Applied Mechanics and Materials Vols. 448-453

Abstract: By conducting field investigation and tests, such as groundwater pumping test and rock mechanics test, and building numerical models to simulate damage of coal mining to aquifers, it was proved that coal mining in some coal mine area caused impacts to groundwater environment, including impact on water cycle, the structure of aquifers, and groundwater flow field, as a result of which some water supply sources in coal mine area become unavailable. In addition, a couple of solutions are presented to mitigate the impacts.

Abstract: In this study, the Fe₃O₄ magnetic nanoparticles (MNPs) were synthesized as heterogeneous catalysts to effectively degrade methyl orange. The coulping method of microwave irradiation and Fenton-like reaction was used for degradation of methyl orange waste water. The effects of Fe₃O₄ dosage, initial H₂O₂ concentration, catalyst cycles, reaction temperature and so on were assessed systematically. The experimental results showed that the microwave-assisted Fenton-like process using H₂O₂/Fe₃O₄ was the most effective treatment process compared with other traditional methods. According to degradation of methyl orange, it has been found that the oxidation by Fenton-likes reagent is dependent on Fe₃O₄ dosage, H₂O₂ dosage, reaction temperature. The results indicate that under the optimal conditions, the removal rate of methyl orange could reach nearly 100%. Moreover, six cyclic tests for methyl orange degradation showed that the magnetic catalyst was very stable, recoverable, highly active, and easy to separate using an external magnet. Hence, the coulping method of microwave irradiation and Fenton-like reaction with magnetic nanomaterials of Fe₃O₄ as the catalyst has potential use in organic pollutant removal.

Abstract: Fenton reactions have been increasingly applied to emergent pollutants degradation. Although homogeneous reaction by classical Fenton enables organic wastewater degradation, long treatment time and high iron catalyst concentrations are needed, raising environmental concerns. This paper proposed an innovative and cheap solution to degrade Rhodamine B (RmB) by combining magnetic nanomaterials of Fe₃O₄ as the catalyst with microwave-enhanced fenton-like system. The main operational parameters were optimized systematically (hydrogen peroxide concentration; Fe₃O₄ dosage; catalyst cycles; reaction time and reaction temperature). The degradation rate of Rhodamine B was increased and accelerated due to the assistance of microwave irradiation, with value of 99% after heated for only 5 min, even higher than that of treated by traditional Fenton process for 20 min. Moreover, six cyclic tests for Rhodamine B degradation showed that the magnetic catalyst was very stable, recoverable, highly active, and easy to separate using an external magnet. Hence, microwave-enhanced Fenton-like system with magnetic nanomaterials of Fe₃O₄ as the catalyst has potential use in organic pollutant removal.

Abstract: Large reservoir ecological risk assessment is an important part of ecological environmental protection and improvement. Taking Nuozhadu reservoir in Lancang river basin as an example, a multi-level risk receptor--multiple risk source evaluation index system which can describe the complicated relationship and mechanism of ecological risk is established in terms of recognizing ecological risk sources and receptors of the valley area of terrestrial ecosystems; Considering fuzziness of human cognition on ecological system, diversity and different measure standard of the risk evaluation indicators, the multi-level fuzzy comprehensive evaluation model based on RRM(Relative Risk Model) thought is constructed. Calculation results show that the ecological-risk fuzzy-evaluation score of each receptor and the overall score can be obtained, which can provide important reference for ecological environment improvement of Nuozhadu reservoir area through the comparative analysis.

Abstract: This paper analyzes the degree of development and the status quo in the process of preservation-exploration of geoheritage landscape resources in Xinjiang in order to define the present model of protection and exploitation. The development pattern and the management pattern for geoheritage landscape resources are believed to be optimized respectively under the perspective of protection and benefit sharing. Based on this idea, this paper points out that the optimization pattern for preservation-exploration of geoheritage landscape resource in Xinjiang is a double-winged optimized pattern for it is the perfect mixture of exploration optimization model from preservation perspective and management optimization pattern from interest sharing perspective.

Abstract: The plant-promoted removal of polycyclic aromatic hydrocarbons (PAHs) in soils ranging from 20.08 to 322.12 mg·kg^-1 was investigated under different planting patterns, and enhancement mechanisms were analyzed. Results showed that the dissipation of PAHs (68.22%~75.06%) in soils growing Brassica campestris and Trifolium repens significantly exceeded those (40.38%~43.26%) vegetating single species. After 80 days plantation, the extractable PAHs in soils under mixed cropping were much lower than those under single cropping. Despite the presence of vegetation evidently enhanced PAHs removal, the plant-microbial interactions are the main pathway for dissipation of pollutions under mixed cropping mode. These results suggested a feasibility of the establishment of multi-species phytoremediation for improvement of the remediation efficiencies of PAHs, which may decrease accumulations of PAHs in crops and thus reduce their risks.

Abstract: Eco-tourism is more and more popular in recent years. Establishing tourism environment detection system, listed the variety factors and indicators that easily make influence on the environment, such as: vegetation, animals, water, air, and so on. Through detect the indicators and the negative impacts timely on tourism environment from tourism activities and non-tourism activities, making the right analysis and appropriate treatment. On this basis, summed up the protection measures of water resources, atmospheric environment, geomorphology environment, soil environment, sound environment and forest resources. Eco-tourism should adopt low-carbon buildings, low-carbon diets, low-carbon traffic, low carbon garbage, low-carbon energy and other low-carbon operation and management mode. Protecting the ecological environment and resources are not infringed, maintain the sustainable development of eco-tourism.

Abstract: The environmental problems in China ports, the present situation and existing problems of environmental protection management system are summarized in this paper. Then the significance of the establishment of environmental protection management system and technical condition are discussed. At the end, the preliminary conception of the establishment and problems to be settled are proposed.

Abstract: Eco-exergy which is a thermodynamic indicator is applied to assess the ecosystem health status of QiXing Lake. And effects of nitrogen and phosphorus on ecosystem health status have been investigated. The results indicate that the ecosystem which contains macrophytes has the better health status than that does not contain macrophytes when they have the same concentration of nitrogen or phosphorus. The ecosystem health status decreased as the concentration of total nitrogen increased when the ecosystem contains macrophytes. However, the ecosystem health status has not significant change as the concentration of total nitrogen increased when the ecosystem does not contains macrophytes. It has the same law for total phosphorus.

Abstract: The method of selective catalytic reduction (SCR) is now one of the mature applications of NOx removal technology, which has the higher denitration rate, less secondary pollution and lower cost. However, the active temperature of traditional SCR catalyst is usually in the temperature range of 300-400°C. This kind of installation leads to the reduction of catalyst activity, and the shortage of working life. The development of efficient and stable performance of catalyst at low temperature has become a key point in the research of SCR.This paper reviews the research progress of carbon catalyst of low temperature SCR. In addition, the future research work is discussed.