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This study evaluates the efficiency of domestic wastewater treatment via Sponge-Based Moving Bed Biofilm Reactor (S-MBBR). The laboratory-based treatment plan uses polyurethane sponge with a specific surface area was 260 m²/m³ as a carrier. The treatment plan operated under four different organic load rate: OLR1 = 0.4 kg BOD/m³.day; OLR2 = 0.6 kg BOD/m³.day; OLR3 = 0.8 kg BOD/m³.day; and OLR4 = 1.0 kg BOD/m³.day. During 80 d of the experiment, the highest treatment efficiency was at the organic load rate of 0.4 kg BOD/m³.day, with COD, SS, TN and TP were found to be 85.0 ± 12.9%, 85.7 ± 5.3%, 68.9 ± 1.7%, and 40.3 ± 0.2%, respectively. In which, the influent SS concentration were from 117.3 to 126.0 mg/L, the effluent concentration were in ranged 18.0 to 34.22 mg/L, respectively. The values of influent and effluent COD were 298.8 ± 12.88 and 44.8 ± 3.78 mg/L in turn. The OLR1 influent TN, TP concentrations were respectively 47.9 ± 2.11 and 3.6 ± 0.15 mg/L; the effluent TN, TP concentration were 14.9 ± 0.18 and 2.2 ± 0.06 mg/L, respectively. The study suggests that the effluent is within the allowable limits of National technical regulation on domestic wastewater (Column B1), indicating the applicability of S-MBBR for the domestic wastewater treatment plant.

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Management of solid waste is a major challenge in urban areas of most parts of the world, especially in developing countries. The study aimed to determine and estimate the willingness to pay (WTP) of the selected households for the improvement of solid waste management in Vietnam. The research evaluated WTP of household solid waste in case studies in Bien Hoa and My Tho cities using contingent valuation method (CVM). The data were collected through a closed-ended questionnaire survey and interviews with 200 households. The results showed that the most willingness to pay was equal to 10,000 and 15,000 VND per month. The respondents were willing to pay in Bien Hoa and My Tho with an average of 14,450 VND (0.63 USD) and 13,000 VND (0.56 USD) per month, respectively. Regression model identified influential factors on WTP of households in the two cities of Vietnam. The factors that significantly influence households’ WTP were monthly household income, education of respondents, age, occupation and solid waste volume (p<0.05). The results of this study can be used for the urban planning and implemented the sustainable development process in Bien Hoa and My Tho cities.