The challenge in clean palm oil production falls on the management of palm oil mill effluent which is a notable source of greenhouse gas emissions and water pollution. To address these critics against edible palm oil, an integrated palm oil-based complex (POBC) considering effluent elimination and refinery integration is suitable for environmental-food-energy-water (EFEW) nexus development. Optimal retrofit of palm oil mill into EFEW nexus-integrated POBC requires multi-objective considerations to balance the trade-offs between profitability, energy contribution, greenhouse gas, water and land footprints via fuzzy optimisation. With limited practical knowledge, potential flowsheet modifications should be investigated for flexible POBC design. In a cooperative game context, interconnecting processes act as multiple players cooperating to achieve the goal of the game, i.e., POBC performance, where each player has a distinctive impact on the outcome. In this work, such process performance was suggested to be distributed using cooperative game model, to target the EFEW-based anchor process, i.e., the process stage of greatest contribution in the weighted EFEW nexus, for desired flowsheet advancement. Considering these aspects, an integrated fuzzy and cooperative game optimisation framework was developed to identify the anchor process of an EFEW nexus-integrated POBC. EFEW objective-based process performance allocation in the fuzzy optimal POBC was weighted by the decision-maker to allocate the anchor process using developed models and Excel tools. Nut/kernel separation and cogeneration stage is the EFEW-based anchor process in the fuzzy optimal POBC with EFEW nexus score of 41% in this work. A comparative analysis between the proposed method with other approach was done. The favourability of EFEW contributions by POBC in terms of benefit-drawback ratio increased with the percentage of boiler efficiency increment within the targeted anchor process. Targeting anchor process aids planning for process maintenance and advancement to avoid resource wastage on sub-critical processes.

The disinfection efficacy of slightly acidic electrolyzed water (SAEW) has been recognized in food industry. However, the application of single SAEW limited its disinfection potential. The efficacy of the two-step disinfection with SAEW for the reduction of L. monocytogenes contamination on different food raw materials was evaluated compared to the one-step disinfection with SAEW in this study. Results demonstrated that SAEW could reduce both the natural aerobic bacterial count and inoculated L. monocytogenes population on endive and chicken immediately after processing and SAEW with approximately 60 mg/L of available chlorine concentration (ACC) had equal or higher antibacterial efficacy compared to NaClO solutions with approximately 150 mg/L of ACC. Moreover, SAEW treatments could control the growth of microbial populations of L. monocytogenes during storage and the efficacy on the microbial reduction was associated to the initial populations. In addition, the SAEW-treated food raw materials were stored and disinfected again after storage and the results showed that the two-step disinfection method could decrease the survival populations of L. monocytogenes by 24.8%–99.6% compared to the one-step disinfection of SAEW. Therefore, considering storage habits, the two-step disinfection of SAEW may be a better choice in the disinfection of non-consumed-directly food raw materials.

An integrated two-phase AD with acidogenic off-gas diversion from a leach bed reactor to an upflow anaerobic sludge blanket was developed for improving methane production. However, this system had its own technical limitation such as mass transfer efficiency for solid-state treatment. In order to optimize the mass transfer in this two phase AD system, leachate recirculation with various water replacement rates regulating the total solids contents (TS) at 12.5%, 15%, and 17.5% was aim to investigate its effect on methane generation. The solubilization of food waste was increased with decreasing TS content, while the enzymatic hydrolysis showed the opposite trend. A TS contents of 15% presented the best acidogenic performance with the highest hydrogen yield of 30.3 L H₂/kg VSₐddₑd, which subsequently resulted in the highest methane production. The present study provides an easy approach to enhance food waste degradation in acidogenic phase and energy conversion in methanogenic phase simultaneously.

Emerging smartphone-based point-of-care tests (POCTs) are cost-effective, precise, and easy to implement in resource-limited areas. Thus, they are considered a potential alternative to conventional diagnostic testing. This review explores food safety and the detection of metal ions in environmental water based on unprecedented smartphone technology. Specifically, we provide an overview of various methods used for target analyte detection (antibiotics, enzymes, mycotoxins, pathogens, pesticides, small molecules, and metal ions), such as colorimetric, fluorescence, microscopic imaging, and electrochemical methods. This paper performs a comprehensive review of smartphone-based POCTs developed in the last three years (2018–2020) and evaluates their relative advantages and limitations. Moreover, we discuss the imperative role of new technology in the progress of POCTs. Sensor materials (metal nanoparticles, carbon dots, quantum dots, organic substrates, etc.) and detection techniques (paper-based, later flow assay, microfluidic platform, etc.) involved in POCTs based on smartphones, and the challenges faced by these techniques, are addressed.

