Attenuation of lead leachability in shooting range soils using poultry waste amendments in combination with indigenous plant species

Chemical immobilization technology utilizing poultry waste (PW) along with a native plant (Panicum maximum Jacq.) application was assessed for the attenuation of downward Pb dissolution and modification of Pb speciation in solid and liquid phases in the soil. A large column study with and without plant and PW applications was conducted using a Pb contaminated soil collected from a shooting range area. The PW application reduced water-extractable Pb by about 43% of that of the treatment without the PW and plant applications (Control). The cumulative Pb amount in column leachates over 100d was increased by the PW amendment (0.32mg) compared to Control (0.27mg), but was reduced to 0.23mg by the combined use of plant and PW amendment. Sequential extraction analysis revealed that the Pb fractions of PW-amended soils were shifted to less soluble phases as indicated by an increased residual fraction (20%) and decreased exchangeable and carbonate fractions (22%) than those in the Control soil. Thermodynamic equilibrium calculations demonstrated that predicted Pb(2+) activity was saturated with respect to cerussite in the Control soil and was supersaturated with respect to chloropyromorphite in the PW-amended soils. Our results suggest that the use of plant in combination with PW as a Pb immobilizing amendment attenuated downward Pb leaching and altered Pb species to more geochemically stable phases.     

滇池和洱海湖滨带水生植被状况与水质的关系研究

在滇池和洱海的湖滨带各设置了6个具有不同水生植被状况的采样点,于2010年8月-2011年5月对水温、pH、ORP、电导率、营养盐(总氮和总磷)、叶绿素a及3种DNA病毒等水质指标进行了现场或采样分析。结果表明,两湖泊中营养盐含量高的湖滨带(滇池草海和洱海沙坪湾),由于水生植物覆盖度高,湖水保持了叶绿素a含量低的状态。对洱海湖滨带的水质分析结果表明,洱海水质有较明显的季节性变化。分析表明,与水温相比,营养盐浓度可能是影响藻类生物量的更重要的因素。3种DNA病毒检测结果初步表明,水生植物不仅能控藻,而且对病毒也有抑制作用。     

Simplified life cycle sustainability assessment of mangrove management: a case of plantation on wastelands in Thailand

Sustainable mangrove management needs to consider trade-offs between multiple benefits provided by mangrove ecosystems and to balance the conflicting objectives of various stakeholders. The aim of the present study is to assess the sustainability of mangrove management based on the life cycle approach. We examine two mangrove management systems in Thailand, namely, the strict preservation and charcoal production systems. The results show that the strict preservation system has an advantage over the charcoal production system from the environmental perspective (the net amount of CO₂ absorbed by mangroves) while the charcoal production is a more favorable system than strict preservation from the social perspective (the amount of employment created in local communities). On the other hand, it is difficult to say that both systems are sustainable from an economic aspect. The charcoal production system needs to develop improved management regimes for commercial charcoal production and requires financial assistance in the period when its net cash flows are negative. As solutions for these problems, the introduction of community forest management and the utilization of a fund for REDD (Reducing Emissions from Deforestation and Degradation in Developing Countries) can be proposed.     

Effects of chemical composition of fly ash on efficiency of metal separation in ash-melting of municipal solid waste

In the process of metal separation by ash-melting, Fe and Cu in the incineration residue remain in the melting furnace as molten metal, whereas Pb and Zn in the residue are volatilized. This study investigated the effects of the chemical composition of incineration fly ash on the metal-separation efficiency of the ash-melting process. Incineration fly ash with different chemical compositions was melted with bottom ash in a lab-scale reactor, and the efficiency with which Pb and Zn were volatilized preventing the volatilization of Fe and Cu was evaluated. In addition, the behavior of these metals was simulated by thermodynamic equilibrium calculations. Depending on the exhaust gas treatment system used in the incinerator, the relationships among Na, K, and Cl concentrations in the incineration fly ash differed, which affected the efficiency of the metal separation. The amounts of Fe and Cu volatilized decreased by the decrease in the molar ratio of Cl to Na and K in the ash, promoting metal separation. The thermodynamic simulation predicted that the chlorination volatilization of Fe and Cu was prevented by the decrease in the molar ratio, as mentioned before. By melting incineration fly ash with the low molar ratio in a non-oxidative atmosphere, most of the Pb and Zn in the ash were volatilized leaving behind Fe and Cu.     

