The natural frozen experiment on the water from Wuliangsuhai lake shows that the pollutants migrate from ice body to water body during the freezing process, which means that freezing process has a good purification effect on pollutants in water environment. The experiment also shows that the removal efficiency of pollutants rises at first and then decreases as the ice thickness increases. At 15cm thickness, the removal efficiency of total dissolved solids(TDS), ammonia nitrogen (NH 3 -N) and chemical oxygen demand (COD) can reach 81.20%, 86.80% and 86.60%.What is more, the removal efficiency is better as the frozen stage increase. The removal efficiency of TDS, NH 3 -N and COD is more than 92% through three stages frozen. Drawing inspiration from the natural frozen experiment and its mechanism of frozen concentration effect, a tentative idea that natural cool energy can be applied in the non-centralized water supply field was put forward and a reasonable technological process of freezing purification was designed, which can not only improve the quality of drinking water in rural area, but also can reduce the drinking water processing cost.
为揭示冰封期氨氮（NH4+-N）在沉积物-水界面的迁移机制及内源性营养盐对全湖污染的贡献，于2018年2月初在乌梁素海湖区7个采样点采集了上覆水体与沉积物样品，得到了冰封期上覆水体与沉积物间隙水中的NH4+-N浓度，估算了沉积物-水界面NH4+-N的扩散通量.结果显示，上覆水体中NH4+-N浓度变化范围为0.55~1.60 mg/L，平均值为1.05 mg/L，0~5 cm表层沉积物间隙水中NH4+-N浓度是上覆水体中的10倍以上，其变化范围为6.64~18.63 mg/L，平均值为11.92 mg/L.估算沉积物间隙水NH4+-N向上覆水体的扩散通量为1.282~4.269 mg/（m2·d），表明在湖水冻结过程中，底泥沉积物接纳了大量的可溶性污染物成为内源污染源，会在冰封稳定期、融冰期和融冰后的一段时间内成为湖水的主要污染源.;Lake Ulansuhai is the largest lake in the Yellow River Basin with an area of 293 km2. The average air temperature is 7.3℃ and the winter is about six months with a cumulative negative accumulated temperature about 610-800℃·day. The lake water usually starts freezing in the early November and melting in the end of March or in the early April of the following year. The lake is completely sealed by ice in terms of ice-sealing period for about 100-130 days with an ice thickness of 0.63 m in average. To get better understanding in the migration mechanism of ammonia nitrogen at the water sediment interface and the impact of endogenous nutrients on the lake environment during the ice-sealing period, the water and sediment samples were collected at seven sampling sites in early February of 2018 in Lake Ulansuhai. The concentrations of ammonia nitrogen of the water samples were analyzed. The diffusion flux of ammonia nitrogen at the water sediment interface was estimated. The results showed that the concentrations of ammonia nitrogen in the water ranged from 0.55 mg/L to 1.60 mg/L with an average of 1.05 mg/L. The concentrations of ammonia nitrogen in the pore water of 0-5 cm surface sediments were one order of magnitude greater than that in overlying water which ranged from 6.64 mg/L to 18.63 mg/L with an average of 11.92 mg/L. The diffusion flux of ammonia from the sediments to the water was 1.282-4.269 mg/(m2·d). This indicated that a large number of soluble pollutants had been transported to the sediments during the process of freezing. It would be the one of the dominated source of water pollution to the lake environment in the period of ice stability, during the period of ice thawing, and in a period of time after ice thawing.
Abstract This study is carried out to promote the precise supervision of dangerous goods transportation training, improve the efficiency of civil aviation supervision and further ensure the safety of air transportation. First, from the perspective of behaviour interaction and interest demands, evolutionary game theory is used to construct a tripartite evolutionary game model of dangerous goods transportation training institutions, the Civil Aviation Administration of China (CAAC) and the public. Then, the evolutionary game equilibrium of the system is further analysed under the joint action of the three parties. Finally, the influences of important parameters of the model on the behavioural strategy selection of the three parties are investigated via MATLAB numerical simulation. The conclusions reveal that the system has three evolutionarily stable strategies under different parameters, namely (non-compliant training, supervision, non-participation in supervision), (non-compliant training, supervision, participation in supervision) and (compliant training, supervision, non-participation in supervision). Moreover, the CAAC supervision cost, the fine amount, the supervision cost of public participation, the supervision success rate and the reporting reward amount are the main parameters that affect the behavioural strategy selection of the tripartite game players. The conclusions and suggestions of this study provide a decision-making basis and guidance for the supervision and management of civil aviation dangerous goods transportation training.
