Characteristics of particulate constituents and gas precursors during the episode and non-episode periods.

UNLABELLED: Size-segregated distribution of ambient particulate matter (PM) was determined using a micro-orifice uniform deposition impactor (MOUDI) and a nano-MOUDI in southern Taiwan. Eleven water-soluble ionic species including six anions (NO3-, SO4(2-), Cl-, F-, NO2-, Br-) and five cations (NH4+, Na+, K+, Ca2+, Mg2+) for particulate inorganic ions and five gaseous pollutants (i.e., HNO2, HNO3, HCl, SO2, NH3) were analyzed during episode and non-episode periods. The particulate mass concentration was about 30 microg/ m3 higher at night than during the day, and it reached 162 microg/m3 during the episode periods. The difference was mainly attributable to the particle size of 0.1-2.5 microm. Nitrate, sulfate, ammonium, and chloride ions were the dominant inorganic ions in PM. HONO and NH3 concentrations were high at night; in contrast, HNO3, HCl, and SO2 were high during the day. The equivalent ratio of {[NO3-] + 2 [SO4(2-)}/[NH4+] was about 0.98 and revealed a high correlation between {[NO3-] + 2[SO4(2-)]} and [NH4+] that clearly pointed to ammonium neutralization or condensation of ammonium nitrate and ammonium sulfate in PM0.32. The precursor gases and ionic species in different particle sizes did not reveal a strong correlation, which could be attributed to the complex of source emissions, atmospheric reactions and meteorological parameters in the area. IMPLICATIONS: Size-segregated distribution and chemical compositions of atmospheric aerosols play important roles in their visibility reduction, health effects, and toxicity in urban areas. Inorganic ionic species are major constituents in particulate matter, except carbonaceous chemicals. In this work, the compositions of water-soluble ions in particulate matter and acid/base gaseous pollutants (such as HNO2, HNO3, HCl, SO2, NH3) were determined during the day and at night during episode and non-episode periods from 2006 to 2007 in southern Taiwan.

Nitrogen Adsorption and Characteristics of Iron, Cobalt, and Nickel Oxides Impregnated on SBA-15 Mesoporous Silica.

Hexagonal SBA-15 mesoporous material was used as a catalytic template for impregnation, with the transition metals Fe, Co, and Ni as catalysts for chemical transformation. Nitrogen adsorption/desorption isotherms, scanning electron microscopy, and transmission electron microscopy were conducted to better understand the physicochemical properties of the metal oxide-impregnated SBA-15. The specific surface area of the original SBA-15 was approximately 680 m2/g, and the abundances of the catalysts impregnated ranged from 2 to 8%, corresponding to specific surface areas of 560-470 m2/g for Fe-SBA-15, 440-340 m2/g for Ni-SBA-15, and 410-340 m2/g for Co-SBA-15. The increase in impregnated metal loadings filled the pores and collapsed the silica walls during the metal oxides impregnation on SBA-15 and calcination procedures, resulting in a decrease in the specific surface area and pore volume of the templates. The results showed that the order of nitrogen adsorbed was SBA-15 > Fe-SBA-15 > Ni-SBA-15 > Co-SBA-15 when the metal loading was 5%. In addition, the metal oxides on SBA-15 increased the wall thickness compared with raw SBA-15. Based on the XRD spectrum analysis, Fe2O3, Co3O4, and NiO were the stable crystals on the Fe-SBA-15, Co-SBA-15, and Ni-SBA-15, respectively. The sequence of the average grain size of metal oxides on SBA-15 was Co-SBA-15 > Fe-SBA-15 > Ni-SBA-15, according to XRD spectra and Scherrer's equation. Isopropanol could be decomposed by metal oxide-impregnated SBA-15 to form carbon filament materials. Therefore, these materials have the potential to be employed for pollutant removal, catalytic reactions for organic solvent and bio-oil/biomass reforming, and recycling waste into high-value materials.

The effect of microwave pyrolysis on product characteristics and bromine migration for a non-metallic printed circuit board.

