风味蛋白酶水解金枪鱼(Eleotridae)碎肉蛋白的动力学模型研究     

杜帅  宋茹  郑斌  杨会成  罗红宇 《海洋与湖沼》2013,44(4):1073-1077

本文对风味蛋白酶水解金枪鱼碎肉蛋白的特性进行了研究, 采用测定不同底物浓度下的瞬时速率的方法来测定米氏常数Km值, 探讨了水解时间、底物浓度与水解速率及水解度的关系, 并拟合出水解时间与水解度之间关系的数学模型。结果表明: 该酶解反应的米氏常数Km=0.0098, 酶解过程的动力学方程为DH = 8.621 ln (1 + 0.053t?0.0003[S]t)。通过动力学方程求得当酶浓度为200U/g时, 最大临界初始底物浓度[S]为176.81g/L。验证实验表明此模型的可信度高(R2=0.99), 实际值与拟合值基本吻合, 可以用于模拟风味蛋白酶水解金枪鱼碎肉蛋白制备活性肽的反应过程和酶解条件的工艺优化。  相似文献   

中低温成矿过程的锰镁碳酸盐矿物化学动力学与矿物成因     

张雪彤 《矿床地质》2007,26(6):666-675

文章使用开放流动反应装置研究了中低温热液矿床中常见脉石矿物碳酸盐(白云石、菱锰矿)在25℃～250℃水中化学动力学溶解反应速率。在25℃条件下,碳酸盐矿物的溶解速率r(Ca)>r(Mn)>r(Mg)。碳酸盐矿物在水中200℃时具有最大溶解速率。随着温度的继续升高,Mg、Mn碳酸盐的溶解反应速率会下降,容易形成白云石和锰碳酸盐。实验研究结果有助于理解中低温环境下,金属矿石的主要伴生碳酸盐矿物与水反应的化学动力学限制,试图说明中低温矿石伴随白云石和锰碳酸盐的沉淀机理。  相似文献   

磁黄铁矿催化分解苯酚反应动力学及其产物特征   总被引：2，自引：0，他引：2  

吴大清  刁桂仪  袁鹏 《矿物岩石地球化学通报》2007,26(2):132-135

本文用批量实验法研究了天然磁黄铁矿在过氧化氢参与下催化分解苯酚的动力学反应。结果表明,在pH=3.81～5.88时,苯酚都可被有效的分解,分解速率k=4.0～212h-1(g/L)-1,高于氧化铁矿物类催化剂,可与Fenton试剂相比拟。同时它具有反应速率可控、催化剂与反应产物易于分离和回收等优点。对反应液中Fe(II)、Fe(Ⅲ)浓度和紫外光谱分析表明,反应过程与Fenton反应类似,苯酚先是被快速转化成多酚类化合物,接着被分解成羧酸类化合物。溶液pH不同,产物不同,总有机碳(TOC)矿化率也不同,一般可达50%～58%。  相似文献   

Role of organic acids in desorption of mercury from contaminated soils in eastern Shandong Province, China   总被引：2，自引：0，他引：2  

Hong Jiang  Lei Zhang  Binghui Zheng  Guoqiang Wang 《中国地理科学(英文版)》2012,22(4):414-421

Batch experiments were conducted to study the effects of low-molecular-weight organic acids(LMWOAs) on desorption of Hg from two kinds of soils in the eastern Shandong Province,China.Of all LMWOAs,oxalic and citric acids were chosen as the representatives in this experiment because they are most common in soils.Desorption of Hg increases with the increase of extracting time,until the highest desorption amount at 6-8 h,and then declines.It indicates that timeliness is very important when organic acids are used for phytoremediation in contaminated soils.When the concentrations of organic acids increase from 1.0 mmol/L to 10.0 mmol/L,Hg desorption increases significantly regardless of oxalic or citric acid.Compared with oxalic acid,citric acid is more effective to enhance the desorption of Hg,especially from fluvo-aquic soil.With the increase of initial pH value from 3 to 8,Hg desorption decreases directly in the presence of oxalic acid.However,Hg desorption first decreases,then increases,and eventually decreases again in the presence of citric acid due to the variation of competitive ability between chelating of citric acid and adsorption of soil in different pH values.Citric acid showed greater ability to release Hg from soils than oxalic acid.According to the results of the present study,it is found that the bioavailabilities of heavy metal can be improved with selecting suitable types and concentrations of organic acid amendment and reasonable soil condition.  相似文献   

