Table of Content

Volume 35 Issue 9
25 September 2019
Table of Contents
Table of Contents
2019, 35(9):  0-0. 
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Natural Organic Matter-Metal Ion/Oxide-Phosphorus Complexes in Environment: A Review
WU Wen-li, YAN Jin-long, JIANG Tao, WEI Shi-qiang
2019, 35(9):  1089-1096.  doi:10.19741/j.issn.1673-4831.2018.0636
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Natural organic matter (NOM)-metal ion/oxide (Metal)-phosphorus (P) complexes as major P species widely exist in the aquatic and terrestrial environment. The behaviors of these complexes play an important role in the migration and transformation of P in the environment. The research progress of structure characteristics, determination methods, molecular weight identification, bioavailability and the influencing factors for the stability of NOM-Metal-P complexes at home and abroad are reviewed.The expectation to research on NOM-Metal-P complexes in the future are described. Previous studies indicate that NOM-Metal-P complexes account for more than 50%, whereas in some cases, more than 80% of P in natural water or soil solution. The metal ion/oxide could act as metal bridge which binds P to the surface of NOM. Currently, the high molecular mass fractions of NOM-Metal-P complexes were usually separated from free orthophosphate by 500 or 1 000 Da filters through ultrafiltration. In addition, it is found that NOM-Metal-P complexes can increase P migration in soil and it is also found that the bioavailability of P fertilizer containing NOM-Metal-P complexes is higher than those only containing single phosphate. Meanwhile, researchers also determined that the stability of NOM-Metal-P complexes were affected by ultraviolet light, pH and coexisting ions in both water and soils.
Research Advances in the Assessment of Heavy Metal Bioavailability to Earthworms in Contaminated Soils
WANG Man-li, LUO Qi-shi, RAN Yu-ling, LIN Kuang-fei, CUI Chang-zheng
2019, 35(9):  1097-1102.  doi:10.19741/j.issn.1673-4831.2018.0508
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Bioavailability can reflect the migration and bioaccessibility of heavy metals and it has been widely used in the post stabilization remediation of soils contaminated with heavy metals. To facilitate the use of bioavailability in post stabilization remediation assessments, the methods used to evaluate the heavy metal bioavailability to earthworms in soil were systematically summarized. In addition, the corresponding relationship between these methods and the chemical reagents used for extraction, as well as the factors affecting the bioavailability evaluation methods, were also summarized. Therefore, it is suggested that the effects of the stabilized remediation of soil contaminated with heavy metals be evaluated based on chemical extraction, combined with bioavailability evaluation methods.
Progress of Research on Environmental Criteria for Lead in Soil
GE Feng, YUN Jing-jing, XU Ke-ke, ZHANG Ming-zhu, XU Lin-yue, LI Yan, ZHANG Ai-guo
2019, 35(9):  1103-1110.  doi:10.19741/j.issn.1673-4831.2018.0662
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Environmental criteria are the scientific basis for the revision of environmental standards, quality assessment, risk control, emergency accident management and the whole management system. They are also the foundation for national environment protection and management. The research status and main technical points of environmental criteria on heavy metal lead in soil at home and abroad were comprehensively analyzed from three aspects, human health, ecological safety and agricultural products safety. Possible key issues in its future development in China are further prospected so as to provide reference for the study of relevant environmental criteria in China.
