In shallow burial mining areas, abnormal CO emission and the spontaneous combustion of coal are great threats to safety production at a fully-mechanised working face. In order to prevent the CO concentration in the ai...In shallow burial mining areas, abnormal CO emission and the spontaneous combustion of coal are great threats to safety production at a fully-mechanised working face. In order to prevent the CO concentration in the air return corner from exceeding the critical limit, the paper studied the CO emission regularity and characteristics through theoretical analysis, experimental research and field observation. The results show that the main sources of CO emission were the spontaneous combustion of coal in the goaf and the exhaust emissions coming from underground motorised vehicles. The effect factors of CO emission were also investigated, such as seasonal climate changes, the advancing distance and advancing speed of the working face, the number of underground motorised vehicles and some other factors. In addition to these basic analyses, the influence mechanism of each influence factor was also summarised theoretically. Finally, this study researched the distribution and change law of CO concentration in the fully-mechanised working face in two aspects: controlling the change of monitoring points and time respectively. The research results provide a theoretical basis for preventing the CO concentration from exceeding the critical limit in the air return corner and reducing the possibility of spontaneous combustion of coal. Additionally, the results also provide important theoretical and practical guidelines for protecting miners' health in modern mines featuring high production and high efficiency all over the world.展开更多
Under the pressure of global droughts and water shortage,it is essential to evolve toward a sustainable and robust water system.One possible avenue is the maximum reuse of treated wastewater,but the quality of which d...Under the pressure of global droughts and water shortage,it is essential to evolve toward a sustainable and robust water system.One possible avenue is the maximum reuse of treated wastewater,but the quality of which determines its reuse.Therefore,inorganic(Cd,Pb,Cr,Ni,Cu,and As)and organic(xenoestrogens and polycyclic aromatic contaminants,PACs)contaminants were monthly monitored in an effluent of the wastewater treatment plant(WWTP),the surrounding surface waters and the local groundwater in Belgium.Dissolved and particulate concentrations of inorganic contaminants in these water bodies were analyzed.In addition,Diffusive Gradients in Thin-films(DGT)was used in situ to obtain bioavailable metal fractions.In the WWTP effluent and surface waters,only Ni exceeds the Annual Average-Environmental Quality Standard(AA-EQS),while in the groundwater,dissolved As was the predominant element.Moreover,in the surface and effluent waters the highest lability degrees were observed for Cd and Ni.The concentrations of these metal species in the effluent water were lower than in the other water bodies.Micro-organic pollutants,xenoestrogens and PACs were analyzed by dual Estrogen and Aryl hydrocarbon Receptor-Chemical Activated LUciferase gene eXpression(ER&AhR-CALUX)assays.Since the annual averaged(AA)bioequivalent concentration of E2(0.18 ng/L)is below the AA-EQS standard(0.4 ng/L),and the bioequivalent concentration of benzo[a]pyrene never exceeded the maximum admissible concentration(MAC),the reclamation and reuse of treated wastewater for groundwater replenishment and agricultural irrigation should pose no environmental problems,at least in a short-term.展开更多
Climate change has significantly increased the intensity and frequency of extreme weather events,posing significant challenges to the hydrological ecological security of rural settlements in mountainous areas.There is...Climate change has significantly increased the intensity and frequency of extreme weather events,posing significant challenges to the hydrological ecological security of rural settlements in mountainous areas.There is an urgent need for research that predicts the flood risk of mountainous villages under future climate scenarios.Taking the mountainous area of the Yongding River Watershed in Beijing as an example,this study uses CMIP6 data and the Delta statistical downscaling method to predict precipitation with return periods of 20-a,50-a,and 100-a under the SSP126,SSP245,and SSP585 scenarios at the end of this century.A two-dimensional hydrodynamic model combining SWMM and HEC-RAS has been employed to simulate the flood risks of the villages in the watershed.The results show that:1)overall flood risk is higher for the villages located downstream of the Qingshui River and at the outlet of the Yongding River Gorge,with significantly increased inundation area ratio,maximum inundation depth,and the number of villages affected;2)with the increase in radiative forcing values of the SSP pathways,the inundation area ratio increases by up to 8.22%by 2100,significantly increasing the flood control pressure on settlements in the future;3)the correlation results between village spatial characteristics and flood risks show that the inundation area ratio is significantly negatively correlated with average river width and river sinuosity,and significantly positively correlated with river gradient and floodway proximity;the maximum inundation depth is significantly negatively correlated with average river width and significantly positively correlated with floodway proximity.Finally,this research suggests that it is necessary to integrate various spatial elements and resources from upstream and downstream areas by prioritizing the strategy of key area flood control and sustainable development,to reduce the flood risk to mountainous settlements under future climate change.展开更多
基金supports funded by the National Natural Science FoundationShenhua Corporation Limited Jointly Funded Project of China (No. U1361213)+1 种基金Jiangsu Province Science Fund for Distinguished Young Scholars(BK20140005)College student innovation entrepreneurship Funded Project(CUMT,201405)
文摘In shallow burial mining areas, abnormal CO emission and the spontaneous combustion of coal are great threats to safety production at a fully-mechanised working face. In order to prevent the CO concentration in the air return corner from exceeding the critical limit, the paper studied the CO emission regularity and characteristics through theoretical analysis, experimental research and field observation. The results show that the main sources of CO emission were the spontaneous combustion of coal in the goaf and the exhaust emissions coming from underground motorised vehicles. The effect factors of CO emission were also investigated, such as seasonal climate changes, the advancing distance and advancing speed of the working face, the number of underground motorised vehicles and some other factors. In addition to these basic analyses, the influence mechanism of each influence factor was also summarised theoretically. Finally, this study researched the distribution and change law of CO concentration in the fully-mechanised working face in two aspects: controlling the change of monitoring points and time respectively. The research results provide a theoretical basis for preventing the CO concentration from exceeding the critical limit in the air return corner and reducing the possibility of spontaneous combustion of coal. Additionally, the results also provide important theoretical and practical guidelines for protecting miners' health in modern mines featuring high production and high efficiency all over the world.
