黄家湖沉积物中有机质和总氮、总磷的分布特征

通过测定武汉市黄家湖18个采样点位表面层、过渡层、正常层沉积物中有机质、总氮、总磷的含量,采用综合污染指数内梅罗指数对黄家湖沉积物进行综合评价,分析了各层污染程度、有机质与总氮、总磷的相关性,以及有机质、总氮、总磷三个参数在黄家湖中纵向横向的分布特征及分布趋势。18个点位分析结果表明,垂向上三个参数浓度趋势大多表现为表面层过渡层正常层,平面上呈现周边区域浓度大于湖泊中部区域现象,且在有污水管网排口处浓度远大于其他区域。有机质浓度与总氮、总磷浓度呈现正相关趋势。     

珠江口海域沉积物中总氮总磷的空间分布特征

随着珠江三角洲经济的快速发展,各类废水排放量不断增加,导致珠江口及邻近海域呈现不同程度的污染。为了解珠江口及其邻近海域沉积物中氮、磷污染程度和水生生态环境的现状,采集了珠江口及其临近海域13个站位(珠江主干流入海口8个站位和渡头河入海口5个站位)的表层沉积物样品,研究了珠江口及其邻近海域表层沉积物中的总氮总磷含量以及其空间分布特征。研究结果表明珠江口及其临近海域表层沉积物总氮浓度范围为0.27～0.81 mg/g,均值为0.53 mg/g。珠江主干流入海口一侧污染相对较为严重,表层沉积物中总氮含量均值为0.70 mg/g,显著高于渡头河支流入海口一侧。表层沉积物中总磷浓度为0.28～0.96 mg/g,均值为0.49 mg/g,各位点浓度差异较大,整体并未达到污染程度。珠江口沉积物总氮总磷含量并无相关性,氮污染程度高于磷污染程度。研究结果为全面评价广东近海海水生态健康状况以及管理保护提供科学依据。     

三江堰湿地公园春夏水质的对比分析

三江堰湿地公园春季的水质:p H为7.14,COD值为23.25 mg/L,总氮含量为9.45 mg/L,总磷含量为0.62 mg/L;夏季的水质:p H为7.97,COD值为27.72 mg/L,总氮含量为9.79 mg/L,总磷含量为0.81 mg/L。春夏两季的水质存在一定的差异性,主要是因为夏季高温,蒸发量大,造成夏季的p H、COD含量、总磷含量和总氮含量都比春季的高。但不论春夏哪季,其水质中的总氮和总磷均超《地表水环境质量标准》中5类水的标准。故因在三江堰湿地公园的进水口处修建处理设施,降低污染指标。     

潜流人工湿地中污染物沿高度变化的净化程度研究

通过人工湿地系统模拟实验考察了污染物沿高度的净化程度,分析了垂直潜流湿地系统中COD、氮、磷的去除机理及其迁移转化规律。结果表明,潜流湿地系统对COD的去除主要发生在上层(0~30 cm),主要通过好氧微生物的降解作用;对总磷的去除主要发生在上层(0~30 cm)和中层(30~60 cm),去除途径为填料的吸附和沉淀作用;对总氮的去除则发生在整个系统中,上层主要去除氨态氮,只是将氨态氮转化为亚硝态氮和硝态氮等其他形式的氮,在中层和下层进行的反硝化反应才能真正达到脱氮效果。     

三级深度脱氮除磷工艺及净化效果研究

为探索多级污水深度处理工艺中氮、磷的去除效果,采用生物滤池-植物湿地-活性炭过滤三级工艺组合,在人工模拟废水的基础上,探索各处理单元对污水中氮、磷的去除效应。结果表明,经过三级深度处理后出水中总氮、总磷、COD等污染物有明显的降低,且各单元都能起到一定的去除作用。该实验条件下,经三级单元处理后总磷的去除率达到67.47%~90.18%,铵态氮去除率在89.23%~99.89%,而且去除效能稳定,出水铵态氮基本保持在1mg/L以下;总氮去除率在85.02%~99.60%,整个三级组合工艺对总氮的去除效果良好;COD去除率为84%~97.33%。可见采用生物膜滤池-湿地植物-活性炭过滤三级深度组合处理工艺对污水中氮、磷等污染物表现较好的去除作用,该组合工艺可以用于污染物含量类似的污染水体深度处理之中。     

