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As nations strive for a just transition to net-zero carbon emissions, the equitable distribution of carbon pricing's impact is of significant importance. Carbon pricing, a strategy recognized for its potentially regressive nature, tends to disproportionately burden lower-income households compared to wealthier counterparts. This study examined how the choice of income or expenditure as metrics for assessing carbon burdens and ranking household economic status influences these distributional effects. Our research, employing input-output models and the Taiwan 2021 Survey of Family Income and Expenditure, compared these two metrics. The findings revealed that income-based assessments would amplify the regressive impact of carbon pricing. Conversely, using expenditure as the base for carbon burden exhibited markedly reduced regressive effects. Moreover, the study highlighted the role of employment structures in determining the equity of ranking households by income or expenditure. The stability of distributional outcomes, when employing expenditure as the assessment base, suggested its superiority as a metric unaffected by ranking methodologies. Additionally, our analysis indicated that including gasoline in carbon pricing policies could counteract the regressive nature of such policies. This aligned with a just transition by potentially distributing the burden more evenly across socio-economic groups. By providing insights into the distributional effects of carbon pricing, this study contributed to the global pursuit of net-zero emissions while adhering to the principles of social equity and justice. [ABSTRACT FROM AUTHOR]

Taiwan has pledged to achieve net-zero carbon emissions by 2050, but the current extent of carbon sinks in Taiwan remains unclear. Therefore, this study aims to first review the existing nature-based carbon sinks on land and in the oceans around Taiwan. Subsequently, we suggest potential strategies to reduce CO 2 emissions and propose carbon dioxide removal methods (CDRs). The natural carbon sinks by forests, sediments, and oceans in and around Taiwan are approximately 21.5, 42.1, and 96.8 Mt-CO 2 y -1 , respectively, which is significantly less than Taiwan's CO 2 emissions (280 Mt-CO 2 y -1 ). Taiwan must consider decarbonization strategies like using electric vehicles, renewable energy, and hydrogen energy by formulating enabling policies. Besides more precisely assessing both terrestrial and marine carbon sinks, Taiwan should develop novel CDRs such as bioenergy with carbon capture and storage, afforestation, reforestation, biochar, seaweed cultivation, and ocean alkalinity enhancement, to reach carbon neutrality by 2050., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

In the face of escalating climate change, environmental pollution, and global crises, plant-based eggs are a viable solution for environmental conservation and health promotion. This study uses an integrated framework combining value-belief-norm (VBN) theory and the Theory of Planned Behavior (TPB) to explore the factors influencing Taiwanese consumers' inclination towards plant-based eggs. Through convenience sampling, 417 questionnaires were issued and 387 valid responses were received, indicating a 92.8% valid response rate. The analysis indicates that consumers' biospheric and altruistic values significantly enhance their awareness of outcomes, which, coupled with their sense of responsibility, strengthens personal norms. From the TPB perspective, perceived behavioral control is identified as a critical driver of the intention to purchase plant-based eggs, with attitudes and subjective norms playing significant roles. Subjective norms positively impact personal norms, thereby influencing consumers' behavioral intentions. The findings confirm the integrated model's theoretical and practical validity, and offer valuable insights for businesses. By developing adept marketing strategies that consider market dynamics, this study enhances the effectiveness and value of marketing efforts by boosting consumers' engagement with plant-based eggs. These insights contribute to advancing environmental sustainability goals.

The distribution and mechanisms of photosynthetically dissolved organic carbon (PDOC) released by marine phytoplankton are frequently neglected and inadequately understood because most studies on carbon sequestration capacity have focused on photosynthetic particulate organic carbon. In this study, percentage extracellular release (PER) and its environmental influencing factors were investigated for 10 cruises in the Taiwan Strait during 2006-2023. The results indicated that the PER increased horizontally from the nearshore to the off-shelf and vertically from the surface to the bottom within the euphotic zone. PER tends to be low in eutrophic waters such as upwellings and estuaries and high in oligotrophic waters. The study revealed that the average contribution of PDOC to total primary productivity (TPP) in the Taiwan Strait could reach 18.2 ± 11.7%, which is similar to the previously estimated global oceanic values. PDOC production satisfied approximately 25% the carbon requirements of heterotropic bacteria (HB). A detailed analysis of the PER combined with model simulations proved that the distribution of the PER in the Taiwan Strait was caused by the joint contribution of irradiance, size-fractionated phytoplankton, and nutrient stoichiometry. Our results contradict the view that the PER is a constant factor that is unaffected by TPP. However, there was a significant negative correlation between the PER and TPP. The PDOC was always lower than the bacterial carbon demand for a broad range of bacterial growth efficiencies, suggesting a weak coupling between phytoplankton exudation and bacterial metabolism. This challenges the idea that there is a well-coupled relationship between bacteria and phytoplankton present on the continental shelf. These findings indicate significant discrepancies in PDOC mechanisms and the quantitative importance of nearshore eutrophic and off-shelf oligotrophic environments. Consequently, it is unwise to use uniform PERs without differentiation under trophic conditions when reevaluating and appraising marine carbon fixation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Global air pollution poses a threat to humanity. Specifically, CO directly affects cardiovascular and other organ tissues and leads to numerous chronic diseases and major public health problems. The effective implementation of a deep learning model for predicting variations in CO levels would enable the early formulation of policies for controlling air pollution. In this study, a seasonal gated recurrent unit (SGRU) model, which is a deep learning time-series prediction model, was developed to predict the levels of CO in Taiwan. Atmospheric CO measurements from 2005 to 2021 were collected from the Environmental Protection Administration of Taiwan and preprocessed using the Kalman filter to achieve accurate forecasting. The performance of the proposed SGRU model was compared with that of the autoregressive integrated moving average (ARIMA), seasonal ARIMA, exponential smoothing (ETS), Holt–Winters ETS, support vector regression, and seasonal long short-term memory models in terms of mean absolute percentage error (MAPE) and root mean square error. The SGRU model achieved the lowest MAPE value of 0.94, which demonstrated its superior performance. The construction of an accurate air pollution prediction model can assist government entities in formulating health and social care strategies and in planning future air pollution control measures. • Carbon monoxide (CO) directly affects cardiovascular health. • CO contributes to chronic diseases and major public health concerns. • Using atmospheric CO data, deep learning time-series models can predict CO levels. • We designed an effective predictive model by combining SGRU with the Kalman filter. • Our model has a lower mean absolute percentage error (1.2) than do other models. [ABSTRACT FROM AUTHOR]

