Loading...

Table of Content

Volume 36 Issue 7
25 July 2020
Table of Contents
2020, 36(7):  0-0. 
Abstract ( 30 )   PDF (1883KB) ( 60 )  
Related Articles | Metrics
Ecological Vulnerability of Mining Resource-based Cities: A Review.
TANG Qian, WANG Jin-man, JING Zhao-rui
2020, 36(7):  825-832.  doi:10.19741/j.issn.1673-4831.2019.0790
Abstract ( 203 )   HTML ( 9)   PDF (940KB) ( 214 )  
References | Related Articles | Metrics
With the large-scale exploitation of coal resources, the development of coal resource-based cities is facing serious ecological environment problems. The study of ecological vulnerability provides new ideas for sustainable urban development, ecological civilization construction and regional coordinated development. At present, the ecological vulnerability of coal resource-based cities is resulted from the combined effects of urban historical problems, natural conditions, social activities, and economic development. Based on the review of the ecological vulnerability connotation, evaluation methods, and avoid measures of coal resource-based cities, the development status, evaluation methods, and differences of avoid measures were analyzed from different perspectives on the ecological vulnerability of coal resource-based cities. Some issues, e. g., the uncertainty of vulnerability connotations, the complexity of evaluation indicators, and the applicability of research methods, were discussed. In general, the ecological vulnerability of coal-resource-based cities is an inherent property of the city's own structure and it is a comparative concept; evaluation indicators and methods should be selected with more emphasis on the related indicators of urban development and the measurement of ecological vulnerability. Future research should be focused on the definition of the ecological vulnerability, the improvement of evaluation indicators and methods, and the expansion of spatiotemporal scope of coal resource-based cities.
Progress on the Gene Flow From Genetically Modified Soybeans to Wild Soybeans
LIU Biao, XUE Kun, LIU Lai-pan, ZHOU Yan, HAN Juan
2020, 36(7):  833-841.  doi:10.19741/j.issn.1673-4831.2019.0407
Abstract ( 186 )   HTML ( 5)   PDF (848KB) ( 108 )  
References | Related Articles | Metrics
With the large-scale commercial planting of genetically modified (GM) crops in the world, the gene flow from GM crops to their wild relatives and its environmental risks have become a new topic in the field of biosafety of GMs. Wild soybean is one of the most important biological resources in China. China has not only imported a large number of GM soybeans every year, but also started to carry out field experiments of GM soybeans with intellectual property rights, therefore, the gene flow of GM soybean to its wild relatives and its influence on natural resources are the core problems that must be solved before the commercialized planting of GM soybean in China. The research progress of gene flow from transgenic soybean to wild soybean at home and aboard are reviewed from the aspects of gene flow from GM soybean to its wild relatives and the fitness of hybrid offsprings. In this paper, the research progress of gene flow from GM soybean to wild relatives and the fitness of hybrid offsprings were reviewed. The problems existing in the fitness of hybrid offsprings and the study and the future development trend of gene flow from GM soybean to wild soybean are pointed out.
A Review on Enzymatic Degradation and Its Regulation Mechanisms for Organic Wastes
ZHANG Yong, CHEN Ji, ZHANG Feng
2020, 36(7):  842-853.  doi:10.19741/j.issn.1673-4831.2019.0420
Abstract ( 333 )   HTML ( 11)   PDF (1387KB) ( 245 )  
References | Related Articles | Metrics
There is a growing interest on environmental pollution and loss of resources due to improper disposal of organic wastes. Biodegradation is one of the most effective methods for organic wastes recycle. Enzymes catalyze the rate-limiting steps in biodegradation and their activities are useful and effective proximate agents for the transformation and decomposition of organic wastes. Some earlier reviews have synthesized the microbial functions in biodegradation, yet enzymatic degradation and its regulation mechanisms for organic wastes are poorly known. The roles of enzymes on catalyzing biodegradation of organic matter, accelerating synthesis of humus and reducing toxicity of pollutants are summarized. Further, the regulation mechanisms of enzymatic degradation were explicitly explored including microorganisms, enzyme immobilization, physicochemical factors and additives. Enzymes are highly efficient, environmentally friendly and controllable, which play crucial roles for biodegradation of organic wastes. Finally, the need for further studies are highlighted, such as studies on (ⅰ)pathways and molecular mechanisms of enzymatic degradation, (ⅱ)metabolism of microorganism-enzyme-waste system, (ⅲ)regulation of enzymatic degradation by activators, (ⅳ)enzyme immobilization and (ⅴ)production and application of degrading enzymes. Those efforts are conducive to promote sustainable utilization of organic wastes.
