Background: The incidence of foodborne infectious diseases has been stable and even increased in many countries. Improper use of antibiotics due to the prevalence of microbial diseases has caused drug resistance. So nanotechnology has many attractive applications in the food industry, such as food preservation and food quality control. By the reason, the absorptive and antibacterial features of copper oxide nanoparticles combining with magnesium oxide nanoparticles in killing the bacteria were investigated. Materials and Methods: The antibacterial activities of CuO NP in combination with MgO NP against Escherichia coli and Staphylococcus aureus in culture media and fruit juice (mango, pomegranate, and peach) by agar diffusion and colony count method were explored. Electron microscopy was used to characterize the morphological characteristics of the bacteria tested after treatment with CuO and MgO NPs. Results: The results of one-way ANOVA by 95% confidence showed that CuO and MgO NPs have antimicrobial activity on E. coli and S. aureus. An effect of synergism was observed when combining CuO and MgO NP. Electron microscopy photographs showed that treatment with the combination of MgO and CuO caused damage to the cell membrane. As a result, the leakage of intracellular contents kills the bacteria. Conclusion: The combination of CuO and MgO nanoparticles can successfully control the growth of E. coli and S. aureus in liquid and juice medium. So, this combination treatment can reduce the required amount of CuO and MgO nanoparticles during the pathogen control process in the food industry.

Payment for Ecosystem Services (PES) is not only a prominent, globally promoted policy to foster nature conservation, but also increasingly propagated as an innovative and self-sustaining governance instrument to support poverty alleviation and to guarantee water, food, and energy securities. In this paper, we evaluate a PES scheme from a multi-scalar and political-ecology perspective in order to reveal different power dynamics across the Water-Energy-Food (WEF) Nexus perspective. For this purpose, we analyze the PES scheme implemented in the Hidrosogamoso hydropower project in Colombia. The paper shows that actors’ strongly divergent economic and political power is determinant in defining how and for whom the Nexus-related water, food, and energy securities are materialized. In this case, the PES scheme and its scalar politics, as fostered by the private/public hydropower alliance, are instrumental to guaranteeing water security for the hydropower scheme, which is a crucial building-block of Colombia’s energy security discourse. For this, the water and food securities of the adjacent, less powerful communities are sacrificed. Examining the on-the-ground politics of WEF Nexus is key to understanding their impact on equitable and sustainable governance of water, energy, and food in the everyday lives of millions of resource users. We conclude that politicizing the Nexus can help to trace both the flows of resources and the flows of power.

Supply systems for water, energy and food in the Gulf region are becoming highly interlinked. In the last decades, interdependence was evident in the increase of coproduction plants and the cross-sectoral resource use footprints. In light of increasing integration due to growing scarcities, the construction of mega projects for coproduction, and the use of renewables across sectors, the security notion can be revisited. This paper proposes a view of the resource supply security based on the systems’ characteristics under change and their ability to deal with risks and shocks (resilience). It introduces internal and external risk factors for the water, energy and food supply systems in the Gulf region and highlights recent knowledge on such risks. Further, the paper explains the vulnerability of supply systems to planning risks like scale, integration intensity and level of service provisions together with risks related to growth, technology, market and climate. In light of such insecurities, we stress the importance of investing in risk management and resilience policies in infrastructure planning. Response measures to future risks can focus on options like storage, knowledge, diversification and, importantly, promoting regional cooperation and synergies from common infrastructure planning between countries of the Gulf Cooperation Council (GCC).

