作者机构:
[Li, Tian; Chu, Huaqiang; Liu, Huachen; Dong, Bingzhi; Huang, Weipeng; Yu, Hongjian] Tongji Univ, Coll Environm Sci & Engn, Shanghai 200092, Peoples R China.;[Li, Tian; Chu, Huaqiang; Dong, Bingzhi] Tongji Univ, Minist Educ, Key Lab Yangtze River Water Environm, Shanghai 200092, Peoples R China.;[Li, Tian; Chu, Huaqiang; Dong, Bingzhi] Tongji Univ, State Key Lab Pollut Control & Resource Reuse, Shanghai 200092, Peoples R China.;[Chi, Nianping] Hunan City Univ, Sch Municipal & Geomat Engn, Yiyang 413000, Peoples R China.
通讯机构:
[Tian Li] C;College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China<&wdkj&>State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China<&wdkj&>Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092, China<&wdkj&>Author to whom correspondence should be addressed.
摘要:
The combination of conventional and advanced water treatment is now widely used in drinking water treatment. However, membrane fouling is still the main obstacle to extend its application. In this study, the impact of the combination of coagulation and ultrafiltration (UF) membrane rotation on both fouling control and organic removal of macro (sodium alginate, SA) and micro organic matters (tannic acid, TA) was studied comprehensively to evaluate its applicability in drinking water treatment. The results indicated that membrane rotation could generate shear stress and vortex, thus effectively reducing membrane fouling of both SA and TA solutions, especially for macro SA organics. With additional coagulation, the membrane fouling could be further reduced through the aggregation of mediate and macro organic substances into flocs and elimination by membrane retention. For example, with the membrane rotation speed of 60 r/min, the permeate flux increased by 90% and the organic removal by 35% in SA solution, with 40 mg/L coagulant dosage, with an additional 70% increase of flux and 5% increment of organic removal to 80% obtained. However, too much shear stress could intensify the potential of fiber breakage at the potting, destroying the flocs and resulting in the reduction of permeate flux and deterioration of effluent quality. Finally, the combination of coagulation and membrane rotation would lead to the shaking of the cake layer, which is beneficial for fouling mitigation and prolongation of membrane filtration lifetime. This study provides useful information on applying the combined process of conventional coagulation and the hydrodynamic shear force for drinking water treatment, which can be further explored in the future.
期刊:
IET Image Processing,2021年15(1):155-165 ISSN:1751-9659
通讯作者:
Huang, Changjun
作者机构:
[Huang, Changjun; Zhou, Qingshan] Hunan City Univ, Sch Municipal & Surveying Engn, Yiyang 413000, Peoples R China.;[Huang, Changjun] Key Lab Key Technol Digital Urban Rural Spatial P, Yiyang 413000, Peoples R China.;[Zhou, Xinghua] Zhejiang Inst Hydraulice & Estuary, Hangzhou 310008, Peoples R China.;[Hu, Jiyuan] Wuhan Univ, Sch Geodesy & Geomat, Wuhan 430079, Peoples R China.
通讯机构:
[Huang, Changjun] H;Hunan City Univ, Sch Municipal & Surveying Engn, Yiyang 413000, Peoples R China.
关键词:
Optical, image and video signal processing;Radar equipment, systems and applications;Integral transforms;Principal component analysis
摘要:
In the process of synthetic aperture radar image noise suppression by the bi-dimensional empirical mode decomposition (BEMD) algorithm, the edge effect is a key problem in the BEMD operation. To weaken this effect, an improved BEMD-kernel principal component analysis (BEMD-KPCA) method of image denoising is proposed in this study. Experimental results show that the BEMDKPCA algorithm has a good capability of improving edge effects in the BEMD decomposition process and satisfying the requirement of the reliable decomposition results. Compared with the traditional BEMD method, the proposed approach has a good effect on suppressing speckle noise. Additionally, the denoised image from the decomposed components of the IMFs processed by the BEMD-KPCA method sufficiently preserves the edge and detail information, confirming its high coherency with the original image.