Paddy rice cultivation is an important source of agricultural greenhouse gas emissions in China. The traditional flooded paddy rice fields not only use large amounts of irrigation water, but also produce significant methane (CH₄) emissions. To balance food security with environmental impacts of rice production, many water-saving irrigations technologies have been tested in the field to increase the drainage period during the rice growth cycle. However, whether these management solutions can be implemented at the regional scale needs to be further explored. Because it is too time-consuming and resource-intensive for field experiments to be carried out across large areas, we opt to assess the regional impacts of alternative irrigation schemes via computer modeling, by coupling the well-known DSSAT and DNDC models, which have been extensively validated in China. Irrigation methods tested include the traditional Continuous Flooding (CF), Midseason Drainage (MD) and Alternate Wetting and Drying (AWD). Simulation results show that compared with CF, water-saving irrigation methods can significantly reduce the CH₄ emission from paddy rice field, with slight or no loss in expected rice yields. AWD had the greatest effect in reducing irrigation water amounts and CH₄ emission. Compared with CF, CH₄ emission under the AWD were 60% - 71% lower in Northeast China sites and 34% - 65% lower in South China sites. At the same time, compared to CF, irrigation water use in AWD was reduced by 23% - 34% in northeast China sites and by 18% - 50% in south China sites. Our results suggest that policies that support expansion of AWD in paddy rice cultivation across China can lead to a “win-win” for the food-water-GHG emissions tradeoffs, and offer a viable solution for policy makers and stakeholders in China.

This study presents a comprehensive decision model for the integrative design of a biorefinery for bioethanol production and its supply chain (BPSC) under the water-energy-food-land (WEFL) nexus framework. A new optimization model was developed using a mixed integer linear programming to simultaneously identify the optimal process configuration of a bioethanol production plant and the optimal bioethanol supply network. The objective function of the model is to minimize the total annual cost for establishing and operating the BPSC to meet society’s needs (energy, water and food) under the limited resources and land availabilities, and technology capacity. The proposed model can provide the optimal solutions for design and operation of the BPSC: i) the types, and quantities of feedstocks; ii) types, number, and location of facilities and; iii) regional flows. The capability of the proposed model was validated through the case study of Jeju Island, Korea, with two scenarios: BPSC by cost (COPT) and nexus (NOPT) optimization. As a result, it was identified that the BPSC in NOPT requires higher energy supply cost (8.55 B$) than the COPT (6.44 B$). However, the BPSC in NOPT can satisfy the society demands with relatively smaller consumption of occupied land (2%), fresh water (30%) and primary energy consumption (64%) than that of the COPT, respectively.

MSc (Chemistry) | Department of Chemistry | Antibiotics and perfluoroalkyl substances (PFAS) are groups of anthropogenic substances that are found in industries and consumer products, i.e., antibiotics are used in healthcare facilities, pharmaceutical companies, and agriculture, whereas PFAS are used in industries and households. These compounds find their way into the environment through emission, landfill disposal, agricultural run-offs, irrigations, leaching and wastewater spillage. Their residues are widely detected in almost every environmental compartment. Their detection in drinking water and food is one of the global concerns. Their effect in living organisms have been widely documented ranging from allergic reaction to carcinogenic effect, and in serious situations they can lead to death. In this project, the background review on the behaviour of antibiotics and PFAS in different environments are discussed in chapter two. This has been done by looking into their physico-chemical properties, distribution pathways, accumulation and toxicity in various environmental compartments through available literature. After understanding their behaviour in the environment two review papers, namely Paper I and Paper II, were written. Paper I was a book chapter which focused on the application of miniaturised liquid phase extraction techniques used for extraction of antibiotics in environmental water samples. In this book chapter, the use of liquid-liquid extraction techniques was discussed and the evolution of liquid-liquid extraction technique into miniaturised extraction technique was reviewed. Paper II was a critical review which focuses on the application of dispersive liquid-liquid micro-extraction of PFAS in different environmental samples. In this paper, the principles of dispersive liquid-liquid micro-extraction was explained. Later, its application for pre-concentration of PFAS was reviewed and the future trends were discussed. In chapter four, three lab-based papers, namely Paper III, Paper IV and Paper V, were written. In Paper III, for the first time a dispersive liquid-liquid microextraction technique was developed and applied for extraction of multi-class antibiotics in macadamia nuts prior to UHPLC-qToF-MS analysis. In paper IV, a novel deep eutectic solvent was synthesised and characterised using FTIR spectroscopy. For the first time the synthesised deep eutectic solvent was applied for extraction of multiclass antibiotics in green beans prior to UHPLC-qToF-MS analysis. In Paper V, for the first a dispersive liquid-liquid micro-extraction technique was developed and applied for extraction of PFAS in food contact materials prior to UHPLC-qToF-MS analysis. Owing to their ease of operation, efficiency and sensitivity, these techniques can also be applied for preconcentration of antibiotics and PFAS in different food, environmental and biological samples. | NRF