基金IRP-17(VUB)for the Ph.D.scholarship of M Luo and D J Vandeputte,CSC Ph.D.scholarship for Y Su,Y Jia,and G Li.Aquafin(RWZI Molenbeersel)is thanked for sampling and SRP-II is also thanked for the support of this study。
文摘Under the pressure of global droughts and water shortage,it is essential to evolve toward a sustainable and robust water system.One possible avenue is the maximum reuse of treated wastewater,but the quality of which determines its reuse.Therefore,inorganic(Cd,Pb,Cr,Ni,Cu,and As)and organic(xenoestrogens and polycyclic aromatic contaminants,PACs)contaminants were monthly monitored in an effluent of the wastewater treatment plant(WWTP),the surrounding surface waters and the local groundwater in Belgium.Dissolved and particulate concentrations of inorganic contaminants in these water bodies were analyzed.In addition,Diffusive Gradients in Thin-films(DGT)was used in situ to obtain bioavailable metal fractions.In the WWTP effluent and surface waters,only Ni exceeds the Annual Average-Environmental Quality Standard(AA-EQS),while in the groundwater,dissolved As was the predominant element.Moreover,in the surface and effluent waters the highest lability degrees were observed for Cd and Ni.The concentrations of these metal species in the effluent water were lower than in the other water bodies.Micro-organic pollutants,xenoestrogens and PACs were analyzed by dual Estrogen and Aryl hydrocarbon Receptor-Chemical Activated LUciferase gene eXpression(ER&AhR-CALUX)assays.Since the annual averaged(AA)bioequivalent concentration of E2(0.18 ng/L)is below the AA-EQS standard(0.4 ng/L),and the bioequivalent concentration of benzo[a]pyrene never exceeded the maximum admissible concentration(MAC),the reclamation and reuse of treated wastewater for groundwater replenishment and agricultural irrigation should pose no environmental problems,at least in a short-term.
文摘Climate change has significantly increased the intensity and frequency of extreme weather events,posing significant challenges to the hydrological ecological security of rural settlements in mountainous areas.There is an urgent need for research that predicts the flood risk of mountainous villages under future climate scenarios.Taking the mountainous area of the Yongding River Watershed in Beijing as an example,this study uses CMIP6 data and the Delta statistical downscaling method to predict precipitation with return periods of 20-a,50-a,and 100-a under the SSP126,SSP245,and SSP585 scenarios at the end of this century.A two-dimensional hydrodynamic model combining SWMM and HEC-RAS has been employed to simulate the flood risks of the villages in the watershed.The results show that:1)overall flood risk is higher for the villages located downstream of the Qingshui River and at the outlet of the Yongding River Gorge,with significantly increased inundation area ratio,maximum inundation depth,and the number of villages affected;2)with the increase in radiative forcing values of the SSP pathways,the inundation area ratio increases by up to 8.22%by 2100,significantly increasing the flood control pressure on settlements in the future;3)the correlation results between village spatial characteristics and flood risks show that the inundation area ratio is significantly negatively correlated with average river width and river sinuosity,and significantly positively correlated with river gradient and floodway proximity;the maximum inundation depth is significantly negatively correlated with average river width and significantly positively correlated with floodway proximity.Finally,this research suggests that it is necessary to integrate various spatial elements and resources from upstream and downstream areas by prioritizing the strategy of key area flood control and sustainable development,to reduce the flood risk to mountainous settlements under future climate change.