通讯机构:
[Yaoning Chen] C;College of Environmental Science and Engineering, Hunan University, Changsha 410082, China<&wdkj&>Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
作者机构:
[Long, Yue-hong; Zhu, Lei; Xue, Yun; Zhou, Song-lin] Hunan City Univ, Design Inst Co Ltd, Sch Municipal & Surveying Engn, Yiyang 413000, Peoples R China.;[Xue, Yun; Zou, Bin] Cent South Univ, Sch Geosci & Infophys, Key Lab Metallogen Predict Nonferrous Met & Geol, Changsha 410083, Peoples R China.;[Zhu, Lei] Jiangxi Univ Sci & Technol, Sch Civil & Surveying Engn, Ganzhou 341000, Peoples R China.;[Wen, Yi-min] Guilin Univ Elect Technol, Sch Comp Sci & Informat Secur, Guilin 541004, Peoples R China.
通讯机构:
[Zou, Bin] C;Cent South Univ, Sch Geosci & Infophys, Key Lab Metallogen Predict Nonferrous Met & Geol, Changsha 410083, Peoples R China.
关键词:
convolutional neural network;chlorophyll-a;Dongting Lake
摘要:
For Case-II water bodies with relatively complex water qualities, it is challenging to establish a chlorophyll-a concentration (Chl-a concentration) inversion model with strong applicability and high accuracy. Convolutional Neural Network (CNN) shows excellent performance in image target recognition and natural language processing. However, there little research exists on the inversion of Chl-a concentration in water using convolutional neural networks. Taking China's Dongting Lake as an example, 90 water samples and their spectra were collected in this study. Using eight combinations as independent variables and Chl-a concentration as the dependent variable, a CNN model was constructed to invert Chl-a concentration. The results showed that: (1) The CNN model of the original spectrum has a worse inversion effect than the CNN model of the preprocessed spectrum. The determination coefficient (R-P(2)) of the predicted sample is increased from 0.79 to 0.88, and the root mean square error (RMSEP) of the predicted sample is reduced from 0.61 to 0.49, indicating that preprocessing can significantly improve the inversion effect of the model.; (2) among the combined models, the CNN model with Baseline1_SC (strong correlation factor of 500-750 nm baseline) has the best effect, with R-P(2) reaching 0.90 and RMSEP only 0.45. The average inversion effect of the eight CNN models is better. The average R-P(2) reaches 0.86 and the RMSEP is only 0.52, indicating the feasibility of applying CNN to Chl-a concentration inversion modeling; (3) the performance of the CNN model (Baseline1_SC (R-P(2) = 0.90, RMSEP = 0.45)) was far better than the traditional model of the same combination, i.e., the linear regression model (R-P(2) = 0.61, RMSEP = 0.72) and partial least squares regression model (Baseline1_SC (R-P(2) = 0.58. RMSEP = 0.95)), indicating the superiority of the convolutional neural network inversion modeling of water body Chl-a concentration.
作者机构:
[Li, Huan; Tian, Mao-Jun; Tamehe, Landry Soh] Cent South Univ, Sch Geosci & Info Phys, Minist Educ, Key Lab Metallogen Predict Nonferrous Met & Geol, Changsha 410083, Peoples R China.;[Xi, Zhen] Hunan City Univ, Sch Municipal & Geomat Engn, Yiyang 413000, Peoples R China.
通讯机构:
[Huan Li] K;Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring, Ministry of Education, School of Geosciences and Info-Physics, Central South University, Changsha 410083, China<&wdkj&>Author to whom correspondence should be addressed.
