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A comprehensive profile database of industrial wastewater in Taiwan has been developed. The dataset consists of 244 wastewater samples containing 52 metals and metalloid elements. A Naïve Bayes classifier was applied to establish robust composite profiles for each industrial category. Similarities in the composite profiles were examined using a hierarchical cluster analysis, and most composite profiles were distinct. Finally, 19 composite profiles of the industrial categories were subsequently retrieved and utilized to identify the marker species for each category. During the examination of marker species through statistical methods, three less noticeable characteristic species, Mo, Sb, and Co, were examined further: Molybdenum was confirmed as a marker species for the petrochemical industry, while antimony was identified as a marker for man-made fibers and finishing of textiles. Cobalt was also determined as a marker for nickel-based electroplating products. We compared the regulations of other countries with those of Taiwan in order to offer scientific advice regarding these three species. This study serves as an exemplary application of a profile database, showing how it can be used to analyze less noticeable marker species among the 52 elements for different industries. Moreover, the study results suggest that composite profiles generated from various industries hold potential as tools for future river pollution prevention. Overall, the continuous expansion of the database is highly recommended to increase its practicality and relevance for future research and regulatory efforts. [ABSTRACT FROM AUTHOR]

Enhanced weathering is a negative emissions technology based on the accelerated weathering of alkaline minerals. Such materials can be reduced to a fine powder and applied to land sinks to maximize the area exposed for reaction with rainwater and dissolved CO2. The carbon is captured in the form of bicarbonate ions in the runoff, which ultimately carries it to the ocean for virtually permanent sequestration. Enhanced weathering has been demonstrated in proof-of-concept laboratory and field tests, but scale-up to a level that delivers significant CO2 removal is still an engineering challenge that requires a system-level perspective. Future enhanced weathering networks should be planned like industrial supply chains, taking into account constraints in the supply of alkaline minerals and the availability of land sinks. Optimization of such networks should also take into account techno-economic uncertainties that are inherent in any emerging technology. To fill this research gap, this work develops a fuzzy mixed-integer linear programming model for optimal planning of enhanced weathering networks. The model is capable of handling multiple conflicting objectives and accounting for system uncertainties. The use of the model is illustrated with two case studies. First, a pedagogical example is solved; then, the model is demonstrated for a realistic scenario which shows that 0.69% of Taiwan's CO2 emissions can be offset by the use of blast furnace slag for enhanced weathering. [ABSTRACT FROM AUTHOR]

A point source for environmental pollution may be identified by the spatial association of samples collected in the vicinity of the emission source. In this study, we used a simple permutation test to explore the spatial correlations between the ambient air and soil polychlorinated dibenzo- p-dioxin/dibenzofuran (PCDD/F) congener profile concentrations and their distances to a municipal solid waste incinerator (MSWI) in northern Taiwan. Kendall's τ was applied for the correlation between the PCDD/F concentrations of a total of 9 airborne and 12 soil sampling sites and their distances to the incinerator. The results showed that the correlation was highly negatively associated for soil PCDD/Fs (τ = −0.515, p-value = 0.011) and was marginal for airborne PCDD/Fs (τ = −0.667, p-value = 0.055), conditional on the seasonal wind attributions. For the 17 individual congener profiles, most of the air and soil samples had a negative association, with 7 and 10 reaching statistical significance ( p-value < 0.05) or borderline significance ( p-value < 0.10), respectively. The permutation test provides a simple and robust statistical method for the identification of a potential pollution source from a limited sample size. Our analytical results show that dioxin emissions from the investigated MSWI had a definite environmental impact on the surrounding area. [ABSTRACT FROM AUTHOR]

Wastewater reuse can significantly reduce environmental pollution and save the water sources. The study selected Cheng-Ching Lake water treatment plant in southern Taiwan to discuss the feasibility of wastewater recycling and treatment efficiency of wastewater treatment units. The treatment units of this plant include wastewater basin, sedimentation basin, sludge thickener and sludge dewatering facility. In this study, the treatment efficiency of SS and turbidity were 48.35–99.68% and 24.15–99.36%, respectively, showing the significant removal efficiency of the wastewater process. However, the removal efficiencies of NH3–N, total organic carbon (TOC) and chemical oxygen demand (COD) are limited by wastewater treatment processes. Because NH3–N, TOC and COD of the mixing supernatant and raw water are regulated raw water quality standards, supernatant reuse is feasible and workable during wastewater processes at this plant. Overall, analytical results indicated that supernatant reuse is feasible. [ABSTRACT FROM AUTHOR]

This paper presents an empirical study of how three waste management policies have affected residential waste generation and recycling behavior in Taiwan over the past decade. The three policies are unit-pricing of garbage in Taipei, a mandatory recycling program in Kaohsiung, and a nationwide policy of charging for plastic bags. We estimate policy effects on total waste, total recycling, and recycling of four specific materials, all measured by weight per capita. Unlike prior work, we find that unit-pricing and mandatory recycling policies lead to significant increases in recycling of most materials, as well as increased levels of total recycling and garbage reduction. The “plastic bag” policy is generally found to lower material-specific and total recycling rates, as well as total garbage volumes. [ABSTRACT FROM AUTHOR]