Evaluation of Carbon Storage on Terrestrial Ecosystem in Hebei Province Based on InVEST Model
LI Jin-pu, XIA Shao-xia, YU Xiu-bo, LI Su-xiao, XU Ce, ZHAO Ning, WANG Shu-tao
2020, 36(7):  854-861.  doi:10.19741/j.issn.1673-4831.2019.0918
Abstract ( 267 )   HTML ( 11)   PDF (18035KB) ( 143 )  
References | Related Articles | Metrics
Understanding the spatial distribution and dynamics of carbon storage provides scientific support for the quantification and management of ecosystem carbon pools. Based on the land use data of Hebei Province from 1990 to 2015, the amount of carbon storage in this region was estimated using InVEST model. The impacts of trends in land use change and the expansion of construction land on changes in carbon storage were evaluated and analyzed. The results show that between 1990 and 2015 marsh wetlands and deciduous broad-leaved forests had the largest carbon density in Hebei Province. The total carbon storage was relatively high in the mountainous forest areas in the northwest of Hebei Province, while that in the southern plain area was relatively low. The total carbon storage in Hebei Province showed a decline from 1990 to 2015, the carbon storage decreased by 44.48 Tg between 1990 and 2015. Among land-use changes that cause a reduction in carbon storage, construction land expansion accounts for the highest proportion. Shijiazhuang, the provincial capital, was the region with the largest expansion of construction land, and it also had a large reduction in carbon storage (8.83 Tg), while the Chengde region had the lowest reduction in carbon storage (0.44 Tg). This suggests that the extent and scale of construction land expansion will have the greatest effect on the decline of carbon reserves. In general, the carbon storage in Hebei Province shows a downward trend, and the scale of construction land expansion affects the decline rate of carbon storage. This study provides scientific information for optimizing land use design, reducing carbon emissions, and improving ecological benefits.
Identification and Optimization of Land Ecological Security Pattern in Wuhan Metropolitan Area Based on Machine Learning.
HUANG Lie-jia, YANG Peng
2020, 36(7):  862-869.  doi:10.19741/j.issn.1673-4831.2019.0517
Abstract ( 175 )   HTML ( 11)   PDF (3318KB) ( 218 )  
References | Related Articles | Metrics
The purpose of this research is to analyze the land ecological security pattern and the influencing factors in Wuhan Metropolitan Area, and to provide comments on the regional land ecological construction and sustainable development. Based on the evaluation system of land ecological security, BP neural network in the machine learning and GIS spatial analysis method, this paper explored and identified the status of land ecological security from 2010 to 2017 in Wuhan Metropolitan Area, and to propose the optimization of land ecological security pattern. Results show that:(1) The overall level of land ecological security of Wuhan Metropolitan Area declined slightly from 2010 to 2017, and had been in a critical safe state for a long time. Among them, the status of land natural ecological security was deteriorating, the status of land economic ecological security continued to improve, and the level of land social ecological security changed differently. (2) There were obvious spatial differences in the changes of land ecological security in Wuhan Metropolitan Area:the areas where the level of land natural ecological security decreased greatly were mainly concentrated in the west and south; the level of land economic ecological security of Huanggang and Huangshi decreased slightly, and the security level of other cities increased at different degrees; the level of land social ecological security changed greatly:Wuhan and Qianjiang increased by one security level, Xiantao and Xiaogan decreased by one security level, and Xianning decreased by two security levels. (3) The main reasons for the deterioration of the land natural ecological security are that the per capita cultivated land, the proportion of cultivated land, and the forest coverage rate continue to decline, while the total discharge of industrial and agricultural wastewater and wastes continue to increase; the main reasons for the continuous improvement of land economic ecological security are that industrial and agricultural production efficiency, residents' income, and the proportion of tertiary industry continued to rise; there are many factors affecting the land social ecological security system.