At present, it is necessary to carry out environmentally friendly treatment of non-metallic fractions (NMFs) of waste printed circuit board (WPCB) to improve resource utilization. NMFs of WPCB are pyrolyzed by microwave heating to determine the effect of different operating conditions on the characteristics of pyrolysis products. The results show that yields for residue, oil and gas are 59.03-67.63, 7.10-28.46 and 4.86-33.88 wt%. A high temperature promotes a decrease in oil yield and an increase in non-condensable gas yield. An increase in the NaOH dose results in a more significant cracking of the oil to gas. Increasing the concentration of NaOH increases the mass fraction of the total Br in residues (from 23.62 to 86.94 %), so the addition of NaOH is beneficial to the fixation of Br. A kinetics study shows that there are two thermal decomposition regions (398-625 K and 675-925 K), and NaOH-catalyzed pyrolysis reduces the activation energy to 18.91 and 31.95 kJ mol-1, respectively. The formation of Br-containing substances in the pyrolysis oil and gas can be inhibited if the bromine fixation in pyrolysis residue increases. NaOH-catalyzed pyrolysis can reduce bromine and also reduce energy recovery efficiency. This pyrolysis process still requires further research to improve the recovery of energy and valuable materials.

The effect of prenatal perfluorinated chemicals exposures on pediatric atopy.

BACKGROUND: The role of perfluorinated compounds (PFCs) in the immune system and allergic diseases is not well-known. This study examined the effects of pre-natal exposure to PFCs on immunoglobulin E (IgE) levels and atopic dermatitis (AD). METHODS: In Taiwan Birth Panel cohort study, newborns with cord blood and peri-natal factors (i.e. birth body weight, weeks of gestation, and type of delivery) gathered at birth were evaluated. At the age of 2 years, information on the development of AD, environmental exposures, and serum total IgE were collected. The AD and non-AD children were compared for the concentration of cord blood serum PFCs measured by Ultra-performance liquid chromatography/triple-quadrupole mass (UPLC-MS/MS). Correlations among cord blood IgE, serum total IgE at 2 years of age, and cord blood PFC levels were made. RESULTS: Of 244 children who completed the follow-up and specimen collections, 43 (17.6%) developed AD. Concentrations of cord blood serum perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA), and perfluorohexane sulfonic acid (PFHxS) were median (range) 1.71 (0.75-17.40), 5.50 (0.11-48.36), 2.30 (0.38-63.87), and 0.035 (0.035-0.420)ng/mL, respectively. PFOA and PFOS levels positively correlated with cord blood IgE levels (per ln-unit: ß=0.134 KU/l, p=0.047 for PFOA; ß=0.161 KU/l, p=0.017 for PFOS). Analyses stratified by gender revealed that PFOA and PFOS levels positively correlated with cord blood IgE levels only in boys (per ln-unit: ß=0.206 KU/l, p=0.025 for PFOA; ß=0.175 KU/l, p=0.053 for PFOS). When dividing cord blood serum PFCs into quartiles in the fully adjusted models, AD had no significant association with PFOS. CONCLUSIONS: Pre-natal PFOA and PFOS exposures positively correlated with cord blood IgE levels.

Particulate composition characteristics under different ambient air quality conditions.

Particulate compositions including elemental carbon (EC), organic carbon (OC), water-soluble ionic species, and elemental compositions were investigated during the period from 2004 to 2006 in southern Taiwan. The correlation between the pollutant standard index (PSI) of ambient air quality and the various particle compositions was also addressed in this study. PSI revealed a correlation with fine (r = 0.74) and coarse (r = 0.80) particulate matter (PM). PSI manifested a significant correlation with the amount of analyzed ionic species (r approximately 0.80) in coarse and fine particles and a moderate correlation with carbon content (r = 0.63) in fine particles; however, it showed no correlation with elemental content. Although the ambient air quality ranged from good to moderate, the ionic species including chloride (Cl-), nitrate (NO3-), sulfate (SO4(2-)), sodium (Na+), ammonium (NH4+), magnesium (Mg2+), and calcium (Ca2+) increased significantly (1.5-3.7 times for Daliao and 1.8-6.9 times for Tzouying) in coarse PM. For fine particles, NO3-, SO4(2-), NH4+, and potassium (K+) also increased significantly (1.3-2.4 times for Daliao and 2.8-9.6 times for Tzouying) when the air quality went from good to moderate. For meteorological parameters, temperature evidenced a slightly negative correlation with PM concentration and PSI value, which implied a high PM concentration in the low-temperature condition. This reflects the high frequency of PM episodes in winter and spring in southern Taiwan. In addition, the mixing height increase from 980 to 1450 m corresponds to the air quality condition changing from unhealthy to good.