Over the past two decades, the Taiwan government promulgated some regulatory measures and promotional actions on energy efficiency promotion and renewable energy development. In March 2022, the "Taiwan's Pathway to Net-Zero Emissions in 2050" was announced to respond to the Paris Agreement. In order to achieve the goal, the Climate Change Response Act (CCRA) was passed on February 15, 2023, requiring the de-carbonization measures and adaptation strategies. The main aim of this paper was to analyze the changes in GHG emissions and renewable energy supply by using the updated data from the official statistics in connection with the trends of environmental and energy sustainability since 2000. The findings showed that total installed capacity of renewable power (especially in solar power and wind power) showed an amazing increase over the past decade, leading to the inclined GHG emissions and thus supporting the environmental and energy sustainability toward a low-carbon society. Furthermore, this paper summarized the development history and main differences concerning the carbon neutrality policy and legislation in Japan and South Korea. For achieving the staged targets of GHG emissions by 2030 and 2050, this paper finally addressed the technological approaches for achieving carbon neutrality by 2050 in Taiwan, focusing on the transformation of energy and industry, and the policy implications by all levels of government., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This study investigates the connection between nonrenewable energy productivity, renewable energy productivity, and air quality degradation in Taiwan from 2002 to 2019. We specifically emphasize the novel contribution of analyzing the productivity of renewable energy consumption. Robust estimation models, namely Nonlinear Autoregressive Distributed Lag (NARDL) and Robust Standard Estimation, are employed for comprehensive analyses. Our findings reveal a strong correlation between nonrenewable energy productivity and increased air pollutants, highlighting the significant impact of fossil fuels on air quality deterioration. Although renewable energy productivity demonstrates a negative association with air degradation, its effect is not statistically significant. This can be attributed to Taiwan's continued reliance on non-renewable energy sources within the overall energy mix. Hence, reducing dependence on fossil fuels is crucial for improving air quality. Importantly, the identified relationships have long-term implications, underscoring the necessity of persistent policy measures that promote renewable energy transition and emissions reduction over time. Our research emphasizes the urgency of addressing fossil fuel dependency to mitigate air pollution and highlights the potential benefits of enhancing renewable energy efficiency to achieve cleaner and healthier environments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Perfluoroalkyl acids (PFAAs) are environmentally and biologically persistent chemicals. In this study, we investigated the concentrations of six PFAAs in dust samples collected from different indoor environments in a college campus in Tainan, Taiwan, and assessed the health risk of PFAAs exposure to college students. We also analyzed the effects of dust characteristics (total organic carbon, moisture content, and dust content) on PFAAs levels. With regard to the space type, the median of total PFAAs concentrations were in the order of laboratories (528.9 μg kg -1 ) > offices (304.2 μg kg -1 ) > dormitories (180.1 μg kg -1 ) > classrooms (105.1 μg kg -1 ). With regard to the height from the ground, the median total PFAAs concentrations were in the order of dust near the floors (>2 m; 383.6 μg kg -1 ) > near the ceiling (0-2 m; 202.5 μg kg -1 ) > on the ground (0 m; 145.6 μg kg -1 ). The main species of PFAAs, perfluorooctane sulfonate and short-chain perfluoroalkyl carboxylates, accounted for respectively 30%-60% and ∼20%-37% of total PFAAs pollution in the indoor space types and sampling heights under consideration. The average daily intake (ADI) values of six PFAAs for college students were found to be 0.059-0.126 ng kg -1 BW day -1 (BW: body weight), with dormitories and workplaces (i.e., laboratories and offices) accounting for over 40% and ∼50% of the ADI, respectively. The estimated hazard quotient ranged from 0.0029 to 0.0063, three orders of magnitude lower than 1, suggesting relatively low risks for college students exposed to the six PFAAs monitored in indoor dust. The analysis of dust characteristics revealed that total organic carbon did not have a significant effect on PFAAs levels as we expected. In contrast, dust moisture and cation content dominated PFAAs accumulation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Abstract: Marine gas hydrates, one of the largest methane reservoirs on Earth, may greatly affect the deep sea sedimentary environment and biogeochemistry; however, the carbon geochemistry in gas hydrate‐bearing sediments is poorly understood. In this study, we investigated the carbon variables in sediment core 973‐3 from the southwestern Taiwan Basin in the South China Sea to understand the effect of environmental factors and archaeal communities on carbon geochemistry. The carbon profiles suggest the methanogenesis with the incerase of dissolved inorganic carbon (DIC) and high total organic carbon (TOC) (mean = 0.46%) originated from terrigenous organic matter (mean δ13CTOC value of −23.6±) driven by the abundant methanogen ‘Methanosaeta and Methanomicrobiales'. The active anaerobic oxidation of methane is characterized by the increase of DIC and inorganic carbon (IC), and the depleted δ13CIC, coupled with the increase of TOC and the decrease of δ13CTOC values owing to the methanotroph ‘Methanosarcinales/ANME’ in 430–840 cm. Environmental factors and archaeal communities in core 973‐3 are significantly correlated to carbon variables owing to methane production and oxidation. Our results indicate that the carbon geochemical characteristics are obviously responding to the formation and decomposition of gas hydrates. Furthermore, pH, Eh and grain size, and Methanosaeta greatly affect the carbon geochemistry in gas hydrate‐associated sediments. [ABSTRACT FROM AUTHOR]

Accurate reconstructions of past environments are critical and urgent because they can help understand how modern environments might respond to current climatic and land-use changes. However, the effect of microbial degradation and consequential modification in plant-derived-biomarkers during the early degradation phase is not yet apparent, that might bias the paleoenvironmental investigation. In this regard, a litterbag experiment was conducted to reveal the microbial effects on n-alkane-associated biomarker changes associated with three habitats (ravine, windward, and leeward) in a lowland subtropical rainforest in southern Taiwan. Freshly collected leaves of plant species Iles rotunda, Ficus benjamina, and Castanopsis carlesii were distributed in the habitat leaf litterbag experiment for 15 and 75 days incubation, respectively. The results revealed that the average leaf decomposition rate was 19.4% ± 6.4% during the first 15 days and 39% ± 11% within 75 days incubation for all leaves. The overall leaf mass degradation of I. rotunda, F. benjamina and C. carlesii in the ravine after 75 days was 58%, 51% and 41%, respectively, which were higher than those in the windward (28%, 36% and 38%) and leeward habitats (35%, 26% and 42%, respectively) indicating higher decomposition rate in the ravine habitat than the others. The predominant n-alkanes in I. rotunda were C 31 and C 29 , whereas in F. benjamina these were C 31 , C 29 , and C 33 , and in C. carlesii it was C 31 . After 75 days, the ravine habitat showed a 60% decrease in the total n-alkane concentration compared to windward and leeward habitats, suggesting the microbial community associated with the ravine habitat has a higher efficiency of degrading n-alkanes. However, the biomarkers such as carbon preference index (CPI), average carbon length (ACL) and the C 31 /C 29 ratio did not show statistical difference in all habitats from 15 to 75 days incubation. The next-generation sequencing revealed that microbial communities changed significantly from 15 to 75 days in all habitats. The alkB gene-containing bacteria and their family lineages increased substantially during the first 15 days incubation in all habitats. Furthermore, several bacterial genera were exclusively present in the ravine habitat, whereas some were only in the leeward and windward habitats. Despite the heterogeneity of microbial proliferation, difference in biomass and n-alkane degradation among the three habitats, most of the n-alkane-associated biomarkers remained the same. Therefore, we concluded that the microbial effects on n-alkane degradation during the early phase in plant leaves had little influence on the results of most n-alkane biomarkers., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Trace fossils are structures left in a substrate as the result of the activities of living organisms. The producer of the spindle-shaped trace fossil Rosselia incorporates fine-grained organic rich material into concentric layers surrounding the central shaft. Because Rosselia is common in stressed shallow marine environments where the preservation potential of organic material is generally poor, these trace fossils may act as natural archives, recording changes in the provenance of organic material. Carbon isotope values of organic carbon preserved in laminae of the studied Rosselia typically lie around - 26‰, suggesting a primary terrestrial source. However, increased levels of S and Ca detected from XRF scanning of the laminae indicate that at least some marine material is incorporated. Examination of a diagenetically altered specimen also demonstrates that both elemental composition and δ 13 C values can be substantially altered diagenesis. Nevertheless, the long stratigraphic range of Rosselia, from the Cambrian to the Present, and its ubiquitous occurrence in stressed shallow-marine settings make it a potentially powerful tool to reconstruct variations in the input of organic material in settings otherwise devoid of fine-grained organic matter., (© 2022. The Author(s).)