Analysis on the Characteristics of Spatial and Temporal Changes for Land Desertification in Hotan Area, Xinjiang.
NUERMAIMAITI·Ruzi, WANG Xue-mei
2020, 36(7):  870-878.  doi:10.19741/j.issn.1673-4831.2019.0488
Abstract ( 291 )   HTML ( 13)   PDF (21228KB) ( 120 )  
References | Related Articles | Metrics
The temporal and spatial evolution process of land desertification in Hotan area of Xinjiang was studied with the aim of land desertification control and ecological environment restoration in arid area. Using MODIS 13Q1-NDVI remote sensing data of Hotan area based on RS and GIS technology and taking vegetation coverage as the evaluation index of desertification at different levels, the characteristics in spatial and temporal changes of land desertification in Hotan area from 2000 to 2018 were analyzed. The results show that:(1) the areas with decreasing trend for vegetation coverage accounted for 0.38% of the total study area, of which the area with extremely significant reduction with vegetation coverage accounted for 0.10% of the total area; and the area with significant reduction with vegetation coverage accounted for 0.28% of the total area; the area with increasing vegetation coverage accounted for 12.88% of the total area, of which the area with extremely significant growth with vegetation coverage accounted for only 1.10%, and the area with significant growth with vegetation coverage was accounted for 11.78% of the total study area. (2) The area of severe desertification showed a decreasing trend from 2006 to 2012 and then an increasing trend from 2012 to 2018, with an average annual increasing rate of 0.59%, while the area of moderate desertification showed a decreasing trend with an average annual decreasing rate of 1.43%, while the area of mild desertification and non-desertification maintained an increasing trend with an average annual increasing rate of 2.19% and 3.70%, respectively. (3) According to the area transfer matrix, in the past 20 years, the area of unchanged land types in the study area is 19.841×104 km2, the least transfer area was non-desertification area, and the transfer area of moderate desertification area was relatively larger. Due to the influence of air temperature, precipitation and human activities and other factors, the area of severe desertification in Hotan area has increased slightly in recent 20 years, while the areas of slight desertification and non-desertification have been increased significantly.
Coordination Difference Between Ecosystem Service and Multidimensional Poverty Under Precise Poverty Alleviation Standpoints: A Case Study of Gansu Qinba Mountain Poverty-stricken Core Areas.
PAN Xiang, WU Na, XU Zhong-min, DENG Xiao-hong, SONG Xiao-yu, SHI Pei-ji
2020, 36(7):  879-889.  doi:10.19741/j.issn.1673-4831.2019.0604
Abstract ( 237 )   HTML ( 11)   PDF (6766KB) ( 146 )  
References | Related Articles | Metrics
It is one of the important strategies for poverty alleviation and development in the new era to promote the ecological protection and the coordinated development of economic construction in poverty-stricken areas, and it is also the base of the foundation of building a well-off society in an all-round way in 2020 as scheduled. Taking Qinba poverty stricken core areas in Gansu as a case, based on the InVEST model, market value method and shadow engineering method, the value of regional ecosystem services, mainly including water yield, sediment retention, water purification, and carbon fixation and oxygen release, were comprehensively evaluated. Based on the multidimensional poverty measurement index system of farmers' households (A), the multidimensional poverty index (B) was calculated with the participatory rural assessment method. On the base of the comprehensive measure of the coupling coordination differences between A and B, the main factors of the coupling coordination differences were analyzed, and the classification guidance strategy were put forward pertinently. Results show that:(1) the ecological services value of the 25 poverty sections in Qinba Mountain Poverty Stricken Core Areas in Gansu was estimated as 1 525.05×108 Yuan. Among them, the carbon fixation value is the highest. The average ecosystem service value of the orchards is the highest, and that of the crop land is the lowest. (2) Among the multidimensional poverty factors of the 25 poverty sections, the poverty on income was the most serious, followed by the poverties on health status, cultural education and social relationship, and the poverty on basic material requirements was relatively low; (3) It can be seen from the analysis of the coupling coordination differences, 9 sections such as Chela, Zangzu, etc. belong to the livelihood capital retarded type with income, social relationship and cultural education to be the main factors which restrict the manifestation of the ecosystem services. 12 sections such as Nanyang, Yacheng, etc. are the ecological assets retarded type. In those sections, the continuous improvement of the multi-dimensional poverty is restricted because of the lack of the high ecological services. For example the woodlands and orchards, and so on. Linjiang, Xinzhai and Daqiao belong to the coordinated development type. Only the Lichuan belongs to the recession disorders type. (4) The classification guidance strategies are put forward pertinently according to differentiated coupling characteristics and constraints, providing scientific reference for the strategic decision of targeted poverty reduction.
