Inhibition of sulphate reduction in anoxic marine sediment by Group VI anions     

Ibrahim M. Banat  David B. Nedwell 《Estuarine, Coastal and Shelf Science》1984,18(3):361-366

The addition of various concentrations (1, 10 and 20 mM) of Group VI anions to sediment slurry resulted in inhibition of the rate of sulphate reduction at the two higher concentrations, the degree of inhibition being in the order of molyb-date $\text{(MoO}{}_4{}^{\mathrm{=}}\text{)>selenate(SeO}{}_4{}^{\mathrm{=}}\text{)>tungstate(WO}{}_4{}^{\mathrm{=}}\text{)}$. The addition of 20 mM concentrations of these inhibitors almost entirely eliminated sulphate reduction. Doubling the sulphate concentration while using the highest concentration of inhibitors (20 mM) led to the re-establishment of some sulphate reduction in the $\text{SeO}{}_4{}^{\mathrm{=}}$ and $\text{WO}{}_4{}^{\mathrm{=}}$ treated slurries whereas no such reversal was noticed with $\text{MoO}{}_4{}^{\mathrm{=}}$. These observations suggested that $\text{SeO}{}_4{}^{\mathrm{=}}$ and $\text{WO}{}_4{}^{\mathrm{=}}$ are competitive inhibitors of sulphate reduction, while $\text{MoO}{}_4{}^{\mathrm{=}}$ is a non-competitive inhibitor.  相似文献   

40 ℃时MgO·2B2O3-18%MgSO4-H2O过饱和溶液结晶动力学研究          下载免费PDF全文

马玉涛  夏树屏  朱黎霞  王波 《盐湖研究》2002,10(1)

针对我国盐湖硼资源的特点 ,模拟合成MgO·2B2 O3-1 8%MgSO4 -H2 O过饱和溶液 ,在 40℃恒温静置条件下 ,跟踪结晶动力学过程。拟合并给出结晶动力学方程 ,同时对结晶机制进行了探讨。析出固相采用X射线粉末衍射、红外光谱和热分析进行物相鉴定。  相似文献   

聚乙烯醇硼酸钠新型注浆材料试验研究     

张海青  张玉敏 《岩土工程技术》2004,18(2):107-108,F003

通过对以聚乙烯醇为主剂 ,硼酸钠为交联剂的新型注浆材料进行粘度测试和结石体强度测试 ,分析了该注浆材料的可灌性和强度。并根据试验结果提出了灌注工艺  相似文献   

五硼酸钾水溶液的差示FT-IR和Raman光谱研究   总被引：2，自引：0，他引：2       下载免费PDF全文

王奖  朱黎霞  李淑妮  夏树屏  高世扬 《盐湖研究》2004,12(1):19-22

研究了KB5O8·4H2O水溶液20℃时的差示FT-IR光谱和Raman光谱,对振动频率进行了归属。探讨了KB5O8·4H2O水溶液中硼氧配阴离子的存在形式(主要是B(OH)3、[B3O3(OH)4]-和[B5O6(OH)4]-)和相互作用。  相似文献   

电导检测器—单柱离子色谱法同时测定饮用水中几种微量阴离子     

高秀清  王开义 《吉林地质》2002,(Z1)

本文研究了单柱离子色谱法测定饮用水中微量阴离子的方法 ,样品经微孔滤膜过滤即可直接进样分析。淋洗液最佳浓度为 2 5mmol/L邻苯二甲酸氢钾溶液 ;电导检测器检测灵敏度为 3 2 μS/cm2 。该方法简便快捷、灵敏 ,选择性好  相似文献   

Chemical variations of tephra-fall deposit leachates for three eruptions from Popocatépetl volcano     

M. A. Armienta  S. De la Cruz-Reyna  O. Morton  O. Cruz  N. Ceniceros 《Journal of Volcanology and Geothermal Research》2002,113(1-2)

Leachates from ash samples of the Popocatépetl eruptions of April 30, 1996, May 12, 1997, and October 17, 1998 settled at different distances from the crater were analyzed for anions (SO₄²⁻, Cl⁻, F⁻) and some metals. This study is aimed at determining the causes of the compositional variations of the leachates, to assist the assessment of water, soil and crop contamination due to ash deposits. Different behavior was observed in the ion concentrations with distance for the three eruptions. On April 30, 1996, SO₄²⁻ and F⁻ concentrations increased with distance, and Cl⁻ remained almost constant. On May 12, 1997, concentrations of the three anions decreased with distance. On October 17, 1998, F⁻, Cl⁻ and SO₄²⁻ increased more than three-fold with distance. Tephra size distributions were also different for the three eruptions. The observed trends of the leachates’ anion concentrations may have different causes: the type and intensity of the eruptions, the distribution of the tephra sizes, the degree of interaction of the tephras with volcanic gases, humidity, static charge, the original characteristics of the solid material, the transport time from the crater to the site of settling, and the relative angle between the wind direction and the sampling line. Enrichment factors and concentration trends for metals with distance suggest that Co, Ni, Cu and Pb in the leachates resulted mostly from volcanic gas adsorption.  相似文献   

25℃时K2B4O7-H2O体系的离子相互作用模型研究          下载免费PDF全文

李丽娟  姚燕  宋彭生 《盐湖研究》2004,12(2):23-28

根据硼酸盐水溶液中硼浓度不同时硼物种之间形成多种聚合与解聚的平衡反应理论和光谱学研究结果,利用已有的该体系25℃等压实验数据,拟合获得了该体系的两个化学计量平衡常数、各种硼氧配阴离子单一的以及二离子和三离子之间的相互作用Pitzer参数,确定了该体系在不同总硼浓度范围内各种硼氧配阴离子的存在形式与定量分布,将所获得的离子相互作用模型计算出的渗透系数与实验值进行了比较,获得了令人满意的结果。  相似文献