Abstract This study analyzed the wintertime surface heat exchange for the Inner Mongolia reach of the Yellow River, China, based on the data from the nearby weather station at Wulateqianqi. In this analysis, the solar radiation is based on the observed data. Other components of the surface heat flux, that is, long‐wave radiation, and evaporative and conductive heat fluxes, are calculated. The relative importance of the contributions of long‐wave radiation, conductive, and evaporative heat fluxes are in descending order. The air temperature is the most important meteorological factor to the total heat flux. Although the wind speed influences evaporative and conductive heat fluxes, it has the least correlation with the total heat budget. The heat exchange coefficient for the linearized surface heat exchange equation is 21.87 W/(m 2 °C), which is comparable with published values in the regions of United States and Canada with similar latitudes.
This study measured the primary productivity (PPeu) of phytoplankton in Wuliangsuhai Lake from April 2014 to January 2019 based on the monitoring and on-site exploration of 20 sampling points in the entire lake using a vertically generalized production model (VGPM). The relationship between the spatiotemporal variation in PPeu and environmental factors was also analyzed. Our findings indicated that the temporal heterogeneity of PPeu was strong, and the average annual PPeu of the four seasons was significantly different (P < 0.05, F = 54.74), exhibiting the following descending order: summer (1279.89 ± 111.04 mg C∙m−2∙d−1) > spring (782.42 ± 59.34 mg C∙m−2∙d−1) > autumn (465.03 ± 49.30 mg C∙m−2∙d−1) > winter (96.34 ± 10.36 mg C∙m−2∙d−1). Even in winter with harsh environmental conditions, PPeu under the ice sheet can reach 8 % of that in summer. The spatial heterogeneity was weak, and only the average annual PPeu in spring exhibited a significant spatial difference (P < 0.05, F = 5.18): north > central > south. However, there were no significant differences in other seasons. Redundancy analysis (RDA) and multiple linear regression (MLR) results showed that in addition to directly participating in the calculation of the environmental factors of PPeu, PPeu in spring was mainly affected by total nitrogen (TN), total phosphorus (TP), and dissolved oxygen (DO). PPeu in summer was mainly affected by dissolved inorganic phosphorus (DIP), dissolved oxygen (DO), salinity (S), electrical conductivity (EC), and water temperature (WT). PPeu in autumn was mainly affected by pH, electrical conductivity (EC), suspended solids (SS), and water temperature (WT). PPeu in winter was mainly affected by water temperature (WT) and ice thickness (IT). The mechanisms through which environmental factors affect primary productivity are complex and dynamic. Therefore, long-term monitoring and research of PPeu in Wuliangsuhai Lake are necessary to explore the adaptation strategies of phytoplankton in ice and ice-free periods and understand the operation of natural life support systems under the alternation of ice generation and extinction. In turn, this would facilitate the development of strategies to maintain phytoplankton biodiversity and prevent algal blooms.
以乌梁素海为研究对象,应用化学方法对乌梁素海湖泊表层沉积物有机质含量、腐殖质组成、影响腐殖质的环境因子及腐殖化程度进行了研究,结果表明:乌梁素海表层沉积物有机质含量变化范围为1.06%~5.38%.有机质分布特征与表层沉积物所处的水力条件、水生植物分布、人为活动有关;腐殖质组成中,胡敏酸含量为0.65~2.78 g/kg,富里酸含量为2.19~8.72 g/kg,胡敏素是主体,含量在3.28~20.92 g/kg之间;腐殖质与环境因子的相关性分析中,各组分含量与有机质含量呈极显著相关.pH值与胡敏素含量呈显著负相关.溶解氧与富里酸、胡敏素含量分别呈极显著正相关、显著正相关.腐殖化程度分析中,随着有机质含量的上升,可提取腐殖质的相对含量下降.PQ值介于9.50%~27.06%之间,平均值为21.47%,变异较大,且腐殖化程度较低.;The paper studied the organic matter contents,humus composition and the degree of humification of the surface sediment of Lake Wuliangsuhai by chemical method.Correlation between sediment humus and physical-chemical factors were also discussed.The results showed that the organic matter of the surface sediment varied from 1.06% to 5.38%.Their distribution characteristics were related to hydraulic condition,aquatic plant distribution and human activities.In the humus composition,the content of humic acid and fulvic acid varied from 0.65 to 2.78 g/kg and from 2.19 to 8.72 g/kg,respectively.The humin is the main component in the sediment,ranging from 3.28 to 20.92 g/kg.Based on the correlation analysis of humus and environmental factors, each component is significantly correlated with the organic matter content.The pH value is significantly negative correlated with humin.Dissolved oxygen is significantly positive correlated with fulvic acids and significantly positive correlated with humin.The organic matter content increased while the content of extracted humic substances is decreased in the humification analysis.The PQ values range from 9.50% to 27.06%,with the average of 21.47%,which varied dramatically and with low degree of humification.