An Empirical Study on the Influence Factors of Farmers' Plastic Film Recycling Choice: Based on the Survey Data of 9 Typical Agricultural Counties in Yunnan Province.
ZHENG Zhao-feng, ZHU Run-yun, LU Yao, LONG Wei, CHEN Xiao
2020, 36(7):  890-896.  doi:10.19741/j.issn.1673-4831.2019.0776
Abstract ( 152 )   HTML ( 2)   PDF (803KB) ( 105 )  
References | Related Articles | Metrics
Plastic film plays an important role in agricultural production. It is used widely but recycled rarely. Plastic film has brought on a series of pollution hazards in some areas of China. Based on the survey data of 963 farmers in Yunnan, Logistic model was used to study the influence of ecological cognition and economic conditions on farmers' plastic film recycling choice. The results show that:(1)both ecological cognition and economic conditions had a significant impact on farmers' plastic film recycling choice. Economic conditions played a greater role in promoting farmers' plastic film recycling behavior. (2)Farmers' age, promotion from government, awareness of the importance of ecological protection, household income and environmental protection policy had positive effects on farmers' plastic film recycling behavior. The household agricultural labor had a negative impact on plastic film recycling behavior. Gender and the level of education have no significant influence on the choice of plastic film recycling of farmers. (3)Promotion and supporting policy of government played key role in farmers' choice on plastic film recycling.
Comprehensive Evaluation of Landscape Functions of 5 Restoration Modes Based on the LFA Method: A Case Study of the Dumping Site of a Typical Open-pit Coal Mine in the City of Wuhai.
ZHANG Xin, GUO Xiao-ping, LI Peng-fei, FENG Chang-dong, GUO Guang
2020, 36(7):  897-904.  doi:10.19741/j.issn.1673-4831.2019.0814
Abstract ( 155 )   HTML ( 1)   PDF (837KB) ( 79 )  
References | Related Articles | Metrics
The evaluation of ecological restoration effects of abandoned land in a mining area usually only considers improvement in soil properties by vegetation allocation while few studies have focused on the evaluation and screening of different artificial ecological restoration models from a landscape perspective. Taking the dumping site of the Wuhai open-pit coal mine as a study area, 5 typical recovery modes were selected and the landscape functions of natural shrub communities were used as recovery targets for comparison. The landscape function analysis (LFA) method was adapted and used to evaluate the patch area index (A1), the landscape structure index (A2), soil stability (Sa), infiltration (If) and the nutrient cycle (Ne) index of the dumping site under different recovery modes, and the weight of each index was calculated by the maximum variance method to obtain the comprehensive evaluation index of the landscape structure function (Fl). The results show the following. (1) The recovery mode of bio-integrated engineering measures is superior to a single mode. (2) Under the mode of artificial grass seed application combined with brick sash slope protection and geonet recovery, the A1, A2, Sa, If, and Ne reached to the highest values that were 3.2, 1.8, 1.8, 1.7, and 2.4 times as high as those values obtained from artificial grass seed application mode. (3) The value of Fl was the highest under the recovery mode involving artificial grass seed application combined with brick sash slope protection and geonet which is 1.3-1.9 times as high as the values of other recovery modes and 1.6 times as those of the control group. Fl was the lowest under the artificial grass seed application mode, but with no significant difference to that of the control group (P>0.05). Therefore, all the 5 recovery modes can be helpful to achieve the ecological restoration goals of the dump site in this area, and it is best to artificially distribute grass seeds alongside brick sash slope protection and geonet. The results of this research can provide a scientific basis for screening the ecological restoration modes of mining areas in arid desert areas of north-western China and to promote sustainable development.
