Local residents' perception on factors affecting the willingness to pay for improved urban canal water: a case study in Can Tho city of Vietnam.

Urbanization and economic development cause water pollution in the inner-city canals and rivers globally. Bung Xang canal in Can Tho city of Vietnam is facing problems with water pollution due to the lack of centralized wastewater treatment plants and low public awareness on environmental protection. Perception of local residents was collected using structured questionnaires including both qualitative and quantitative information. Regression analysis was employed to evaluate the factors affecting the decision of respondents on the willingness to pay (WTP) to improve water quality in the Bung Xang canal. Knowledge about the environmental protection fee for domestic wastewater (10% of the VAT-excluded from the selling price of 1 m3 of tap water purchased), age of the respondents and their education levels affected the WTP positively, while respondents' perception on water quality affected the WTP negatively. There was 58.33% of the respondents showed the WTP for improved water quality in the canal. They agreed to pay a small fee of VND 10,000 to 15,000 (equivalent to USD 0.42-0.63)/month (1 US$= 23,700 VND). The result indicates that environmental education is the only way forward for a successful sustainable urban city.

Screening Wetland and Forage Plants for Phytoremediation of Salt-Affected Soils in the Vietnamese Mekong Delta.

This study evaluated the salt tolerance and sodium (Na) bioaccumulation of Typha orientalis, Lepironia articulata, Eleocharis dulcis, Scirpus littoralis, Brachiaria mutica, Paspalum atratum and Setaria sphacelata at five salinity levels of 0, 5, 10, 15 and 20‰ (corresponding to 0, 2.4, 6.9, 12.6 and 18 g NaCl L-1). S. littoralis showed zero-reduction in total dry biomass and was classified as a salt tolerant plant based on the membership function value. The highest Na+ accumulation was observed in S. sphacelata (307.9 mg plant-1) in spite of its salt sensitivity, followed by S. littoralis and T. orientalis at concentration of 155 mg plant-1. Consequently, the Na+ phytoextraction potential of these species can be estimated as 46.2, 23.3 and 23.3 kg ha-1 over 49 days, respectively. Taken together, they show high potential as Na+ hyperaccumulators, and can be selected in the national reclamation program for salt-affected soils in the context adaptation to climate change.