Wen Liang Lai

Distribution and Sources of PAHS and Sediment Properties in Southern Taiwan

Abstract. The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) and surface sediment properties were analyzed from 31 locations in Dapeng Bay and neighboring rivers (Kaoping River, Tungkang River and Lingbeng River), southern Taiwan. Principal component factor analysis (PCFA) was performed to explain the latent factors and spatial variations of sediment quality. And canonical discriminant analysis (CDA) was applied to identify the source of pollution of Dapeng Bay from neighboring rivers. The results show that the most important latent factors in Dapeng Bay and neighboring rivers on wet seasons are the soil texture caused factor, the PAHs caused factor, and the nutrient caused factor. Contour maps incorporating the factor scores showed phenanthrene (Phn) and pyrene (Pyr) of PAHs had the highest content at the entrance of the northern side of the lagoon. Benzo(a)pyrene (BaP) had the highest content located in mid-section of the Kaoping River and in Dapeng Bay. Total nitrogen (TN) and total phosphate (TP) had the highest content located in the last-section of Tungkang River. And CDA shows that sediment quality in Dapeng Bay was not similar to the other three rivers.

Evaluation of the influence of the chlorophyll fluorescence of plant after fumigated with ozone gas

This study utilized a custom-made fumigation chamber to evaluate the chlorophyll fluorescence of 7 species sidewalk trees with 60 ppb O3 for 10 days. The results showed that during the fumigation period, the plants showed a noticeable variation. At the first 6 days fumigation, the chlorophyll fluorescence of all tested trees showed a stable status with the values over 0.75. As of the 7th days fumigation, the chlorophyll fluorescence of tested trees was lower than 0.75 except Cerbera manghas and Nageia nagi. After 9 days fumigation, the chlorophyll fluorescence values for all tested trees are significantly lower than before. Among all tested trees, the chlorophyll fluorescence of Palaquium formosanum had the most variant than before fumigation experiment, the next was Tournefortia argentea, than the Cerbera manghas, Terminalia catappa, Aglaia formosana, Millettia pinnata and Nageia nagi in series.

Study on the Tolerance of Common Tree Species to Nitrogen Dioxide

The present study analyzed the tolerance of 10 common woody plants to gaseous nitrogen dioxide (NO2). Experimental trees species were placed in fumigation chambers and exposed to different concentrations of NO2 (600, 1000, and 2000 ppb) for 48 hours. Their physiological health was determined by measuring how chlorophyll fluorescence varied, identifying which tree species were more adaptive and resistant to NO2. The results showed that NO2-affected plants were harmed to some extent by reduced levels of chlorophyll fluorescence, which decreased more serous with higher concentrations of NO2. Among the experimental tree species, the tolerance to NO2 was ranked as Melia azedarach > Decussocarpus nagi > Palaquium formosanum > Pongamia pinnata > Messerschmidia argentea > Diospyros morrisiana > Lagerstroemia speciosa > Semecarpus gigantifolia > Aglaia formosana > Koelreuteria formosana.

Correlation Analysis between Primary Productivity Factors and Water Environment Factors

In this study, we use canonical correlation analysis to interpret the relationship between water quality parameters (T, Alk, Cl, EC, TN, TP, UV-254, pH, HPC, DO) and primary productivity parameters (algae and chlorophyll-a). In these two sets of constructed canonical variables, the water quality parameters can account for 39.25% of the total variance of primary productivity. The majority of the explanatory power is from the first set of canonical variables, which has a correlation coefficient of 0.84. The main factors that control chlorophyll-a are HPC, Alk, T, TN, and pH.

Effects of Backwashing on the Characteristics of Sand Filtration Effluents: Organic and Microbial Analyses

In this study, the head loss, turbidity, particle size, and zeta potential were monitored from the effluent of the sand filtration system after backwashing located in Cheng-Ching Lake (CCL) Water Treatment Plant. Moreover, the non-purgeable dissolved organic matter (NPDOC) and excitation emission fluorescent matrix (EEFM) were measured for the collected water samples with or without the pretreatment process. Results indicate that the turbidity of the influent dropped to 0.06 NTU and remained stable after flowing through the sand filter during the 4-hr operation period. However, a continuous increase of the head loss and sand particle size for the sand filter was observed. This phenomenon was opposite with the absolute value of zeta potential. The water samples were collected from the effluent of the sand filter and were treated by a 0.2 μm membrane filter. Thus, higher NPDOC values of sample without pretreatment were observed in comparison with sample with treatment. Results indicate that the sand filter was able to remove NPDOC, and bacteria might proliferate among the sand filter in rapid filtration. Results from the EEFM analyses show that effluents without membrane filtration pretreatment contained a higher percentage of aromatic protein. Compared to the water samples without pretreatment, more humic-like substance was found in the effluent. This reveals that microbial products or bacteria were detached from the fillers after the backwashing process.

