Generation of solid wastes in typhoon disasters and their emergent cleaning and treatment means

In Taiwan, typhoons usually result in a large amount of waste that needs to be removed in a short time from July to October. This study reviewed the relevant regulations on the clean-up of typhoon waste, including emergency response regulations, organizations and information systems; and we also discuss different typhoon waste clean-up and disposal methods. The results indicate that the parameters other than the maximum wind speed, such as the maximum accumulated rainfall, flooded area, waste output, sludge output, disinfected area and government dispatched attendance reached statistical significance (p < 0.05). Waste, tree branches and bird carcasses were primarily incinerated, while silt and building materials were buried, and pig and cattle carcasses were placed in a landfill with the tertiary treatment of wastewater. This study also reports on the relevant regulations for prevention of epidemics among personnel working in disaster areas. The results can provide important references for the disposal of typhoon waste in developing countries. As Asian countries have similar life styles and are often attacked by typhoons, the results of this study provide Asian countries with the operating experience of Taiwan in emergency treatment of solid waste resulting from typhoons as a reference for them to plan response systems and operation.     

Enhanced science–stakeholder communication to improve ecosystem model performances for climate change impact assessments

In recent years, climate impact assessments of relevance to the agricultural and forestry sectors have received considerable attention. Current ecosystem models commonly capture the effect of a warmer climate on biomass production, but they rarely sufficiently capture potential losses caused by pests, pathogens and extreme weather events. In addition, alternative management regimes may not be integrated in the models. A way to improve the quality of climate impact assessments is to increase the science–stakeholder collaboration, and in a two-way dialog link empirical experience and impact modelling with policy and strategies for sustainable management. In this paper we give a brief overview of different ecosystem modelling methods, discuss how to include ecological and management aspects, and highlight the importance of science–stakeholder communication. By this, we hope to stimulate a discussion among the science–stakeholder communities on how to quantify the potential for climate change adaptation by improving the realism in the models.     

A method to estimate the impact of clear-cutting on nutrient concentrations in boreal headwater streams

Large-scale forestry operations, like clear-cutting, may impair surface water quality if not done with environmental considerations in mind. Catchment and country level estimates of nutrient loads from forestry are generally based on specific export values, i.e., changes in annual exports due to the implemented forestry operations expressed in kg ha⁻¹. We introduce here a specific concentration approach as a method to estimate the impact of clear-cutting on nutrient concentrations and export in headwater streams. This new method is potentially a more dynamic and flexible tool to estimate nutrient loads caused by forestry, because variation in annual runoff can be taken into account in load assessments. We combined water quality data from eight boreal headwater catchment pairs located in Finland and Sweden, where the effect of clear-cutting on stream water quality has been studied experimentally. Statistically significant specific concentration values could be produced for total nitrogen, nitrate, ammonium, and phosphate. The significant increases in the concentrations of these nutrients occurred between 2 and 6 years after clear-cutting. Significant specific concentration values could not be produced for total phosphorus and total organic carbon with the whole dataset, although in some single studies significant increases in their concentrations after clear-cutting were observed. The presented method enables taking into account variation in runoff, temporal dynamics of effects, and the proportional size of the treated area in load calculations. The number of existing studies considering large site-specific variation in responses to clear-cutting is small, and therefore further empirical studies are needed to improve predictive capabilities of the specific concentration values.     

Screening risk areas for sediment and phosphorus losses to improve placement of mitigation measures

Identification of vulnerable arable areas to phosphorus (P) losses is needed to effectively implement mitigation measures. Indicators for source (soil test P, STP), potential mobilization by erosion (soil dispersion), and transport (unit-stream power length-slope, LS) risks were used to screen the vulnerability to suspended solids (SS) and P losses in two contrasting catchments regarding topography, soil textural distribution, and STP. Soils in the first catchment ranged from loamy sand to clay loam, while clay soils were dominant in the second catchment. Long-term SS and total P losses were higher in the second catchment in spite of significantly lower topsoil STP. A higher proportion of areas in the second catchment were identified with higher risk due to the significantly higher risk of overland flow generation (LS) and a significantly higher mobilization risk in the soil dispersion laboratory tests. A simple screening method was presented to improve the placement of mitigation measures.     