三门湾沉积物中总氮和总磷的分布特征

根据2013-2014年对三门湾17个站位的四期调查结果,与20世纪80年代的结果进行分析比较,讨论了沉积物中营养盐的含量及分布特征。结果表明,调查海区沉积物中总氮和总磷的含量较之前有所降低,说明了三门湾富营养化程度在降低。不同营养盐表现出了不同的年内变化特点,有机碳含量2月5月8月11月,总氮含量8月11月5月2月,总磷含量8月5月11月2月。     

河流中氨氮、总氮和总磷污染情况及相关性分析

使用流动注射分光光度法在2020年7～10月间,对一河流的上中下游3个监测断面(河段1～河段3)的氨氮、总氮和总磷进行了监测,并做了综合分析。结果表明,该河流的氨氮、总氮和总磷浓度几乎均超过Ⅴ类水标准,且水体富营养化严重。氨氮-总氮与总磷-总氮比值分别多在0.8～0.9和0.1,说明水体受到的氮污染主要是氨氮污染,而且氮污染比磷污染严重。相关性分析表明,河段1和河段2的氨氮与总氮、氨氮与总磷有显著相关性,相关系数r的范围为0.810 6～0.986 9,而河段3的氨氮与总氮、氨氮与总磷无相关性。该河流需要及时进行富营养化治理,控制污染源,避免水质进一步恶化。     

黄山学院水西湿地氮磷时空变化特征研究

为了考察枯水期水西湿地对高校微污染水体氮和磷的净化作用,2017年10月-2018年4月,对水西湿地中总氮(TN)、总磷(TP)的污染状况进行连续性的定点监测。结果表明,枯水期黄山学院水西湿地水体TN、TP的空间变异性小,但时间变化性表现明显,其水体富营养化情况较为严重。水西湿地对高校微污染水体具有显著的净化效果。水西湿地对高校微污染水体总氮和总磷具有较好的净化效率,可为湿地在微污染水体中的应用及管理提供依据。     

沼液成分与重金属含量分析

沼气工程产生的大量沼液已成为制约沼气发展的瓶颈问题。我们对江苏省16家规模化养殖场的沼气工程排放沼液进行了成分和重金属含量的调查,结果表明,沼液的pH值偏高,在7.87-8.57之间,重金属元素Cr普遍超标,但As元素含量基本符合排放标准。然而总氮、总磷、COD含量都严重超标。对于降低沼液中总氮、总磷和重金属含量,提出了可能的解决方法。     

总氮、总磷监测中存在的相关问题

在社会经济不断发展的背景下,各种各样的环境问题随之体现了出来。通过相关的探究得出,引起水资源缺乏的实质性原因是因为水质受到了不良的污染,而总磷总氮的占据比例的多少是明确判断水质是否受到损坏以及水质污染程度的基本依据,基于此,就需要加大对水质总磷总氮的监测力度,制定出相应的对策。通常来讲,应当将水质总磷总氮量控制在合理的区域中,不然的话,很有可能会使水环境质量降低。当地表内的水含磷量处于//L的情况下,或者是氮含量远远超出了/L,水质长时间处于富营养化状态,就会增加藻类植物的增殖速度,减少水质的透明程度,进而使得水质受到污染。基于此,在本文中,主要分析了总氮、总磷监测期间存在的相关问题,结合实际现状提出了解决对策。     

涂料剖析

简要分析了不同涂料体系分析程序,说明了每种涂料剖析体系中应该注意的事项。     

芒果苷元的人工全合成研究

以2-溴-4,5-二甲氧基苯甲酸(6)和均苯三酚三甲醚(5)为起始原料,经Friedel-Crafts酰基化、选择性脱甲基、Ullmann成醚环合、全部脱甲基四步反应,合成了芒果苷元(1),总收率51%。目标产物经高效液相检测,纯度达99.5%,其结构经IR、MS、1H NMR和13C NMR表征。     

E-白藜芦醇化学全合成

以3,5-二羟基苯甲酸为起始原料,由羟基保护,酯基硼氢化钠还原,羟基氯代制备氯苄,制备了膦酸酯;经Wittig-Horner反应,脱甲基反应合成了E-白藜芦醇。合成总收率达47.6%。     

周期全回流间歇精馏中全采出操作时的塔顶浓度平台期(英文)

The total withdrawal operation is an inevitable section in cyclic total reflux batch distillation.In the operation,an interesting phenomenon "overhead concentration platform"(OCP) appears,which is defined as a period of time with high overhead concentrations when the operation is changed from total reflux to total withdrawal.The OCP phenomenon and its influential factors,such as the theoretical stage number,feed concentration,and feed composition,are examined by simulations and experiments.The experimental equipment is a column with random packings.It is shown that the number of theoretical stages influences the OCP more significantly than the other factors.     