为探明草型湖泊乌梁素海水体营养状态及演变趋势,明确水体富营养化的关键影响因子,本文采用2006-2017年每年7月份湖泊水质监测数据,利用综合营养指数法评价了湖泊不同区域监测点的水体营养状态,模拟分析了湖泊水体营养状态的演变过程及趋势特征,定性分析了湖泊富营养的关键影响因子.研究结果表明:乌梁素海湖区北部、西部和南部监测点处于轻度富营养状态的极限概率分别为0.588、0.633和0.329,而湖泊的中部和东部监测点处于中营养状态的极限概率分别为0.810和0.536,说明乌梁素海湖区北部、西部和南部区域夏季水体营养状态将呈现向轻度富营养化演变的趋势,而湖区中部和东部区域则呈现向中营养化演变的趋势.水环境因子中水体理化指标对湖泊富营养化起决定性作用,且盐度指标响应概率高达55%,是水体理化指标中第1位影响因子,同时pH值与水深指标也是影响乌梁素海水体富营养化程度的重要因子.;In order to ascertain the eutrophication status, evolution trend, and its main impact factors in Lake Ulansuhai, the water quality monitoring data in July between 2006 and 2017 were applied to evaluate the eutrophication status at different monitoring sites by which could represent the typical regions of the lake. The evolution process and trend characteristics of the eutrophication of lake water nutrient status were simulated and analyzed. The key influencing factors of lake eutrophication were qualitatively analyzed. The results showed that the limit probability of slight eutrophication at the northern, western and southern monitoring sites was 0.588, 0.633 and 0.329, respectively, while that in the central and eastern monitoring sites was 0.810 and 0.536, respectively. This indicated that the water eutrophication in the northern, western and southern regions of the lake would present a slight eutrophication evolution trend. Meanwhile the central and eastern regions of the lake present a moderate eutrophication evolution trend. The physical and chemical indexes of water body played a decisive role in the lake eutrophication, among which the response probability of salinity index was as high as 55%, meaning that salinity index was the most important impact factor to the lake eutrophication. pH and water depth also played a quite important role in influencing the lake eutrophication.
The composition and source information of the aquatic dissolved organic matter （DOM） in the Daihai Lake, a typical saline lake at the ecologically fragile agro-pastoral area, were explored with three-dimensional excitation and emission matrix fluorescence （3DEEM）, parallel factor analysis （PARAFAC）, and fluorescence peaks （B, T, A, M, C, D, and N）. Further, the relationship between aquatic DOM fluorescence characteristics and environmental factors were analyzed using correlation analysis in the Daihai Lake. The results showed that the water of Daihai was weakly alkaline, with high nutrient salt concentration and serious organic pollution. Two protein-like substances （C1 and C3） and one humic-like substance （C2） were identified using PARAFAC. The sum of C1 + C2 accounted for 80% of DOM. The results of fluorescence peaks showed that the total percentage of protein-like fluorescence absorption peaks （B, T, and N） was 49.67%. Aquatic DOM of Daihai demonstrated both terrigenous and endogenous characteristics. Terrestrial inputs were mainly from intensive agricultural activities and rapid ecological degradation of the watershed leading to large amounts of organic matter entering the lake. The environmental behavior of DOM was highly correlated with the metabolic activity of organisms and nutrient status of lakes. NH
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