strategies for designing more effective consumption reduction campaigns. Using data from an internet survey of Swiss and German respondents (N = 849) we investigated the role of, social norms, affect and image on water consumption. Results suggest that these psychological factors play a role in water consumption choice. Convenience was the only contextual predictor - the inconvenience of transporting bottled water has a negative effect on its consumption, and a positive effect on tap water consumption. Although concern about the effect of bottled water on the environment was not a significant predictor of tap water consumption, we found that for some people, a link exists between environmental concern and consumption choice. Ways through which consumers may be more effectively influenced towards environmentally-friendly consumption are discussed