Protection against Ultraviolet A-Induced Skin Apoptosis and Carcinogenesis through the Oxidative Stress Reduction Effects of N-(4-bromophenethyl) Caffeamide, A Propolis Derivative.

Ultraviolet A (UVA) is a major factor in skin aging and damage. Antioxidative materials may ameliorate this UV damage. This study investigated the protective properties of N-(4-bromophenethyl) caffeamide (K36H) against UVA-induced skin inflammation, apoptosis and genotoxicity in keratinocytes. The protein expression or biofactor concentration related to UVA-induced skin damage were identified using an enzyme-linked immunosorbent assay and western blotting. K36H reduced UVA-induced intracellular reactive oxygen species generation and increased nuclear factor erythroid 2-related factor 2 translocation into the nucleus to upregulate the expression of heme oxygenase-1, an intrinsic antioxidant enzyme. K36H inhibited UVA-induced activation of extracellular-signal-regulated kinases and c-Jun N-terminal kinases, reduced the overexpression of matrix metalloproteinase (MMP)-1 and MMP-2 and elevated the expression of the metalloproteinase-1 tissue inhibitor. Moreover, K36H inhibited the phosphorylation of c-Jun and downregulated c-Fos expression. K36H attenuated UVA-induced Bax and caspase-3 expression and upregulated antiapoptotic protein B-cell lymphoma 2 expression. K36H reduced UVA-induced DNA damage. K36H also downregulated inducible nitric oxide synthase, cyclooxygenase-2 and interleukin-6 expression as well as the subsequent generation of prostaglandin E2 and nitric oxide. We observed that K36H ameliorated UVA-induced oxidative stress, inflammation, apoptosis and antiphotocarcinogenic activity. K36H can potentially be used for the development of antiphotodamage and antiphotocarcinogenic products.

Adsorption characteristics of Orange II and Chrysophenine on sludge adsorbent and activated carbon fibers.

Sludge adsorbent (SA) and commercial activated carbon fibers (ACFC and ACFT) were applied to Orange II and Chrysophenine (CH) adsorption (BET surface area: ACFC>ACFT>SA). ACFT was primarily in the micropore range, while SA was approximately 500 A (macropore) and 80 A (mesopore). The ACFC pore volume was high in both the mesopore and micropore regions. Measurement of the oxygen surface functional groups of the adsorbents using Boehm's titration method showed a similar distribution on the carbon fibers (mainly in the carbonyl group), while SA was mainly in the carboxyl, lactone and phenolic groups. The SA, ACFC and ACFT adsorption capacities of Orange II (30-80 mg/l) ranged from 83 to 270, 209-438, and 25-185 mg/g at temperatures ranging from 10 to 60 degrees C, respectively. CH concentration ranged from 30 to 80 mg/l, corresponding to SA and ACFC adsorption capacities of 39-191 and 48-374 mg/g over the defined temperature range, from 10 to 60 degrees C. CH adsorption on ACFT was low. The adsorption capacity of Orange II on ACFT was lower than on SA at 10 degrees C, but at higher temperatures the Orange II molecules were transported into the ACFT, producing an adsorption capacity similar to that of SA. Mass transfer increased with temperature, overcoming the adsorption energy barrier. Overall, SA and ACFC were more effective than ACFT.

Comparison of exhaust emissions resulting from cold- and hot-start motorcycle driving modes.

This study investigated the emissions of criteria air pollutants (carbon monoxide [CO], hydrocarbons [HCs], and oxides of nitrogen [NOx]) from motorcycle exhaust at cold- and hot-start driving cycles on a chassis dynamometer. Seven four-stroke carburetors and two fuel-injection motorcycles were tested. As expected, the emission factors (g/km) of CO and HCs increased during cold-start driving. The ratio of emission factors (g/km) for cold- and hot-start driving cycles ranged from 1.1-1.5 (for CO) to 1.2-2.8 (for HCs). However, the difference of NOx emissions between the cold- and hot-start cycles was not pronounced. Further, the cold-/hot-start ratios of CO and HCs from 50-cm3 motorcycles were higher than those of 100- and 125-cm3 motorcycles; however, the carbon dioxide (CO2) emission was the lowest for the four-stroke motorcycles. High engine temperature and poor combustion efficiency of smaller cylinder-capacity motorcycles may contribute a significant amount of exhaust emission. Additionally, the fuel-base emission factor (g/L-fuel) ratios were low compared with the distance-base emission factor (g/km) in cold- and hot-start driving. This indicates that the effect of catalyst efficiency was greater than the effect of fuel combustion in the tested motorcycles. A comparison of emission ratios of motorcycles and passenger cars shows that the warm-up may be more important for cars, especially under low-temperature conditions. However, the motorcycle contributes a large proportion of CO and HC emissions in many Asian counties. The difference between cold- and hot-start emissions may affect inventory

Adsorption characteristics of acetone, chloroform and acetonitrile on sludge-derived adsorbent, commercial granular activated carbon and activated carbon fibers.

