Call for planning policy and biotechnology solutions for food waste management and valorization in Vietnam.

Food waste (FW) is more harmful than previously imagined. A large amount of Vietnam's FW ends up in landfills, only 20 % of which are sanitary. This causes significant environmental problems such as greenhouse gas emissions, high carbon footprint, leachate, and landfill-related conflicts. The FW from Vietnam's urban areas is 0.29 kg⸳p-1⸳d-1, accounting for 31.7 % of total waste. 38.81 % of families discharge FW which, along with municipal waste, corresponds to 4,429.21 ton⸳d-1 for the entire country. For FW collection, under transportation and treatment heads, 80,416.95 $⸳d-1 and 74,605.57 $⸳d-1 were spent, respectively. An analysis of Vietnam's national strategy for the integrated management of solid waste indicates that the amount of attention and concern currently given to FW issues is not adequate to address them. To resolve FW issues, Vietnam needs to be more proactive regarding solutions and efforts, in addition to implementing strict regulations. These include the setting of national goals under the priority of national strategy, strict regulations, stakeholder engagement, FW recycling to animal feed, biorefinery, and awareness-raising campaigns.

Two-step system consisting of novel vertical flow and free water surface constructed wetland for effective sewage treatment and reuse.

This study developed a unique system by combining the novel vertical flow (NVF) using expanded clay (ExC) and free flow surface constructed wetland (FWS) for dormitory sewage purification and reuse. The NVF tank consisted of filter layers of ExC, sandy soil, sand, and gravel. The FWS consisted of sandy soil substrate and was installed after the NVF. Colocasia esculenta and Dracaena sanderiana was planted in NVF and FWS, respectively. The treatment system was operated and tested for more than 21 weeks by increasing the hydraulic loading rate (HLR) from 0.02 m/d to 0.12 m/d. The results demonstrated that effluents in the system changed proportionally to the HLRs, except for nitrate nitrogen. Furthermore, the maximum removal efficiencies for TSS, BOD5, NH4-N, and Tcol were 76 ± 13%, 74 ± 11%, 90 ± 3%, and 59 ± 18% (0.37 ± 0.19 log10MPN/100 mL), respectively. At HLRs of 0.04-0.06 m/d, the treatment system satisfied the limits of agriculture irrigation.