In this study, the concentrations of marine fine particles (PM 2.5 ) and their chemical fingerprints were inter-compared at two islands located aside from the west and east waters of Taiwan Island and the variability of west and east passages (i.e., Routes A1 and A2) were explored. Marine PM 2.5 was simultaneously sampled at the Green and Dongsha Islands and five chemical components (i.e., water-soluble ions, metallic elements, carbonaceous content, anhydrosugars, and organic acids) were further analyzed in PM 2.5 to characterize their chemical fingerprints. The highest concentrations of chemical composition and PM 2.5 were commonly observed during the Asian Northeastern Monsoons (ANMs) via long-range transport (LRT). Water-soluble ions (WSIs) were dominated by secondary inorganic aerosols (SIAs), and followed by oceanic spray. The major metallic content of PM 2.5 was crustal elements, while trace metals originated from anthropogenic sources with an enrichment factor (EF) > 10. In terms of carbonaceous content in PM 2.5 , organic carbon (OC) was superior to elemental carbon (EC). High levoglucosan concentrations were also observed during the periods of ANMs. Secondary organic aerosols (SOAs) were formed by atmospheric chemical reactions during the LRT procedure. The PM 2.5 concentration of Route A1 was 37.51 % higher than that of Route A2, and trace metals (V, Mn, Ni, Pb, Cr, and Cu) increased significantly by 96.16-325.83 %. Positive matrix factorization (PMF) results revealed that the dominant factor of PM 2.5 for Route A1 was shipping emissions and vehicular exhausts (41.2 %), while that for Route A2 was oceanic spray (30.2 %). Route A1 was mainly attributed to highly industrialized regions, densely populated urbanized areas, and ship-intensive traffics in East Asia., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Blue carbon ecosystems (BCEs) are a promising resource for the mitigation of global warming; however, climate spectrums and anthropogenic activities could influence the fragile balance of BCEs as carbon sinks or sources. We assess how oyster farming affects dissolved inorganic carbon (DIC) and total alkalinity (TA) on CO 2 fluxes in a mangrove-dominated lagoon. Water physical, chemical and biological parameters were recorded by in-situ buoys within the lagoon and at its inflow. Structural equation modeling was adopted to clarify the factors/processes controlling the partial pressure of CO 2 (pCO 2 ). A three-dimensional environmental model followed by a conceptual DIC model was used to quantify the spatiotemporal patterns of capture and release of DIC and TA by oyster production. The results showed that 49% of TA and DIC released from mangroves was depleted by oyster shell formation. DIC was reduced by algal photosynthesis and algal was served as a food source supporting oyster production. Annual oyster production through phytoplankton photosynthesis accounted for 11% of the atmosphere carbon inflows, suggesting that oyster production served as a significant atmospheric/terrestrial carbon sink in the lagoon. The results indicate that mangroves benefit local oyster production by acting as an important source of DIC and TA, and that the oyster aquaculture contributed to carbon capture in a mangrove-dominated lagoon ecosystem., Competing Interests: Declaration of competing interest The authors declared that they have no competing interests., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Constructed wetlands are an ecological engineering technology that has been widely applied to treat anthropogenic wastewater. Until now, few studies have focused on soil carbon (C) in the constructed treatment wetlands in tropical regions. Therefore, this study provides insight into the changes in soil C composition of tropically constructed wetlands at different ages. Five constructed wetlands were investigated in northern Kaohsiung, Taiwan. Soil C was analyzed at three different depths using an acid-hydrolysable method. The results showed that soil TOC content was highest on the soil surface (0-2 cm) and decreased at greater soil depths (2-5 and 5-10 cm) in all the studied constructed wetlands. There was more soil acid-hydrolysable C in the older constructed wetlands than in the younger ones at all depths. On the contrary, the soil recalcitrant carbon (RP-C) did not vary much across the wetland soils. In addition, the RP-C to TOC ratios were higher in the younger than older constructed wetlands, implying that the soil bioavailable C sources for microbial growth increased with the wetland's age. As a result, the compositions of organotrophic microbes, such as methanogens (mcrA copies), appeared to increase with wetlands' ages (i.e., negatively correlated with RP-C/TOC), while the total microbial abundance (16S rDNA) and abundance of lithotrophic microbes, such as methanotrophs (pmoA copies), were not correlated with RP-C/TOC or AHPI-C/TOC ratios, based on the results of our canonical correspondence analysis. Furthermore, the constructed wetlands accumulated soil RP-C from 2.33 to 0.08 g C m -2  day -1 in the constructed wetlands 1 to 30 years old, respectively., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Danshuei River Estuary (DRE) total and inorganic nitrogen in the dissolved (TDN, DIN) and particulate (TPN, PIN) phases were analyzed to study their distribution and partitioning. The carbon contents in particles were also analyzed. The upper estuary contained higher ammonium concentration (304-557 μM), leading to TDN completely dominating (>95%) the total N (TDN + TPN) pool within the DRE. Ammonium played a crucial role in controlling the speciation variation of DIN and partitioning between dissolved and particulate phases. Nitrification seemed to occur in the salinity >30 region where elevated percentages of nitrite and nitrate were observed. PON dominated the particulate N and contributed an average of 62% of the TPN pool. A constant organic C/N ratio (6.55) was observed in particles, indicating that POM was mainly from phytoplankton detritus. The N distribution coefficient values, log(K D ), ranged from 3 to 4, suggesting that the affinity of DIN for particles was weak., (Copyright © 2021. Published by Elsevier Ltd.)

