In situ nitrogen removal processes in intertidal wetlands of the Yangtze Estuary

Estuarine and intertidal wetlands are important sites for nitrogen transformation and elimination. However, the factors controlling nitrogen removal processes remain largely uncertain in the highly dynamic environments. In this study, continuous-flow experiment combined with ¹⁵N isotope pairing technique was used to investigate in situ rates of denitrification and anaerobic ammonium oxidation (anammox) and their coupling with nitrification in intertidal wetlands of the Yangtze Estuary. The measured rates varied from below the detection limit to 152.39 µmol N/(m²·hr) for denitrification and from below the detection limit to 43.06 µmol N/(m²·hr) for anammox. The coupling links of nitrogen removal processes with nitrification were mainly dependent on nitrate, organic carbon, sulfide, dissolved oxygen and ferric iron in the estuarine and intertidal wetlands. Additionally, it was estimated that the actual nitrogen removal processes annually removed approximately 5% of the terrigenous inorganic nitrogen discharged into the Yangtze Estuary. This study gives new insights into nitrogen transformation and fate in the estuarine and intertidal wetlands.     

电厂冷却系统对梭幼鱼和对虾仔虾卷载效应的初步探讨

根据青岛电厂运行观测和模拟实验，分析了卷载效应中机械损伤和高温冲击对梭幼鱼和对虾仔虾的危害。研究表明，电厂冷却系统内流速≥２．０ｍ／ｓ，滤网孔径８ｍｍ时，对体长７－１７ｍｍ和２０－３４ｍｍ仔虾的致死率分别为２８．３％－５５．３％和２８．６％－６６．９％；对体长２０－４０ｍｍ梭幼鱼的致死率为６３．４％－７８．８％。卷载致死率与生物的密度、体长及形态特征有关。模拟实验结果为：０．９－１．０５ｍ／ｓ的流     

有机废弃物氢发酵制备生物氢气的研究

在批式培养实验中以有机废弃物为原料,通过厌氧生物发酵制备生物氢气研究了菌种来源、有机废弃物种类对产氢能力的影响,以及生物氢发酵过程中液相组成的变化以活性污泥为菌种来源,以淀粉为底物,在30L改进的UASB反应器中进行了放大实验,生物气中氢气浓度达40%～51%,CO₂浓度为49%～60%,且没有检测到甲烷气体,生物气经碱液吸收后氢气纯度大于97%持续产氢时间超过120d.     

河流中BOD-DO动态的数学模拟方法

本文讨论了河流中BOD—DO动态的数学模拟方法,并将该方法应用于图们江,利用在图们江上取得的实测数据建立了江中BOD—DO动态的数学模型。在所得到的模型中,耗氧系数κ_1,复氧系数κ_2,BOD沉淀-再悬浮系数κ_3被表达为流量与水温的函数。表达式中的参数通过系统识别与参数估计方法确定,因此能较好地反映河流的地理环境特点。特别是κ_3的表达式,它以流量为自变量,用一个单一的解析函数同时描述了江中的沉淀与再悬浮现象,具有独创性。 本文所提出的BOD—DO动态模型可以做为图们江水质规划与管理的基础。     

大骨节病病情下降与环境因素的定位研究

１９８７年４月－１９８９年９月对内蒙三个大骨节病村进行了随诊观察，结果表明，大骨节病病情逐年下降，人体硒营养水平相应提高，病情与硒营养水平之间呈显负相关，每日由外源性食物中摄取的硒与病情呈显负相关，而由当地产粮，菜中摄取的硒与情呈显正相关。由肉蛋类食物中摄取与病情呈显负相关，生态环境中的硒基本无变化，增加外源性高硒食物输入病区和改变病区食物构成是控制硒反应性疾病的主要途径。     

含溴自由基对臭氧光解损耗的影响

本文研究了２５３．７ｎｍ的紫外光照条件下臭氧的损耗,以及在有Ｎ２和Ｏ２的体系中臭氧损耗的状况,得到不同条件下氧损耗的量子产额。并进一步测定了近似同层条件下溴损氧的量子产额为２４±１,计算出ＢｒＯ＋ＢｒＯ反应的两个分支反应通道的速率比为５．２５±０．２６。     

气态CF3Br的光氧化反应

本文应用气相色谱。富里叶红外光谱和紫外,可见光谱等技术研究了２５３．７ｍｍ紫外光照射睛ＣＢＦ３Ｂｒ－Ｏ２体系听光化学反应过程。实验结果表明,当作为自由基捕促剂的Ｏ２足量时,ＣＦ３Ｂｒ的光解离呈一级反应,其反 速率常数２．６７＊１０＾－５ｓ＾１,ＣＦ３Ｂｒ的表观量子产额近似为１,主要的反应产物是ＣＦ２Ｏ,Ｂｒ２,在此基础上上讨论了ＣＦ３Ｂｒ光氧化反应的机理。     

Photochemistry in the mixed aqueous solution of nitrobenzene and nitrous acid as initiated by the 355 nm UV light

The 355 nm photon-initiated microscopic reaction mechanisms of the mixed aqueous solution of nitrobenzene and nitrous acid in the presence or absence of O(2) were studied by the laser flash photolysis technique. The main transient absorption peaks in the recorded spectra were assigned and the growth/decay trends of several transient species were investigated. It was found that the OH radical formed from the photolysis of nitrous acid triggered most of the subsequent radical reactions. The rate constant of the reaction between OH radical and nitrobenzene was measured to be (3.4 +/- 0.1) x 10(9) l mol(-1) s(-1). The product from this reaction, namely C(6)H(5)NO(2)-OH adduct, was found to react with O(2) to yield C(6)H(5)NO(2)-OHO(2) adduct with a rate constant of (1.6 +/- 0.2) x 10(9) l mol(-1) s(-1). Final steady-state products were identified by GC/MS analysis and were in accordance with the transient spectroscopic results. The possible reaction pathways were proposed.     

瞬态吸收光谱技术研究4-氯酚水相降解的微观反应

利用瞬态吸收光谱技术进行了不同条件下４－氯酚水溶液的电子脉冲辐解,分别研究了体系中瞬时出现的·ＯＨ,Ｈ和水合电子等活性粒子与溶质的反应．对瞬态吸收光谱中的主要吸收峰做了归属,得到了ＯＨ－ａｄｄｕｃｔ,Ｈ－ａｄｄｕｔ和氯代酚氧基等一系列中间产物,并初步研究了这些瞬态物种的生长、衰减行为和可能的反应机理,得出了一些微观反应的速率常数．     

环境污染物干扰鱼类体色的研究及其生态毒理学意义

鱼类体色对环境污染物十分敏感,使其成为污染监测中理想的生物指示物,具有广阔的应用前景.鱼类体色调控复杂,涉及的基因丰富.本文综述污染物对鱼类体色的干扰作用及可能的干扰机制,为鱼类体色应用于污染监测相关生物标志物筛选及生态风险评估提供参考资料;同时,从鱼类色素合成和代谢、色素细胞发育和迁移、体色变化的调控等方面,综述鱼类...