RESUMO
Improving sewage disposal rates is an important policy for maintaining the health of aquatic organisms in river environments. In Japan, the rate is not yet 100 %. Two measures are necessary to eliminate the discharge of untreated greywater: (1) increase the number of households connected to sewage lines in areas with sewage systems, and (2) replace single-type household onsite wastewater treatment systems (OWTSs) with combined-type systems. To estimate the effect of improving the disposal rate on river water quality, we developed a hydrology-based organic pollution assessment model with a gridded spatial resolution of 250 m to estimate the biochemical oxygen demand (BOD) in rivers in Gunma Prefecture, Japan. We considered three scenarios based on the sewage disposal rate of 70.5 % in 2015. In Scenario A, the disposal rate is increased to 75.2 % in 2030 by increasing the connection rate to sewage lines. In Scenario B, the rate is increased to 88.2 % in 2030 through additional progress in converting from single-to combined-type OWTSs. In Scenario C, the rate reaches 100 % by 2040. The ecological status of rivers was evaluated using taxon richness of Ephemeroptera, Plecoptera, and Trichoptera estimated from its reported relationship to BOD. The number of sites in Gunma Prefecture polluted by organic waste classified as III (poor) and IV (very poor) was estimated to be 1610 under the present state (2015) and decreased to 1212 (25 % reduction) in Scenario A, 619 (62 % reduction) in Scenario B, and 50 (97 % reduction) in Scenario C, with the improvements mainly in small branch rivers. The effects of improved disposal rates were mainly evident in areas with relative high population densities using single-type OWTSs outside of areas with a sewage system, and measures taken in these areas were shown to be effective.
RESUMO
Amid the 4th wave of COVID-19, Vietnam reopened its economy, which placed extra burdens on the COVID-19 waste management system. This study analyzed existing issues and recommended adaptations to secure appropriate management of COVID-19 waste under the 'new normal' pandemic period. Results showed changes in COVID-19 waste characteristics (e.g., rapid rise in waste generation, lower percentage of plastic) and multiple other issues (e.g., presence of COVID-19 waste in municipal waste, lack of temporary storage sites and local treatment capacity), along with greater waste-handling responsibilities placed on authorities and higher infection risks. To adapt to the 'new normal', introduction of separate handling routes and collaboration in waste treatment were recommended. Employing the network of pharmacies used for vaccination would require COVID-19 waste collection from scattered, small-scale sources as part of the waste management solution. Also, following the 4R initiatives (reduce, reuse, recycle, recovery) could help ease the burden on the country's waste system and provide additional opportunities to move towards a circular economy in the post-acute COVID-19 era. The findings should contribute to a safer co-existence with the virus through appropriate waste management in Vietnam and could be used to tackle waste problems in other developing countries. Supplementary Information: The online version contains supplementary material available at 10.1007/s10163-022-01563-x.
RESUMO
The accelerated generation of COVID-19 waste under the Delta-fuelled outbreak placed a sudden burden on waste disposal in Vietnam. To secure the treatment of COVID-19 waste amid the pandemic uncertainty, treatment capacity was assessed by determining treatment occupancy rate-the ratio of estimated demand to calculated capacity-both nationally and in Ho Chi Minh City. At the general occupancy rate for COVID-19 waste treatment of 7.4%, the country was capable of handling COVID-19 waste, with a capacity to treat 62 191 t month-1. However, Ho Chi Minh City became overwhelmed, indicated by a treatment occupancy rate of up to 780% during the Delta outbreak, as the unanticipated growth of demand for COVID-19 waste treatment caused waste to back up. The assessment results, in addition to current legislation, support collaboration in waste treatment as a solution to using existing resources to address the acute shortage of treatment capacity, so as to secure COVID-19 waste treatment. The findings could be used by other developing countries to tackle the waste problem in the pandemic era. Supplementary Information: The online version contains supplementary material available at 10.1007/s10163-022-01529-z.
RESUMO
Despite its initial success in COVID-19 pandemic control, Vietnam faces a growing risk of outbreaks as new infection waves driven by the highly contagious Delta variant surge in the region. In the context of preparedness through waste management, this study estimated the rate and quantity of generation and the composition of COVID-19 waste in Vietnam from the supply of resources and equipment. Over a year under COVID, 1486 t of COVID-19 waste was produced from the treatment of isolated COVID-19 patients (4.64 kg bed-1 day-1), quarantine in medical facilities (3.86 kg bed-1 day-1), centralised quarantine (46.43 g bed-1 day-1), testing (50 g test-1) and vaccination (10.46 g shot-1). Plastic dominated the waste at 76.7%, followed by paper. The additional management of waste from households with persons under quarantine is likely to reduce infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) - contaminated waste. Thorough assessment is recommended for the establishment of regional collaboration to secure COVID-19 waste treatment capacity. These findings will support COVID-19 waste planning in Vietnam in association with pandemic scenarios and could be used as a reference by other developing countries for pandemic control.