Landscape Ecological Security Pattern in Central Guizhou Urban Agglomeration
WANG Yuan, ZHOU Chang-wei
2019, 35(9):  1111-1117.  doi:10.19741/j.issn.1673-4831.2018.0561
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The ecological security of urban landscape pattern is the pre-condition for the sustainable development of urban agglomerations. With the aim to clarify the ecological security of landscape pattern of agglomerated cities in Guizhou Province, ENVI and ArcGIS were used to interpret for local land use type in 2017. Therein, the ecological source plots were identified from the analysis on importance of ecosystem services and ecological environment sensitivity. Based on the proportion of rocky desertification and land use type, the areal surface of the resistance to agglomerated cities was constructed. Furthermore, the buffering zone was detected, hence the ecological node can be identified to generate the corridor by analyzing the cost at distance and path. The landscape ecological security pattern in Central Guizhou urban agglomeration was then constructed. And the following results were obtained. The low level security pattern in the landscape ecological security pattern in Central Guizhou urban agglomeration was 30 354.95 km2, accounting for 56.42% of the total area, the middle level occupied 35 132.14 km2, accounting for 65.30% of the total area, and the high level occupied 39 780.76 km2, accounting for 73.94% of the total urban area. As the protection of the large area of Central Guizhou urban agglomeration need to be strengthened, attention should be paid to urban construction planning, so as, not to destroy the ecological environment in Central Guizhou urban agglomeration.
Spatial-Temporal Dynamic Evolution Characteristics of Land Use/Cover in the Middle and Lower Reaches of Yarkant River Basin in Recent 35 Years
Malika AMAT, Mansur SHABIT, ZHANG Xue-qi
2019, 35(9):  1118-1126.  doi:10.19741/j.issn.1673-4831.2019.0162
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Based on remote sensing image data the middle and lower reaches of Yarkant River Basin in 1982, 1990, 2000, 2010 and 2017, GIS technology was employed to analyze the land use/cover change of the area within the 35 a. The results show that:from 1982 to 2017, the proportion of cultivated land and construction land in the study area was continuously increased, the increasing extent is from 4.92% and 0.33% to 13.06% and 0.67%, respectively; The areas of forest land, grassland and unused land decreased by 8.43×104, 4.48×104 and 2.81×105 hm2, respectively. The change of wetland and water area is relatively minor, meanwhile, they generally showed a decreasing trend. The reduced area accounts for 0.08% and 0.14% of the total area of the River basin, respectively. Among all land use types, the change rate of cultivated land was the highest, up to 4.73%, which followed by construction land. The reduction of forest land, grassland, wetland and water area was mainly affected by natural factors such as annual average temperature rise, relative humidity decline and evaporation increase; The increase of cultivated land and construction land areas and the decrease of unused land area were mainly influenced by human factors such as population, gross domestic product of primary industry and sharp growth of GDP. In addition, the adjustment of policy factors also had a significant impact on land use/cover change in the study area.
Assessing the Responsive Relationships Between Straw Burning From MODIS Data and Air Quality in Shandong Province
SU Hui-yi, ZHAI Meng-zhen, WANG Wen-lin, LI Ming-shi
2019, 35(9):  1127-1135.  doi:10.19741/j.issn.1673-4831.2018.0537
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Among various sources of pollution, outdoor straw burning has a great impact on air quality through releasing various kinds of air pollutants and fine particles, shaping one of the sources of air pollution. MODIS instrument has the advantages of high sensitivity, timeliness and wide spatial coverage and using its data to monitor straw burning events can quickly identify the location, amount and severity of fire spots across a wide region. MODIS data in partnership with the contextual algorithm was used to extract fire spots in Shandong Province in the current work. The values of six air quality indices including PM10, PM2.5, NO2, SO2, CO, O3, as well as the meteorological data were collected. Additionally, 17 cities in Shandong Province were grouped into two categories, coastal region and inland region according to their proximity to the coastlines to derive a targeted analysis that focuses on the influential differences in air quality imposed by straw burning. Specifically, by carrying out the spatial interpolation with daily air quality data for the two regions, the correlation between the fire points and the total air quality index of all grid points in the region was analyzed. And then the impact of contamination caused by burning straws on environmental air quality, as well as differences of air quality between coastal and inland region were discussed. As a result, a significantly positive correlation between the amount of fire spots and the total air quality index was observed. Of which, there was a significant correlation between straw burning and AQI, PM2.5, PM10 and O3, indicating that the increase in fire spots leads to an increase of air quality indices, accordingly, a poor air quality gained. Furthermore, the correlation presented in the coastal region was stronger than that presented in the inland region, indicating that the atmospheric spread condition is one of the important prerequisites when examining the environmental impacts of straw burning.