Regarding the honey industry, market prices are strongly affected by the origin and composition of products. In particular, the adulteration of honey can be divided into cases of honey being mixed with artificial syrup, the different origin of the adulteration and the presence of cane sugar residue. Unfortunately, recent studies mentioned that most honey is mixed with artificial syrups. Thus, determining such unnaturally present sugar is necessary to maintain the trust of the consuming populations. To investigate the possibility of syrup augmentation, this study first clarifies two points of great importance. First, long-term feeding of cane sugar to honey bee colonies in winter and the continuous harvest of honey were investigated to evaluate the C 4 sugar ratio in spring through inspection of the 13 C/ 12 C isotopic ratio. As the results indicated, C 4 sugar was detected as "sugar residue" in honey samples when the honey bee colonies were fed with cane sugar in winter and when the honey was collected in the first and second harvests in March. As indicated from the samples of 89 Taiwanese longan honeys, 54 Thai longan honeys, and 20 Taiwanese non-longan honeys for analysis, such "sugar residues" were in 40% (8/20) of the Taiwanese non-longan honeys, 15% (3/20) of 2017 Taiwanese longan honeys and 20% (4/20) of 2017 Thai longan honeys; these samples were classified as adulterated honey (C 4 % > 7). Second, as revealed in the honeys' protein contents, statistically significant differences were found between Taiwanese (>1.00 mg/g) and Thai longan honeys (<1.00 mg/g). Apparently, this significant difference could be used to classify the difference in origins of longan honeys. This novel inspection of "sugar residue" and "origin" in honey could represent the first attempt for a protocol to guarantee both the quality and quantity assurance of honey in the marketplace., (Copyright © 2018. Published by Elsevier Taiwan LLC.)

This study aims to investigate the spatiotemporal variation, chemical composition, and source apportionment of marine fine particles (PM 2.5 ) as well as their regional transport toward the Matsu Islands located near the coastline of northwestern Taiwan Strait. Four offshore island sites located at the Matsu Islands were selected to conduct both regular and intensive sampling of marine PM 2.5 . Water-soluble ionic species, metallic elements, and carbonaceous contents were then analyzed to characterize the chemical characteristics of marine PM 2.5 . In order to identify the potential sources and their contributions to marine PM 2.5 , chemical mass balance (CMB) receptor model was employed along with the backward trajectory simulation to resolve the source apportionment of marine PM 2.5 and to explore their transport routes in different seasons. The results showed that high PM 2.5 concentrations were commonly observed during the northeastern monsoon periods. Additionally, marine PM 2.5 concentration decreased from the west to the east with the highest PM 2.5 at the Nankang Island and the lowest PM 2.5 at the Donyin Island in all seasons, indicating an obvious concentration gradient of PM 2.5 transported from the continental areas to the offshore islands. In terms of chemical characteristics of PM 2.5 , the most abundant water-soluble ions of PM 2.5 were secondary inorganic aerosols (SO 4 2- , NO 3 - , and NH 4 + ) which accounted for 55-81% of water-soluble ions and 29-52% of marine PM 2.5 . The neutralization ratios of PM 2.5 were always less than unity, indicating that NH 4 + cannot solely neutralize nss-SO 4 2+ and NO 3 - in marine PM 2.5 at the Matsu Islands. Although crustal elements (Al, Ca, Fe, K, and Mg) dominated the metallic content of marine PM 2.5 , trace anthropogenic metals (Cd, As, Ni, and Cr) increased significantly during the northeastern monsoon periods, particularly in winter. Organic carbons (OCs) were always higher than elemental carbons (ECs), and the mass ratios of OC and EC were generally higher than 2.2 in all seasons, implying that PM 2.5 was likely to be aged particles. During the poor air quality periods, major air mass transport routes were the northern transport and the anti-cyclonic circulation routes. Source apportionment results indicated that fugitive soil dusts and secondary aerosols were the major sources of marine PM 2.5 at the Matsu Islands, while, in winter, biomass burning contributed up to 15% of marine PM 2.5 . This study revealed that cross-boundary transport accounted for 66~84% of PM 2.5 at the Matsu Islands, suggesting that marine PM 2.5 at the Matsu Islands has been highly influenced by anthropogenic emissions from neighboring Fuzhou City as well as long-range transport from Northeast Asia.

Background/purpose: Microbial biomass plays an important role in nutrient transformation and conservation of forest and grassland ecosystems. The objective of this study was to determine the microbial biomass among three vegetation types in subalpine mountain forest soils of Taiwan., Methods: Tatachia is a typical high-altitude subalpine temperate forest ecosystem in Taiwan with an elevation of 1800-3952 m and consists of three vegetation types: spruce, hemlock, and grassland. Three plots were selected in each vegetation type. Soil samples were collected from the organic layer, topsoil, and subsoil. Microbial biomass carbon (Cmic) was determined by the chloroform fumigation-extraction method, and microbial biomass nitrogen (Nmic) was determined from the total nitrogen (Ntot) released during fumigation-extraction. Bacteria, actinomycetes, fungi, cellulolytic microbes, phosphate-solubilizing microbes, and nitrogen-fixing microbes were also counted., Results: The Cmic and Nmic were highest in the surface soil and declined with the soil depth. These were also highest in spruce soils, followed by in hemlock soils, and were lowest in grassland soils. Cmic and Nmic had the highest values in the spring season and the lowest values in the winter season. Cmic and Nmic had significantly positive correlations with total organic carbon (Corg) and Ntot. Contributions of Cmic and Nmic, respectively, to Corg and Ntot indicated that the microbial biomass was immobilized more in spruce and hemlock soils than in grassland soils. Microbial populations of the tested vegetation types decreased with increasing soil depth., Conclusion: Cmic and Nmic were high in the organic layer and decreased with the depth of layers. These values were higher for spruce and hemlock soils than for grassland soils. Positive correlations were observed between Cmic and Nmic and between Corg and Ntot., (Copyright © 2014. Published by Elsevier B.V.)

Dissolved and particulate (210)Pb and (210)Po were determined at 15 stations along the coastline off western Taiwan in April 2007. The (210)Pb activities in dissolved and particulate phases fell within a relatively small range of 2.4-5.2 dpm 100 L(-1) and 1.0-3.2 dpm 100 L(-1), respectively. The dissolved and particulate (210)Po activities also fell within a small range of 0.8-3.4 dpm 100 L(-1) and 1.1-2.9 dpm 100 L(-1), respectively. The correlation of the distribution coefficients (K(d)) of (210)Pb and (210)Po with particle concentration in turbid waters are not as evident as in the open ocean. The mass balance calculation shows that the residence times of (210)Pb and (210)Po with respect to particle removal from the nearshore waters ranges from 3 to 15 days and from 14 to 125 days, respectively. The flux of particulate organic carbon was estimated by (210)Po proxy and ranged from 4.8 to 33.7 mmol-C m(-2) d(-1)., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

This study investigates the removal efficiency of disinfection by-products (DBPs) in raw water at a water treatment plant using a biological powder-activated carbon system (BPACS). The presence of an excessive amount of DBPs has a large impact on the water quality of drinking water treated from the purification process. This study collected rapidly filtered water from an advanced water treatment plant for use in experiments on raw water. The removal efficiency of the trihalomethane formation potential (THMFP) and haloacetic acids formation potential (HAAFP) was studied under various hydraulic retention times and under organic DOC loadings. The results showed that the BPACS lowered the average concentration of dissolved organic carbon (DOC), UV(254) and the SUVA value (equivalent to UV(254)/DOC) in raw water. The system efficiently removed the THMFP and HAAFP during the treatment of the three primary organic carbon items. These results highlight the importance of the BPACS for efficiently treating disinfection by-products. These discoveries provide important information on biological degradation behaviors that can remove excessive amounts of disinfection by-products from drinking water.

