奇特的极地景观

神秘莫测的南极南极大陆是最高大,最冷酷,最纯洁,最美丽,最神秘莫测,最桀骜不驯的。南极真是高得出奇,有2350米。犹如一个巨人。然而它又是最低的大陆。南极大陆上的本特莱冰下槽谷,在海平面以下2500多米．比北冰洋的平均深度还要深两倍多呢!这是由于在巨大冰盖的重压之下,大陆地壳产生了向     

A selective N,N-dithenoyl-rhodamine based fluorescent probe for Fe3+ detection in aqueous and living cells

A novel N,N-dithenoyl-rhodamine based fluorescent and colorimetric Fe3+probe 1 was designed and synthesized by only one step from Rhodamine B hydrazide and 2-thiophenecarbonyl chloride.The structure of probe 1 was characterized by ~1 H NMR/~(13)C NMR spectroscopy,IR spectroscopy,and HRMS spectrometry.Accompanying with significant changes in visual color and fluorescent spectrum,probe 1 displayed good sensitivity for Fe~(3+)with an abroad pH span.The detection limit(3.76 μmol/L,0.2 mg/L) for Fe~(3+)was lower than WHO recommended value(0.3 mg/L) for drinking water.Using two thiophene carbonyl groups as coordinating functional recognition group,probe 1 showed excellent selectivity towards Fe3+over diverse coexistent metal ions and anions.The sensing mechanism between dithenoyl-substituted probe 1 and Fe~(3+)was further confirmed by ~1 H NMR and IR titration experiments,binding constants study,and Job's plot analysis.Furthermore,probe 1 also exhibited good cell membrane permeability and could be used as an efficient Fe~(3+) probe in living human cells.     

利用化学混凝法处理钻井污水实验研究

采用化学混凝法对江汉油田钻井污水进行了室内处理实验。实验结果表明,污水处理时所选絮凝剂的种类、加入量、加入顺序、温度和加入后的沉降时间等都会影响处理效果。采用单一无机化学药剂,沉降速度较慢,故考虑将无机和有机药剂复配使用,即利用先加无机药剂后再加入有机药剂的顺序处理该油田钻井废水。该实验结果为油田钻井污水无害化处理提供了基础资料。     

Characterization of the pesticide chlordane in estuarine river sediments

Sediments are increasingly recognized as both carrier and potential source of contaminants in aquatic environments. This study investigated the characteristics and spatial distribution of total chlordane and its three most abundant compounds, including alpha-chlordane, gamma-chlordane, and trans-nonachlor, in sediments from the Cedar and Ortega rivers, Florida, USA, using geographic information system (GIS)-based kriging analyses and field measurements. Kriging analysis showed that two areas, one from the Cedar River area and the other from the northern end of the Ortega River area, were contaminated. The maximum concentrations of total chlordane, gamma-chlordane, alpha-chlordane, and trans-nonachlor in the sediments were, respectively, 101.8, 20.1, 26.3, and 19.2 microg/kg. A plot of total organic carbon (TOC)-normalized chlordane concentrations showed that effects of grain size on sediment chlordane contamination were negligible. A principal axis analysis further revealed that a linear correlation existed between alpha-chlordane and total chlordane as well as between gamma-chlordane and total chlordane, whereas no correlation existed between trans-nonachlor and total chlordane. Comparison of total chlordane concentration with Florida Sediment Assessment Guidelines showed that the Cedar River and the northern end of the Ortega River had total chlordane concentrations above the probable effect level (4.79 microg/kg), which could pose a potential risk to aquatic life.     

The toxicity of the glyphosate herbicide for Pardosa spiders’ predatory activity depends on the formulation of the glyphosate product

Environmental Chemistry Letters - Glyphosate is an herbicide which was previously considered safe for non-target organisms. 825.8 million kilograms of glyphosate-based products were used...     