Evolution of Ecosystem Service Value and Analysis of Driving Forces in the East Region of Sichuan Province, China
HAN Rui, SUN Si-qi, GUO Luo, CHEN Yi-zhu
2019, 35(9):  1136-1143.  doi:10.19741/j.issn.1673-4831.2018.0596
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The east region of Sichuan Province(C)huandong is a crucial ecological barrier in the upper reaches of the Yangtze River, which is of great significance. Using the dataset of 6 period from 1990 to 2015, both land-use change dynamics and value of ecosystem services were investigated by employing the methods of ArcGIS application and spatial statistics. Moreover, the driving factors were also researched in this study. It is found that:(1) Farmland and forest land were the main type of land use, which experienced low comprehensive dynamics. (2) The total ecosystem services value presented a trend of continuously increase. The greatest contribution of land use types to the total ecosystem services value was forestland (42%); and farmland (31%), water land (22%), grassland (5%) ranked 2nd, 3rd and 4th, respectively. Unused land (0%) endured the lowest level. Besides, the ecosystem services value of unit area showed a declining trend from both northeast and southeast toward the central and west of the study area. Meanwhile,different types of land use had different impact on the ecosystem service value. The results show that both forestland and water land had strong positive correlation with ecosystem service value. (3) The main driving forces, which affected regional ecosystem service value, includes population density, rural population, industrial output and domestic tourism income. In addition, spational correlation analyais revealed that socio-economic factors had negative correlation with ecosystem service value. Low-Low and High-Low areas were clustered in the west, and Low-High and High-High areas were clustered in the south. Therefore, the results of this research can provide reasonable scientific basis on the ecological security and sustainable development for the east region of Sichuan Province.
Research of Material Metabolism and Dematerialization in Heilongjiang Province Based on MFA
REN Jia-min, MA Yan-ji, GUO Fu-you
2019, 35(9):  1144-1153.  doi:10.19741/j.issn.1673-4831.2018.0697
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Based on MFA framework, Heilongjiang Province was chosen as the study area to analyze the changing trend of material input and output from 2003 to 2015. Direct material input(DMI) and domestic processed output(DPO) were selected to explore the interactions between environments and economic development and logarithmic mean weight divisia index(LMDI) was used to measure the influences of related factors. The results are as follows. First, during the study period, total material requirement (TMR) and Total Material Output (TMO) declined gradually after 2011, but their total amount was still higher than the initial period. DMI mainly consists of biological material and fossil fuels, and solid waste is the main part of DPO. Second, DMI and DPO were at different evolutionary stage. The influence of DMI was declining in relation to the environmental total impacts, but the relationship was not stable. And DPO was in the stage from the peak of output per unit of GDP to the peak of output per capita. Third, economic scale effect contributed greatly to the growth of DMI and DPO. Population size had a positive impact on the growth of DMI and DPO at the beginning but turned to negative impact later on. While technology progress made great contribution to the DMI and DPO reduction, cleaner production effect did not function properly to restrain the growth of DPO.