Multifunctional polymeric microspheres were prepared using hyper-cross-linking chemistry combined with surface-initiated atom transfer radical polymerization. The synthesized microspheres exhibited good water dispersibility, a high surface area, and pH/thermo dual-responsiveness. Fluoroquinolones (FQs), which contains a hydrophilic piperazine ring and hydrophobic fluorine atoms, were used as target analytes to assess the performance of the microspheres as a sorbent for dispersive solid-phase extraction (d-SPE). The d-SPE experimental parameters, including extraction time, amount of microspheres, extraction temperature, and sample solution pH, as well as the desorption conditions, were systematically studied. Coupled with LCMS/MS, an analytical method for analysis of trace-level FQs in water samples was developed and validated. Under optimal conditions, linearity with correlation coefficients (r) of >0.99 was achieved in the concentration range of 0.02–10 μg L−1. The limits of detection and quantification for the selected FQs were 5.0–6.7 and 12–20 ng L−1, respectively. High recovery values (93.1%–97.2%), a high enrichment factor (˜180), and good precision (RSD < 8%, n = 6) were obtained for FQ determination in spiked purified water samples. It was proposed that hydrophilic–hydrophobic transition induced by stretching and shrinking of polymer chains under different pH and temperature conditions offered good control of the surface wettability and altered the extraction behavior. The developed method was validated and was successfully applied to the analysis of FQs in environmental water samples, meat and milk samples. These results demonstrated that the water-dispersible polymeric microspheres have good potential for use in separation and extraction techniques.

Questions related to the safety of alternative water sources, such as recycled water or reclaimed water (including grey water, produced water, return flows, and recycled wastewater), for produce production have been largely un-explored at the detail warranted for protection of public health. Additionally, recent outbreaks of Escherichia coli (E. coli) in fresh produce, in which agricultural water was suspected as the source, coupled with heightened media coverage, have elevated fruit and vegetable safety into the forefront of public attention. Exacerbating these concerns, new Federal regulations released by the U.S. Food and Drug Administration (FDA) as part of implementation of the FDA Food Safety Modernization Act (FSMA), require testing of agricultural water quality for generic E. coli. Here, we present a review of water quality criteria – including surface water, groundwater recreational water, and water reuse – in an attempt to better understand implications of new FDA regulations on irrigated produce. In addition, a Quantitative Microbial Risk Assessment (QMRA) was conducted to estimate risks from pathogen contamination of food crops eaten fresh under the context of FDA regulations to provide perspective on current water reuse regulations across the country. Results indicate that irrigation water containing 126 CFU/100 mL of E. coli correspond to a risk of GI illness (diarrhea) of 9 cases in 100,000,000 persons (a 0.000009% risk) for subsurface irrigation, 1.1 cases in 100,000 persons (a 0.0011% risk) for furrow irrigation, and 1.1 cases in 1000 persons (a 0.11% risk) for sprinkler irrigation of lettuce. In comparison to metrics in states that currently regulate the use of recycled water for irrigation of food crops eaten fresh, the FDA FSMA water quality metrics are less stringent and therefore the use of recycled water presents a reduced risk to consumers than the FDA regulations. These findings, while limited to a one-time exposure event of lettuce irrigated with water meeting FSMA water quality regulations, highlight the need for additional assessments to determine if the scientific-basis of the regulation is protective of public health.

Dissertation (MSc)--University of Pretoria, 2019. | As mining and industry continue to impact agricultural lands and waterways, and as competition for access to fresh water increases, the agricultural industry must adapt to grow crops in increasingly polluted lands using ever more contaminated water sources. As a result, the likelihood that crops grown under such conditions could pose a food safety risk is set to rise. This research assesses the extent to which potentially hazardous trace elements, As and Pb, present in irrigation water at concentrations deemed acceptable by the Irrigation Water Quality Guidelines, impact the food (and feed) safety of crops. Four crops are investigated under two glasshouse trials. The first assesses foliar absorption of As and Pb under irrigation to the aboveground biomass and the second assesses root uptake of As and Pb via the effects of medium- to long-term irrigation programs. Results indicate that under such trace element loaded conditions, some crop parts exceed food (or feed) safety thresholds, with concentrations ranging from 0.01 mg.kg-1 to 33.38 mg.kg-1 As, and 0.01 mg.kg-1 to 62.41 mg.kg-1 Pb, on a dry mass basis. Leafy vegetables present the highest food safety risk. Therefore, if international food safety standards for fresh produce are to be adhered to, the Irrigation Water Quality Guidelines for As and Pb should be critically reviewed so as to negate all possible future contamination of fresh produce as a result of irrigation inputs. A food (and feed) safety consequence matrix is proposed as a means of modelling the effect of irrigating according to the Irrigation Water Quality Guidelines on food (and feed) safety. | Plant Production and Soil Science | MSc | Unrestricted

