Algal bloom in a closed water basin is sometimes problematic, especially in terms of the off-flavor in tap water because of an increased amount of odorous metabolites produced by them. Unfortunately, the current water purification process does not always function properly to remove odorants in tap water. Fishy odor is one of the most frequently detected off-flavor in tap water across the world and a number of papers have studied its occurrence mechanism; however, the determination of its causal substance remains rather formidable. The objective of this review paper is therefore to pave a way for unequivocal identification of a causal substance of the fishy odor. We propose that focusing on already reported odorants is not enough to achieve this; an unknown odorant possibly contributes to the occurrence of the fishy odor. An extensive exploration using a novel technique, such as a combination of high-resolution mass spectrometry and multivariate analysis, can be a promising methodology to discover proper odorant.

The influence of the infrastructure system on flood drainage is increasingly concerned in recent years. It is the foundation for socio-economic development planning. The study was carried out the downstream of Kone-Ha Thanh river basin. In this study, the integrated hydro-hydraulic models are applied to evaluate the impacts of these objects on the flood drainage issue. The models are calibrated and validated to be consistent with the observed data. By simulating the whole system, the model shows that the roads are the main hindrance objects to flood drainage. The drainage capacity of current culverts cannot adapt to the design flood. It causes flooding upstream of the main roads crossing over the basin. The residential/industrial areas also have a significant impact on flooding. Urban/industrial areas increase the inundation level in the surrounding areas while flooding duration is insignificantly affected. This shows the shortcomings of current standards in Vietnam for the design of roads as well as residential areas.

As the need for sustainable rice cultivation increases, irrigation with treated sewage effluent (TSE) has become a reasonable solution and its impact on the emission of greenhouse gas (GHG), CH₄ and N₂O, has gained increasing attention. Despite TSE containing dissolved GHGs, previous studies have not focused on the spatiotemporal profile and impact of TSEs on GHG assessments. Therefore, we conducted an experiment with the pilot-scale reactor using TSE irrigation to assess the importance of the dissolved GHG profiles. The TSE originally contained dissolved CH₄ and N₂O. The results showed that the dissolved CH₄ concentrations in the TSE were higher than those in the paddy fields. Although the TSE contained dissolved N₂O, it was also produced in the soils. Moreover, microorganisms, such as Candidatus Nitrotoga arctica and Methanospirillum, became dominant species. Our study demonstrates that measuring the spatiotemporal profiles of dissolved GHGs in paddy fields, as well as in TSE, can lead to more reliable GHG monitoring by assessing the dissolved GHGs in the inflow and outflow of paddy fields.