Characteristics of Spatial-Temporal Dynamic Change in Ecological Land: A Case Study in Huaqiao International Service Business Park, Suzhou
WANG Ming-can, WANG Chang-tian, ZHANG Yin-long, ZHOU Man-li, LI Shuang, LI Jia-xi, LI Hai-fu, WU Yong-bo
2019, 35(9):  1154-1162.  doi:10.19741/j.issn.1673-4831.2018.0554
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The study area was located in a rapidly urbanized small-scale region-Huaqiao International Service Business Park. High-resolution remote sensing images and GIS technology were used to investigate the spatial and temporal dynamic of ecological land, landscape pattern, and spatial pattern of ecological quality by means of the transition matrix of land use change, centre of gravity, the indexes of landscape pattern, and equivalent area, respectively. The results show that (1) from 2005 to 2015, ecological land decreased by 913.11 hm2 due to the speedy expansion of construction during the rapid urbanization in the study area, and the centre of gravity of ecological land moved southward; (2) from 2005 to 2009, the cultivated land decreased while the other ecological land did not change significantly; from 2009 to 2015, the degree of patch fragmentation and landscape complexity decreased, while the ecological land, except for the cultivated land, increased rapidly; (3) from 2005 to 2015, the average equivalent area for ecological land increased from 0.28 to 0.31, indicating that the ecological quality was improved; the land quality of 57.01% of the whole region was improved, while only for 17.22% the land quality declined. Overall, the policy of ecological construction has played an effective role during the rapid urbanization, especially under the situation of shortage of ecological land. In the future, the Huaqiao administration should emphasize on improving the ecological quality of land in the central region and further on optimizing the land resource allocation in order to improve the overall ecological quality of land.
Effects of Biochar Addition on Soil Microbial Community Structure Under Different Water Conditions
YU Xiao-yan, YANG Yan-fang, ZHANG Ping-jiu, ZHANG Qun, DU Yong-gu
2019, 35(9):  1163-1171.  doi:10.19741/j.issn.1673-4831.2018.0638
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Soils with biochar pyrolyzed from reed straw at 350 and 600℃, were incubated under different water conditions[75% field water holding capacity (FWHC); drying rewetting cycle; water flooding] for 240 and 720 days, respectively. Soil PLFAs were measured to investigate the effect of water conditions on soil microbial community structure under biochar addition. The results show that biochar addition significantly increased total PLFAs content and the individual group microbial PLFAs content after 240-day incubation under 75% FWHC. However, their PLFAs content was significantly decreased under biochar addition under drying-rewetting cycle and water flooding, especially in the drying-wetting cycle treatment. Moreover, after 240-day incubation, PLFAs content of most microbial groups was higher in soils with biochars at 350℃ than those in soils with biochars at 600℃. Except for actinobacteria under 75% FWHC, comparing with the controls (no biochar addition), total PLFAs content and most group microbial PLFAs content was higher under 240-day incubation than those under 720-day incubation. Different from the controls, except for G+ bacteria, the other groups of microbial PLFAs content in soils with biochar was the highest under water flooding, and the lowest under drying-rewetting cycle. Under 75% FWHC, biochar addition increased soil microbial Shannon-Wiener index (H) and Pielou index (J), and decreased soil Simpson index (D). However, biochar addition decreased soil microbial H and J, and increased D under water flooding only after 240-day incubation. By contrast, biochar addition did not show clear effect on these indexes under drying-rewetting cycle. Redundancy analysis and partial correlation analysis indicated that there was a significant correlation between soil pH, nitrate N, available P and microbial community structures, and more similar soil microbial community structures under the same wet conditions. Moreover, the duration of incubation and water condition controlled the effect of biochar addition on soil microbial community structures. Soil microbial PLFAs content was promoted only by biochar addition under 75% FWHC within 240-day incubation, and decreased or not affected on microbial PLFAs under other treatments.
