Estimating greenhouse gas fluxes from constructed wetlands used for water quality improvement

Methane (CH4 ), nitrous oxide (N2O) and carbon dioxide (CO2 ) fluxes were evaluated from constructed wetlands (CWs) used to improve domestic wastewater quality. Experiments employed subsurface flow (SF) and free water surface flow (FWS) CWs planted with Cyperus spp. Results showed seasonal fluctuations of greenhouse gas fluxes. Greenhouse gas fluxes from SF-CWs and FWS-CWS were significantly different (p<0.05) while pollutant removal efficiencies of both CWs were not significantly different. The average CH4 , N2O and CO2 fluxes from SF-CWs were 2.9±3.5, 1.0±1.7, and 15.2±12.3 mg/m2 /hr, respectively, corresponding to the average global warming potential (GWP) of 392 mg CO2 equivalents/m2 /hr. For FWS-CWs, the average CH4 , N2O and CO2 fluxes were 5.9±4.8, 1.8±1.0, and 29.6±20.2 mg/m2 /hr, respectively, having an average GWP of 698 mg CO2 equivalents/m2 /hr. Thus, FWS-CWs have a higher GWP than SF-CWs when they were used as a system for domestic water improvement

A brief report on air pollution and heath in Thailand

ผลงานวิชาการคณาจารย์มหาวิทยาลัยเทคโนโลยีสุรนาร

Estimates the Emission of Passenger Cars Based on the First Developed Driving Cycle in Nakhon Ratchasima Municipality, Thailand

This study aims to estimate emissions of passenger cars traveled on the highways in Nakhon Ratchasima Municipality (NRM) based on recently developed driving cycles. A mobile phone application (SafeMate) was used to record speed-time of passenger car on the highways both weekday and weekend. The results showed that the driving cycles of the passenger cars on highway 224 and 304 were quite different. More traffic congestion on highway 224 impacted the average speeds, ranging from 10 to 34 km/h with longer idling time. The average speeds on highway 304 ranged from 49 to 69 km/h with more cruise time. The combined driving cycles on both highways showed the average speeds of 20-40 km/h depending upon the time of days. The traffic density on weekday was higher than the weekend. Peak-hour weekday showed lower traffic flow than off-peak hour which was the opposite of the weekend. Based on the derived driving cycles, the passenger car traveled on the highways in NRM emitted CO, NOx and HC approximately 90.7-129.8, 25.5-34.5 and 6.9-11.7 tons/year, respectively. The passenger cars were estimated to emit about 13,927.7-20,419.3 tons/year of carbon dioxide on the highways. The highway 2 accounted more of the emissions due to the traffic volume and coverage distance in NRM