The adsorption characteristics of chloroform, acetone, and acetonitrile on commercial activated carbon (C1), two types of activated carbon fibers (F1 and F2), and sludge adsorbent (S1) was investigated. The chloroform influent concentration ranged from 90 to 7800 ppm and the acetone concentration from 80 to 6900 ppm; the sequence of the adsorption capacity of chloroform and acetone on adsorbents was F2>F1 approximately C1 approximately S1. The adsorption capacity of acetonitrile ranged from 4 to 100 mg/g, corresponding to the influent range from 43 to 2700 ppm for C1, S1, and F1. The acetonitrile adsorption capacity of F2 was approximately 20% higher than that of the other adsorbents at temperatures<30 degrees C. The Freundlich equation fit the data better than the Langmuir and Dubinin-Radushkevich (D-R) equations. The adsorption rate of carbon fibers is higher than that of the other adsorbents due to their smaller fiber diameter and higher surface area. The micropore diffusion coefficient of VOC on activated carbon and sludge adsorbent was approximately 10(-4) cm2 s(-1). The diffusion coefficient of VOC on carbon fibers ranged from 10(-8) to 10(-7) cm2 s(-1). The small carbon fiber pore size corresponds to a smaller diffusion coefficient.

Volatile organic compound constituents from an integrated iron and steel facility.

This study measured the volatile organic compound (VOC) constituents of four processes in an integrated iron and steel industry; cokemaking, sintering, hot forming, and cold forming. Toluene, 1,2,4-trimethylbenzene, isopentane, m,p-xylene, 1-butene, ethylbenzene, and benzene were the predominant VOC species in these processes. However, some of the chlorinated compounds were high (hundreds ppbv), i.e., trichloroethylene in all four processes, carbon tetrachloride in the hot forming process, chlorobenzene in the cold forming process, and bromomethane in the sintering process. In the sintering process, the emission factors of toluene, benzene, xylene, isopentane, 1,2,4-trimethylbenzene, and ethylbenzene were over 9 g/tonne-product. In the vicinity of the manufacturing plant, toluene, isopentane, 1,2,4-trimethylbenzene, xylene and ethylbenzene were high. Toluene, 1,2,4-trimethylbenzene, xylene, 1-butene and isopentane were the major ozone formation species. Aromatic compounds were the predominant VOC groups, constituting 45-70% of the VOC concentration and contributing >70% to the high ozone formation potential in the stack exhaust and workplace air. The sequence of VOC concentration and ozone formation potential was as follows: cold forming>sintering>hot forming>cokemaking. For the workplace air, cokemaking was the highest producer, which was attributed to the fugitive emissions of the coke oven and working process release.

Characteristics of water-soluble ionic species in fine (PM2.5) and coarse particulate matter (PM10-2.5) in Kaohsiung, southern Taiwan.

Eleven ionic species and fine and coarse particle mass concentrations of fine (PM2.5) and coarse (PM10-2.5) particulate matter were investigated in Kaohsiung, southern Taiwan. The PM2.5 and PM10-2.5 particulate concentrations were 49-64 and 34-37 microg x m(-3), respectively. Fifty-five to 64% of the particulate matter less than 10 microm in aerodynamic diameter (PM10) mass was attributed to the PM2.5. PM2.5 concentrations at Daliao (a rural and industrial complex area) were higher than at Tzuoying (an urban and industrial complex area). Ionic species contributed 45-53% and 42-45% of PM2.5 and PM10, respectively. Potassium ions (K+), sulfate (SO4(2-)), and ammonium (NH4+) were predominant in PM2.5, whereas sodium, calcium, and magnesium ions were foremost in PM10-2.5. Nitrate (NO3-) existed in both the PM2.5 and PM10-2.5. Chloride (Cl-), NO3-, and NH4+ concentrations were higher at night than during the day, and they were easily transferred into the gas phase by photochemical reactions and temperature-induced volatilization. The NH4+/SO4(2-) ratios were 2.6 and 2.5 at Daliao and Tzuoying, respectively, which indicated that both sampling sites were rich in NH4+. Therefore, ammonium nitrate would be present in the area.

