海水中活性硅酸盐的流动注射-分光光度快速测定法及其应用

基于酸性条件下硅酸盐与钼酸铵反应生成硅钼黄而后被还原成硅镅蓝的原理,利用流动注射分析技术,建立了快速测定海水中活性硅酸盐的分析方法.在优化的条件下,方法检测限为0.5 μmol·L-1,线性范围为2.5～110.0 μmol·L-1,实际海水的加标回收率为103.6%～109.3%,同一水样连续测3次仅需4.5 min...     

广东省环境经济系统的物质流分析

运用物质流分析(MFA)方法.对广东省经济系统在1990～2005年间的物质输入与输出进行系统地分析,探讨了广东省经济发展与环境压力的关系.研究结果表明:①在不考虑水的情况下.物质输入与输出量均在不断增加(年均分别为4.50%和3.87%),但均小于GDP的增长速度(14.62%),二者成正比,物质消耗强度和物质输出强度也在逐渐上升,说明区域社会经济的发展带动了人们物质消费的增长,从而导致输出的增加;②水输入输出量以及废水排放强度均在不断增加,尤其是生活污水排放量及排放强度的增长速度较快,加重了对区域水环境的压力;③单位GDP的物质输入与输出均在不断降低,表明区域资源综合利用效率和废弃物输出效率得到明显提高;④物质输入输出与GDP回归分析表明.区域物质输入与GDP、区域物质输出与GDP呈良好的线性关系;⑤IPAT模型分析表明,区域过程排放(RPO)受到技术水平提高的限制,但由于国民福利与人口增长的压力,使得RPO仍以年均2.67%的速度增长.但远小于GDP的增长速度,表明区域经济和环境处在相对解耦状态,广东省正逐步走向区域环境与经济的协调发展.     

Functional groups assisted-photoinduced electron transfer-mediated highly fluorescent metal-organic framework quantum dot composite for selective detection of mercury (II) in water

The presence of toxic mercury (II) in water is an ever-growing problem on earth that has various harmful effect on human health and aquatic living organisms. Therefore, detection of mercury (II) in water is very much crucial and several researches are going on in this topic. Metal-organic frameworks (MOFs) are considered as an effective device for sensing of toxic heavy metal ions in water. The tunable functionalities with large surface area of highly semiconducting MOFs enhance its activity towards fluorescence sensing. In this study, we are reporting one highly selective and sensitive luminescent sensor for the detection of mercury (II) in water. A series of binary MOF composites were synthesized using in-situ solvothermal synthetic technique for fluorescence sensing of Hg²⁺ in water. The well-distributed graphitic carbon nitride quantum dots on porous zirconium-based MOF improve Hg²⁺ sensing activity in water owing to their great electronic and optical properties. The binary MOF composite (2) i.e., the sensor exhibited excellent limit of detection (LOD) value of 2.4 nmol/L for Hg²⁺. The sensor also exhibited excellent performance for mercury (II) detection in real water samples. The characterizations of the synthesized materials were done using various spectroscopic techniques and the fluorescence sensing mechanism was studied.