This study investigated the correlations between the system treatment efficiencies and total nitrogen (TN) and total phosphorus (TP) accumulations of aboveground tissues of the wetland macrophytes of Hsin-Hai Bridge phase II constructed wetland. Among 19 emergent macrophytes studied, the optimal TN contents, 3.82% and 3.52% (w/w) were found for water spinach (Ipomoea aquatica) and Ludwigia x taiwanensis; while the optimal TP contents were found for the above two macrophytes at 0.64% and 0.83% (w/w). The accumulations of total plant TN and TP uptakes increased from 213 to 403 kg and 41 to 75 kg from March 2007 to the peak at September 2007, respectively. The TN ratios between plant tissue accumulations and the removals from the influents were 1.57%, 2.76%, 1.51% and 3.2% from March 2007 to March 2008. In the same period, the TP ratios between plant tissue accumulations and the removals from influents were 1.71%, 8.0%, 0.58% and 10.1%. The roles of the uptakes by aboveground portions of emergent macrophytes in system nutrient removals from the influents were more significant during growth seasons., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

This study examines size-resolved particle-bound water-soluble ions and carbons (element carbon (EC) and organic carbon (OC)) collected near a busy road and at an urban site. The traffic-related fine and coarse particles were collected using two manual dichotomous samplers (Dichots) equipped with Quartz filters. The PM(2.5)/PM(2.5-10) value during rush hour (3.57) exceeded that during slack time (2.72). During weekdays and weekends, although the roadside PM(2.5) concentration correlated well with traffic flow (R(2)= 0.91 and 0.81, respectively), the roadside PM(2.5-10) concentration did not. The lowest second aerosol concentrations were observed from 19:00 to 21:00 during weekdays and weekends. The average content of total water-soluble ions in PM(2.5) was 30.7% and 35.7% for weekday and weekend samples, respectively (a total average of 33.2%). In PM(2.5), the content of NO(3)(-) (8.95-11.0%) exceeded that of SO(4)(2-) (7.08-8.10%) at the roadside site. Conversely, the content of PM(2.5)-bound SO(4)(2-) was higher than that of PM(2.5)-bound NO(3)(-) at the urban site. The mean content of PM(2.5)-bound TC was 35.8%, while that of PM(2.5-10)-bound TC was 15.9%. Moreover, the R(2) values of traffic flow versus PM(2.5)-bound EC concentration on weekdays and weekends were 0.89 and 0.56, respectively, and were 0.82 and 0.38, respectively, for those of traffic flow versus PM(2.5)-bound OC concentration.

Mercury speciation and distribution in a 660-MW tangential-fired utility boiler in Taiwan burning Australian and Chinese bituminous coal blends was investigated. Flue gases were simultaneously sampled at the selective catalytic reduction (SCR) inlet, the SCR outlet, the electrostatic precipitator (ESP) outlet, and the stack. Samplings of coal, lime, bottom ash/slag, fly ash, and gypsum slurry were also conducted. Results indicated that flue gases at the inlet to SCR contained a great potion of particle-bound mercury (Hg(p)), 59-92% of the total mercury. Removal of mercury was not observed for the SCR system. However, repartitioning of mercury species across the SCR occurred that significantly increased the portion of elemental mercury (Hg0) to up to 29% and oxidized mercury (Hg2+) to up to 33% in the SCR outlet gas. Overreporting of Hg(p) at the inlet of SCR may cause the observed repartitioning; the high ammonia/nitric oxide circumstance in the SCR unit was also speculated to cause the mercury desorption from ash particles and subsequent reentrance into the gas phase. ESP can remove up to 99% of Hg(p), and wet flue gas desulfurization (FGD) can remove up to 84% of Hg2+. Mercury mass balances were calculated to range between 81 and 127.4%, with an average of 95.7% wherein 56-82% was in ESP fly ash, 8.7-18.6% was retained in the FGD gypsum, and 6.2-26.1% was emitted from the stack. Data presented here suggest that mercury removal can be largely enhanced by increasing the conversion of Hg0 into Hg(p) and Hg2+.

In this study, we used the multiple toxicity characteristic leaching procedure to test the long-term leaching behavior of bottom ash, scrubber residue, and baghouse ash from a municipal solid waste incinerator (MSWI). We used the short-term viability percentage of African green monkey kidney cells (Vero cells) as a bioindicator to investigate the cytotoxicity of the leachates from the MSWI ash wastes. We found that strontium was a significant contributor to the cytotoxicity of the bottom ash.

Printed circuit board wastewater typically contains organics and metal ions. The study explored the feasibility of a sequential procedure, FFP (the combination of the Fenton method and the Ferrite process), for treating printed circuit board wastewater, and established the optimum parameters for it. The analytical results showed that the proper pH level was 2 for Fenton oxidation, and the appropriate H2O2 dosing type was batch dosing. For the Ferrite process, the suitable Fe/M (Fe is the total dose of Fe2+ added to a solution and M is the initial total moles of various metal ions in untreated wastewater) molar ratio was 10 and the sludge met the toxicity characteristic leaching procedure (TCLP) standards. Following FFP treatment, effluent water or sludge easily met Taiwan's standards. Finally, the SEM/EDS test demonstrated that particle sizes of the sludge were approximately 50-80 nm, and the saturation magnetization was 67.5 emu/g.

In this study, municipal solid waste incinerator fly ash was vitrified using a plasma torch. The fly ash contained rich Ca, causing a high basicity of 2.43. Pure quartz was used as an additive to adjust the basicity. BET surface area analysis, X-ray diffraction analysis, and a scanning electron microscope were used to examine the physical properties of slags. The chemical stability and the acid resistance of slags were evaluated using the toxicity characteristics leaching procedure and tests of acid bathing. The results indicate that the plasma torch effectively vitrified the fly ash. Anthropogenic metals with low boiling points, such as Cd, Pb, and Zn, were predominately vaporized into flue gas. Most of the metals with high boiling points, such as Cr, Cu, and Mn, remained in the slag. After the vitrification, hazardous metals were noticeably immobilized in all slags. However, the slags with higher amorphous volume fractions were more effective in metal immobilization and in resisting acid corrosion. This indicates that SiO(2) enhanced the formation of the glassy amorphous phase and improved the resistance of acid corrosion and the immobilization of hazardous metals.

Aerosol is frequently transported by a southward high-pressure system from the Asian Continent to Taiwan and had been recorded a 100% increase in mass level compared to non-event days from 2002 to 2005. During this time period, PM2.5 sulfate was found to increase as high as 155% on event days as compared to non-event days. In this study, Asian emission estimations, Taiwan Emission Database System (TEDS), and meteorological simulation results from the fifth-generation Mesoscale Model (MM5) were used as inputs for the Community Multiscale Air Quality (CMAQ) model to simulate a long-range transport of PM2.5 event in a southward high-pressure system from the Asian Continent to Taiwan. The simulation on aerosol mass level and the associated aerosol components were found within a reasonable accuracy. During the transport process, the percentage of semi-volatile PM2.5 organic carbon in PM2.5 plume only slightly decreased from 22-24% in Shanghai to 21% near Taiwan. However, the percentage of PM2.5 nitrate in PM2.5 decreased from 16-25% to 1%. In contrast, the percentage of PM2.5 sulfate in PM2.5 increased from 16-19% to 35%. It is interesting to note that the percentage of PM2.5 ammonium and PM2.5 elemental carbon in PM2.5 remained nearly constant. Simulation results revealed that transported pollutants dominate the air quality in Taipei when the southward high-pressure system moved to Taiwan. Such condition demonstrates the dynamic chemical transformation of pollutants during the transport process from continental origin over the sea area and to the downwind land.

