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The Keelung River is one of the major branches of the Danshuei River estuarine system, which runs the metropolitan capital city of Taipei, Taiwan, and receives a large of amount of wastewater. The dissolved oxygen (DO) concentration is generally low in the tidal portion of the Keelung River. Hypoxia/anoxia occurs often, particularly during a low-flow period. The sediment oxygen demand (SOD) amounts to a significant value, hence increasing the total oxygen demand load of the river. The present work reports on laboratory SOD made on grab sediment core samples in situ that are undisturbed. The results reveal that SOD values fluctuate with variations in seasons and are higher in summer due to a high-temperature effect. It was found in the laboratory tests that the average SOD (at 20 °C) value is 0.76 g/m2/day and the maximum SOD (at 20 °C) value reaches 1.58 g/m2/day. The mean values of measured SOD at each station were adopted in the vertical two-dimensional water quality model to simulate the DO distribution along the tidal Keelung River. The simulated results are in reasonable agreement with the measured DO distribution in the river. Model sensitivity analyses were also conducted with increasing and decreasing SOD. It reveals that SOD is an important parameter that affects the DO distribution in the tidal estuary. [ABSTRACT FROM AUTHOR]

Unit pricing is a program in solid waste management that integrates market instruments to encourage households to reduce waste generation and increase recycling. Many studies have shown that unit pricing is effective, especially when the evaluation is based on comparing outcomes before and after implementation. In this paper, we use the so-called difference-in-differences approach to evaluate unit pricing. This approach can provide a less-biased estimation, and can help to examine whether a unit pricing program generates less waste and higher recycling or results in illegal dumping in neighboring regions. Using the fee-per-bag program implemented in Taipei City, Taiwan, as a case study, we found that unit pricing does reduce the amount of garbage but its impact on recycling is not as significant as the current literature suggests. Moreover, the program causes a serious negative externality: more than 60% of the garbage reduction in the city is due to increased dumping of waste in neighboring regions. As the impact of unit-pricing on recycling is limited, policy-makers cannot rely solely on this program to enhance recycling in the management of municipal solid waste. [ABSTRACT FROM AUTHOR]

This paper examines how issues of environmental citizenship play out in the context of an industrial waste facility siting controversy in Taipei, Taiwan, and the implications of this complex predicament for justice and sustainable development generally. It shows the ways in which local activists perceive the adverse effects of a development project that generates industrial waste and incinerator ash in their hometown. Local activists feel excluded from decision-making and frustrated by the lack of recognition by authorities. They complain that their local, contextualized knowledge and experiences are ignored. Local activists are concerned about ecological devastation and feel responsible for future generations. Instead of a NIMBY protest of selfish residents, local activists imagine themselves as active citizens fighting for justice and sustainability on a scale beyond their neighborhood. The case highlights the needs for institutional transparency, the recognition of multiple ways of knowing and new conceptions of the good life. Copyright © 2008 John Wiley & Sons, Ltd and ERP Environment. [ABSTRACT FROM AUTHOR]

As is often assumed, rapid mix effectively distributes the dosed coagulant in suspension to promote subsequent flocculation of suspended particles and coagulant molecules. This study determined that the role of rapid mix is considerably more complex than conventionally assumed. Particles in the raw water samples from the Banxing Water Works of Taipei City were coagulated at high shear environment, during which flocs of size 40–70 μm were produced. The produced floc interior was compacted, and residual turbidity and the amount of dissolved natural organic matter (NOM) in suspension were substantially reduced. The subsequent stage of rapid mix slightly reduces floc size, further compacts the floc interior, and expels fine particles and some adsorbed NOM from the flocs. A sudden reduction in shearing rate produced large sized flocs with not so compact structures. Moreover, this action released fine particles from flocs into the suspension and enhanced adsorption of NOM onto solid surfaces. [ABSTRACT FROM AUTHOR]

Municipal solid waste (MSW) management is a major concern for highly urbanized societies. Among proposed MSW management systems, regionalization programs generally have received considerable attention. This study analyzes real-world operational data to assess different MSW management policies, especially regionalization strategies, and their impact on MSW management systems in the Taipei metropolitan area. Linear programming is also used to identify the minimum costs sustained by each policy. The linear programming results show that regionalization programs are more economical and also improve incinerator operation efficiency. Sensitivity analysis indicates that the minimum treatment requirement of incinerators is a very sensitive influence on the MSW flows distributed through the entire region. The MSW of several "sensitive" administrative districts will be allocated to different treatment facilities according to different management strategies. A list of preferential sequences of MSW treatment and disposal facilities can also be identified by the model presented in this study. The results of this study may provide a useful tool for aiding decision-making related to real-world MSW management problems. [ABSTRACT FROM AUTHOR]

Two MBR pilot systems were constructed and tested in the Bali Primary WVVTP. The pilot study shows that two MBR systems, i.e. the Green-MenBio system (MBR-1) and the Bio-MF system (MBR-2), can both fulfill the requirement of wastewater reclamation standard, The MBR-2 system is more economical compared with MBR-1 system. The cost of US$ 0.10–0.16/m³ is estimated to reclaim the effluent of primary WWTP in Taiwan. The Bali Primary VVWTP has the capacity of 1,320,000 cmd which is the biggest in Taiwan. The domestic wastewater of partial Taipei City and Taipei County are collected and transported to the Bali Primary WWTP. The effluent of the Bali Primary WVVTP is then discharged into the ocean through two 3.8 m marine outfalls. The AO processes are installed in both MBR systems. More than 90% of the NH3-N can be removed through the AO and membrane processes. The outflow of the MBR systems (without RO) can reach the quality of COD < 30 mg/l, BOD < 10 mg/l, SS < 5 mg/l, NH3-N < 3 mg/L. The outflow of the MBR system is proposed to transport 40 km south to the Taoyuan County where four new industrial parks are to be constructed. Part of the reclaimed water is to be used on irrigation and another portion is to be sent to the industries after RO treatment. [ABSTRACT FROM AUTHOR]