Study on the Corrosion of Coral Sand by Oxalic Acid.
LI Yue-xuan, LI Peng-fei, PAN Jie, LIU Yun, WANG Ping, DONG Yuan-hua
2020, 36(7):  905-913.  doi:10.19741/j.issn.1673-4831.2019.0229
Abstract ( 219 )   HTML ( 3)   PDF (4871KB) ( 113 )  
References | Related Articles | Metrics
A vegetation ecosystem is essential to maintain a livable environment in a tropical reclamation land. In this paper, kinetics of coral corrosion in the presence of the different concentration of oxalic acid was studied. According to the kinetic model established, main factors affecting corrosion of coral sand were elucidated. The results show that Ca2+ and Mg2+ in the coral sand were rapidly dissolved during the beginning stage of the reaction, followed by the fixation of a large amount of Ca2+ by oxalate to form calcium oxalate precipitate. As the concentration of oxalic acid increased, the concentration of Ca2+ in the solution gradually decreased and the concentration of Mg2+ gradually increased. The maximum concentrations of Ca2+ and Mg2+ were 0.65 and 2.87 mmol·L-1, respectively. The corrosion kinetics of Mg2+ was fitting with Stumm model, indicating this process was mainly governed by diffusion. In addition, dissolution and loss of Ca2+ in coral sand was inhibited at high concentration of oxalic acid. The results of XRD and SEM show that the calcium oxalate precipitates formed by the reaction of high concentration oxalic acid are attached onto the surface of coral sands, and magnesian calcite is preferentially dissolved, followed by aragonite and calcite.
FEEM Analysis of Fulvic Acid Pretreatment by Advanced Oxidation Processes.
LIU Dan, LI Lu, SONG Kang, ZHOU Xiao-hong
2020, 36(7):  914-920.  doi:10.19741/j.issn.1673-4831.2019.0534
Abstract ( 222 )   HTML ( 8)   PDF (9242KB) ( 57 )  
References | Related Articles | Metrics
Removing fulvic acid from surface water using conventional drinking water treatments is difficult and generates harmful disinfection byproducts during the disinfection process. In this study, ultraviolet (UV), peroxydisulfate (PDS), and H2O2 treatments were applied as advanced oxidation processes (AOP) for degrading fulvic acid. The degradation performances of the different AOPs in treating fulvic acid were compared. The fluorescence excitation emission matrix (FEEM) spectroscopy results indicate that the UV/PDS co-treatment can effectively remove recalcitrant fulvic acid within 10 min, which can reduce the odor and color problems caused by fulvic acid and mitigate disinfection byproduct generation in the follow-up disinfection process.
The Effect of Different Ways and Amount of Straw Returning on Cd Sorption for Different Soils.
FAN Ting-ting, LI Qun, ZHOU Yan, SUN Qian, WAN Jin-zhong, ZHANG Sheng-tian, WANG Qing-yu, WANG Zi-chen
2020, 36(7):  921-929.  doi:10.19741/j.issn.1673-4831.2019.0137
Abstract ( 203 )   HTML ( 18)   PDF (1045KB) ( 130 )  
References | Related Articles | Metrics
Straw return, as one of the measures to utilize the agricultural byproduct worldwide, can not only improve soil fertility and crop yield, but also sequestrate carbon emission and remediate soil heavy metal contamination. To further explore the influence of straw return on the sorption of heavy metals by soils and make a foundation for the remediation of soil heavy metal pollution with straw return, four typical soils[black soil (BS), paddy soil (PS), latosol (LS), and red soil (RS)] were selected to conduct isothermal adsorption experiment to investigate the influence of different ways of straw return on Cd2+ adsorption by soils, including crushed straw, burned straw, and fermented straw. In this study, the