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Sulfur is found in petroleum fuels and is oxidized to create sulfur oxides during combustion, resulting in air pollution and acid rain. It is therefore important to monitor the trace sulfur content in petroleum fuels. An accurate, sensitive, and fast method is developed to determine the total sulfur content in petroleum fuels by means of sector field inductively coupled plasma mass spectrometry (SF-ICP-MS). Gasoline- and diesel-type samples are directly introduced into the SF-ICP-MS system with a steady flow rate after 1000-fold dilution with isopropanol (IPA) and IPA containing 10% toluene, respectively. The concentration of sulfur in the petroleum fuels is quantified using a certified standard diluted in IPA or IPA–toluene solution as the external calibration system, without the need for any other pretreatments such as digestion or emulsion. The method detection limit values range from 0.12 to 0.17 ng g−1 for different petroleum fuels. Fourteen petroleum fuels containing gasoline, ethanol-blended gasoline, diesel, and biodiesel obtained from the international proficiency testing program of the American Society for Testing and Materials and the Institute for Interlaboratory Studies are analyzed using the developed method. The Z-score values are in the range of −0.39 to 1.27 for all analytes, indicating good analytical accuracy for this method. Thirty petroleum fuels taken from refueling guns at petrol stations across Taiwan are analyzed directly using the developed method to demonstrate its practicality.

This paper evaluated the economic and environmental benefits of using riparian constructed wetlands (CWs) for municipal wastewater treatment in an urban watershed. The monitoring data were collected from seven CWs in Tan-Shui River basin of the metropolitan Taipei, and were compared with a centralized wastewater treatment plant in the same watershed. Operation parameters such as site conditions, effluent quality, construction and operation/maintenance (O&M) costs were analyzed and used to calculate the first order reaction kinetics ( k v20 ) of three pollutants, i.e. TSS, BOD, and NH 4 –N. The reaction kinetics and costs vary significantly among the CWs and treatment plant. The overall treatment performances of BOD and NH 4 –N generally confirmed with the references, with variation only among the different sites, but the removal of TSS was less desirable for all CWs. The total costs of the CWs were between 0.425 and 3.621 USD per kg total BOD removed, and the costs of the centralized wastewater treatment plant was approximately 1.186 USD per kg total BOD removed. The wetlands provide reasonable pollutants removal and show additional benefits on education and recreation while the sanitary sewer system and new treatment plants are under construction. The experiment results confirmed with the references and the methodology can be used to developing water quality management plans for urbanized watersheds in subtropical areas.

Wetland biomass has potentials for bioenergy production and carbon sequestration. Planted with multiple species macrophytes to promote biodiversity, the 3.29 ha constructed wetland has been treated 4000 cubic meter per day (CMD) domestic wastewater and urban runoff. This study investigated the seasonal variations of aboveground biomass of the constructed wetland, from March 2007 to March 2008. The overall aboveground biomass was 16,737 kg and total carbon content 6185 kg at the peak of aboveground accumulation for the system emergent macrophyte at September 2007. Typhoon Korsa flood this constructed wetland at October 2007, however, significant recovery for emergent macrophyte was observed without human intervention. Endemic Ludwigia sp. recovered much faster, compared to previously dominated typha. Self-recovery ability of the macrophyte community after typhoon validated the feasibility of biomass harvesting. Incinerating of 80% biomass harvested of experimental area in a nearby incineration plant could produce 11,846 kWh for one month.

Flood damage as a result of an extreme weather event is always a potential threat to constructed riparian wetlands in subtropical regions, and such damage can significantly impair the pollutant-removing performance of these wetlands The present study compares the pollutant-removal performance of the Hsin-Hai Bridge constructed wetland in the Tan-shui River basin of metropolitan Taipei in September 2000 (before the system was inundated by flood as a result of Typhoon Aere’) and in mid-October 2004 (after reconstruction of the wetland). The study analyses biochemical oxygen demand (BOD), ammonia nitrogen (NH 4 -N), and total phosphorus (TP) of influents and effluents in each of several compartments and for the system as a whole before the typhoon and after reconstruction. The study finds that performance with respect to BOD and NH 4 -N was marginally reduced (with no statistical significance) after reconstruction, but that performance with respect to TP was markedly improved (with statistical significance) after reconstruction. The study provides possible explanations for these findings and concludes that wetlands can be successfully reconstructed after extreme flood damage.