Residue characteristics of sludge from a chemical industrial plant by microwave heating pyrolysis.

Sludge from biological wastewater treatment procedures was treated using microwave heating pyrolysis to reduce the environmental impact of a chemical plant. In this study, major elements, trace elements, PAHs and nitro-PAHs in raw sludge, and pyrolysis residues were investigated. The contents of major element from raw sludge were carbon 46.7 ± 5.9%, hydrogen 5.80 ± 0.58%, nitrogen 6.81 ± 0.59%, and sulfur 1.34 ± 0.27%. Trace elemental concentrations including Zn, Mn, Cr, Cd, As, and Sn were 0.410 ± 0.050, 0.338 ± 0.008, 0.063 ± 0.006, 0.019 ± 0.001, 0.004 ± 0.001, and 0.003 ± 0.002 mg/g, respectively. For various pyrolysis temperatures, Ca, Fe, Sr, Cr, and Sn contents remained at almost the same level as those in raw sludge. Results indicated that these elements did not easily volatilize. The content of 16 PAH species was about 4.78 µg/g in the raw sludge and 23-65 µg/g for pyrolysis residues associated with various temperatures. The content of ten nitro-PAHs was about 58 ng/g for the raw sludge and 141-744 ng/g for pyrolysis residues. The total nitro-PAH content was highest at 600 °C and then decreased when the temperature was over 600 °C. Total nitro-PAH content was about 247 ng/g at 800 °C.

Emission factors and characteristics of criteria pollutants and volatile organic compounds (VOCs) in a freeway tunnel study.

Carbon monoxide (CO), nitrogen oxide (NO(x)), hydrocarbon (HC), sulfur oxide (SO(2)), particulate matter <10 microm (PM(10)), and 57 VOC species of emissions were confirmed in a freeway tunnel in southern Taiwan. Emission factors were 1.89 (CO), 0.73 (NO(x)), 0.46 (HC), 0.02 (SO2) and 0.06 (PM(10)) g/km-vehicle for all vehicle fleets. Heavy-duty truck and trailer vehicles contributed 20% of the emissions on workdays and 9.5% on weekends in this study. Paraffins and aromatics were the main VOC groups in the tunnel. Isopentane, toluene, n-pentane, isoprene, 2,3-dimethylbutane, acetone, 2-methylpentane, 1-hexene, 1,2,4-trimethybenzene, 1-butene and propene emissions were the major VOC species. Their emission factors were over 10 mg/km-vehicle. Rainfall and high humidity in the tunnel could have reduced the VOC concentrations and increased the portion of aromatics. In addition to paraffins, olefins, and aromatic compounds, oxygenated compounds (i.e., acetone) were found. The pollutant ratios between the inside center and the outside of the tunnel were about 2-3 for CO, SO2, and PM(10) and 42 for NO(x). In addition, the emission factors of the vehicles could reflect real-world vehicle emissions on the highway and be used as baseline information for development of a vehicle control strategy.

Pyrolysis characteristics of integrated circuit boards at various particle sizes and temperatures.

A pyrolysis method was employed to recycle the metals and brominated compounds blended into printed circuit boards. This research investigated the effect of particle size and process temperature on the element composition of IC boards and pyrolytic residues, liquid products, and water-soluble ionic species in the exhaust, with the overall goal being to identify the pyrolysis conditions that will have the least impact on the environment. Integrated circuit (IC) boards were crushed into 5-40 mesh (0.71-4.4mm), and the crushed particles were pyrolyzed at temperatures ranging from 200 to 500 degrees C. The thermal decomposition kinetics were measured by a thermogravimetric (TG) analyzer. The composition of pyrolytic residues was analyzed by Energy Dispersive X-ray Spectrometer (EDS), Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). In addition, the element compositions of liquid products were analyzed by ICP-AES and ICP-MS. Pyrolytic exhaust was collected by a water-absorption system in an ice-bath cooler, and IC analysis showed that the absorbed solution comprised 11 ionic species. Based on the pyrolytic kinetic parameters of TG analysis and pyrolytic residues at various temperatures for 30 min, the effect of particle size was insignificant in this study, and temperature was the key factor for the IC board pyrolysis. Two stages of decomposition were found for IC board pyrolysis under nitrogen atmosphere. The activation energy was 38-47 kcal/mol for the first-stage reaction and 5.2-9.4 kcal/mol for the second-stage reaction. Metal content was low in the liquid by-product of the IC board pyrolysis process, which is an advantage in that the liquid product could be used as a fuel. Brominate and ammonium were the main water-soluble ionic species of the pyrolytic exhaust. A plan for their safe and effective disposal must be developed if the pyrolytic recycling process is to be applied to IC boards.