Spatial and temporal variations of polychlorinated biphenyl (PCB) concentrations in cultivated oysters from five aquaculture areas along the western coast of Taiwan were investigated. Poor correlations between total PCB concentrations (ng/g dry weight [dw]) and physiologic parameters of oysters (shell length, width, thickness, and lipid content) were found. Total PCB concentrations ranged from 3.4 to 94 cng/g dw. The highest value was found in oysters from the Lu’ermen aquaculture area, which receives wastewater from a sodium hydroxide and pentachlorophenol factory. Furthermore, principal component analysis confirmed that the PCB congener pattern in this area was distinct from others and that two additional pollution sources might exist in the Tainan and Hsinchu areas. Oysters with PCB concentrations > 1 SD above the geometric mean were found mainly in Tainan (stations TN5 to TN9) with only one increased concentration in the Yunlin (station YL2) and Hsinchu (station HC4) aquaculture areas. Except for four confined stations, TN3 to TN6, where total PCB concentrations were higher ( p = 0.028) in the warmer (May and July) than in the colder season (November and March), seasonal variation of total PCB concentrations in oysters was not significant. Geometric mean and geometric mean plus 1 SD of total PCB concentrations in this study are lower than those in South Korea and the United States (Mussel Watch). [ABSTRACT FROM AUTHOR]

The chemical and fiber industries in Taiwan are very important contributors to economic development of Taiwan over the past several decades, but it often associated with serious air pollution problems. The study was initiated in response to odor complaints from residents of neighborhoods located adjacent to the largest chemical fiber manufacturing plant in Taiwan. The purposes of this article are: (1) to characterize the source emissions; (2) to quantify some odorous components and VOCs in the ambient air around the plant; and (3) to compare measured ambient concentrations of emitted compounds with Taiwan's guidelines for Hazardous Air Pollutant (HAP) ambient concentrations. Gas samples were analyzed for target sulfurous and volatile organic compounds, e.g., sulfides, mercaptans, BTX, etc. Ambient samples were collected using Tenax adsorbent tubes for mass spectrometric analysis. On-site sampling and analysis was also conducted for SO2 by Continuous Emission Monitoring (CEM). The resulting measured ambient air concentrations were compared to published odor threshold limits and Taiwan's regulatory standards for hazardous air pollutants. Subsequently, a Gaussian dispersion model incorporating the measured data was applied to estimate the source emissions and provide advance warning to the affected neighborhoods. The factors controlling formation of the odors at the facility and in the residential neighborhoods were identified. Additionally, environmental conditions (wind speed and wind direction) that could affect concentrations of emission constituents were discussed. [ABSTRACT FROM AUTHOR]

In Taiwan, aquatic toxicity tests for industrial effluents are not required for discharge permits. However, relying on traditional chemical and physical characteristics of an effluent to monitor and regulate such discharges to manage water quality of a receiving water is insufficient. In this study, we used two fish species, Japanese medaka (Oryzias latipes) and tilapia (Oreochromis mossambicus), and three toxic endpoints, including acute and subacute toxicity, to determine toxicity of seven different types of industrial effluents. Prior to the study, two reference toxicants were tested on two fish species. The LC50s of CdCl2 for tilapia and medaka juveniles were 29.6 ± 15.3 mg/L and 2.2 ± 1.2 mg/L, respectively. The sensitivity of medaka embryo mortality and hatching inhibition to CdCl2 were about the same, with the LC50 and EC50 of 0.3 ± 0.1 mg/L and 0.1 ± 0.1 mg/L, respectively. The LC50s for tilapia and medaka juveniles to sodium dodecyl sulfate (SDS) were 19.7 ± 10.6 mg/L and 12.5 ± 5.9 mg/L. The medaka embryo was less sensitive to SDS than to CdCl2. The embryo's LC50 for SDS was 5.8 ± 2.8 mg/L and the hatching inhibition EC50 was 1.3 ± 1.1 mg/L. Results of toxicity tests on different effluents showed that the electroplating effluent was the most toxic, followed by acrylonitrile manufacturing and pulp/paper mill discharges. The LC50s of the electroplating effluent to different assays were in the range of several percents of the whole effluent. The pulp/paper effluent was toxic only to the medaka embryo. The rest of the industrial effluents tested showed either moderate or no toxicity to the animals. [ABSTRACT FROM AUTHOR]

Recreation is one of the functions of national parks. Nevertheless, heavy tourism has started to impose serious problems on the maintenance of some national parks in Taiwan. This study has tried to survey as well as calculate the impact problems resulting from park tourism in terms of environmental loads. A simple method is proposed to calculate the quantity of environmental loads. Only visitor information from questionnaires and per capita data are needed in the calculation process. Shei-Pa National Park was taken as an example. The water demand, the electricity used and the various forms of the environmental loads, including wastewater and solid waste discharge, were all surveyed and calculated on a per capita basis. [ABSTRACT FROM AUTHOR]