Validation of a conductometric bienzyme biosensor for the detection of proteins as marker of organic matter in river samples

This article describes a conductometric bi-layer based bienzyme biosensor for the detection of proteins as a marker of organic matter in rivers. Proteins were chosen to be used as indicators of urban pollution. The working mechanism of the bienzyme biosensor is based on the enzymatic hydrolysis of proteins into several fractions (peptides and amino acids), which results in a local conductivity change depending of the concentration of proteins. In this work, we began with the optimization of biosensor response using bovine serum albumin (BSA) as standard protein. For this objective seven enzymatic biosensors were prepared: four enzymatic sensors with only one layer of enzyme (proteinase K, trypsin, pronase or protease X) and three other enzymatic sensors with two layers (first layer: membrane containing proteinase K; second layer: one of the three other enzymes: trypsin, pronase or protease X). The biosensors were obtained through the deposition of enzymatic layers and the cross-linking process between enzymes and BSA in saturated glutaraldehyde vapour. The response of the various biosensors, described previously, were compared with the values of total organic carbon (TOC), and those of organic nitrogen (Norg), as determined by the laboratory accredits (CEMAGREF of Lyon) using the traditional method of analysis (NF EN 1484, infrared spectroscopy) and (NF EN 25663, mineralization/colorimetry assay) respectively for each water sample obtained from di erent sites in Lyon (France). The linear correlations obtained with the response of the seven biosensors showed the most important indices of correlations for the biosensor with two enzymatic layers: proteinase K + pronase (pkp). The optimum conditions for the preparation of the pkp biosensor increased the sensitivity and gave a limit of quantification of 0.583 g/L for TOC and 0.218 g/L for Norg in water samples. This sensor shows good reproducibility (2.28%), a capacity to be used at temperatures range 10– 30°C (depending on the season) and moreover a long lifetime (5 weeks).     

SDBS胶束体系热力学性质的研究

文章选用十二烷基苯磺酸钠为研究对象,在(25±0.02)℃下,用Na+选择性电极法测量不同浓度的电动势(EMF),求出其临界胶束浓度(cmc)及反离子结合度,得出反离子与胶束结合的经验平衡常数Kass。在25～50℃范围内,每隔5℃电导率随温度的变化,求出对应温度下的cmc及其相应的一系列热力学参数。在实验温度范围内,吉布斯自由能均为负值,胶束化可以自发进行;焓变为正值,胶束化过程吸热,且属于熵驱动过程,有18.67%的T△micS0增加对胶束稳定性增加有贡献,以上特征参数的确定,可为研究表面活性剂溶液的各种应用以及处理技术提供重要参考。     

唐菖蒲对大气氟污染的生理生化反应(Physiological and Biochemical Responses of Gladiolus to Atmospheric Fluoride Pollution)

通过唐菖蒲在石家庄不同大气环境中叶片的形态、叶绿素总量、细胞膜透性以及过氧化物酶活性的变化,研究了唐菖蒲对氟污染胁迫的生理生化反应及适应调节机理.结果表明:石家庄市各监测点的大气中均存在氟污染,其污染物浓度由高到低依次为:市热电厂>元南小区>棉七生活区>阳光公园;从严重污染区到清洁区,随着污染程度的减小,唐菖蒲的叶绿素含量显著增加,细胞膜相对电导率及过氧化物酶活性明显降低.初步分析显示,唐菖蒲可作为大气氟污染的指示植物.     

南通长江口北支咸潮上溯对水环境的影响

针对长江口北支近20多年来咸潮超常上溯的状况,通过现场调查监测及与文献资料对比,分析了咸潮上溯对水源地供水水质、河口区河道水质和地下水水质的影响。结果表明,长江口北支咸潮上溯对北支水环境影响主要在于入侵时水体中电导率和氯化物浓度急剧升高,一定程度上影响了北支沿线水源地的供水功能。咸潮对现有水质评价体系下的水质类别影响尚不明显,但高氯离子对化学需氧量的测定有明显的干扰。由于受堤围和水闸控制,咸潮期间入江闸门普遍关闭,导致间接水环境影响,主要集中在入海主河道。部分区域咸潮上溯严重时氯化物浓度升高,水质已不能满足农田灌溉需求。北支沿线启东市24%的地下水采样点氯化物浓度已属轻度入侵水,采样区域已属于海水轻度入侵范围。     