Chemical constituents in particulate emissions from an integrated iron and steel facility.

Particle emissions from four integrated iron and steel plant processes, i.e., coke making, sintering, cold forming, and hot forming, were investigated in this study. Particle compositions of 21 element species, 11 ionic species, elemental carbon (EC), organic carbon (OC) and 16 polyaromatic hydrocarbons (PAHs) were analyzed to create "fingerprints" of the particles emitted from various processes in an integrated iron and steel plant. Results indicated that element compositions (0.11-0.42 g/g), water-soluble ions (0.34-0.52 g/g), elemental carbon (0.008-0.14 g/g), organic carbon (0.02-0.06 g/g) and PAHs (0.52-6.2 mg/g) contributed to the particle mass. In general, sulfur had a higher mass contribution than the other elements, which resulted from the use of coal, flux, heavy oil, and many recycled materials in the iron and steel plant. The particle mass contribution of potassium and chlorine in the sinter plant was higher than in other processes; this may be attributed to the lower boiling point and volatility of potassium. In addition, many recycled materials were fed into the sinter plant, causing a high concentration of potassium and chlorine in the particle phase. Eight PAH compounds were analyzed in the four processes. The carcinogenic compound Benzo(a)pyrene (BaP) was detectable only in the sintering process.

Determination of volatile organic profiles and photochemical potentials from chemical manufacture process vents.

The main objective of this study was to monitor the volatile organic compounds (VOCs) in the stack gas released from organic chemical industrial plants to determine emission factors. Samples from 52 stacks, with or without air pollution control devices (APCDs), from seven industrial processes were taken and VOCs measured using U.S. Environmental Protection Agency (EPA) Method 18. These 7 processes, including 26 plants, were the manufacturers of acrylonitrile-butadiene-styrene (ABS), polyvinyl chloride (PVC), polystyrene (PS), acrylic resin (ACR), vinyl chloride (VC), para-terephthalic acid (PTA), and synthetic fiber (SYF). The results clearly indicate significant variations of emission factors among the various industrial processes, particularly emission factors for those without APCDs. As expected, those with APCDs yield much less emission factors. Regardless of those with or without APCDs, the order of manufacturing processes with regard to VOC emission factors is SYF > ABS > PS >ACR > PTA > PVC > VC. The emission factors for some processes also differ from those in EPA-42 data file. The VOC profiles further indicate that some VOCs are not listed in the U.S. VOC/Particulate Matter Speciation Data System (SPECIATE). The potential O3 formation is determined from the total amount of VOC emitted for each of seven processes. The resultant O3 yield varied from 0.22 (ACR) to 2.33 g O3 g(-1) VOC (PTA). The significance of this O3 yield is discussed.

Temperature influence on product distribution and characteristics of derived residue and oil in wet sludge pyrolysis using microwave heating.

Sludge taken from a wastewater treatment plant of the petrochemical industry was dewatered and pyrolyzed to produce liquid oil as an alternative fuel via microwave heating. Element contents of dried sludge were 45.9±3.85wt.% carbon, 7.70±1.43wt.% hydrogen, 4.30±0.77wt.% nitrogen and 3.89±0.52wt.% sulfur. Two major thermal degradation peaks of sludge were determined during the microwave pyrolysis process, one at 325-498K (most of the water was vaporized, and the weight loss was over 85wt.%) and the other at 548-898K for sludge constituent decomposition. Zn content was high in the dried raw material and residues. Other toxic elements such as Ni, Cr, Pb, As and Cd contents were 0.61-0.99, 0.18-0.46, 0.15-0.25, 0.018-0.034, and 0.006-0.017mg/g, respectively. About 14-20wt.% of oil was produced based on the dried sludge cake, and the oil major elements were C (69-72wt.%), H (5.7-6.7wt.%), N (1.9-2.2wt.%), and S (0.58-0.82wt.%). The heat values of liquid oils were 8700-9200kcal/kg at 400-800°C.

