原子荧光光度法测定海水中硒的不确定度评定研究

通过实例对原子荧光法测定海水中硒的不确定度进行评定。根据(JJF 1059-1999)《测量不确定度评定与表示》中对测量和评定不确定度的要求评估了不确定度。测量不确定度的产生包括标准溶液的逐级稀释、工作曲线的非线性和原子荧光光度计的测量性能及取样体积。结果表明取样体积是导致该方法不确定度产生的主要影响因素,在测定时应加强这方面的控制,从而提高测量结果的准确性。当海水中硒的含量为1.99μg/L时,硒含量的扩展不确定度为0.40μg/L,置信水平为95%。     

ABR-好氧颗粒污泥处理黄连素废水的启动研究

实验研究了ABR-好氧颗粒污泥组合工艺处理黄连素制药废水的启动运行,通过分析发现,ABR装置在HRT为4 d,黄连素浓度为50 mg/L的运行方式下成功启动,反应器运行稳定后每个格室MLSS平均值分别为25 840、21 560、27 500和11 200 mg/L。以ABR出水为营养物,成功培养出粒径在2～10 mm,沉降速率为104～137 m/h,沉降性能优良的好氧颗粒污泥。该组合工艺在启动实验的末期,进水COD浓度为3 000～4 000 mg/L左右,出水COD浓度到达168.4～271mg/L,系统总的去除率保持在90%～95%之间,表明ABR-好氧颗粒污泥组合工艺能够有效地处理黄连素制药废水。     

Interval-parameter Fuzzy-stochastic Semi-infinite Mixed-integer Linear Programming for Waste Management under Uncertainty

An interval-parameter fuzzy-stochastic semi-infinite mixed-integer linear programming (IFSSIP) method is developed for waste management under uncertainties. The IFSSIP method integrates the fuzzy programming, chance-constrained programming, integer programming and interval semi-infinite programming within a general optimization framework. The model is applied to a waste management system with three disposal facilities, three municipalities, and three periods. Compared with the previous methods, IFSSIP have two major advantages. One is that it can help generate solutions for the stable ranges of the decision variables and objective function value under fuzzy satisfaction degree and different levels of probability of violating constraints, which are informative and flexible for solution users to interpret/justify. The other is that IFSSIP can not only handle uncertainties through constructing fuzzy and random parameter, but also reflect dynamic features of the system conditions through interval function of time over the planning horizon. By comparing IFSSIP with interval-parameter mixed-integer linear semi-infinite programming and parametric programming, the IFSSIP method is more reasonable than others.     

Evaluating Controlling Factors to Ali/(Ca + Mg) Molar Ratio in Acidic Soil Water, Southern and Southwestern China: Multivariate Approach

Al_i/(Ca + Mg) molar ratio in soil water has been used as an indicator to the effects of acid deposition on terrestrial ecosystems. However, the main factors controlling this ratio have not been well documented in southern and southwestern China. In this study, we presented the variation in inorganic aluminum (Al_i) and Al_i/(Ca + Mg) molar ratio in different sites and soil horizons based on two to three years monitoring data, and evaluated the main factors controlling Al_i/(Ca + Mg) molar ratio using principle component analysis (PCA) and partial least square (PLS) regression. Monitoring data showed although Al_i/(Ca + Mg) molar ratios in most soil water were lower than assumed critical 1.0, higher molar ratios were found in some soil water at TSP and LXH site. Besides acid loading, both soil properties and soil water chemistry affected the value of Al_i/(Ca + Mg) molar ratio in soil water. Partial least square (PLS) indicated that they had different relative importance in different soil horizons. In A-horizon, soil aluminum saturation (AlS) had higher influence on Al_i/(Ca + Mg) molar ratio than soil water chemistry did; higher soil aluminum saturation (AlS) led to higher Al_i/(Ca + Mg) molar ratio in soil water. In the deeper horizons (i.e., B₁-, B₂- and BC-horizon), inorganic aluminum (Al_i) in soil water had more and more important role in regulating Al_i/(Ca + Mg) molar ratio. On regional scale, soil aluminum saturation (AlS) as well as cation exchange capacity (CEC) was the dominant factor controlling Al_i/(Ca + Mg) molar ratio. This should be paid enough attention on when making regional acid rain control policy in China.     