Total desalination of brackish water

With desalination of brackish water far inland, the discharge of the concentrated brine which -is -inevitably produced as a by-product by all the desalination processes may pose a serious problem.

Deep well injection and discharge into rivers can be a solution in many cases. These methods however have serious disadvantages with respect to ecology and a pipeline to the sea can only be considered for shorter distances.

As an alternative, a hybrid plant consisting of a Reverse-Osmosis unit and a crystallization section has been studied. Such a combination converts brackish water into fresh water and a crystal sludge which can be either stored or treated for further use. Because of the scale-forming substances in brackish water, only modified crystallization processes can be employed as second stage of the hybrid plant. In this study, two versions are discussed: agitated thin-film evaporators and a modified MSF-process employing oil as a heat-carrier.

Cost figures for the total process will be given and the sensibility of the fresh-water-price to variations of the main parameters like capacity, fuel price etc. will be discussed.     

Total synthesis of zoanthamine alkaloids

Zoanthamine alkaloids, isolated from organisms in the Zoanthus genus, constitute a distinctive family of marine metabolites. These molecules exhibit a broad spectrum of unique biological properties. For example, norzoanthamine inhibits interleukin-6, the key mediator of bone resorption in osteoporosis, providing a promising drug candidate for a disease that affects more than 10 million people over age 50 in the United States. In addition, these natural products are characterized by a densely functionalized heptacyclic framework, as exemplified by the structures of zoanthamine, norzoanthamine, and zoanthenol, which makes them extremely attractive targets for chemical synthesis. Prior to our first total synthesis of norzoanthamine in 2004, the densely functionalized and complex stereostructures of the zoanthamine alkaloids had impeded synthetic studies of these molecules. In this Account, we describe our synthetic approach toward the total synthesis of zoanthamine alkaloids, focusing on how we overcame various synthetic challenges. At the beginning of our synthetic studies, we aimed to develop an efficient route that was flexible enough to provide access to several members of the family while allowing the synthesis of various analogues for biological testing. Our first project was the total synthesis of norzoanthamine, and we established an efficient synthetic route based on a novel strategy involving the following key features. First, we used a sequential three-component coupling reactions and subsequent photosensitized oxidation of a furan moiety to synthesize the precursor for the key intramolecular Diels-Alder reaction. Second, the key intramolecular Diels-Alder reaction constructed the ABC-ring carbon framework bearing two adjacent quaternary asymmetric carbon atoms at the C12 and C22 positions in a single stereoselective step. Third, we installed the third quaternary asymmetric carbon center at the C9 position by an intramolecular acylation of a keto alcohol followed by successive O-methylation and C-methylation reactions with complete stereoselectivity. Through the exploitation of a deuterium kinetic isoptope effect, we then efficiently synthesized the alkyne segment. Next, a coupling reaction between the alkyne segment and the amino alcohol segment and several subsequent synthetic transformations afforded the bis-aminoacetalization precursor. Finally, bis-aminoacetalization reactions carried out in one-pot constructed the DEFG-ring system and culminated in the total synthesis of norzoanthamine. Our synthetic route to norzoanthamine also allowed access to other zoanthamine alkaloids from a common synthetic intermediate, by way of stereoselective introduction of the C19 methyl group for zoanthamine, and isoaromatization for construction of the aromatic A-ring in zoanthenol. The chemistry described here not only allowed us to overcome formidable synthetic challenges but also opened a completely chemical avenue to naturally occurring zoanthamine alkaloids and their synthetic derivatives.     

克螨特原药的全分析

采用气相色谱—质谱联用技术，分离和鉴定了克螨特原药标样、工业品及本实验室合成克螨特原药中的杂质，并探讨了其成因。     

全卤制碱新工艺

叙述２０ｋｔ／ａ全卤隔膜法制烧碱工艺;探讨３０ｋｔ／ａ全卤离子膜法制烧碱工艺的两个方案。针对全卤隔膜法烧碱工艺存在４个关键问题提出新的工艺方案并已用于工业生产