Analysis of Phytoplankton Community Structure Changes and the Driving Factors in Summer of Luoma Lake
QIN Bao-li, TANG Jin-yu, WANG Xuan-peng, WU Chun, YE Jian-yong, DING Chen-long
2019, 35(9):  1172-1181.  doi:10.19741/j.issn.1673-4831.2018.0784
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In order to provide a scientific basis for the ecological protection of Luoma Lake, northern Jiangsu Province, in the summer of 2017, the phytoplankton community in the lake was investigated to explore the relationship between phytoplankton community structure changes and environmental factors. A total of 6 phyla, including 32 genera of phytoplankton were identified. The number of Chlorophyta was the largest, followed by Cyanophyta and Diatoma, and the dominant genera were mainly Planktothrix, Microcystis and Chlorella. The phytoplankton abundance of the whole lake was ranged from 2.63×105 to 2.85×107 cells·L-1, and biomass was ranged from 0.092 to 4.522 mg·L-1. Shannon-Wiener index of phytoplankton in the whole lake ranged from 0.60 to 2.60, with an average of 1.75, moreover, the index in September was significantly higher than that in August (P<0.05), but the difference in diversity index between different locations was no significant (P>0.05). Compared with the results of previous investigations in Luoma Lake, the diversity index of the whole lake did not have much difference, the cell abundance was significantly increased, and the dominant genera were concentrated in Cyanophyta and Chlorophyta, especially the number of Planktothrix increased distinctly. From the changes of dominant genera and algae cell density in recent years, the eutrophication degree of Luoma Lake has still been increasing. The results of RDA analysis show that the combination of water temperature, dissolved oxygen and nitrogen-phosphorus ratio explained 28.16% of the phytoplankton community structure change in the summer of Luoma Lake. Sand mining, purse seine culture and summer human activities had a comparatively large impact on this change. Therefore, it is imperative to reduce the disturbance of human activities to protect the water quality of Lake Luoma and the water quality of the South-to-North Water Transfer Project.
Distribution Pattern of Genes Conferring Resistance to Macrolides in Rhizosphere Soil of Maize
CHEN Yun-jie, GUO Xin-yan, YANG Yi, WANG Na, YANG Ye
2019, 35(9):  1182-1189.  doi:10.19741/j.issn.1673-4831.2019.0029
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Antibiotic residues in crop soils create selection pressure on the occurrence and dissemination of antibiotic resistance genes (ARGs), rendering rhizosphere soils "hot spots" for ARGs. In the present study, the soil microbiome was monitored for macrolide resistance genes (erms) arising from the rhizosphere in maize during different crop growth periods over a duration of 63 days using real-time polymerase chain reaction (PCR) technology. The relative abundance (erms:16S rDNA) of erms in the soil was in the order of ermF > ermX > ermB > ermC. The relative abundance of ermF, ermX, ermB, and ermC in bulk soil were 4.72×10-2, 1.98×10-3, 7.13×10-1, and 1.75×10-2, respectively, on D7, whereas, on D63, the relative abundance were 1.74×10-3, 3.24×10-4, 3.53×10-3 and 2.28×10-3, respectively. The corresponding gene proliferation rates in bulk soil were -96.3%,-83.6%,-99.5%, and -87.0%, respectively, compared to -88.3%, 103.0%, -88.6%, and 71.5%, respectively, in rhizosphere soil. These results suggest that the maize rhizosphere had a significant effect on the proliferation or transfer of ermC and ermX. The relative abundance of erms at different soil depths was in the order of 0-0.2, > 0.2-0.4, and > 0.4-0.6 m, indicating that the resistance genes had a downward migration tendency, with relative abundance of resistance genes decreasing with an increase in soil depth. The detection rate of resistance genes at corresponding depths of soil for the same sample was in the order of RH > CK, suggesting that the presence of the plant rhizosphere not only promotes an increase in resistance gene abundance in the soil but also promotes vertical migration in the soil profile.
