Induced alkoxyresorufin-O-dealkylases in tilapias (Oreochromis niloticus) from Guandu river, Rio de Janeiro, Brazil

The activity of fish monooxygenases has been extensively used as a monitoring tool to detect contamination of water bodies by cytochrome P450-inducing agents. In this study we evaluated the activities of ethoxy- (EROD), methoxy- (MROD) and pentoxy- (PROD) resorufin-O-dealkylases in the liver of Nile tilapias (Oreochromis niloticus) collected at the Guandu river, at a reference clean site (Lake 1) and at two other sampling sites (Lakes 2 and 3) in Rio de Janeiro state, Brazil. Alkoxyresorufin-O-dealkylases were measured fluorimetrically in the hepatic S9 fraction. EROD (17.7-fold), MROD (14.2-fold) as well as PROD activities were considerably higher in tilapias from Guandu river. A moderate increase of EROD (5.0-fold) and MROD (5.4-fold) was also found in tilapias from Lake 3. These findings suggest that Guandu river watershed, the main source of urban drinking water supply in Rio de Janeiro, is polluted with CYP1A-inducing xenobiotics. Furthermore, we also found a good linear relationship between EROD and MROD, a finding that agrees with the hypothesis that the two reactions are catalysed by the same CYP1A isoform in O. niloticus.     

复合菌种协同发酵混合酒糟最佳C/N的测定

通过测定混合酒糟发酵液初始碳源氮源的含量及复合菌种协同发酵后发发酵液中碳源氮源残留含量，计算复合菌种对碳源氮源的利用率或转化率，研究了最佳C／N的新测定法，同时对细胞干重法作了改进，发酵试验条件为：100mL混合酒糟培养液中接种量10％，温度30．0℃，转速170r/min，摇床培养48h，通过正交试验得绝干菌体质量高达14.693g/L，碳利用率是高灰98．13％，氮转化率最高达78．14％，最佳C／N比为5．1。     

Relating cadmium concentrations in three macrophyte-associated freshwater invertebrates to those in macrophytes,water and sediments

We found that Cd concentrations in three species of macrophyte-associated invertebrates (the gastropods Bithynia tentaculata and Physa gyrina, and the amphipod Gammarus fasciatus) collected at twenty sites along the St. Lawrence River were correlated with Cd concentrations in their main food source, i.e. macrophytes and associated periphyton. Cd in these invertebrates was not significantly correlated with Cd concentrations in the sediments (even when corrections for iron oxide or organic carbon content were applied) or to calculated free-cadmium concentrations in the water. Cd levels in juveniles of B. tentaculata were very tightly linked to Cd concentrations in macrophytes, which is consistent with the close relationship that these organisms have developed with macrophytes. Linear models predicting Cd levels in juveniles of B. tentaculata from Cd levels in different macrophyte species were strong (R2 = 0.69-0.90). Analysis of covariance on these models showed no statistical difference of slope or intercept for any of the macrophyte species, except Vallisneria americana. We suggest that the macrophyte-periphyton complex is a key link in the transfer of cadmium to some aquatic invertebrates in the littoral zone of the St. Lawrence River and that macrophytes and their associated epiphytes should also be used as biomonitors.     

城市污水污泥对环境的污染及其防治

本文论述了城市污水污泥对水源和土壤的污染,并对其污泥特性作了分析,指出在我国的现有条件下污泥的处置主要为农业上的利用.     

沈阳市填埋场填埋气利用途径比较

通过对国外填埋气体的利用情况介绍和国内现有填埋气体利用途径的比较,得出沈阳市填埋气体适于发电的结论。     

秦皇岛市废矿物油资源化初探

在分析秦皇岛市废矿物油的产生和排放现状的基础上，指出废矿物油资源化是解决近岸海域油污染的最佳条件，并提出了一些可操作性的废矿物油资源化对策。     

我国利用水生植物监测和净化污水的研究进展

本文综述了我国利用水生植物监测和净化重金属废水、化工废水、生活污水、放射性核素废水以及抑制富营养化水体中藻类研究进展。并讨论了各种生态因子对水生植物净化效率的影响。为建立低投资、高效率、易管理的植物净化处理设施提供参考。     

略谈奎河的水环境保护与水资源利用

依据奎河水污染的现状和国家对奎河水质要求达到的目标以及奎河流域的经济状况，提出了整治奎河河道及沿岸环境、开发利用奎河水资源，引奎河水入徐沙河，既用于航运又供农田灌溉的奎河水污染综合治及奎河水资源利用方案。除雨季和特大洪灾，奎河污水将不再进入安徽省，较好地解决了奎河的跨省污染问题。     

利用电石渣代替石灰处理酸性废液

文章介绍了一种以废治废的新工艺,该工艺利用电石渣代替石灰作为中和剂处理酸性废液,具有成本低,使用方便等特点,不仅可以节约酸性废液的处理成本,改善操作环境,而且使电石渣得到了综合利用,减轻环境污染,达到"以废治废"的目的,环境效益及经济效益显著.同时该工艺对危险废物处理广的这行也有一定的借鉴作用.     

辽北地区水生昆虫与水质监测试验

辽北地区水生昆虫与水质监测的试验是采用美国昆虫学家莫尔斯．约翰提出的监测模式进行的。文中重点阐明了水生昆虫的采样方法、生境观察指标、污染指数值确定方法、评价标准，并进行了应用实例分析。研究结果表明，水生昆虫监测方法适用于快速监测和评价河流水质。