Short chain chlorinated paraffins (SCCPs) are listed as persistent organic pollutant candidates in the Stockholm Convention and are receiving more and more attentions worldwide. In general, concentrations of contaminants in sewage sludge can give an important indication on their pollution levels at a local/regional basis. In this study, SCCPs were investigated in sewage sludge samples collected from 52 wastewater treatment plants in China. Concentrations of total SCCPs (ΣSCCPs) in sludge were in the range of 0.80-52.7 μg/g dry weight (dw), with a mean value of 10.7 μg/g dw. Most of SCCPs in the sludge samples showed a similar congener distribution patterns, and C(11) and Cl(7,8) were identified as the dominant carbon and chlorine congener groups. Significant linear relationships were found among different SCCP congener groups (r(2) ≥ 0.9). High concentrations of SCCPs in sewage sludge imply that SCCPs are widely present in China. 相似文献
Dioxin is the common name for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), and is abbreviated as PCDD/Fs. In the case of Southern Vietnam, is of high concern dioxin contamination in the areas affected by past-use chemical defoliants. Our study related to the zone considered as a "hot spot"--Bien Hoa Airbase and surrounding areas (Bien Hung Lake). Although the war ended over 30 years ago, the adverse effects on this territory still continue. Soil and sediment were selected for our research as they act as a sink for PCDD/Fs. The samples were taken and analyzed in CECOTOX laboratory following certified procedures. The total amounts of PCDD/Fs (2,3,7,8 related congeners) in the samples were converted into WHO-TEQ and compared with standard values proposed by Canadian environmental quality guidelines. The obtained data shows a relatively high risk (up to 20.4 times higher than (probable effect level) PEL value for sediment and 46 times higher than standard value for soil). The research is continuing on the assessment of dioxin transport in food chain. Moreover, considering the obtained data a complete solution should be found urgently to solve the problem of dioxin contamination in the studied areas. 相似文献
Detrimental effects of synthetic pesticides on health, environment and organisms have necessitated the exploration of alternative strategies for insect control. The insect attractants represent an important link within these systems. In Vietnam, since 1970, methyleugenol and its analogues have been synthesized for mass trapping of the fruitfly Daccus dorsalis Hendel. This chemical reduced the damage on the oranges of many plantations in our country. In the period 1978–1980, for the first time some selected types of pheromones were tested. The trials verified and provided evidence of the occurrence of six species of moth in southeast Vietnam: Archips micaceanus, Archips seminubilus, Cadra caustella, Spodoptera exigua, Chysodeixis eriosoma and Parapoynx sp. The last decade has seen intense activity in the elaboration and application of some complex systems of fighting plant pests. Pheromones of moth and weevils have been prepared in the Institute of Agrochemistry and the Institute of Tropical Biology NCST: Ostrinia nubilalis Hbn, Heliothis armigera Hbn, Plutella xylostella Curt, Adoxophyes sp, Lyonetia clerckella, Trogoderma granarium, Diabrotica virgifera virgifera, Diabrotica undecimpunctata, Blattela germanica, Diprion, Neodiprion, Scolytus multistriatus, Scolytus scolytus, Lasioderma sericorne, Tribolium cofusum. Some synthetic aspects of these pheromones are described. The use of pheromone traps for monitoring and mass trapping the Scolytus multistriatus, Tribolium confusum, Plutella xylostella Curt, Heliothis armigera Hbn, Cylas formicarius elegantulus will be discussed. 相似文献
The inactivation effects of pressurized CO2 against bacteriophage Qβ and ΦX174 were investigated under the pressure of 0.3–0.9 MPa, initial concentration of 107–109PFU/mL, and temperature of17.8°C–27.2°C. The optimum conditions were found to be 0.7 MPa and an exposure time of 25 min. Under identical treatment conditions, a greater than 3.3-log reduction in bacteriophage Qβ was achieved by CO2, while a nearly 3.0 log reduction was observed for phage ΦX174. The viricidal effects of N2O(an inactivation gas with similar characteristics to CO2), normal acid(HCl), and CO2 treatment with phosphate buffered saline affirmed the chemical nature of CO2 treatment. The pumping cycle, depressurization rate, and release of intracellular substances caused by CO2 were its viricidal mechanisms. The results indicate that CO2 has the potential for use as a disinfectant without forming disinfection by-products. 相似文献
The study tries to discover the impact of financial and social indicators’ growth towards environmental considerations to understand the drivers of economic growth and carbon dioxide emissions change in G7 countries. The DEA-like composite index has been used to examine the tradeoff between financial and social indicator matters in environmental consideration by using a multi-objective goal programming approach. The data from 2008 to 2018 is collected from G-7 countries. The results from the DEA-like composite index reveals that there is a mixed condition of environmental sustainability in G-7 countries where the USA is performing better and Japan is performing worse among the set of other countries. The further result shows that the energy and fiscal indicators help to decrease the dangerous gas emissions. Divergent to that, the human and financial index positively contributes to greenhouse gas emissions. Fostering sustainable development is essential to successfully reduce emissions, meet established objectives, and ensure steady development. The study provides valuable information for policymakers.
The impact pathway approach (IPA) is used to estimate quantitatively the level of health effects caused by particulate matter
(PM10) and sulfur dioxide (SO2) emission from a lignite-fired power plant located in the Mae Moh area in northern region of Thailand. Health benefits are
then assessed by comparing the levels of estimated health impacts without and with the installation of the flue gas desulfurization
(FGD) equipment. The US EPA industrial source complex model is used to model air pollution dispersion at the local scale,
and the sector average limited mixing meso-scale model is used to model air pollution transport at the regional scale. The
quantification of the health end points in physical terms is carried out using the dose–response functions established recently
for the population in Bangkok, Thailand. Monetarization of these effects is based on the benefit transfer method with appropriate
adjustment. Finally, it has been found that the installation of the FGD to control SO2 emission at Mae Moh significantly reduces adverse health effects not only on the population living near the power plant but
also all over the country. A FGD unit installed at the 300-MW power unit can result, on average, in 16 fewer cases of acute
mortality, 12 fewer cases of respiratory and cardiac hospital admissions, and almost 354,000 fewer days with acute respiratory
symptoms annually. In monetary terms this benefit is equivalent to US $18.2 million (1995 prices) per annum. This benefit
is much higher than the annualized investment and operation costs of FGD (US $7.4 million/yr). 相似文献
Vietnam is a tropical to subtropical country located on the eastern Asian coast where the Red (Song Hong) and Mekong rivers discharge into the sea. The catchments of these two transboundary rivers cover parts of six countries, and their water and sediment discharges greatly influence the coastal seas of Vietnam. The impact of human activities include changes in the supply and distribution of water, sediments, and nutrients; changes in the relationships and balance among dynamically interacting factors and processes; and changes in the quality of the coastal and marine environments due to the increased use and accumulation of pollutants and the loss of habitats. These impacts have resulted in increasing unpredictability and severity of coastal problems such as floods, erosion, sedimentation, and saltwater intrusion; environmental pollution; and the degradation of ecosystems, with accompanying decrease in biodiversity and fishery productivity. 相似文献