基于生态分区的我国湖泊营养盐控制目标研究

为更好地控制我国湖泊的富营养化水平,在五大湖泊生态分区的基础上,对不同生态分区的100个湖泊总氮(TN)、总磷(TP)、TN/TP与叶绿素a(Chl-a)的关系进行了分析,进而提出了不同生态分区的湖泊营养盐控制目标.结果表明,五大湖泊生态分区中,东北湖区富营养化水平最低,华北湖区富营养化水平最高,近几年五大湖区湖泊富营养水平呈上升趋势.从TN、TP对五大生态分区湖泊Chl-a浓度的影响看,TP是东北和华北湖区湖泊藻类生长的限制性营养盐,而TN和TP同时是中东部、云贵和蒙新湖区湖泊藻类生长的限制性营养盐.从TN/TP判断,在TN/TP<10的湖泊中,除华北湖区外的其他4个湖区湖泊Chl-a均受TN显著影响;TP仅对东北、蒙新湖区湖泊的Chl-a有显著影响.在TN/TP>17的湖泊中,除蒙新湖区外的其他4个湖区湖泊Chl-a均受TP显著影响,而在中东部、云贵和蒙新湖区,TN对Chl-a也有显著影响.在10相似文献   

机动车排放检测和维修制度实施效果分析

实施检测和维修制度是机动车污染控制的重要措施 ,机动车排放检测是检测和维修制度的主要内容 .本研究利用累积分布曲线 ,通过双怠速检测排放限值对各类型高排放车辆的识别率 ,从检测数据、现行标准、上线合格率 3个角度对北京市检测和维修制度的排放限值制定、组织形式和实施效果进行分析 ,提出各受检物排放限值的匹配原则 .     

UV/H2O2降解水中2,4-二氯酚实验研究

研究溶液浊度、pH值及不同光源等因素对 2 ,4 二氯酚降解的影响 ,确定了UV/H2 O2 光氧化降解 2 ,4 二氯酚反应器的水质适用范围 (浊度小于 6NTU)。在 30W的紫外光照射下 ,2 0mg/L 2 ,4 二氯酚 ,H2 O2 的投加剂量为 1 .2 8mg/L时 ,90min内 2 ,4 二氯酚去除率可达到 95 % .实验证明UV/H2 O2 光氧化技术是低浊度水深度处理的一种有效方法 .     

Fractionation of residual Al in natural water treatment from reservoir with poly-aluminum-silicate-chloride (PASiC): Effect of OH/Al, Si/Al molar ratios and initial pH

An aluminum fractionation study was conducted for a surface reservoir water treatment to understand the performance of poly-aluminum-silicate-chloride (PASiC) in terms of the residual Al fractions as a function of initial pH. The coagulation performance expressed as turbidity and organic matter removal was established as supporting data. Some extra data were evaluated in terms of the residual Al ratio of the composite PASiC coagulant. The main residual Al sources were the Al fractions derived from the use of PASiC. The turbidity and organic matter removal ability was optimal at initial pH 6.00-7.00, while the concentrations of various residual Al species and the residual Al ratio of PASiC were minimal at an initial pH range of 7.00-8.00. Under the conditions of OH/Al molar ratio = 2.00 and Si/Al molar ratio = 0.05, PASiC had superior coagulation performance and comparatively low residual Al concentrations. The Al fraction in the composite PASiC coagulant seldom remained under such conditions. Experimental data also indicated that the suspended (filterable) Al fraction was the dominant species, and organic-bound or organo-Al complex Al was considered to be the major species of dissolved Al in water treated by PASiC coagulation. Additionally, the dissolved inorganic monomeric Al species dominated the dissolved monomeric Al fraction.     

Effect of manufacturing methods of AgCl/Al2O3 catalyst on selective catalytic reduction of NOx

The AgCl/Al2O3 catalyst has potential for use in the selective catalytic reduction (SCR) of NOx. A compound hydrocarbon, following oxygenation is used as a type of reducing agent. In this experiment, the AgCl/Al2O3 catalyst was produced by four different methods, and the differences among their reduction catalysis of NOx were compared. Ethanol was used as a type of reducing agent. X-ray diffraction analysis was performed to study the crystalline structure and scanning electron microscope and transmission electron microscope (TEM) were applied to determine the microindentation. The results indicated that, in the range of 350–400°C, there was no significant difference on the NOx reduction rate; however, there was dispersion at high and low temperature ranges. The size of the AgCl particles was about 20–100 nm.     