摘要:
The boundary between the Gondwana and Yangtze plate is still controversial. In southwest China, the Sanjiang region marks the collision zone which accreted several blocks coming from the northern Gondwana margin. In this region, subduction of the Paleo-Tethys Ocean and associated continental blocks during the Triassic Period led to the formation of an N-S trending complex involving intrusive and volcanic rocks. The intrusive rocks are important for constraining the evolution of the Paleo-Tethyan in southwestern China. This study presents new geochronological, geochemical, and Sr-Nd-Hf isotopic data of granite porphyries from northern Lancangjiang, in order to discuss the origin of these granites and their tectonic significance. Representative samples of the Zengudi and the Tuobake granite porphyries from the Yezhi area yielded weighted mean Pb-206/U-238 ages of 247-254 Ma and 246 Ma, respectively. The Zengudi granite porphyries display zircon (Hf)(t) values of -12.94 to -2.63, (Nd)(t) values of -14.5 to -9.35, and initial Sr-87/Sr-86 ratios of 0.708 to 0.716. The Tuobake granite porphyries have zircon (Hf)(t) values of -14.06 to -6.55, (Nd)(t) values of -10.9 to -9.41, and initial Sr-87/Sr-86 ratios of 0.716 to 0.731. Both the Zengudi and Tuobake granite porphyries exhibit strongly peraluminous signatures with high A/CNK nAl(2)O(3)/(K2O + Na2O + K2O) ratios (1.07-1.86 and 0.83-1.33, respectively). These granites are enriched in Rb and Th, and depleted in Ti, Nb, Ta, Sr, and P, with negative Eu anomalies (Eu/Eu* < 0.61). These geochemical and isotopic data indicate that the primary magma of the granite porphyries originated from partial melting of ancient continental crust as a result of basaltic magma underplating and underwent fractionation crystallization during their emplacement. We propose that the Triassic subduction of the Paleo-Tethys Ocean led to crust shortening and thickening in the Sanjiang region, while the northern Lancangjiang area was involved in the continental collision after the subduction of the Paleo-Tethys Ocean before 254 Ma.
通讯机构:
[Yaoning Chen; Yuanping Li] C;College of Municipal and Mapping Engineering, Hunan City University, Yiyang, Hunan 413000, China<&wdkj&>College of Environmental Science and Engineering, Hunan University, Changsha 410082, China<&wdkj&>Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
摘要:
To reclaim and utilize wastepaper (WP), a WP/acrylamide double-network hydrogel (WP/PAM) was prepared to transform WP into efficient adsorbent for heavy metals and dye wastewater treatment. The structure and properties of the WP/PAM were characterized systematically by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), swelling performance (SR), Fourier transform infrared spectrum (FTIR), and X-ray photoelectron spectroscopy (XPS). Batch experiments showed that the adsorption process of Cu(ii) and MB followed the pseudo-second-order kinetic model and the Langmuir model. The maximum adsorption capacities of the WP/PAM for Cu(ii) and MB were 142.2 mg g(-1) and 1714.5 mg g(-1), respectively. The adsorption mechanism of Cu(ii) on the WP/PAM was related to ion exchange and complexation, while MB adsorption was driven by hydrogen bonding and electrostatic interaction. Besides, the WP/PAM performed well in treating simulated wastewater. The regeneration test indicated that the WP/PAM could be successfully reused after 6 cycles. This work provided an alternative choice for the recycling of WP and produced a potential adsorbent for the dye and heavy metals wastewater treatment.
作者机构:
[Zhong, Teng; Ye, Cheng; Wang, Zian; Tang, Guoan] Nanjing Normal Univ, Key Lab Virtual Geog Environm, Minist Educ, Nanjing 210023, Peoples R China.;[Zhong, Teng; Ye, Cheng; Wang, Zian; Tang, Guoan] Nanjing Normal Univ, State Key Lab Cultivat Base Geog Environm Evolut, Nanjing 210023, Peoples R China.;[Zhong, Teng; Ye, Cheng; Wang, Zian; Tang, Guoan] Nanjing Normal Univ, Jiangsu Ctr Collaborat Innovat Geog Informat Reso, Nanjing 210023, Peoples R China.;[Zhang, Wei] Cent South Univ, Sch Geosci & Infophys, Key Lab Metallogen Predict Nonferrous Met & Geol, Minist Educ, Changsha 410083, Peoples R China.;[Zhang, Wei] Hunan City Univ, Sch Municipal & Mapping Engn, Yiyang 413000, Peoples R China.