For nexus approaches to be successful in their analysis and influence, integration dynamics must be understood in the context of larger power dynamics. Current analysis barely take this dimension into account. In this article, we aim to delimit and understand the power-related enabling conditions for integration processes in a situation of water, food and energy conflicts in Cambodia. To do so, we reflect on our experiences and outcomes in a knowledge co-production approach for identifying nexus indicators in a WWF Conservation Mekong Flooded Forest Landscape. We conduct an analysis of stakeholder and partner qualitative interview data collected within the LIVES (Linked Indicators for Vital Ecosystem Services) project to explore three examples how we engaged with power dynamics in the course of the research. By doing so, this article provides first (1) learning on existing challenges regarding integration in the nexus, then (2) it analyses effects of coproduction processes when considering power dynamics in the nexus both in terms of stalemate and enabling conditions for reinforced integration. Finally (3), this article analyses the role that plays structure and agency in such integration processes.

The rising CO2 content in the atmosphere causes chemical changes in the oceans and a reduction in the pH value. Especially calcifying organisms, such as cold water corals, are expected to be negative affected by this chemical change. Several laboratory studies have shown that cold water corals are less affected by the effects of ocean acidification than previously thought, but there are only a few in-situ studies available so far. The cold water coral Desmophyllum dianthus is ubiquitous in the Comau Fjord in Chile along a natural vertical and horizontal pH gradient. None of the parameters measured so far limits the occurrence or growth of the coral. The reason why D. dianthus is able to adapt so well to environmental conditions is still unknown. Many studies have already suggested that the reason for this adaptability depends on the energy status. In order to obtain information on how the growth of D. dianthus could change in the course of ocean acidification, the protein concentrations of D. dianthus in austral autumn and austral winter as well as at six stations along a pH gradient at a depth of 20m were determined in this study. In addition, corals were cross-transplanted between the stations at the head and the mouth of the fjord. The measured protein concentrations were finally linked to the available phytoplankton biomass and growth. The results revealed seasonal differences between the protein concentrations as well as differences during a season along the stations. Additionally, a positive correlation of protein concentrations and pH values was found. No differences between protein concentrations and growth were found between the transplanted corals, but this was expected as there was no large difference in pH values between the stations. The available phytoplankton biomass, measured using chlorophyll-a-fluorescence, showed seasonal differences with higher values in austral autumn compared to austral winter. A positive relationship between the phytoplankton biomass and the pH values along the stations could be established. No relationship could be established between the protein content and the phytoplankton biomass. The results of this study lead to the conclusion that D. dianthus has enough energy available to withstand the conditions of ocean acidification, but it is not reflected by the phytoplankton biomass.

Humanity’s future sustainable supply of energy, fuels and materials is aiming towards renewable sources such as biomass. Several studies on biomass value chains (BVCs) have demonstrated the feasibility of biomass in replacing fossil fuels. However, many of the activities along the chain can disrupt the food–energy–water (FEW) nexus given that these resource systems have been ever more interlinked due to increased global population and urbanisation. Essentially, the design of BVCs has to integrate the systems-thinking approach of the FEW nexus; such that, existing concerns on food, water and energy security, as well as the interactions of the BVCs with the nexus, can be incorporated in future policies. To date, there has been little to no literature that captures the synergistic opportunities between BVCs and the FEW nexus. This paper presents the first survey of process systems engineering approaches for the design of BVCs, focusing on whether and how these approaches considered synergies with the FEW nexus. Among the surveyed mathematical models, the approaches include multi-stage supply chain, temporal and spatial integration, multi-objective optimisation and uncertainty-based risk management. Although the majority of current studies are more focused on the economic impacts of BVCs, the mathematical tools can be remarkably useful in addressing critical sustainability issues in BVCs. Thus, future research directions must capture the details of food–energy–water interactions with the BVCs, together with the development of more insightful multi-scale, multi-stage, multi-objective and uncertainty-based approaches.