Effects of Spraying Uniconazole (S3307) on Cadmium Accumulation of Two Ecotypes of Bidens pilosa
HUANG Ke-wen, SHAN Shi-yao, LU Chun-yan, OU Ruo-han, SUI Li-yun, WANG Ting, LIU Lei, LIAO Ming-an, LIN Li-jin, REN Wei
2019, 35(9):  1190-1196.  doi:10.19741/j.issn.1673-4831.2018.0655
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With the intensification of soil heavy metal contamination, it is of great practical to explore ways to improve the soil remediation efficiency by hyperaccumulator plants. To reveal the effects of uniconazole (S3307) on the growth and heavy metal accumulation of hyperaccumulator plants, pot experiment was conducted to study the effects of spraying S3307 solution with different concentrations(0, 25, 50, 75, 100 and 125 mg·L-1) on the growth and cadmium accumulation of two ecotypes (farmland and mining) of Bidens pilosa. The results show that S3307 inhibited the growth of both the two ecotypes of Bidens pilosa by significantly decreasing the biomass and plant height. Compared with the control, S3307 significantly increased the photosynthetic pigment (chlorophyll a, chlorophyll b and carotenoid) contents and cadmium contents in two ecotypes of Bidens pilosa. When the concentration of S3307 was 125 mg·L-1, the cadmium contents in the shoots of farmland and mining ecotypes of Bidens pilosa got the maximum, which were 91.44% and 77.79% higher, respectively, than the control. For the cadmium accumulation amount of Bidens pilosa, the cadmium accumulation amount by the shoots and whole plants of two ecotypes of Bidens pilosa got the maximum when the concentration of S3307 was 25 mg·L-1. The suitable concentrations of S3307 could effectively improve the remediation ability of farmland and mining ecotypes of Bidens pilosa to cadmium-contaminated soil, and the best dose is 25 mg·L-1.
Remediation of Simulated Heavy Metal-Contaminated Yellow Brown Soil by Integrated EGTA Washing With TSP Stabilization and Its Environmental Risk Assessment
WANG Cai-cai, ZHANG Jin-yong, XIAO Yang, WANG Shi-ze, WANG Ming-xin
2019, 35(9):  1197-1205.  doi:10.19741/j.issn.1673-4831.2018.0562
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Considering that chelant-enhance washing may increase the activity of residual metals in soil, the risk reduction of heavy metal-contaminated soil by integrated soil washing with immobilization was investigated. Ethylenebis (oxyethylenenitrilo) tetraacetic acid (EGTA) and triple super phosphate (TSP) were used as washing and stabilization agent, respectively, to remediate Cu-, Zn-, Pb-and Cd-contaminated yellow brown soil. The effects of EGTA dosage, washing time, liquid-to-solid ratio and TSP dosage on heavy metal removal rate and leaching concentration were explored. The relationship between the environmental risk reduction rate and EGTA dosage, liquid-to-solid ratio and TSP dosage was fitted by response surface method (RSM). The remediation performance was evaluated by the environmental risk assessment method involving heavy metal content in soil, leaching concentration and toxicity. The results show that with EGTA enhanced-washing, the elution rate of Cu and Cd was relatively higher and the leaching concentration of Zn and Cd was significantly reduced. By increasing the washing time, the removal rate of Cu, Zn, Cd was improved, while the leaching concentration declined. However, the leaching concentration of Pb was increased. With the increase of liquid-to-solid ratio, the removal rate of Zn and Pb was increased, while that for Cd was decreased and for Cu was firstly increased and then decreased. Meanwhile, the leaching concentration of Cu, Zn and Cd was decreased while for Pb was increased. The leaching concentration of Pb was significantly reduced by the passivation of TSP. The total environmental risk reduction rate (β) had a significant quadratic relationship with the EGTA dosage, liquid-to-solid ratio and TSP dosage. The model results are similar to the verification experiment results when the liquid-to-solid ratio, EGTA, TSP and β were 10, 1.0 g·L-1, 2% and 62.80%, respectively, which indicate that the model has good simulation and prediction ability. The environmental risk of Cu, Zn, and Cd could be significantly reduced by increasing the EGTA dosage and liquid-to-solid ratio. The passivation of TSP possessed a positive effect on the environmental risk reduction of Pb. In addition, the synergistic effect on β was observed between EGTA dosage and liquid-to-solid ratio, as well as EGTA and TSP dosage.
Nitrogen Budgets Characteristics of Different Land Use Patterns in a Small Catchment.