Spectrometric Characteristic of Superficial Chlorella Sp. Grown in Photo-Bioreactor under Different Flow Rates

In this study, photo-bioreactor designed with 4 L of volume to cultivate Chlorella sp. was conducted for comparing the differences of biomass increase among three gas flow rates. All experiments were controlled at light reaction of 12 hrs. with 1,700 lux. The organic fluorescence of algae, expressed in excitation emission fluorescent matrix (EEFM), was obtained from algal solution deducted from EEFM of the filtrate obtained from the filtration of algal solution using 0.2 μm membrane filter. Also, the surface charge and functional group for Chlorella sp. were respectively measured by zeta meter and Fourier transform infrared spectroscopy (FTIR). Biomass was measured by absorbance wavelength of 683 nm or dried biomass. Current results reveal that high flow rate produced more biomass than low flow rate did. Regarding to the fluorescent characteristic derived from Chlorella sp., two peaks were appeared in both wavelengths of excitation and Emission (EX/EM) respectively located at 280/330 nm (protein-like) and 440-480/680 nm (pigment). For the variation of autofluorescent intensities during algal incubation, algal image captured by epofluorescent microscope equipped with CCD (Charge-Coupled Device) could be further dealt using image software, showing that there were divergences of fluorescent intensities derived from varied amount of protein-like substance or pigment. Functional group of Chlorella sp. analyzed by FTIR, hydroxyl, peptidic bond, carboxylic acids and polysaccharide were existed with variations of transmittance (%) while gas flow rate was changed.

Specific Fluorescent Fingerprint of Organic Matter in Advanced Water Treatment and its Molecular Weight

In this research, the UV absorbance values of wavelength at 210 and 254 nm, excitation emission fluorescent matrix were measured for source water and treated water in CCL (Cheng Ching Lake) water treatment plant during five months. The whole data produced from EEFM was analyzed by PARAFAC operated in MATLAB software. The variation of molecular weight for organic matter was measured by HPLC (high performance liquid chromatography) with UV and fluorescent detectors. Observed from the variation of UV210/UV254, high value in treated water compared with source water was found. More molecular weight less than 5 k Da was formed in the treated water with relative to source water. Also, both major components in source water were located at wavelengths of excitation/emission of 250/410 nm and 230/330 nm and those in treated water were 240/410 nm and 220/290 nm. Also, the fluorescent intensity, long excitation wavelength was higher than short excitation wavelength in source water. This phenomena was opposite with treated water.

A Study on the use of the NDVI as Distribution Factors for Water Resources Conservation and Compensation Fees

This study aims to discuss the use of water resources conservation and compensation fees in 2008, 2009, and 2010. The study also discusses the feasibility of using the conservation indicator the Normalized Difference Vegetation Index (NDVI) as a distribution factor for the compensation fee. Results from this study demonstrate that whilst NDVI is able to show changes in forested areas, the analysis is limited by large technical requirements and results are dependent on the quality of the satellite imagery. Therefore, the acceptability of the proposal to use the NDVI as a distribution factor for compensation fees by the township offices that make compensation fee applications is uncertain. This method requires more in-depth research to determine its feasibility.

Assessment of the Influence of Carbon Absorption Efficiency of Plants with High Concentration Sulfur Dioxide

The experiment tests carried out on the sulfur dioxide (SO2) will reduce the amount of carbon dioxide (CO2) into the plant body. When the plants absorb CO2, SO2 enters the stomata at the same time, and the photosynthesis rate will immediately fall. The carbon absorption potential showed decreased as SO2 concentration increasing. However, after 600 ppb SO2 gas fumigated for 48 hours, Hibiscus tiliaceus had the most carbon absorption potential reducing rate as 76% and the least influence by this concentration was Acacia confusa which reduced 2% carbon absorption potential. When the fumigation concentration rose to 1000 ppb, except the leaves of Camellia axillaries had all fallen, the Hibiscus tiliaceus also showed the most variance of carbon absorption potential as 81% reducing than before fumigation and the Hibiscus taiwanensis was the second with 65% reducing rate. As the fumigation concentration rose to 2000 ppb, the Camellia axillaries, Hibiscus taiwanensis, Viburnum odoratissimum and Hibiscus tiliaceus could not tolerate the high SO2 concentration environment and the leaves all fell away. The carbon absorption potential reduced more significant than two other fumigation concentration. The most variance was Palaquium formosanum which with 92% decrease. The Neolitsea parvigemma and Leea indica also had 85% and 84% reduce rate than before fumigation, respectively.

Spatial and Temporal Variation on Heavy Metals in the Sediments of Dapeng Bay and Neighboring Rivers

The Typhoon Morakot raged through Taiwan bringing torrential rain for two days, which led to debris-flow in mountains and severe flooding in the coastal areas of southern Taiwan. In order to realize the impact of the Typhoon Morakot on heavy metals in the sediments this research discriminate the pollution brought from three neighboring rivers to the Dapeng Bay lagoon by using the R. A. Fisher Method. The results generally indicate that the samples from Dapeng Bay and the three neighboring rivers are displaying individual crowd-distribution phenomena, which means that the heavy metal content in the sediments of Dapeng Bay and the three neighboring rivers are not totally similar. Today, due to a massive variation in eco-habitat and a more frequently changing climate, the understanding of spatial-temporal variation of heavy metal pollution of sediments in Dapeng Bay and pollution sources from three neighboring rivers will provide useful information regarding disaster management, habitat recovery, operative management, as well as ecotourism specification.