Spatial pattern and heterogeneity of soil organic carbon and nitrogen in sand dunes related to vegetation change and geomorphic position in Horqin Sandy Land, Northern China

To assesses the effect of geomorphology, topography, and vegetation changes on spatial pattern of soil organic carbon (C) and total nitrogen (N) in sand dunes, we used the quantitative methods to examine the spatial heterogeneity of vegetation cover, soil organic C, and total N in an 11-year naturally restored mobile dune (RMD11) and a 20-year naturally restored mobile dune (RMD20) that had been fenced to exclude grazing in Horqin Sandy Land, northern China. Our results showed that the vegetation cover, plant density, species number and diversity, soil organic C, and total N increased from RMD11 to RMD20 and increased from the 50 × 50-m plot (crest) to the 100 × 100-m plot (slope) in each dune. Geostatistical analysis showed that the spatial structural variance accounted for the largest proportion of the total sample variance in vegetation cover, soil organic C, and total N in each dune plot. Calculated spatial autocorrelation ranges of vegetation cover, soil organic C, and total N increased from RMD11 to RMD20, indicating that longer time since vegetation restoration results in a more homogeneous distribution of vegetation cover, soil organic C, and total N in sand dunes. In addition, the spatial continuity of vegetation cover, soil organic C, and total N decreased from the 50 × 50-m plot (crest) to the 100 × 100-m plot (slope) in each dune. These results suggest that the spatial distribution of soil organic C and total N in sand dunes is associated closely with geomorphic position related to the dune crest and slope, relative elevation of sampling site, and vegetation cover. Understanding the principles of this relationship between them may guide strategies for the conservation and management of semiarid dune ecosystems.     

A grey multi-objective programming approach for sustainable land-use in the Miyun Reservoir basin, China

Miyun Reservoir is the most important water source to Beijing City. Land-use of the basin plays a great role in the protection of water resources. Hence a sustainable land-use planning is required to optimize land-use structure and protect water resources in the basin. Based on the complete land-use system analysis in Miyun, a grey multi-objective programming to basin land-use(GMOPBLU)model was developed and applied to land-use planning. Two alternatives were produced and analyzed by means of interactive adjustment and scenano analysis. The results showed the GMOPBLU model is a valuable approach for basin land-use planning.     

Distribution and contamination assessment of heavy metals in sediment of the Second Songhua River, China

The Second Songhua River was subjected to a large amount of raw or primary effluent from chemical industries in Jilin city in 1960s to 1970s, resulting in serious mercury pollution. However, an understanding of other trace metal pollution has remained unclear. The objective of this study was to investigate trace metal contamination in the sediment of the river. Bottom sediment samples were taken in the river between Jilin city and Haerbin city in 2005. An uncontaminated sediment profile was taken in the Nen River at the same time. Total concentrations of Al, Fe, Mg, Ca, K, Na, Ti, Mn, V, Sc, Co, Cu, Cr, Ni, Pb and Zn in the sediment samples were measured by ICP-MS or ICP-OES, following digestion with various acids. Concentrations of Co, Cu, Cr, Ni, Pb and Zn in the surface sediments were 5.1–14.7, 18.5–78.9, 2.4–75.4, 7.2–29.0, 13.5–124.4, and 21.8–403.1 mg/kg, respectively, generally decreasing along the course of the river from Jilin city to Haerbin city. Background concentrations of trace metals were reconstructed by geochemical normalization to a conservative element scandium. Results showed that concentrations of Co, Cr, and Ni in the sediment were generally only slightly higher than or equal to their background values, while concentrations of Cu, Pb, and Zn in the some sediment samples were significantly higher than their background values. In detail, the sediment at Jilin city was moderately contaminated by Cu, and the sediment of the Second Songhua River was moderately contaminated by Pb and Zn. The top layer (0–10 cm depth) and bottom layers (30–46 cm depth) of one sediment profile at Wukeshu town were generally moderately polluted by Pb and Zn. Synthetically, the surface sediment in the studied river section was classified as natural sediment without ecological risk by the sediment pollution index (SPI) of Cu, Cr, Ni, Pb and Zn. Only the 30–45 cm depth of the sediment profile at Wukeshu town was classified as low polluted sediment by the SPI of these metals, recording a historical contamination of the river in the 1960s to 1970s. This buried contamination of trace metals might pose a potential risk to water column under disturbance of sediment. Foundation item: The National Basic Research Priorities Program of China (2004CB418502)     

