In order to improve membrane reactor( MBR) performance for micro-polluted surface water treatment in start-up phase,removals of nitrogen and organic matters especially synthetic organic matters by MBR and a simultaneo...In order to improve membrane reactor( MBR) performance for micro-polluted surface water treatment in start-up phase,removals of nitrogen and organic matters especially synthetic organic matters by MBR and a simultaneous application of powdered activated carbon( PAC) with MBR( PAC-MBR) using flat sheet membrane are investigated. The results confirm that MBR treatment can be effective for the removal of organic matters including trace organics. The added PAC can improve contaminant removal efficiency especially in the beginning of operation when MBR cannot effectively remove contaminants and effluent satisfying quality standards is obtained. Moreover,the removal efficiency of target trace synthetic organics is investigated and the removal mechanism is discussed. Biodegradation by microorganism,rejection by filtration of membrane with biofilm and adsorption all contribute to the removal performance. Furthermore,volatile organic compounds can be removed by aeration. The filtration process is confirmed important for natural organic matters( NOM)removal in both MBR and PAC-MBR systems. Combining with PAC,the MBR can remove all fractions of NOM while the single MBR can hardly reduce fulvic or humic acid in water even during the steady operation.展开更多
The Mesozoic tectonic framework of the eastern South China is mainly controlled by subduction,turning toward,and rollback of the Pacific Plate.Recent studies of receiver function imaging and ambient noise tomography h...The Mesozoic tectonic framework of the eastern South China is mainly controlled by subduction,turning toward,and rollback of the Pacific Plate.Recent studies of receiver function imaging and ambient noise tomography have revealed the“Yshaped”thinnest crustal belt in the eastern South China under the overall extension of the lithosphere.However,the deep dynamic environment and formation mechanisms of the thin crustal belt remain debatable.Here we obtained high-resolution images of the crustal thickness and Poisson’s ratio in the eastern South China Block applying the recently proposed H-κ-c receiver function method,using data recorded by 305 dense portable broadband stations and 219 permanent stations surrounding.Additionally,we discussed the deep dynamic formation mechanism of the“Y-shaped”thinnest crustal belt coupled with two common conversion point stacked images at key locations.Results show that the average crustal thickness of the study area is 33 km(thin crust)and the average Poisson’s ratio is 0.24(low ratio).The overall crustal thinning toward the continental margin is likely because eastern South China was in a back-arc extension environment,which was induced by the rollback of the subducted plate in the Early Cretaceous.The crustal thickness of the“Y-shaped”thinnest crustal belt is<30 km,which is 3-5 km thinner than that outside the zone.The eastern branch is distributed along the trajectory of Nanchang-Ji’an-Ganzhou-Shaoguan-Guangzhou,and the western branch is around the Jianghan-Xiangzhong Basin,both of which intersect in Nanling.The eastern branch of the thin crustal zone indicates the potential location of the Pacific subduction slab breakoff,and the formation mechanism may be related to the interaction of deep-shallow processes,including the upwelling of mantle heat flow through the slab window and transtensional pre-existing faults.We developed a dynamic model that combines subduction-breakoff-rollback processes of the Paleo-Pacific Plate and accompanying deep fluid upwelling to explain the regional extension of the South China lithosphere,the formation mechanism of the thinnest crustal belt,and the distribution of granitic plutons.展开更多
基金Sponsored by the National Natural Science Foundation of China(Grant No.51408149)
文摘In order to improve membrane reactor( MBR) performance for micro-polluted surface water treatment in start-up phase,removals of nitrogen and organic matters especially synthetic organic matters by MBR and a simultaneous application of powdered activated carbon( PAC) with MBR( PAC-MBR) using flat sheet membrane are investigated. The results confirm that MBR treatment can be effective for the removal of organic matters including trace organics. The added PAC can improve contaminant removal efficiency especially in the beginning of operation when MBR cannot effectively remove contaminants and effluent satisfying quality standards is obtained. Moreover,the removal efficiency of target trace synthetic organics is investigated and the removal mechanism is discussed. Biodegradation by microorganism,rejection by filtration of membrane with biofilm and adsorption all contribute to the removal performance. Furthermore,volatile organic compounds can be removed by aeration. The filtration process is confirmed important for natural organic matters( NOM)removal in both MBR and PAC-MBR systems. Combining with PAC,the MBR can remove all fractions of NOM while the single MBR can hardly reduce fulvic or humic acid in water even during the steady operation.
基金geological survey project of China Geological Survey(Grant Nos.12120114067701,DD20179357,and DD20160082)the National Natural Science Foundation of China(Grant No.41574092)supported by the National Natural Science Foundation of China(Grant Nos.91962110,41774113,42174069,41874055,and 42104099).
文摘The Mesozoic tectonic framework of the eastern South China is mainly controlled by subduction,turning toward,and rollback of the Pacific Plate.Recent studies of receiver function imaging and ambient noise tomography have revealed the“Yshaped”thinnest crustal belt in the eastern South China under the overall extension of the lithosphere.However,the deep dynamic environment and formation mechanisms of the thin crustal belt remain debatable.Here we obtained high-resolution images of the crustal thickness and Poisson’s ratio in the eastern South China Block applying the recently proposed H-κ-c receiver function method,using data recorded by 305 dense portable broadband stations and 219 permanent stations surrounding.Additionally,we discussed the deep dynamic formation mechanism of the“Y-shaped”thinnest crustal belt coupled with two common conversion point stacked images at key locations.Results show that the average crustal thickness of the study area is 33 km(thin crust)and the average Poisson’s ratio is 0.24(low ratio).The overall crustal thinning toward the continental margin is likely because eastern South China was in a back-arc extension environment,which was induced by the rollback of the subducted plate in the Early Cretaceous.The crustal thickness of the“Y-shaped”thinnest crustal belt is<30 km,which is 3-5 km thinner than that outside the zone.The eastern branch is distributed along the trajectory of Nanchang-Ji’an-Ganzhou-Shaoguan-Guangzhou,and the western branch is around the Jianghan-Xiangzhong Basin,both of which intersect in Nanling.The eastern branch of the thin crustal zone indicates the potential location of the Pacific subduction slab breakoff,and the formation mechanism may be related to the interaction of deep-shallow processes,including the upwelling of mantle heat flow through the slab window and transtensional pre-existing faults.We developed a dynamic model that combines subduction-breakoff-rollback processes of the Paleo-Pacific Plate and accompanying deep fluid upwelling to explain the regional extension of the South China lithosphere,the formation mechanism of the thinnest crustal belt,and the distribution of granitic plutons.