WANG Huan-xiao, WANG Xiao-yan, DU Yi, LI Yu-xin
2019, 35(9):  1206-1213.  doi:10.19741/j.issn.1673-4831.2018.0724
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Taking land use as the research unit, nitrogen budget of different land use in Sheyuchuan small catchment was studied on the basis of actual survey. Input, output and surplus of nitrogen in different land use were estimated to discuss the sources and route of nitrogen cycle in this small catchment. Results show that, the breeding area had the highest intensity of nitrogen input and output, and the ecological forest had the lowest; the input intensity of economic forest was three times that of cultivated land. Fertilizer was the main nitrogen input in economic forest and cultivated land, which organic fertilizer in economic forest accounting for 83.32%, while chemical fertilizer was the main input in cultivated land accounting for 56.44%, which resulted in fertilizer application loss as the main output source. The main input source of ecological forest was nitrogen fixation accounting for 70.05%, and the output was mainly natural. Nitrogen in residential and breeding areas were mainly based on food and feed inputs. Nitrogen in all land use types in the catchment was surplus, while the difference in surplus intensity of different land use types was obvious. Among them, the breeding area (4 795.15 kg·hm-2) and economic forest (493.72 kg·hm-2) have the highest surplus intensity, followed by cultivated land (139.13 kg·hm-2). Ecological forest (77.17 kg·hm-2) and residential area (68.52 kg·hm-2) have the lowest surplus intensity. The results imply that reducing fertilization, controlling fertilizer loss and strengthening nitrogen management in livestock and poultry systems are the focuses of nitrogen management in this catchment.
Study on Quantitative Structure-Activity Relationship Model for Ozone Radical Reaction Constant of Organic Chemicals
FAN De-ling, WANG Zhen, WANG Lei, ZHOU Lin-jun, GU Wen, LIU Ji-ning, SHI Li-li
2019, 35(9):  1214-1218.  doi:10.19741/j.issn.1673-4831.2018.0641
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The reaction rate constants of ozone radical (KO3) is of vital importance to the characterization of the environmental fate and the evaluation of the persistence of organic pollutants in the atmosphere. In this study, quantum chemistry method was used for the structure optimization of 152 organic chemicals. Based on eight Dragon descriptors, the QSAR model was developed by employing genetic algorithm-multiple linear regressions (GA-MLR) and the model quality was evaluated according to the QSAR model development and validation guideline issued by Organization for Economic Cooperation and Development (OECD). The results show that the adjust determination coefficient (Radj2), the root mean square error (RMSE), leave-one-out cross-validation squared correlation coefficient (QLOO2) were 0.784, 1.127, and 0.744, respectively, indicating that the model has high goodness-of-fit and robustness. The external validation coefficient QEXT2, REXT2 and ERMS,EXT were 0.664, 0.761 and 1.039, respectively, indicating that the model has good predictive ability. The Williams plot were used to visualize the applicability domain (AD) of the model and the result indicate that there was only one X outlier. Thus, the QSAR model can be employed to predict -lg KO3 values of other compounds within the AD of the model.
Genetic Diversity of Cyanotoxins Synthesis Gene of Toxin-producing Cyanobacteria in Haigeng of Dianchi Lake in Yunnan
LIU Yu-shan, WANG Yang, LI Chun-xiao, LI Ning-hao, DONG Shu-wei, LIU Li
2019, 35(9):  1219-1224.  doi:10.19741/j.issn.1673-4831.2018.0688
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Cyanobacteria bloom is a global environmental issue, and the cyanotoxins produced by cyanobacteria seriously endanger aquatic ecosystem and human health. In order to analyze the genetic diversity of cyanotoxins synthesis genes of the toxin-producing cyanobacteria in Dianchi Lake, the expression and sequences of microcystin synthase gene mcyE, anatoxin synthase gene anaC and paralytic shellfish toxins sxtA gene were investigated by Polymerase Chain Reaction(PCR) and TA-cloning-sequencing in Haigeng from March 2017 to February 2018. These three genes were detected in all sampling area. Phylogenetic trees were conducted for analysing of these genes and it was found that the genetic diversity of the three cyanotoxins synthesis genes was relatively single, the mcyE gene was mainly produced by Microcystis, whereas anaC and sxtA genes were mainly produced by Aphanizomenon.