磷石膏改善苏打碱土理化性质效果分析

分析了磷石膏对苏打碱土团聚体稳定性、饱和导水率和盐分淋洗效果的影响.结果表明:水稳定大团聚体质量分数和饱和导水率均随磷石膏施用量的逐渐增加而不断提高,磷石膏施用量达到100%GR时,水稳性大团聚体质量分数从对照的0.03%增加到33.31%,饱和导水率从对照的0.13 mm·d~(-1)提高到3.14 mm·d~(-1);出流液电导率和pH均随磷石膏施用量的增加而降低,磷石膏施用量达到100%GR时,出流液电导率和pH分别从对照的8.85 mS·cm~(-1)和10.26降低到3.46mS·cm~(-1)和9.83.因此,磷石膏对苏打碱土理化性质的改良效果十分显著.     

希夏邦马峰北坡达索普冰川区冰、雪、河水的化学特征

１９９７－０９～１９９７－１０间在希峰地区达索普冰川采集的４类水样（表层雪、冰塔冰、冰面河水和河水）的实测资料表明,本区各类水体ｐＨ值的大小顺序为：河水＞冰面河水＞冰塔冰＞表层雪．表层雪和冰面河水所测的阴离子中以ＮＯ－３为最大,而冰塔冰样品以Ｃｌ－最大;阳离子含量基本上以Ｃａ２＋为主．ＳＯ２－４、Ｃａ２＋、Ｍｇ２＋、电导率和ｐＨ值都与所测的阴、阳离子总量有较好的相关关系,随所测的阴、阳离子总量升高而增大．表层雪的电导率、Ｎａ＋、Ｃｌ－、所测的阴、阳离子总量和ＳＯ２－４与海拔高度都有较好的相关关系,随着海拔高度上升而上升．     

应用蚕豆微核技术对煤矿塌陷塘水质的监测

用蚕豆微核技术对淮南大通和谢二煤矿塌陷塘的水体水质进行监测,同时测定了水体的氯化物、电导率、CODCr、BOD5、DO和总磷、总氮。结果表明:大通和谢二煤矿塌陷塘水质已经受到中度污染;蚕豆微核技术与氯化物、电导率、CODCr、BOD5、DO和总磷、总氮具有一定的相关性。     

浓缩液回灌出水电导率与离子浓度的灰色关联度研究

研究渗滤液浓缩液回灌出水电导率与离子浓度的关系对完善渗滤液浓缩液回灌体系具有重要的意义。采用成都某垃圾填埋场的渗滤液浓缩液,在实验室矿化垃圾填埋柱中开展了回灌实验,分别得到了回灌出水中电导率和8种离子浓度的变化规律。基于灰色关联模型,对电导率与离子浓度的灰色关联度进行了分析,结果表明,电导率与K+的关联系数最大,其次是NO-3、Na+和Cl-。因此在回灌出水中这4种离子与电导率的关联性较大、可将其作为回灌体系中优先控制的离子。     

一种四电极电导率传感器的研制与实验

采用高温共烧结技术制备将工作电极与激励电极热压并一次共烧成一体的电导敏感芯体,测量范围0~200μS/cm,精度小于±1.5%FS。介绍了该电导传感器的测量原理、电路方案、封装结构及工艺流程。通过对其进行性能实验,验证该传感器具有测量精度高的特定,并考核了传感器的长期稳定性。     

城市污水中电导率与COD相关性分析

标准法－重铬酸钾法测定COD的缺点是测定时间长，氯离子干扰大。微波密封消解法对此有了改进，具准确度高，精密度好等优点，但存在着设备较贵，试剂消耗量大，分析费用较高的问题。通过对郑州市金水河、东风渠、熊耳河三条河流的连续定位监测，结果表明，废水中的电导和COD两者之间存在着线性关系，在正常情况下，测定电导后，根据两者之间的线性关系，求算COD的值，从而缩短了实验的繁琐，减轻了污染，节约时间和费用。