National Kaohsiung University of Applied Sciences

The effects of thermal treatment temperature and CaO addition on polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) content in the fly ashes from a medical waste incinerator with high chlorine content (7.5

The chemical mass balance model was applied to estimate the major sources of atmospheric polycyclic aromatic hydrocarbons (PAHs) at an Industrial Region in Kaohsiung, Taiwan. The gaseous and particulate phases of 16 individual compounds were analyzed between March 2012 and August 2012. The mean total concentrations and total BaPeq were higher during the cold season and lower during the warm summer, with gaseous PAHs predominant at all sites. Low weight-PAHs and median weight-PAHs were found predominantly in the gaseous phase, while high weight-PAHs were predominant in the particle phase. Results from the receptor model revealed that the average contributions were 38.2%, 27.2%, 20.7%, 6.8%, 5.2%, and 2.0% from vehicles, heavy oil combustion, natural gas combustion, incinerator, tetrabromobisphenol A production, and diesel combustion at the seven receptors, respectively. Vehicle emissions appear to be the significant source of PAHs in the investigated area, although other industrial sources, as described above, also have an impact on the total PAHs.

The development of biodiesels is being driven by the need for reducing emissions from diesel engines without modifying engines and for saving energy. The major obstacle to biodiesel commercialization is the high cost of raw materials. Biodiesel from waste cooking oil is an economical source and an effective strategy for reducing the raw material cost. Although biodiesels made from waste cooking oil have been previously investigated, PAH emissions from heavy-duty diesel engines (HDDEs) with catalyzer fueled with biodiesel from waste cooking oil and its blend with ultra-low sulfur diesel (ULSD) for the US-HDD transient cycle have seldom been addressed. Experimental results indicate that ULSD/WCOB (biodiesel made from waste cooking oil) blends had lower PM, HC, and CO emissions but higher CO2 and NOx emissions when compared with that of ULSD. Using ULSD/WCOB blends instead of ULSD decreased PAHs by 14.1

Sewer construction in Taiwan lags other developed nations, and the authorities are undertaking major sewerage system construction projects in several cities. In Kaohsiung City, sewerage networks pass through residential, commercial and industrial areas. The composition of sewage thus is highly complicated. Eight target monitoring positions are chosen to analyze the compounds and concentrations of hazardous air pollutants. Pollutant concentrations are used to evaluate the cancer risk increment based on inhalation intake for sewer workers under using exhaust ventilation and wearing personal gas filtering equipment. GC/MS analysis confirmed that concentrations of benzene and trichloromethane compounds in sewer air for all the monitoring positions exceeded the minimum risk levels (MRLs) of 0.009 ppm benzene and 0.1 ppm trichloromethane, and the maximum concentrations reached 148.4 and 327.3 ppm, respectively. The cancer risks of benzene and trichloromethane for workers without personal protection approached 2.77-3.98×10^(-3) and 29.74-42.70×10^(-3), respectively. Through ventilation for 15 minutes and the wearing of gas filtering equipment, the cancer risks for benzene and trichloromethane were reduced to 0.0003-0.0004×10^(-3) and 0.0029-0.0041×10^(-3), respectively. The authorities thus must order all workers to follow a strict code of practice for sewer entry before entering sewer systems. This code of practice should include a minimum time for general exhaust ventilation and the use of personal protection equipment.

The direct conversion of methane (CH4) into methanol (CH3OH) and HCHO in an Argon (Ar) 50W radio-frequency plasma system was applied and the effects of various feed compositions, CH4/O2 ratio, and plasma discharge areas were compared. Additionally, the effects of various methane to oxygen ratios and plasma discharge areas were studied. It was found that in an Ar stream, the CH3OH conversion ratio in the CH4/O2 plasma system was higher than that in CH4/CO, CO/H2 and CH4/H2/O2 plasma systems. The conversion of CH4 reached 19.1% at CH4/O2 = 40/60; the yield of CH3OH was 1.12% and 16.0% CO, the major product, was produced. A larger plasma discharge area, resulting in a longer residence time, corresponded to higher CH4 conversion, but a lower CH3OH conversion ratio, because of further decomposition into CO and CO2. Interestingly, no carbon deposition was observed in the RF plasma system, and the carbon balance was between 0.94 and 1.19.