In the last years, Singapore has set clear targets to transition towards a circular economy. To advance on those targets, the country has introduced policies and strategies to encourage businesses and society to adopt sustainable practices. In 2019, Singapore launched a Zero Waste Master Plan, which lays out strategies for waste and resource management within the context of the circular economy. With this plan, Singapore aims to reduce the amount of waste sent to landfills by 30% by 2030. And it targets food, electronics, and packaging, including plastics, as priority waste streams. This report provides an overview of Singapore’s food waste management with special emphasis on food waste valorization strategies. Through an exploratory study and conducting interviews with different stakeholders, i.e., individuals, government, businesses, research institutes, key drivers and constraints to increasing food waste valorization were identified. The report also includes the view of food waste experts on valorization strategies that can be applied in the Singaporean context.

Current patterns of agricultural expansion and intensification are bringing unprecedented environmental externalities, including impacts on water quality. While water pollution is slowly starting to receive the attention it deserves, the contribution of agriculture to this problem has not yet received sufficient consideration.We need a much better understanding of the causes and effects of agricultural water pollution as well as effective means to prevent and remedy the problem. In the existing literature, information on water pollution from agriculture is highly dispersed. This repost is a comprehensive review and covers different agricultural sectors (including crops, livestock and aquaculture), and examines the drivers of water pollution in these sectors as well as the resulting pressures and changes in water bodies, the associated impacts on human health and the environment, and the responses needed to prevent pollution and mitigate its risks.

Current patterns of agricultural expansion and intensification are bringing unprecedented environmental externalities, including impacts on water quality. While water pollution is slowly starting to receive the attention it deserves, the contribution of agriculture to this problem has not yet received sufficient consideration. We need a much better understanding of the causes and effects of agricultural water pollution as well as effective means to prevent and remedy the problem. In the existing literature, information on water pollution from agriculture is highly dispersed. This repost is a comprehensive review and covers different agricultural sectors (including crops, livestock and aquaculture), and examines the drivers of water pollution in these sectors as well as the resulting pressures and changes in water bodies, the associated impacts on human health and the environment, and the responses needed to prevent pollution and mitigate its risks.

As for oily water treatment in food industries, the membrane technology has a large potential to reduce the operation time, equipment space and total costs. Using crude lecithin/water emulsion as a model of oily waste water, filtration characteristics on the flux and total organic carbon (TOC) rejection were investigated with a wide range of membranes in reverse osmosis, nanofiltration, ultrafiltration, and microfiltration. Constant flux and TOC rejection were obtained in crossflow filtration with hydrophilic membranes having smaller pores than the emulsion droplets (1-2 mum). Free phospholipids were removed with reverse osmosis membranes or nanofiltration membranes having high NaCl rejection abilities. When microfiltration membranes having larger pores than the emulsion droplets were used, the membrane characteristics such as the pore structure and hydrophobicity largely affected the filtration characteristics: asymmetric membranes gave relatively high fluxes when its loose side was used against the feed emulsion as a depth filter, symmetric membranes having a spongoid pore structure and a pore size similar to the emulsion droplets brought about almost 0 flux owing to an extreme progress of pore blocking, hydrophobic membranes of adequate pore sizes showed a possibility to result in the negative TOC rejection

Large quantities of food are wasted globally. Sugars such as monosaccharides and oligosaccharides are valuable carbohydrate compounds that can be hydrolyzed from food waste, particularly from carbohydrate-rich bakery waste. These sugars can be extracted from the waste as a value-added compound for manufacturing other food products. Sub-critical water treatment is a new and emerging extraction technique that is considered as a green extraction technology. Water at high temperature and pressure can be used to hydrolyze and extract the sugars. This paper reviews (1) the general process for producing sugars from food wastes, (2) recovery of sugar (particularly oligosaccharides) from food waste via sub-critical water treatment, and (3) the potential of bakery waste as the resources of sugar recovery.

The objective of this study was to evaluate the feasibility of anaerobic co-digestion of brown water (BW) [feces-without-urine] and food waste (FW) in decentralized, source-separation-based sanitation concept. An effort has been made to separate the yellow water (urine) and brown water from the source (using no-mix toilet) primarily to facilitate further treatment, resource recovery and utilization. Batch assay analytical results indicated that anaerobic co-digestion [BW+FW] showed higher methane yield (0.54–0.59L CH4/gVSadded) than BW or FW as a sole substrate. Anaerobic co-digestion was performed in the semi-continuously fed laboratory scale reactors viz. two-phase continuous stirred-tank reactor (CSTR) and single-stage sequencing-batch operational mode reactor (SeqBR). Initial 120d of operation shows that SeqBR performed better in terms of organic matter removal and maximum methane production. At steady-state, CODs, CODt, VS removals of 92.0±3.0, 76.7±5.1 and 75.7±6.6% were achieved for SeqBR at 16d HRT, respectively. This corresponds to an OLR of 2–3gCOD/Ld and methane yield of about 0.41L CH4/gVSadded. Good buffering capacity did not lead to accumulation of VFA, showing better process stability of SeqBR at higher loading rates. The positive findings show the great potential of applying anaerobic co-digestion of BW+FW for energy production and waste management. In addition, daily flush water consumption is reduced up to 80%. Decentralized, source-separation-based sanitation concept is expected to provide a practical solution for those countries experiencing rapid urbanization and water shortage issues, for instance Singapore.

The gasification of some selected components of food wastes using H₂O₂ as the oxidant and in the presence of NaOH has been investigated under subcritical water conditions. Hydrogen production was enhanced when both NaOH and H₂O₂ were used compared to when either NaOH or H₂O₂ alone was used or in their absence. Results indicated that the H₂O₂ acted to partially oxidize the samples while NaOH significantly increased hydrogen gas yields by promoting the water-gas shift reaction with subsequent CO₂ capture. In the presence of NaOH, the main components were Na₂CO₃, CH₃COONa and CH₃COONa·3H₂O. Char and tar production were suppressed in the presence of NaOH.

A simple and highly selective and sensitive catalytic adsorptive stripping voltammetric procedure for determination of ultra trace levels of chromium(VI) on hanging mercury drop electrode is reported. The method is based on the adsorptive preconcentration of the Cr(III)–dithiooxamide (rubeanic acid) complex and the utilization of the catalytic reaction in the presence of nitrate. At optimized conditions the calibration graph is linear from 0.01 to 6ng/ml and detection limit is 0.002ng/ml for accumulation time of 50s. The interference of some common ions was studied and this method has been applied to the determination of chromium in food and waste water samples with satisfactory results.

Food industry processing wastes are produced in enormous amounts every year, such wastes are usually disposed with the corresponding economical cost it implies, in the best scenario they can be used for pet food or composting. However new promising technologies and tools have been developed in the last years aimed at recovering valuable compounds from this type of materials. In particular, sub-critical water hydrolysis (SWH) has been revealed as an interesting way for recovering high added-value molecules, and its applications have been broadly referred in the bibliography. Special interest has been focused on recovering protein hydrolysates in form of peptides or amino acids, from both animal and vegetable wastes, by means of SWH. These recovered biomolecules have a capital importance in fields such as biotechnology research, nutraceuticals, and above all in food industry, where such products can be applied with very different objectives.Present work reviews the current state of art of using sub-critical water hydrolysis for protein recovering from food industry wastes. Key parameters as reaction time, temperature, amino acid degradation and kinetic constants have been discussed. Besides, the characteristics of the raw material and the type of products that can be obtained depending on the substrate have been reviewed. Finally, the application of these hydrolysates based on their functional properties and antioxidant activity is described.