To investigate the seasonal variations of microbial ecology in grassland of Tatachia forest, soil properties, microbial populations, microbial biomass, and 16S rDNA clone library analysis were determined. The soil had temperatures 6.6-18.4 degrees C, pH 3.6-5.1, total organic carbon 1.11-10.68%, total nitrogen 0.18-0.78%, and C/N ratios 3.46-20.55. Each gram of dry soil contained bacteria, actinomycetes, fungi, cellulolytic, phosphate-solubilizing microbes, and nitrogen-fixing microbes 4.54 x 10(4) to 3.79 x 10(7), 3.43 x 10(2) to 2.17 x 10(5), 5.74 x 10(3) to 3.76 x 10(6), 1.97 x 10(3) to 1.34 x 10(6), 8.49 x 10(2) to 5.59 x 10(5), and 3.86 x 10(2) to 3.75 x 10(5) CFU, respectively. Each gram of soil contained 117-2,482 microg of microbial biomass carbon, 23-216 microg of microbial biomass nitrogen and 9-29 microg of DNA. The microbial populations, microbial biomass, and DNA decreased stepwise with the depth of soil, and they had low values in winter seasons. The microbial populations, microbial biomass carbon, microbial biomass nitrogen, and DNA at the BW2 horizon were 8.42-17.84, 19.26-64.40, 16.84-61.11, and 31.03-46.26% of those at the O horizon, respectively. When analyzing 16S rDNA library, members of Proteobacteria, Acidobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, Firmicutes, candidate division TMI, candidate division TM7, Gammatimonadetes, and Verrucomicrobia were identified. Members of Proteobacteria (44.4%) and Acidobacteria (33.3%) dominated the clone libraries. Within the phylum Proteobacteria, alpha-, beta-, and gamma-Proteobacteria were most numerous, followed by delta-Proteobacteria.

The principal sources of organic carbon (OC) and elemental carbon (EC) are anthropogenic or biogenic, whereas secondary sources are atmospheric oxidation processes of specific precursor gases. These compounds are considered atmospheric contaminants and adversely affect human health. Numerous studies have monitored atmospheric particulates and gaseous phases of OC and EC in Asia over the last decade. This work compares and analyzes different sample collection, pretreatment and analytical approaches. The principal carbonaceous sources are traffic exhaust and industrial emissions. The OC and EC concentrations are highest in high traffic areas, followed by urban sites, and lowest in suburban sites. Many characteristics of these sites, such a dense population, are important to research. The major OC to EC ratios in Asia cities were 1.0-3.0. This work elucidates the characteristics, sources, distributions, and characteristics of atmospheric carbonaceous species in Asia.

In recent years, suspended particle pollution has become a serious problem in Taiwan. The carbonaceous materials EC and OC are play important roles in various atmospheric processes. The primary OC/EC ratio approach is applied to assess the contribution of secondary organic aerosol (SOA) to the PM(2.5) and PM(10) mass at the Taichung harbor sampling site. The results indicated that the average EC and OC concentration were 1.06 and 6.50 microg m(-3), respectively, in fine particulate. And the average EC and OC concentration were 4.04 and 40.32 microg m(-3), respectively, in coarse particulate at Taichung Harbor sampling site. In addition, and the average EC/OC rations was 8.72 in fine particle, respectively, at Taichung Harbor, Taiwan during summer and autumn period of 2005. The fine particle exhibited high particulate concentrations in October, and lower concentration particulate occurred in August. And in this study OC and EC concentrations in this study are compared with those in other cities. The results of EC and OC concentration in this study are also compare with those other cities.

In order to understand the fate of pesticides in marine environments, concentrations of pesticides and different carbonaceous fractions were determined for surface sediments in the Danshui River and nearby coastal areas of Taiwan. The major compounds detected were tetrachlorobenzene, HCHs, chlordane, aldrin, DDDs, DDEs and DDTs. Total concentrations of pesticides in the sediments ranged from not detectable to 23 ng g(-1), with the maximum value detected near the discharge point of the marine outfall from the Pali sewage treatment plant. These results confirm that pesticides persist in estuarine and nearby coastal environments of the Danshui River well after their ban. Concentrations of total pesticides significantly correlate with concentrations of total organic carbon and black carbon in these sediments, suggesting that total organic carbon and black carbon regulate the distribution of trace organic pollutants in fluvial and coastal marine sediments.

Objective: It is still unknown whether specific components in fine particles are associated with heart rate variability (HRV) reduction., Methods: We recruited 46 patients with or at risk for cardiovascular diseases to measure 24-hour HRV by ambulatory electrocardiographic monitoring. Fixed-site air-monitoring stations were used to represent participants' exposures to particles with aerodynamic diameters less than 10 microm (PM 10) and 2.5 microm (PM2.5), and particulate components of sulfate, nitrate, organic carbon (OC) and elemental carbon, and gaseous pollutants., Results: We found that HRV reduction was associated with sulfate, OC, and PM2.5 but not with the other five pollutants in single-pollutant models. Sulfate was found to remain in significant association with HRV reduction adjusting for OC and PM2.5 in three-pollutant models., Conclusions: Exposures to sulfate and OC in PM2.5 were associated with HRV reduction in patients with or at risk for cardiovascular diseases.

The algal extracellular products (ECPs) in three cultures of cyanobacteria species (Anabaena, Microcystis, and Oscillatoria) dominating the eutrophic reservoir populations and their toxins have been investigated in the present work. Using gas chromatography coupled with high-resolution electron-impact mass spectrometry (GC/EI-MS) and high performance anion-exchange chromatography (HPAEC) techniques, more than 20 compounds were found in the algal culture (including cells and filtrates) extracts. The main identified ECPs were classified to polysaccharides, hydrocarbons, and aldehydes. Odor causing substances such as trans-1,10-dimethyl-trans-9-decalol (geosmin) and 2-methylisoborneol (2-MIB)were also found in the algal cultures. The potential mutagenicity of the algal suspensions was also studied with the Ames test. The organic extracts of the algal suspension from the axenic cultures were mutagenicity in TA98 without S9 mix and in TA100 with and without S9 mix. The results indicate that the ECPs of three algae species dominating the eutrophic reservoir were mutagenic clearly in the bacterial test.