乙醇溶析结晶法从白炭黑废母液中回收硫酸钠

以乙醇为溶析剂,通过过滤—中和—蒸馏浓缩—溶析结晶等工序,从白炭黑废母液中回收硫酸钠。考察了硫酸钠回收效果的影响因素,并进行了热能消耗和处理成本的分析。实验结果表明：乙醇的加入量对硫酸钠溶解度和蒸馏浓缩过程有着显著影响;在蒸馏醇水比（乙醇与中性废母液的体积比）为0.27,浓缩废母液中硫酸钠质量浓度为69.27 g/L,溶析醇水比（乙醇与浓缩废母液的体积比）为1的最佳工艺条件下,白炭黑废母液中硫酸钠的一次回收率可达69.94%,硫酸钠产品的纯度达到97.3%。     

微乳液增敏罗丹明B氧化褪色光度法测定微量亚硝酸根

基于微乳液对亚硝酸根催化溴酸钾氧化罗丹明B褪色反应具有增敏作用的原理,建立了催化动力学光度法测定痕量亚硝酸根的新方法。实验结果表明：该方法的最佳反应条件为1×10^-4 mol/L的罗丹明B溶液加入量0.60 mL,1 mol/L的稀磷酸加入量1.50 mL,0.1 mol/mL的溴酸钾溶液0.50 mL,反应温度20 ℃,反应时间15 min;对亚硝酸根测定的线性范围为ρ（NO₂^-）= 0.048~0.800 μg/mL,检出限为0.003 0 μg/mL;加入微乳液后催化反应的灵敏度增大了3倍。     

Dynamic Changes of Sandy Land in Northwest of Beijing, China

The area northwest of Beijing is one of the most important regions where many organizations invest and pay most attention. The environmental problems in this region affect not only Beijing but also the surrounding area. Based on observation of the characteristics of the change in sandy land, this study classified four types of dynamic change of sandy land, including extended sandy land, the reversely changed sandy land, the potential sandy land and no change in sandy land. Then the process and the trend of changes in sandy land and their environmental impact on the area northwest of Beijing were analyzed. The results show that the area of sandy land has increased in this region in the period of 1991 to 2002. Change between sandy land and grassland was the dominant change. It is found that the monitoring zones of Hunshandake sandy land and north of Yin Shan are regions with high ratio of extended sandy land, and are connected with widespread potential change of sandy land. This implies that these two regions have a high probability of increase in sandy land in the future. On the other hand, in the monitoring zone of Horqin sandy land and Ba Shang Plateau and its surrounding area, desertification had been controlled and the area of sandy land is expected to decrease. This indicates that the direction of the sandstorm to Beijing is expected to gradually move to the northwest. Furthermore, the decreases in sandy land and the reversing change from arable land to grassland and forests in the study region will affect the land quality and atmosphere. And the logistic multiple regression (LMR) model was employed to better understand the complexity and processes of increases in sandy land. This model predicts that there is a high probability of increases in sandy land in north of Siziwang Banner, Zhengxiangbai Banner and Zhenglan Banner. Finally, suggestions to the ecological construction of the study area have been proposed.