Adsorption characteristics of benzene on biosolid adsorbent and commercial activated carbons.

This study selected biosolids from a petrochemical waste-water treatment plant as the raw material. The sludge was immersed in 0.5-5 M of zinc chloride (ZnCl2) solutions and pyrolyzed at different temperatures and times. Results indicated that the 1-M ZnCl2-immersed biosolids pyrolyzed at 500 degrees C for 30 min could be reused and were optimal biosolid adsorbents for benzene adsorption. Pore volume distribution analysis indicated that the mesopore contributed more than the macropore and micropore in the biosolid adsorbent. The benzene adsorption capacity of the biosolid adsorbent was 65 and 55% of the G206 (granular-activated carbon) and BPL (coal-based activated carbon; Calgon, Carbon Corp.) activated carbons, respectively. Data from the adsorption and desorption cycles indicated that the benzene adsorption capacity of the biosolid adsorbent was insignificantly reduced compared with the first-run capacity of the adsorbent; therefore, the biosolid adsorbent could be reused as a commercial adsorbent, although its production cost is high.

Characteristics of Carbon Material Formation on SBA-15 and Ni-SBA-15 Templates by Acetylene Decomposition and Their Bioactivity Effects.

Carbon spheres and tubes were formed from acetylene decomposition on SBA-15 and Ni-SBA-15 at 650-850 °C. At 650 °C, the decomposed carbons covered the surface of the support, and no carbon spheres and filament materials were formed. Carbon sphere formation occurred at 750 °C-850 °C; with diameters ranging from 0.8 µm-1.1 µm. For Ni-SBA-15, the diameters of the spheres and filaments were 0.8 µm and 62 nm, respectively, at 650 °C. At 750 °C, the diameter of the ball carbon materials ranged from 0.7 µm-0.8 µm, the diameter of the carbon tubes formed was 120-130 nm, and their pore diameter was 8.0 nm-11 nm. At 850 °C, the diameters of ball carbon materials and carbon tubes were similar to those of the materials at the formation temperature, 750 °C. Si, O and C were the main constituents of SBA-15; Ni-SBA-15 and carbon material formation supports. High-ring PAHs (such as BaP (five rings); IND (six rings); DBA (five rings) and B[ghi]P (six rings)) exist in carbon materials. SBA-15 revealed insignificant cytotoxicity, but Ni-SBA-15 inhibited the proliferation of human lung cancer cells (A549). Less inhibition on cell viability and reactive oxidative species (ROS) generation on A549 were determined for carbon material formation on the Ni-SBA-15 compared to the Ni-SBA-15.

Water-soluble ionic species of coarse and fine particulate matter and gas precursor characteristics at urban and rural sites of central Taiwan.

Coarse and fine particulate matter (PM) were taken by a dichotomous sampler, and gas precursors were determined by a denuder sampler at two stations in central Taiwan. Water-soluble ionic constituents of PM and their precursor gases were analyzed by ionic chromatograph. In summer, the daytime/nighttime PM10 concentrations were 37 ± 10/41 ± 18 µg m(-3) and 36 ± 14/34 ± 18 µg m(-3) for Xitun and Jhushan, respectively. Average PM10 concentration in winter was 1.55 and 1.76 times that of summer for Xitun and Jhushan, respectively. PM mass concentrations were similar for both stations, although one station is located in the downtown area of Taichung, and the other is in a rural area with no heavy pollution sources. Water-soluble ionic species content was 38-53 % of PM2.5 and 43-48 % of PM10 mass concentration. HNO3, HCl, and SO2 were high in the daytime; the daytime-to-nighttime concentration ratio was 3.75-6.88 for HNO3,1.7-7.8 for HCl, and 1.45-2.77 for SO2. High NH3 levels were determined in the area, especially in winter, which could be a precursor of NH4 (+) to form particulate matter. In Xitun, motor vehicles downtown and in the industrial district could be sources of air pollution. In contrast, there are few industrial sources at Jhushan; therefore, the transport of air pollutants from upwind of other regions and the accumulation of pollutants could be important PM sources at Jhushan.