优势菌种活细胞对天然水体中Pb^2＋和Cd^2＋的吸附

通过对天然水环境———伊通河中优势菌种活细胞吸附Pb2 、Cd2 的研究发现 :pH对Pb2 、Cd2 吸附的影响是不同的 ,对Pb2 的吸附量在 pH =5 .0～ 7.0时变化不大 ,对Cd2 的吸附量在 pH =6 .0～ 8.0时变化不大 ;温度对活细胞吸附Pb2 、Cd2 影响明显不同 ;活细胞对Pb2 、Cd2 的吸附量随着细菌密度的增加而增大 ,随着渗透压的增大而降低 .图 5表 1参 8     

双波长胶体光度法测定天然水锌

根据胶体光学吸收行为研究Zn~(2+)-S~(2-)胶体反应测定Zn~(2-)双波长新光度分析方法。该方法简单方便、曲线稳定、精密度(RSD)<3％,加标回收率为93％～103％,检出限:0.3mg/L.适合于0～10.0μg/ml天然水测定。     

天然水中痕量钼的示波极谱测定法

天然水中痕量钼的示波极谱测定法阮琼，陈国庆（云南教育学院环境资源教育分院昆明６５００３１）钼是动植物所必须的营养元素，缺钼会引起一些疾病，而钼过多，又会出现中毒症状。一般天然水中含钼量增高，水有苦涩味，对作物有危害作用。因此，了解和测定天然水中钼的含...     

不经蒸馏直接测定天然水中氰化物

本文采用EDTA掩蔽天然水中常见的干扰组份,可不经蒸馏直接测定天然水中的氰化物。在加入5％EDTA5ml进行测定时,方法的摩尔系数为6.0×10~4l/mol·cm。对含氰为4.0～6.0ppb的天然水的测定,回收率为92.6～104.8％,相对标准偏差为4.5～11.3％。     

Influence of stabilizers on the antimicrobial properties of silver nanoparticles introduced into natural water

Physical, chemical and biochemical properties of silver nanoparticles(AgNPs) depend to a great extent on their size, shape, size distribution, and stabilizers located on their surface. This study focused on two typical stabilizers, namely citrates(cit), low molecular ions protecting nanoparticles by electrostatic repulsion, and polyvinylpyrrolidone(PVP), a hydrophilic, neutral, high molecular polymer protecting nanoparticles by steric stabilization. Natural bacterioplankton was collected from a eutrophic, downtown lake and exposed to five concentrations(0.1–5 mg/L) of AgNPs-PVP and AgNPs-cit. Responses were monitored after 1, 3, 5 and 7 days of exposure, by evaluating the survival rate of bacteria, their respiratory activity, and the general activity of extracellular esterases. A significantly better(greater) survival rate of bacterioplankton was observed in water with an addition of AgNPs-cit. The inhibition of extracellular esterases was observed only in samples containing AgNPs-PVP. The inhibitory effect increased proportionally to the concentration of AgNPs-PVP applied. Within the studied concentration range, there was no statistically significant inhibition of bacterioplankton respiratory activity by AgNPs-PVP and AgNPs-cit.     

水中含盐量过高对锅炉的危害

水的含盐量是指水中所含盐类的总量,以mg／1来表示,同时也是衡量水质好坏的一项重要指标,天然水中含盐量的多少可作如下分类：低含盐量的水含盐量在200mg／l以下。