丹江口库区及上游生态系统土壤保持效益价值评估

以RUSLE为模型的基本框架,以GIS、RS软件为技术平台,利用GIS强大的空间数据组织分析运算能力,将项目规划区各土壤侵蚀影响因子的遥感数据与非遥感数据网格化,通过网格数据的空间分析和模型运算,实现生态系统土壤保持量的区域性宏观定位定量评价。估算结果表明:研究区土壤保持总量林地最高,草地次之,水域等其它类型土壤保持量都非常少,这与植被覆盖度和植被净第一性生产力的分布是一致的,说明高植被覆盖类型分布区的植被能有效防止和控制土壤流失。1987、2000和2008年不同土地利用/覆被类型土壤保持价值分别为355.21亿元3、41.37亿元和367.41亿元。其中林地和灌木林地生态系统的土壤保持价值占到近60%,草地生态系统占到近30%,林、灌、草共占到服务总价值的近90%,林、灌、草在土壤保持生态系统服务中具有决定性的作用。     

Principal component analysis to assess the efficiency and mechanism for enhanced coagulation of natural algae-laden water using a novel dual coagulant system

A novel dual coagulant system of polyaluminum chloride sulfate (PACS) and polydiallyldimethylammonium chloride (PDADMAC) was used to treat natural algae-laden water from Meiliang Gulf, Lake Taihu. PACS (Al_n(OH)_mCl_3n-m-2k(SO₄)_k) has a mass ratio of 10 %, a SO₄ ^2?/Al₃ ⁺ mole ratio of 0.0664, and an OH/Al mole ratio of 2. The PDADMAC ([C₈H₁₆NCl]_m) has a MW which ranges from 5?×?10⁵ to 20?×?10⁵ Da. The variations of contaminants in water samples during treatments were estimated in the form of principal component analysis (PCA) factor scores and conventional variables (turbidity, DOC, etc.). Parallel factor analysis determined four chromophoric dissolved organic matters (CDOM) components, and PCA identified four integrated principle factors. PCA factor 1 had significant correlations with chlorophyll-a (r?=?0.718), protein-like CDOM C1 (0.689), and C2 (0.756). Factor 2 correlated with UV₂₅₄ (0.672), humic-like CDOM component C3 (0.716), and C4 (0.758). Factors 3 and 4 had correlations with NH₃-N (0.748) and T-P (0.769), respectively. The variations of PCA factors scores revealed that PACS contributed less aluminum dissolution than PAC to obtain equivalent removal efficiency of contaminants. This might be due to the high cationic charge and pre-hydrolyzation of PACS. Compared with PACS coagulation (20 mg L^?1), the removal of PCA factors 1, 2, and 4 increased 45, 33, and 12 %, respectively, in combined PACS–PDADMAC treatment (0.8 mg L^?1?+?20 mg L^?1). Since PAC contained more Al (0.053 g/1 g) than PACS (0.028 g/1 g), the results indicated that PACS contributed less Al dissolution into the water to obtain equivalent removal efficiency.     

Long-term evaluation of activated carbon as an adsorbent for biogas desulfurization

ABSTRACT

In this study, granular activated carbon (GAC) was used as an adsorbent for biogas desulfurization. Biogas containing 932–2,350 ppm of H₂S was collected from an anaerobic digester to treat the wastewater from a dairy farm with about 200 cows. An adsorption test was performed by introducing the biogas to a column that was packed with approximately 50 L of commercial GAC. The operation ceased if the effluent gas had an H₂S concentration of over 100 ppm. The GAC was replaced by a given weight of new GAC in a subsequent test. According to the results, for H₂S concentrations in the range of 932–1,560 ppm (average±SD = 1,260 ± 256 ppm), 1 kg of the GAC yielded biogas treatment capacities of 568 ± 112 m³ and H₂S adsorption capacities of 979 ± 235 g. For the higher influent H₂S concentrations of 2,110 ± 219 ppm, the biogas treatment and H₂S-adsorption capacities decreased to 229 ± 18 m³ and 668 ± 47 g, respectively. An estimation indicated a requisite cost of US$16.5 for the purification of 1,000 m³ of biogas containing 2,110 ppm of H₂S. This cost is approximately 5% of US$330, the value of 1,000 m³ of biogas.     

浅谈烟气脱硫技术

叙述了几种烟气脱硫方法,其中重点介绍了3种新的技术,即用沸石、活性焦和脉冲电晕来脱除烟气中的SO2.     

影响原油脱水效果分析及提高脱水效果的应用

介绍了原油脱水机理,对影响脱水效果的因素进行分析,重点介绍影响原油脱乳化水效果重要因素之一的破乳荆,以及影响脱水效果的作用时间的加药破乳方式,特别是对难脱出乳化水的稠油进行了详细阐述。有针对性的对井楼稠油筛选出了更加高效的破乳荆,并且利用管道破乳方式,延长药荆作用时间,进一步提高了稠油整体脱水效果,取得了明显的经济效益。