Groundwater pollution containing ammonium,iron and manganese in a riverbank filtration system: Effects of dynamic geochemical conditions and microbial responses     

Li Meng  Rui Zuo  Mark L. Brusseau  Jin-sheng Wang  Xin Liu  Can Du  Yuanzheng Zhai  Yanguo Teng 《水文研究》2020,34(22):4175-4189

Bench-scale experiments were conducted to investigate the effect of hydraulic loadings and influent concentration on the migration and biotransformation behaviour of three groundwater pollutants: ammonium (NH₄⁺), iron (Fe²⁺) and manganese (Mn²⁺). Columns packed with aquifer media collected from a riverbank filtration (RBF) site in Harbin City, NE China were introduced synthetic groundwater (SGW) or real groundwater (RGW) were at two different constant flow rates and initial contaminant concentrations to determine the impact of system conditions on the fate of the target pollutants biotransformation. The results showed that the biotransformation rate of Fe²⁺ Mn²⁺ and NH₄⁺ decreased by 8%, 39% and 15% under high flow rate (50 L d⁻¹) compared to low flow rate (25 L d⁻¹), which was consistent with the residence-time effect. While the biotransformation rate of Fe²⁺ Mn²⁺ and NH₄⁺ decreased by 7%, 14% and 9% under high influent concentration comparing with original groundwater. The 16S rRNA analysis of the aquifer media at different depths after experiments completion demonstrated that the relative abundance of major functional microbes iron-oxidizing bacteria and manganese-oxidizing bacteria under higher flow rate and higher influent concentration decreased 13%, 14% and 25%, 24%, respectively, whereas the ammonium-oxidizing bacteria and nitrite-oxidizing bacteria exhibited minimal change, compared to the lower flow rate. Above all results indicated that both high flow rate and high concentration inhibit the biotransformation of NH₄⁺, Fe²⁺ and Mn²⁺. The biotransformation of Fe²⁺ and Mn²⁺ occurs primarily in the 0–40 cm and 20–60 cm depth intervals, respectively, whereas the NH₄⁺ biotransformation appears to occur relatively uniformly throughout the whole 110 cm column. The biotransformation kinetics of NH₄⁺ in RGW and SGW, Mn²⁺ in RGW at different depths accords with the first order kinetics model, while Fe²⁺ in RGW and SGW, Mn²⁺ in SGW presented more complicated biotransformation process. The results should improve understanding of the transport and fate of common groundwater pollutants in RBF and other groundwater recharge environments.  相似文献   

临界区流体与矿物和岩石在地球内部极端条件下的反应   总被引：4，自引：0，他引：4       下载免费PDF全文

张荣华  张雪彤  胡书敏 《地学前缘》2009,16(1):53

极端条件下水热化学反应是一个新的科学问题。借助于高温超高压原位直接测量方法、各种谱学方法和同步辐射光源技术研究地球内部流体物质相互作用,可以获得反应过程的产物的分子-原子尺度信息,这些信息可以提供认识极端条件下水和矿物(岩石)反应动力学的新实验途径。地球内部的流体性质随所处高温高压条件发生变化。水的密度、介电常数等物理参数随温度压力变化而改变,在临界态会出现突变。水的性质的剧变会影响水与岩石(矿物)相互作用。文中报道了在极端条件下(20～435℃和23～35MPa)实验测量矿物(钠长石、辉石、石英和阳起石等)和岩石(玄武岩、正长岩)在水溶液里的溶解反应速率的研究结果,发现矿物里各种不同类型金属离子与水反应的速率不同,随温度变化而改变。在升温过程中,进入临界态时,矿物(岩石)与水反应出现一次反应速率的涨落。在恒压升温过程中(临界压力,或略高于临界压力),硅酸盐矿物溶解速率会逐步升高,如硅近临界区(300℃)抵达最大值,然后随升温溶解反应速率减低。地球内部的流体由深处上升到浅处,会从超临界区域进入近临界的气与液的两相不混溶区域。含金属流体里的金属会在气相与液相分离时出现再分配。实验表明:金属Au、Cu、Sn、W、Zn会进入气相,气体可以迁移金属。事实说明:地球内部流体结构和性质从深到浅在不断变化,在跨越临界区时的水的性质异常变化会导致水与矿物(岩石)反应动力学涨落,并且促使金属在临界区出现沉淀和在气液相分离过程中进行再分配及迁移。  相似文献   

Adsorption of oleate on fluorite surface as revealed by atomic force microscopy     

K. Chennakesavulu  G. Bhaskar Raju  S. Prabhakar  C. Madhavan Nair  K.V.G.K. Murthy 《International Journal of Mineral Processing》2009,90(1-4):101-104