Seasonal variation and spatial distribution of atmospheric mercury and its gas-particulate partition in the vicinity of a semiconductor manufacturing complex

This study investigated the tempospatial variation of atmospheric mercury and its gas-particulate partition in the vicinity of a semiconductor manufacturing complex, where a plenty of flat-monitor manufacturing plants using elemental mercury as a light-initiating medium to produce backlight fluorescence tubes and may fugitively emit mercury-containing air pollutants to the atmosphere. Atmospheric mercury speciation, concentration, and the partition of total gaseous mercury (TGM) and particulate mercury (Hg_p) were measured at four sites surrounding the semiconductor manufacturing intensive district/complex. One-year field measurement showed that the seasonal averaged concentrations of TGM and Hg_p were in the range of 3.30–6.89 and 0.06–0.14 ng/m³, respectively, whereas the highest 24-h TGM and Hg_p concentrations were 10.33 and 0.26 ng/m³, respectively. Atmospheric mercury apportioned as 92.59–99.01 % TGM and 0.99–7.41 % Hg_p. As a whole, the highest and lowest concentrations of TGM were observed in the winter and summer sampling periods, respectively, whereas the concentration of Hg_p did not vary much seasonally. The highest TGM concentrations were always observed at the downwind sites, indicating that the semiconductor manufacturing complex was a hot spot of mercury emission source, which caused severe atmospheric mercury contamination over the investigation region.     

Simultaneous Sampling of Gas- and Aerosol-Phase TDI with a Triple Filter System

Abstract

A new triple filter system sampler/model is proposed for the precise and accurate simultaneous sampling and determination of gas- and aerosol-phase 2,4-toluene diisocyanate (TDI). The system consists of two front Teflon filters for sampling aerosol-phase TDI and a final coated glass fiber filter to collect gas-phase TDI. The aerosol-phase TDI is collected on the first Teflon filter, while the second Teflon filter is used to estimate gaseous TDI adsorbed by the first. According to the gas adsorption test of two Teflon filters in series, the TDI gas adsorption fraction of the two filters is almost the same. Results of the evaporation test using pure TDI aerosols collected on the Teflon filter show that significant evaporation of the compound does not occur during sampling. These two findings allow the use of a model to estimate accurate gasand aerosol-phase TDI concentrations. The comparison test with an annular denuder shows that the triple filter system can minimize the TDI sampling bias between the dual filter and the annular denuder systems.     

Characterizing Driving Patterns for Zhuhai for Traffic Emissions Estimation

Abstract

Zhuhai, a relatively less developed city on the western coast of the Pearl River Delta (PRD) of China, is planning to undergo major development in coming years. A Hong Kong-Zhuhai-Macao Bridge project has been approved by the Central Government of China. The project will have great impact on the driving pattern and vehicular emissions to the city. This baseline study collected speed-time data of two instrumented private cars in morning and evening periods, as well as a daytime nonpeak period of >10 consecutive days in the spring and winter of 2003. The authors used the microwave speed sensor and global positioning system installed in the instrumented cars and used car-chasing technique to perform the data collection. They used the statistical package SPSS to assess the consistency, as well as to evaluate the variability of the data. Nine parameters, namely, average speed, average running speed, average acceleration rate, average deceleration rate, mean length of a driving period, time proportions of driving modes, average number of acceleration-deceleration changes, root mean square acceleration, and positive acceleration kinetic energy are calculated to represent the driving characteristics. A driving cycle for private cars was developed. If emission tests were conducted using the Zhuhai driving cycle, the level of vehicle emissions measured is likely to be in between that of the Federal Test Procedure (FTP) cycle and the Melbourne Peak cycle.     

The Adsorptive Capacity of Vapor-Phase Mercury Chloride onto Powdered Activated Carbon Derived from Waste Tires