关键词:
urban color planning;urban façade color;street-view images;deep learning;Shenzhen
摘要:
Precise urban façade color is the foundation of urban color planning. Nevertheless, existing research on urban colors usually relies on manual sampling due to technical limitations, which brings challenges for evaluating urban façade color with the co-existence of city-scale and fine-grained resolution. In this study, we propose a deep learning-based approach for mapping the urban façade color using street-view imagery. The dominant color of the urban façade (DCUF) is adopted as an indicator to describe the urban façade color. A case study in Shenzhen was conducted to measure the urban façade color using Baidu Street View (BSV) panoramas, with city-scale mapping of the urban façade color in both irregular geographical units and regular grids. Shenzhen’s urban façade color has a gray tone with low chroma. The results demonstrate that the proposed method has a high level of accuracy for the extraction of the urban façade color. In short, this study contributes to the development of urban color planning by efficiently analyzing the urban façade color with higher levels of validity across city-scale areas. Insights into the mapping of the urban façade color from the humanistic perspective could facilitate higher quality urban space planning and design.
期刊:
Journal of Analytical and Applied Pyrolysis,2021年156:105173- ISSN:0165-2370
作者机构:
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, China;Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, China;State Key Laboratory of Utilization of Woody Oil Resource and Institute of Biological and Environmental Engineering, Hunan Academy of Forestry, Changsha, 410004, China;College of Municipal and Mapping Engineering, Hunan City University, Yiyang, Hunan, 413000, China
摘要:
The magnetic MnFe2O4-sludge biochar composites (MFSB) was synthesized in one-step hydrothermal approach, realizing hydrothermal carbonization of sludge and preparation of MnFe2O4 simultaneously. The characterizations of prepared adsorbents indicated that the combination of hydrothermal sludge biochar and MnFe2O4 enhanced the structure of the hydrothermal sludge, prevented the agglomeration of MnFe2O4, and endowed the composites with magnetism and higher specific surface area. Batch adsorption experiments showed higher adsorption efficiency of MnFe2O4-sludge biochar composites with sludge content of 1.5 g (MFSB-1.5) to Pb2+. In the Pb2+ adsorption process on MFSB-1.5, the better fit of Pseudo-second-order model and the Langmuir isotherm was demonstrated, with a maximum adsorption amount of 174.216 mg/g at the reaction temperature of 25 ℃. Based on adsorption mechanism analysis, the Pb2+ adsorption onto MFSB-1.5 mainly resulted from physical adsorption, electrostatic attraction, co-precipitation, and complexation. Due to simple operation, strong adsorption capacity, effortless magnetic separation, and sludge resource utilization, MFSB-1.5 composites have great potential in removing Pb2+ from the water body.
作者机构:
[周乐陶; 刘宇琪; 段怡欣; 李好; 蒋海燕] Hunan Province Engineering & Technology Research Center for Rural Water Quality Safety, College of Municipal and Mapping Engineering, Hunan City University, Yiyang, 413000, China;[段怡欣] School of Civil Engineering, University of South China, Hengyang, 421001, China
通讯机构:
[Duan, Y.] S;School of Civil Engineering, University of South China, Hengyang, China
作者机构:
[Wen Y.; Feng C.; Zhou Q.] Guangxi Key Laboratory of Image and Graphic Intelligent Processing, Guilin University of Electronic Technology, Guilin, China;[Xue Y.] School of Municipal and Surveying Engineering, Hunan City University, Yiyang, China
会议名称:
27th International Conference on Neural Information Processing, ICONIP 2020