Feminization of genetic males by a symbiotic bacterium in a butterfly,Eurema hecabe (Lepidoptera: Pieridae)

Wolbachia are symbiotic bacteria found in many arthropods and filarian nematodes. They often manipulate the reproduction of host arthropods. In the present study, female-biased sex-ratio distortion in the butterfly Eurema hecabe was investigated. Breeding experiments showed that this distorted sex ratio is maternally inherited. When treated with tetracycline, adult females of the thelygenic line produced male progeny only. After PCR using Wolbachia-specific primers for the ftsZ gene a positive result was seen in the thelygenic females, but not in male progeny from tetracycline-treated females, or individuals from a Tokyo population with normal sex ratio and reproduction. Cytological observations showed that thelygenic females lack the sex chromatin body (W chromosome). The results strongly suggest that the sex-ratio distortion in E. hecabe is due to feminization of genetic males by Wolbachia.     

Improved quartz furnace method for chlorine and sulfur determination in municipal solid waste

 A method of determining the chlorine (Cl) and sulfur (S) in municipal solid waste (MSW) was studied. The quartz furnace method was improved in two ways: recovery from ash by hot extraction with dilute nitric acid, and avoidance of the volatilization of alkali (earth) metal chlorides by setting the sample combustion temperature at 600°C. In a comparison with the bomb method, using nine sets of kitchen garbage and waste plastics, the bomb method yielded a 15%–25% lower value than the improved quartz furnace method. Combustion in the bomb was frequently incomplete, resulting in recovery losses of Cl and S. The average kitchen garbage involved 5.2 mg Cl/g, of which at least 24.1% would be converted to HCl. Plastics contained 23 mg Cl/g generating 88.1% HCl on average. In the same way, kitchen garbage contained 3.0 mg S/g, generating 52.3% SO _x , whereas plastics contained 1.1 mg S/g with 55.1% SO _x formation. Received: March 20, 2002 / Accepted: October 13, 2002     

Analysis of driving forces behind diversified carbon dioxide emission patterns in regions of the mainland of China

China has large regional disparities in carbon dioxide CO₂ emissions with economic development among its 31 provincial mainland regions. This paper investigates these disparities in CO₂ emission patterns and identifies the factors underlying the differences. Results show that the 30 study China's mainland provinces (Tibet not included) can be divided into seven groups with three typical CO₂ emission patterns. Index decomposition results indicate that changes in economic development, the industrial sector, and technology contribute far more to increased CO₂ emissions than do population, energy structure, and other sectors. Close inspection reveals that different industry structures and technology contribute greatly to the differences observed in CO₂ emissions between provinces with similar economic output. This study highlights the importance of region-specific industrial structure adjustment policies, especially for regions transitioning to heavy industry and for those still in the primary stages of industrialization. The potential application of a domestic carbon emissions trading system, to encourage regional investment in updated technology, is also discussed.     

Evaluation of remedial countermeasures using the analytic network process

The aim of this paper is to present an evaluation method to aid decision makers in the prioritization and selection of appropriate countermeasures at the planning stage of site remediation. We introduced a hierarchical network (hiernet) decision structure and applied the Analytic Network Process (ANP) supermatrix approach to measure the relative desirability of the remedial alternatives using the decision maker's value judgment as input. A simplified illustrative example is presented to elucidate the process, as it is being applied to evaluate the feasible remedial countermeasures of a contaminated site caused by uncontrolled landfill. Four decision models derived from the generalized hiernet were examined to describe the effect of hierarchic functional dependence, inner dependence and feedback cycle on the derivation of the priority weights. The ANP could provide a more flexible analytical framework to break down one's judgment through a more elaborate structure in a systematic way to understand the complexity of the decision problem. The proposed method therefore may not only aid in selecting the best alternative but also may help to facilitate communication to understand why an alternative is preferred over the other alternatives through the analysis of the derived weights and its underlying decision structure.     

Online measurements of low-volatile organic chlorine for dioxin monitoring at municipal waste incinerators

In this study, an automatic sampling device and an analysis device have been developed for the measurement of low-volatile organic chlorine (LVOCl) in flue gas. The concentrations of dioxins (polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and dioxin-like polychlorinated biphenyls) have been estimated by online measurements of LVOCl at a municipal solid waste incinerator (MSWI) using these devices. The LVOCl concentration at the outlet of the selective catalyst reactor (SCR) of the MSWI increased momentarily up to 95 μg Cl m⁻³ during the startup period of the MSWI; subsequently, it gradually decreased to less than 1.0 μg Cl m⁻³ after 50 h from the start of waste feeding. The concentration of toxic equivalent quantity (TEQ)-Dioxins at the SCR outlet had a linear positive relationship with the LVOCl concentrations. Moreover, the level of TEQ-Dioxins concentration can be estimated by using this relationship with LVOCl. From our results, since the LVOCl concentrations in a flue gas can thus be automatically analyzed every hour by online measurements, the operators of an MSWI would be able to monitor approximate TEQ-Dioxin emissions on a daily basis.