气溶胶中不同类型碳组分粒径分布特征

了解气溶胶碳组分粒径分布特征对于研究区域气溶胶生成转化机制、辐射特性等非常重要,但北京地区针对气溶胶碳组分粒径分布特征的相关研究非常少.本研究利用MOUDI-120采样器在北京地区3个季节开展气溶胶分级样品的采集,并分析其中不同类型的碳组分的含量,进而系统研究不同季节及污染状况下,各碳组分的粒径分布特征、来源及相互关系.结果表明,碳组分主要富集在细粒子中,秋冬季细粒子中碳组分的比重高于夏季.碳组分主要分布在两个模态,即积聚模态和粗模态. OC1和OC2主要分布在积聚模态,在0. 056～0. 56μm范围内有较高比例,OC3+OC4在粗模态的分布较为明显.Soot-EC浓度较低,没有明显的粒径分布特征,在0. 10～0. 18μm粒径段浓度较高,表明高温燃烧排放的EC主要分布在超细粒径段. Char-EC浓度远高于Soot-EC,在EC中占绝大部分比重.各主要碳组分在白天和夜晚的分布形态基本一致.夏季和冬季较有利于SOC的形成,OC/EC比值明显高于秋季. OC/EC值在不同粒径区间中差异很大,由于水溶性有机物(WSOC)主要分布在0. 056～0. 10μm,OC/EC值明显高于其他粒径段.白天及高温有利于气态有机物氧化生成SOC,致使夏季白天的OC/EC比值明显高于夜晚.各碳组分之间,EC1和OC1相关性最强,此外EC1和K+也有很强的相关性.     

Optimization of C/N ratio for preparation of protein-rich and multi-enzymes feed thallus through synergic fermentation of mixed distillers'grains

A new procedure of determining optimal C/N (the rate of carbon source to nitrogen source) of mixed distillers' grains for combined bacteria synergic fermentation is established. At the same time an improved method evaluating bacteria growth, called method of dry cell weighing by filtering is developed. For each combination of C and N , their initial and residual contents before and after fermentation respectively are determined. Then followed the calculation of utilization of C and N sources by the compound bacteria. The optimal C/N is finally located from among the utilization of C and N of several combinations and the weight of produced mass of oven-dried thallus The conditions of fermentation are: inoculum size 10%, temperature 30.0℃, rotational speed 170 r/min, shake culture time 48h. The best results obtained from orthogonal experiments are: maximum mass of oven dried thallus is 14.693g in a liter liquid medium, maximum utilization rate of carbon source is 98.13% and maximum utilization rate of nitrogen is 78.14%. Optimal C/N is 5.1.     

硝酸盐对矿化垃圾中兼/厌氧甲烷氧化的影响

设计全因子实验研究了NO-3-N对填埋10~12 a的矿化垃圾中兼/厌氧甲烷氧化作用的影响.结果表明,兼/厌氧条件下,NO-3-N能促进矿化垃圾中CH4的去除.初始CH4和NO-3-N对CH4去除和N2产生有明显影响,且两者具有交互作用(P<0.05).CH4去除量随着初始CH4体积分数的增加而增加,添加一定含量的NO-3-N能促进CH4去除,同时通入一定体积分数CH4可以明显促进反硝化作用,说明矿化垃圾中NO-3-N还原能与兼/厌氧甲烷氧化耦合.本实验条件下,初始CH4体积分数为30%,NO-3-N含量为110 mg·kg-1时耦合效应较好.     

气相色谱法测定大气中的丙酮、甲醇、甲苯

：使用经1．0％KOH-CH3OH处理过的405白色硅藻土担体，涂渍10％PEG-20000固定液，填充φ3mm＊3m的不锈钢色谱柱，在气相色谱仪上可直接进气体样品分析，经色谱柱分离，以FID为检测器，可以准确地测出空气工业废气中的丙酮、甲醇、甲苯，以保留时问定性，峰高定量。     

矿产资源总体规划对四川省甘孜州资源-环境承载力影响分析研究

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