Analysis of trends in water quality: constructed wetlands in metropolitan Taipei

Meandering through the most densely populated metropolitan areas of Taipei, Taiwan, the Danshui River and its tributaries have undergone the construction of 14 wetlands since 2004, as a means to improve water quality. This study was conducted to examine the functional capabilities associated with treating non-point source pollution through these riparian wetlands. Trend analysis was used to differentiate dissolved oxygen, biochemical oxygen demand, suspended solids, ammonia, and Escherichia coli, among 13 sampling sites using both functions of a Mann-Kendall test and a seasonal Mann-Kendall test. The results show that water quality in Taipei metropolitan rivers has been improving since increasing the number of constructed wetlands and connecting households to the public sewage system. The concentration of pollutants such as those influencing biochemical oxygen demand have gradually declined in drought seasons because riparian wetlands contribute a base flow to dilute riverine pollutants. This paper indicates that the creation of treatment systems influences dissolved oxygen conditions at the municipal scale, suggesting that constructed wetlands could stabilize water quality during extreme hydrological events and improve water quality particularly in times of drought.     

Determination of Reactivity of Aspartame with Flavor Aldehydes by Gas Chromatography, HPLC and GPC

The reactivity of Aspartame with several aldehydes in ethanol was determined by gas chromatographic analysis of the reacted aldehyde. The model aldehydes were benzaldehyde, cinnamaldehyde, citral, n-decanal, and vanillin. The data showed that Aspartame is quite reactive with the aldehydes, although the reactivity differed with each. Detection of and analysis for the reaction products were done by HPLC and GPC. Molecular weights of cinnamaldehyde-Aspartame and benzaldehyde-Aspartame reaction products were determined by GPC. The reactivity is dependent on the relative concentrations of the reactants. It is also influenced by the reaction medium.     

Influence of preparation process of MEA with mesocarbon microbeads supported Pt–Ru catalysts on methanol electrooxidation

The effects of mesocarbon microbeads support for platinum–ruthenium (Pt–Ru) catalysts on anode performance of the direct methanol fuel cell (DMFC) were investigated. Polarization characteristics of the anode electrode were low due to the fast rate of mass transport in the electrode. The effects of the Nafion^® content in the catalyst, the MEA hot press condition, the cell operation temperature and methanol concentration on the polarization curves of the anode were also investigated.     

Vulnerability of Korean water resources to climate change and population growth.

Freshwater availability is affected by changes in climate and growth. We assessed the freshwater vulnerability for five major Korean river basins for 2015 and 2030. We used a regional climate model based on the IPCC SRES A2 scenario, US Geological Survey's Precipitation Rainfall Simulation Model, and population and industrial growth scenarios for impact assessment. The model simulation results suggest increasing spatial and temporal variations of water stress for the basins that are already developed. While freshwater is more vulnerable to growth scenarios than the climate change scenario, climate change alone could decrease mean annual runoff by 10% in four major river basins by 2030. As the first national assessment of climate change, we suggest possible adaptive water resource management and policy strategies for reducing climate related risks in Korea.