Langmuir fitting results indicate that the adsorption capacity of Cd2+ by soils was in the order of black soil (4 703-10 598 mg·kg-1) > paddy soil (2 804-4 100 mg·kg-1) > latosol (2 387-3 906 mg·kg-1). The n value of Freundlich fitting results show an ascending order of latosol (0.13-0.19) < paddy soil (0.28-0.43) < black soil (0.27-0.65) < red soil (0.91-2.74), indicating that the affinity of Cd2+ to four soils gradually decreased. For three different ways of straw return, the adsorption capacity for control (i. e., without addition of straw) was the highest, 10 598 mg·kg-1, on black soil. For paddy soil and latosol, the addition of burned straw significantly increased the adsorption capacity (3 109-4 100 mg·kg-1), compared with the addition of other straws (2 387-3 290 mg·kg-1) and controls (2 444-2 872 mg·kg-1). Similarly, the adsorption energy of the addition of burned straw was the minimum (-6.40--5.01 kJ·mol-1) on black soil. On the contrary, for paddy soil, latosol and red soil, the adsorption energy was in the following order with the addition of different ways of straw returning, burned straw (-16.67--3.13 kJ·mol-1) > control (-10.54--2.35 kJ·mol-1) > other straws (-10.66--2.17 kJ·mol-1). The addition of burned straw significantly increased pH in favor of heavy metal adsorption. Besides, the inorganic mineral composition in ash played an important role in Cd2+ adsorption. For tested soils, straw returning is not suitable for black soil with high content of organic matter, but more suitable for soil with low content of organic matter. Generally speaking, on the same type soil, burned straw ash has positive significance on the adsorption capacity and affinity of Cd2+ to soils.
Degradation and Adsorption of Four Non-agricultural Pesticides and Simulation of the Environmental Fate.
GUO Min, ZHOU Lin-jun, JI Gui-xiang, WU Wen-zhu, SHI Li-li
2020, 36(7):  930-937.  doi:10.19741/j.issn.1673-4831.2019.0284
Abstract ( 214 )   HTML ( 6)   PDF (913KB) ( 87 )  
References | Related Articles | Metrics
The hydrolysis, photolysis and adsorption behavior of s-bioallethrin, cypermethrin, spinosad and emamectin benzoate were systematically studied through in-laboratory simulation experiment, and the fate and transport fluxes of the 4 non-agricultural pesticides in environmental matrix were estimated using the Equilibrium Criterion (EQC) model based on the experimental data. The results show that at pH 4, 7 and 9, the hydrolysis half-life (t0.5) of s-bioallethrin was 77.00, 57.80 and 4.41 d; the t0.5 of cypermethrin was >180, 40.80 and 5.64 d; the t0.5 of spinosad was >180, >180 and 6.03 d; and the t0.5 of emamectin benzoate was >180, >180 and 46.20 d, respectively. The hydrolysis rates of the 4 non-agricultural pesticides were gradually enhanced with the increases of temperature and pH. Under the irradiation of xenon lamp, the photolysis half-life of cypermethrin, s-bioallethrin, emamectin benzoate and spinosad was 0.100, 0.738, 1.720 and 6.130 h, respectively. Molecule structure and physico-chemical characteristics were determinative factors affecting their photolysis rates. The adsorptions of 4 non-agricultural pesticides fit with Freundlich equation well in three soils, and pH, organic matter contents, cation exchange capacity and solubility in water significantly affected the adsorption. The predicted results show that soil is the dominant sink of cypermethrin, spinosad and emamectin benzoate, and holds more than 95.0% of these 3 non-agricultural pesticides under steady state and equilibrium conditions. The amounts of s-bioallethrin left in soil, water and air were 70.1%, 18.2% and 10.8%, respectively.