A photosynthetic species, isolated from an alkaline hot spring in eastern Taiwan, was applied to enhance the dissolved inorganic carbon (DIC) uptake capability under high alkaline and temperature conditions and was identified. The strain was found to be close to Thermosynechococcus elongatus BP-1 and Synechococcus elongatus based on phylogenetic analysis of 16S rRNA genes. The result was verified with morphological observations. This strain was named as Thermosynechococcus sp. CL-1 (TCL-1). A study of the effects of pH and DIC on the content variations of four elements (C, N, H, and O), lipids (LI), proteins (PR), carbohydrates (CA), and the bioenergy potential was carried out. The concentrations of PR and LI were the highest under the cultivation of pH 7 and CA was at 10.5. According to the analysis of three compositions, the production pathway of LI might be shifted to CA from pH 7 to 10.5 and then shifted to inorganic compounds from pH 10.5 to 11. Regarding the effect of DIC at pH 9, the results revealed that the uptake pathway shift (such as metals uptake) might happen while DIC is less than 18.9 mM. From 18.9 to 47.2 mM DIC, the production pathway of LI shifted to CA and the contents of CA increased quickly from 47.2 to 94.3 mM without a further decrease of LI. Regarding the pyrolysis experiments with a thermogravimetric analyzer coupled with Fourier transform infrared spectroscopy (TG-IR), the transformation of xylan, cellulose, and lignin contents was observed under various pHs and DIC concentrations.

River and sediment have unique carbon dynamics and are important sources of the dominant greenhouse gases (GHG), carbon dioxide (CO2) and methane (CH4). To understand the relationship between CO2/CH4 emissions and water quality/sediment characteristics, we have investigated critical parameters in the river water. Eight parameters of water quality (dissolved oxygen, oxidation-reduction potential [ORP], chemical oxygen demand, biochemical oxygen demand [BOD5], suspended solid, nitrate [NO3-], NH4+, and bacteria) and four sediment characteristics (total organic carbon [TOC], total nitrogen [T-N], NO3-, and ammonium [NH4+]) were measured in two of the larger rivers in Taiwan, and relevant environmental conditions were recorded. The experimental results indicated that CO2 emissions from the river were mainly affected by BOD5 concentrations and the levels of bacteria. CH4 emissions, on the other hand, were greatly affected by the ORP in the river. The correlation between CO2 emissions and sediment characteristics was insignificant (R2 < 0.3). However, TOC and T-N in the sediment may lead to increases in CH4 emissions into the atmosphere. A deeper analysis of the relationship between the different parameters and GHG emissions by ANOVA and the multiple regression method revealed that CO2 emission (y) was significantly related to bacteria number (x1) and BOD concentration (X2). The regression equation takes the form y = 0.00032x1 + 3.18089x2 + 25.37304. Also, the regression relationship between CH4 emission (y) and ORP (x) in the river can be described as y = -0.825216x + 169.02257. The relationship between CH4 emission and sediment characteristics may be described as y = 5.073962x1(TOC) + 2.871245x2(T-N) - 12.3262. Extra sampling data were collected to examine the feasibility of the developed multiple regression equations. The experimental results suggest that the emissions of such GHGs as CO2 and CH4 from rivers can be predicted using the regression equations developed here. Moreover, the emissions may be reduced by manipulating the proper factors.

Persistent organic pollutants, POPs (e.g., polychlorinated biphenyls) can seriously and deleteriously affect environmental quality and human health. These organic pollutants are exhibiting high affinities to solid phases and thus, quickly end up in sediments. To better understand the role of carbonaceous materials in the transport and distributions of POPs in terrestrial and near-shore environments, concentrations of PCBs and carbonaceous materials (including total organic carbon, black carbon and total carbohydrates), were determined in surface sediments of the Danshui River and nearby coastal areas, Taiwan. Total concentrations of PCBs in the sediments ranged from non-detectable to 83.9 ngg(-1), dry weight, with the maximum value detected near the discharge point of the marine outfall from the Pali Sewage Treatment Plant. These results suggest that the sewage treatment plant has discharged PCBs in the past and the concentrations are still high due to their persistence; alternatively, PCBs are still being discharged in the estuarine and near-shore environment of the Danshui River. Organic carbon and black carbon concentrations correlated well with those of total PCBs in the sediments, suggesting that both organic carbon and black carbon significantly affect the distribution of trace organic pollutants through either post-depositional adsorption, or by co-transport of similar source materials. The field results demonstrate that black carbon and plays an important role in the general distribution of PCBs, while concentrations of some specific PCBs are affected by both black carbon and organic carbon concentrations.

The concentrations of total suspended particulate (TSP), fine particles PM(2.5) (with aerodynamic diameter <2.5 microm), coarse particles PM(2.5-10) (with aerodynamic diameter 2.5-10 microm,), and water-soluble inorganic ions were studied at two offshore sampling sites, Taichung Harbor (TH) and Wuci Traffic (WT), near Taiwan Strait in central Taiwan during March 2004 to January 2005. Statistical analyses were also carried out to estimate the possible sources of particulate pollution. Experimental results showed that the average mass concentrations of TSP, PM(2.5) and PM(2.5-10) at TH and WT sampling sites were 154.54 +/- 31.45 and 113.59 +/- 31.94 microg m(-3), 54.03 +/- 16.92 and 42.76 +/- 12.52 microg m(-3), and 30.31+/- 9.79 and 24.16 +/- 7.27 microg m(-3), respectively. The dominant inorganic ions at two sampling sites were SO(4)(2-), NO(3)(-), and NH(4)(+) for TSP and PM(2.5), but that were Ca(2+), Cl(-), and Na(+) for PM(2.5-10). The concentrations of most particulates and inorganic ions were higher in winter at both two sampling sites, and were higher at TH than WT sampling site in each season. From statistical analysis, air-slake of crust surface, sea-salt aerosols, agriculture activities, coal combustion, and mobile vehicles were the possible emission sources of particulate pollution at TH and WT sampling sites.

Due to the complex nature of landfill leachates, the leachate treatment plants have difficulty to meet the current Taiwan EPA's effluent standards. Three typical types of landfills, closed landfill A, mixed landfill B (disposal of MSW with bottom ashes from MSW incinerators) and direct MSW landfill C, (disposal of MSW only), are investigated in this research in order to have a better understanding of characteristics of leachates. Factors investigated in this research include landfill age, pH, BOD, COD, TS, DS, VS, seasons, metals (Pb, Ca, Cd, Hg, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, and Zn), humic substances (humic acid, fulvic acid, and non-humic substance), aromaticity and toxicity. Results show that the active landfills B and C had the significant higher concentration of COD, VSS, TS, PtCo, TOC and conductivity. The mixed landfill B had the higher DS, TS, Na, Ca, Mg and conductivity than that of direct MSW landfill C. Direct MSW landfill C had the highest contents of Fe, Cr, Ni and acute toxicity among these landfills. A significant degree of variation was encountered and factors which may influence leachate quality were identified and discussed.

