Simultaneous removal of gaseous benzene and toluene with photocatalytic oxidation process at high temperatures under UVC irradiation.

Organic air pollutants represent many different pollutants, including persistent toxic organics and volatile organic compounds (VOC). The VOC group includes about 150 different compounds, the majority of which are considered harmful and toxic to human health. Considering all these features, the removal of VOC is of great importance. According to the Industrial Air Pollution Control Regulation, VOCs in flue gases are classified, and the limit value for the most dangerous group is specified as 20 mg/m3 according to the degree of damage. From past to present, many different removal technologies have been developed and continue to be developed. Removal of pollutants at low concentrations by conventional methods is more inadequate than those above certain concentrations. Photocatalytic oxidation (PCO) is one of the technologies used for VOC removal recently. It has been determined that many different organic pollutants can be removed with this method. Within the scope of this study, the removal of benzene and toluene pollutants, which are two important VOCs frequently encountered in flue gases, by the photocatalytic oxidation method has been studied under UVC irradiation. In this study, a new photocatalyst by doping silver (Ag), a noble metal, and nickel (Ni), one of the transition metals, on TiO2 nanoparticles was developed and a laboratory-scale reactor system was designed. Many experiments were carried out by changing the system parameters such as ambient temperature (120 °C, 150 °C, 180 °C), humidity (25% and 50%), and percentage of Ag and Ni doping on TiO2 (0.5%, 1%, 2.5%, %5) and the most successful conditions for the removal of benzene and toluene contaminants were tried to be determined based on the results obtained. When all experiments carried out within the scope of this study were considered, the average removal efficiency for benzene was found as 89.33%, while the average removal efficiency for toluene was 88.23%. According to the obtained results, the most suitable conditions for the simultaneous removal of benzene and toluene pollutants with photocatalytic oxidation method under UVC light were determined as 120 °C temperature, 25% humidity, and 0.5% doping photocatalyst.

Measurement and evaluation of particulate matter and atmospheric heavy metal pollution in Konya Province, Turkey.

Air pollution has negative effects on human health, visibility, materials, plants, and animal health. Particulate matters are one of the most important air pollutants that may create a risk for human health. Especially particulate matters, which are composed of heavy metals and cancer-causing chemicals such as PAH, dioxin, furan, can cause serious reactions in the respiratory tract. Heavy metals are so important because of their capability of accumulation in human tissues. Almost 0.01-3% of heavy metal content may be found in particulate matter. Coarse particulate matters (PM10) which have smaller diameters than 10 microns may enter from the respiratory system and reach the lungs. In this study, PM10 concentrations and heavy metal content (Lead, Nickel, Arsenic, Cadmium) of the samples were measured and evaluated concerning present regulations and limit values for different points in Konya Province, Turkey. The samples were taken at different seasons such as winter, summer, and spring for 16 days. According to the results of this study, in the winter season, PM10 concentration of the measurement point (Directorate Building) located at the settlement area was found the highest. In the summer season, PM10 concentration of the measurement point (Sille Junction) located at crossroads was found the highest. In spring season, maximum PM10 concentration was detected on the measurement point (KOS base station) located in the industrial area. Moreover, daily average nickel (Ni) concentration measured at KOS base station was found the highest and some other station located close to the industrial area and settlement areas were detected higher than average annual limit values in the winter period. Daily average lead (Pb) value was found at least 67% and maximum 98% higher at Sille and Besyol Junctions, but below the annual average limits. Daily average cadmium (Cd) value was mostly calculated in the Directorate Building winter measurement, but it did not exceed the limit value during the measurement periods. Daily average arsenic (As) values at Directorate Building and Karkent measurement points in the winter period were found higher than the annual average limit values. Only daily average nickel concentrations were detected higher than the annual average limits for the summer and spring period at the KOS base station measurement point.