Characteristics of Phosphorus Forms in Sediments of Multilevel Digestate Stabilization Ponds in a Large-scale Swine Farm
LIU Wei, SHI Jin-xia, GUAN Yi-dong, FU Qiang, ZHU Yan-yun, JIN Hong-mei
2020, 36(7):  938-944.  doi:10.19741/j.issn.1673-4831.2019.0481
Abstract ( 178 )   HTML ( 6)   PDF (4487KB) ( 75 )  
References | Related Articles | Metrics
A large-scale swine farm was selected for fixed monitoring to study the change characteristics of phosphorus forms in sediments of multilevel digestate stabilization ponds. The standards, measurement and testing (SMT) method was used to analyze the contents of total phosphorus (TP), inorganic phosphorus (IP), organic phosphorus (OP), NaOH-extracted phosphorus (NaOH-P) and HCl-extracted phosphorus (HCl-P). The results show that the contents of various forms of phosphorus in the sediment of 0-10 cm depth were higher than those in the sediment of >10-20 cm depth. In addition, their contents in the primary stabilization pond (S1) were higher than those from the secondary stabilization pond (S2). The change trend of various phosphorus in the S1 was HCl-P > NaOH-P > OP; while that in the S2 was OP > NaOH-P > HCl-P. The proportion of HCl-P, which was considered as the stable form, in the sediment of 0-10 cm was higher than that in the sediment of >10-20 cm, and higher in S1 than in S2. The results indicate that the phosphorus in the deep layer of sediment is more active than that in the superficial layer. The study will provide a reference for reasonable utilization of phosphorus of sediment of stabilization ponds in animal farms.
Comparative Study on Different Coal Dust Suppression Measures in Coal Yard of Mining Area.
LU Si-qi, ZHAO Ting-ning, XIN Zhi-ming, DUAN Rui-bing, XIAO Hui-jie
2020, 36(7):  945-952.  doi:10.19741/j.issn.1673-4831.2019.0781
Abstract ( 167 )   HTML ( 8)   PDF (4516KB) ( 64 )  
References | Related Articles | Metrics
Coal yard is the main dust source for coal dust diffusion from the mining area to the surrounding environment. Using dust suppression nets and dust suppressants in the coal yard of the mining area can reduce pollution from coal dust. To optimize coal dust suppression measures in the coal yard, a wind tunnel simulation test was conducted to compare the amount, concentration, and wind speed of coal dust blowing through flexible polyester dust suppression nets in various layouts and the performance of three composite dust suppressants at various ratios. The results show that the best dust suppression was achieved through the spraying of 30 g·L-1 environmental friendly dust suppressant and use of a double-layer dust suppression net. The findings indicate that spraying environmental friendly dust suppressant at a concentration of 30 g·L-1 resulted in a threshold wind velocity of coal dust that was 17% higher than that of a double-layer dust suppression net, while the double-layer suppression net reduces the quantities and concentrations of coal dust. Altogether, spraying an environmental friendly dust suppressant at a 30 g·L-1 concentration is effective in accounting for the threshold wind velocity of coal dust, while a double-layer dust suppression net is the optimal measure for reducing the quantity and concentration of coal dust.
Evaluation of Heavy Metal Pollution in Farmland Around a Thermal Power Plant in Shanxi Province.
FAN Bei-xi, ZHANG Yong-qing
2020, 36(7):  953-960.  doi:10.19741/j.issn.1673-4831.2019.0662
Abstract ( 182 )   HTML ( 6)   PDF (15955KB) ( 107 )  
References | Related Articles | Metrics
In order to determine the impact of a thermal power plant in Shanxi Province on the pollution of soil heavy metals in the surrounding farmland, 27 soil samples were collected and the contents of Cd, Cr, Cu, Hg, Mn, Ni, Pb and Zn in the samples were determined. The soil pollution was evaluated from the aspects of the characteristics of element contents, the correlation and the distribution in the surface layer. The results show that the average content of eight heavy metal elements were lower than GB 15618-2018 standard in the soil samples of the study area, but higher than the background value of Shanxi soil environment with the exceeding rate of 100%, 93%, 100%, 44%, 93%, 15%, 96% and 78%, respectively. The evaluation result of single factor pollution index method show that the farmland soil around the power plant were not polluted according to GB 15618-2018 standard, but the heavy metal elements in the farmland soil around the power plant were accumulated to a certain extent based on the background value of the soil environment in Shanxi Province. The evaluation result of the comprehensive pollution index method show that the farmland soil around the power plant was at the clean level on the basis of the soil environmental quality standard, but the content of heavy metals reached the moderate cumulative level around the power plant on the basis of Shanxi soil environmental background value. Evaluation results of surface soil comprehensive quality index method around power plant show that only one sample point in the south-central part was slightly polluted, and the rest of the sampling points were in a pollution-free state. In summary, the farmland soil around the power plant needs to take effective measures to avoid the continued accumulation of threats to the soil quality and crop production damage.