The adsorption of oleic acid / oleate on fluorite surface could be visualized using tapping mode of atomic force microscopy (AFM). The natural fluorite crystals were equilibrated with 10^− 3 to 10^− 7 M oleate solutions and their AFM images at each concentration along with height profiles were recorded. Even at low oleate concentration of 1 × 10^− 7 M, concomitant monolayer and bilayer structures were observed. It suggests that normal–normal bonding of hydrocarbon chains takes place before the surface is completely covered by the monolayer. Multi-layer adsorption of oleate was observed at oleate concentrations of above 10^− 4 M. The tapping mode AFM can be utilized to visualize the topography of surfaces adsorbed with surfactant molecules.  相似文献   

聚合羟基铁铝蒙脱石复合体对磷的吸附行为及其动力学   总被引：2，自引：0，他引：2  

丁葵英  朱茂旭  卞永荣 《矿物学报》2009,29(1)

在一定条件下利用钠基化蒙脱石合成了聚合羟基铝-蒙脱石复合体(HyA1-Mt)、2个不同铁含量的聚合羟基铁-蒙脱石复合体(HyFe-Mt)和3个不同Fe:Al摩尔比的聚合羟基铁铝-蒙脱石复合体(HyFeAl-Mt),研究了酸性和弱酸性条件下(pH=3.0～6.5)以上蒙脱石复合体对磷的吸附行为和动力学特征。结果表明,HyFeAl-Mt对磷的吸附容量大于HyA1-Mt和HyFe-Mt复合体,且随着Fe:Al摩尔比的增大,对磷的吸附容量依次增加。随pH升高,蒙脱石复合体对磷的吸附量容量变小。但随Fe:Al摩尔比增大,HyFeAl-Mt复合体零电荷点(pHZPC)升高,pH对磷的吸附的影响越来越小,HyFe-Mt对磷的吸附几乎不受pH的影响。随Fe:A1摩尔比的增大,HyFeAl-Mt对磷的吸附能力增强,铁含量是磷吸附量的重要控制因素。磷在各蒙脱石复合体上的吸附实验数据可很好地用Langmuir吸附等温方程拟合。磷在各蒙脱石复合体上的吸附动力学过程可分为快速和慢速两个过程,快速过程中的动力学受铁含量影响明显。动力学数据可同时用准二级动力学方程和Elovich方程拟合。  相似文献   

铁柱撑蒙脱石可见光催化降解活性艳橙性能及动力学研究   总被引：1，自引：0，他引：1  

陈秋强  吴平霄  李涛  李媛媛  邢宁 《矿物岩石》2009,29(2)

采用铁柱撑蒙脱石（Fe-Mt）作为光催化剂,与H2O2在可见光条件下形成异相photo—Fenton（异相光芬顿）试剂对活性艳橙（X—GN）进行降解实验,研究不同反应体系对X—GN的降解情况,以及X—GN浓度、PH值、催化剂用量、H2O2浓度、反应温度等不同因素对X—GN光解过程的影响。结果表明：可见光照射下,在反应温度为30℃,pH为3．0,H2O2浓度为4．9mmol／L,Fe—Mt用量为0．6g／L,Fe-Mt／H2O2的可见光体系下,降解X—GN效果最好,140min后X—GN的降解率为98．5％;在此基础上进行的动力学研究则表明反应接近于表观一级反应。  相似文献   

莺歌海盆地东方1-1气田天然气来源与运聚模式   总被引：6，自引：2，他引：4  

赵必强  肖贤明  胡忠良  黄保家 《沉积学报》2005,23(1):156-161

莺歌海盆地东方 1-1气田以其埋藏浅、天然气成份变化大、气藏位于底辟构造带等特征一直是研究的热点。长期以来对其气源、充注历史等问题存在不少疑问。该研究应用生烃动力学与碳同位素动力学方法通过对典型烃源岩的研究,建立起了烃源岩在地质条件下的生气模式与碳同位素分馏模式。结合天然气地质地球化学特征,研究认为:东方 1-1气田烃类气体主要来源于梅山组烃源岩,非烃气体来源于三亚组或更深部含钙地层;天然气藏形成相当晚,与底辟作用有关,烃类气体主要充注时间在 1.3Ma以后,CO₂气体主要充注时间在 0.1Ma左右;天然气成份的非均一性主要受控于底辟断裂活动所控制的幕式充注。  相似文献