This paper reports the fluvial fluxes and estuarine transport of organic carbon and nutrients from a tropical river (Tsengwen River), southwestern Taiwan. Riverine fluxes of organic carbon and nutrients were highly variable temporally, due primarily to temporal variations in river discharge and suspended load. The sediment yield of the drainage basin during the study period (1995-1996, 616 tonne km(-2) year(-1)) was ca. 15 times lower than that of the long-term (1960-1998) average (9379 tonne km2 year(-1)), resulting mainly from the damming effect and historically low record of river water discharge (5.02 m3 s(-1)) in 1995. The flushing time of river water in the estuary varied from 5 months in the dry season to >4.5 days in the wet season and about 1 day in the flood period. Consequently, distributions of nutrients, dissolved organic carbon (DOC) and particulate organic carbon (POC) were of highly seasonal variability in the estuary. Nutrients and POC behaved nonconservatively but DOC behaved conservatively in the estuary. DOC fluxes were generally greater than POC fluxes with the exception that POC fluxes considerably exceeded DOC fluxes during the flood period. Degradation of DOC and POC within the span of flushing time was insignificant and may contribute little amount of CO2 to the estuary during the wet season and flood period. Net estuarine fluxes of nutrients were determined by riverine fluxes and estuarine removals (or additions) of nutrients. The magnitude of estuarine removal or addition for a nutrient was also seasonally variable, and these processes must be considered for net flux estimates from the river to the sea. As a result, nonconservative fluxes of dissolved inorganic phosphorus (deltaDIP) from the estuary are -0.002, -0.09 and -0.59 mmol m(-2) day(-1), respectively, for dry season, wet season and flood period, indicating internal sinks of DIP during all seasons. Due to high turbidity and short flushing time of estuarine water, deltaDIP in the flood period may be derived largely from geochemical processes rather than biological removal, and this deltaDIP should not be included in an annual estimate of carbon budget. The internal sink of phosphorus corresponds to a net organic carbon production (photosynthesis-respiration, p-r) during dry (0.21 mmol m(-2) day(-1)) and wet (9.5 mmol m(-2) day(-1)) seasons. The magnitude of net production (p-r) is 1.5 mol m(-2) year(-1), indicating that the estuary is autotrophic in 1995. However, there is a net nitrogen loss (nitrogen fixation-denitrification < 0) in 1995, but the magnitude is small (-0.17 mol m(-2) year(-1)).

Surface and gravity-cored sediments were collected from the Kaoping coastal area off southwestern Taiwan to determine particle size, organic carbon, trace metal concentration and enrichment factor (EF), 210Pb dating, and 206Pb/207Pb ratio for determining present and historical metal pollution. Surface distributions of trace metals ranged from 0.02 to 0.13 mg/kg for Cd (EF: 0.16-1.65), from 35 to 189 mg/kg for Cr (EF: 0.85-2.92), from 25 to 64 mg/kg for Ni (EF: 0.53-2.38), from 10 to 32 mg/kg for Pb (EF: 1.20-4.94), and from 29 to 129 mg/kg for Zn (EF: 1.18-3.50). Trace metal concentrations correlate closely with distributions of mud (<63 microm) and organic carbon which accumulate largely around river mouths and within the Kaoping Canyon. With the exception of Cd, Cr and Ni in certain areas with rather coarse sediments, metals were generally elevated above the baseline levels over the studied area. Metals were also relatively enriched in areas with high contents of mud and organic carbon. Sedimentation rates derived from the excess 210Pb data in core sediments sampled from the canyon illustrate metal pollution beginning around 1970 that is corresponding to the booming time of economic growth in Taiwan. Meanwhile, the status of Pb pollution in core sediments is verified by an inversed correlation between 206Pb/207Pb ratios and Pb concentrations. Anthropogenic Pb and other metals in the studied area were apparently derived primarily from the Kaoping River and accumulated around the river mouth and within the Kaoping Canyon. The Kaoping Canyon appears to act as a major sink for river borne trace metals.

To investigate the role of microorganisms in the ecology and the nutrient transformation of forest soil, soil property, microbial population, biomass and organic acid content of Spruce soil in Tatachia mountain were determined during January 1997 to November 1999. Soil temperatures were between 5.5 and 15.6 degrees C and soil pH ranged from 3.6 to 5.0. Total organic carbon and nitrogen contents ranged from 5.83% to 34.35% and from 0.90% to 3.19%, respectively. C/N ratio was between 7.07 and 18.24. Each gram of dry soil contained microbial biomass carbon 308-870 microg, microbial biomass nitrogen 107-240 microg, malic acid 74-211 nM and succinic acid 32-175 nM. In addition, each gram of dry organic layer contained microbial biomass carbon 216-653 microg, microbial biomass nitrogen 10.3-33.8 microg, formic acid 256-421 nM, acetic acid 301-435 nM, malic acid 795-1027 nM and succinic acid 204-670 nM. About 45.5-90.9% of topsoil samples had higher microbial population than those of subsoil especially in actinomycetes, cellulolytic and phosphate-solubilizing microorganisms. Although rhizosphere of Spruce had higher total organic carbon and total nitrogen content than non-rhizosphere and dwarf bamboo areas, the microbial population had no significant difference among them.

The potential for anaerobic biodegradation of 1,1,1-trichloro-2,2-bischlorophenylethane (DDT), 1,1-dichloro-2,2,-bischlorophenylethane (DDD), and dichlorodiphenylchloroethylene (DDE) in anoxic sediment slurries collected from the Keelung River was investigated in this study. o,p'- and p,p'-DDT were dechlorinated to o,p'- and p,p'-DDD, respectively, and then transformed to other compound(s). 1-Chloro-2,2-bis (p-chlorophenyl) ethylene (DDMU) and trace amount of dichlorobenzophenone (DBP) were detected in sediment slurries amended with p,p'-DDT or p,p'-DDD. DDMU was also detected in sediment slurries amended with p,p'-DDE. The relative transformation rates for both o,p'- and p,p'-isomers of DDT, DDD, and DDE were DDT>DDD>DDE. Re-addition of DDT, DDD, or DDE to the sediment slurries after initial removal enhanced the respective dechlorination rates. The transformation rates of the p,p'-isomers of both DDT and DDD were faster than those of the respective o,p'-isomers. p,p'-DDT dechlorination in the p,p'-DDT-adapted sediment slurries were inhibited by the addition of molybdate, or molybdate plus sulfate, but not inhibited by the addition of sulfate. Addition of bromoethane-sulfonic acid (BESA) slightly inhibited p,p'-DDT dechlorination. Non-adapted sediment slurries lost the ability to dechlorinate pentachlorophenol during adaptation to p,p'-DDT. p,p'-DDD was the major transformation product of p, p'-DDT in 3,4,4',5-tetrachlorobiphenyl-adapted sediment slurries, which suggested that the microbial community in the 3,4,4',5-CB-adapted sediment was unable to remove chlorine from the aromatic rings of p,p'-DDT.

Coal, fly ash and bottom ash samples were taken from a 300-MWe coal-fired power plant with a daily coal consumption of 2400 tons. A high volume sampler coupled with several mesh testing sieves was used to separate fly ash samples into different size fractions. Determination of the concentrations of 40K, 238U, 226Ra, 210Pb, 210Po, 228Th and 228Ra was carried out either by gamma or alpha spectrometry. For elements volatilized during combustion, their radionuclide concentrations decrease with increasing particle size. The enrichment factors for all radionuclides mentioned above were studied. Their values range from 31.0 for 210Po to 2.2 for 228Ra. Of all radionuclides studied, 210Po and 210Pb are the most volatile elements; therefore, an increase in the natural radiation level should first be indicated by an increase in these two nuclides.