Ecosystem restoration projects (ERPs) are effective for achieving sustainable development goals. However, a nexus perspective has not yet been effectively used to examine the regimes and interconnections between the sectors of agricultural production, ecosystem restoration, and the livelihoods of farmers, which may have constrained the efficacy of ERPs. In this study, the evolution of these different sectors in ecosystem restoration hotspot cases was investigated using a novel nexus perspective, and their interconnections and implications for ecosystem management were determined. Rapid urbanisation, reclamation, and ERPs have profoundly altered landscape patterns and caused significant ecological changes. Prior to 1999, extensive reclamation proved unsustainable because deforestation activities and cultivation on sloping cropland resulted in severe soil loss and ecosystem deterioration, despite providing significant increases in grain productivity and economic profits. Although revegetation practices after 1999 accelerated vegetation regeneration and enhanced soil retention and carbon sequestration, they also resulted in a decline in grain productivity and economic profits during the initial period of implementing ERPs (1999–2008). However, subsequent policy adjustments and the construction of terraced fields have mitigated cropland loss and maintained the grain supply. The nexus perspective was effective in identifying and coordinating relationships among the sectors, and timely policy interventions have transformed the relationships from trade-offs to synergies and provided win–win outcomes. However, the ongoing urbanisation continues to be a challenge for conserving ecosystems and ensuring food security; therefore, further optimised, and targeted strategies are required to balance contrasting goals and maximise co-benefits according to the environmental and socio-economic conditions.

This study aims to develop a decision model to optimise the oil palm biomass value chains by minimising the environmental impact whiles generating economy value from their bioproducts. The model considers two major components, namely, a fuzzy analytic hierarchy (FAHP) framework and a multi-objective optimisation model. Both components will be used by integrating the priorities of the environmental and economic impacts obtained from experts' judgement with the multi-objective optimisation model to generate an optimal solution based on expert's judgement. The framework used to study different case study for the oil palm industry in Peninsular Malaysia. Results show that a maximum profit of 267,116,398 USD per year can be achieved. However, to minimise the environmental impact, a 34% cut of the profit is needed to reduce 91% of CO₂ emissions generated and 97% of water consumption. Moreover, the model generates optimal pathways by selecting the processing facilities that are needed in the value chain to achieve the objectives. The biomass or bio-product distribution networks around Peninsular Malaysia are also presented in this paper. Several scenarios are discussed to observe the effects on the optimal value chain solutions by manipulating the production level. On the basis of the results, the interactions of the environment–food–energy–water nexus are investigated. Therefore, this study can contribute to the improvement of oil palm industry policies while addressing sustainability issues through the proposed value chain model.

Concerns regarding sustainability have prompted the search of value in the by-products of food manufacturing. Such is the case of the cooking water (CW) of chickpeas, which has shown its potential as a vegan egg white replacement. This study aimed to characterize and compare the CW from three novel legumes (black soybeans, BSB; yellow soybeans, YSB; and small black beans, SBB) obtained from the processing of Korean soybean foods, and the widely used CW from chickpeas (CH), with regard to total polyphenol, total carbohydrate, and protein contents, and further compare their foaming and emulsifying abilities and stabilities. Compositional analysis revealed that all the studied legumes possessed higher values than CH for all parameters. Furthermore, the CW from these legumes exhibited enhanced functional properties, particularly foaming capacity and stability. Taken together, our results suggest that the CW from BSB, YSB, and SBB, sourced from the manufacturing of legume food products, has the potential of being revalorized as a plant-based functional ingredient for vegan product development.