Abstract

Injection of powdered activated carbon (PAC) upstream of particulate removal devices (such as electrostatic precipitator and baghouses) has been used effectively to remove hazardous air pollutants, particularly mercury-containing pollutants, emitted from combustors and incinerators. Compared with commercial PACs (CPACs), an alternative PAC derived from waste tires (WPAC) was prepared for this study. The equilibrium adsorptive capacity of mercury chloride (HgCl₂) vapor onto the WPAC was further evaluated with a self-designed bench-scale adsorption column system. The adsorption temperatures investigated in the adsorption column were controlled at 25 and 150 °C. The superficial velocity and residence time of the flow were 0.01 m/sec and 4 sec, respectively. The adsorption column tests were run under nitrogen gas flow. Experimental results showed that WPAC with higher Brunauer–Emmett–Teller (BET) surface area could adsorb more HgCl₂ at room temperature. The equilibrium adsorptive capacity of HgCl₂ for WPAC measured in this study was 1.49 × 10^?1 mg HgCl₂/g PAC at 25 °C with an initial HgCl₂ concentration of 25 μg/m³. With the increase of adsorption temperature ≤150 °C, the equilibrium adsorptive capacity of HgCl₂ for WPAC was decreased to 1.×34 10^?1 mg HgCl₂/g PA≤C. Furthermore,WPAC with higher sulfur contents could adsorb even more HgCl₂ because of the reactions between sulfur and Hg²⁺ at 150 °C. It was demonstrated that the mechanisms for adsorbing HgCl₂ onto WPAC were physical adsorption and chemisorption at 25 and 150 °C, respectively. Experimental results also indicated that the apparent overall driving force model appeared to have the good correlation with correlation coefficients (r) >0.998 for HgCl₂ adsorption at 25 and 150 °C. Moreover, the equilibrium adsorptive capacity of HgCl₂ for virgin WPAC was similar to that for CPAC at 25 °C, whereas it was slightly higher for sulfurized WPAC than for CPAC at 150 °C.     

Assessing the Potential for Salmon Recovery via Floodplain Restoration: A Multitrophic Level Comparison of Dredge-Mined to Reference Segments

Pre-restoration studies typically focus on physical habitat, rather than the food-base that supports aquatic species. However, both food and habitat are necessary to support the species that habitat restoration is frequently aimed at recovering. Here we evaluate if and how the productivity of the food-base that supports fish production is impaired in a dredge-mined floodplain within the Yankee Fork Salmon River (YFSR), Idaho (USA); a site where past restoration has occurred and where more has been proposed to help recover anadromous salmonids. Utilizing an ecosystem approach, we found that the dredged segment had comparable terrestrial leaf and invertebrate inputs, aquatic primary producer biomass, and production of aquatic invertebrates relative to five reference floodplains. Thus, the food-base in the dredged segment did not necessarily appear impaired. On the other hand, we observed that off-channel aquatic habitats were frequently important to productivity in reference floodplains, and the connection of these habitats in the dredged segment via previous restoration increased invertebrate productivity by 58%. However, using a simple bioenergetic model, we estimated that the invertebrate food-base was at least 4× larger than present demand for food by fish in dredged and reference segments. In the context of salmon recovery efforts, this observation questions whether additional food-base productivity provided by further habitat restoration would be warranted in the YFSR. Together, our findings highlight the importance of studies that assess the aquatic food-base, and emphasize the need for more robust ecosystem models that evaluate factors potentially limiting fish populations that are the target of restoration.     

Estimating the Cumulative Ecological Effect of Local Scale Landscape Changes in South Florida

Ecosystem restoration in south Florida is a state and national priority centered on the Everglades wetlands. However, urban development pressures affect the restoration potential and remaining habitat functions of the natural undeveloped areas. Land use (LU) planning often focuses at the local level, but a better understanding of the cumulative effects of small projects at the landscape level is needed to support ecosystem restoration and preservation. The South Florida Ecosystem Portfolio Model (SFL EPM) is a regional LU planning tool developed to help stakeholders visualize LU scenario evaluation and improve communication about regional effects of LU decisions. One component of the SFL EPM is ecological value (EV), which is evaluated through modeled ecological criteria related to ecosystem services using metrics for (1) biodiversity potential, (2) threatened and endangered species, (3) rare and unique habitats, (4) landscape pattern and fragmentation, (5) water quality buffer potential, and (6) ecological restoration potential. In this article, we demonstrate the calculation of EV using two case studies: (1) assessing altered EV in the Biscayne Gateway area by comparing 2004 LU to potential LU in 2025 and 2050, and (2) the cumulative impact of adding limestone mines south of Miami. Our analyses spatially convey changing regional EV resulting from conversion of local natural and agricultural areas to urban, industrial, or extractive use. Different simulated local LU scenarios may result in different alterations in calculated regional EV. These case studies demonstrate methods that may facilitate evaluation of potential future LU patterns and incorporate EV into decision making.