典型沉水植物修复富营养水体的最优种植密度

沉水植物因其完全水生的特点使得其在水生植物各生活型中对环境胁迫的反应最为敏感,它的存在对水域生态系统中的结构和功能的稳定性起着支撑作用。因此,沉水植物对于生态修复中水生植物群落的构建起着关键作用。通过室内人工栽培的模拟试验,研究不同种植密度下中国典型沉水植物耐污种金鱼藻（Ceratophyllum demersum L）和穗花狐尾藻（Myriophyllum spicatum L）对氮、磷营养盐的去除能力,并筛选最优定植密度。结果表明,金鱼藻种植密度为4.0 g/L时,对总氮（TN）、总磷（TP）去除率最高,分别达86.78%和91.82%;穗花狐尾藻种植密度为2.0 g/L和4.0 g/L时,对总氮、总磷去除率最高,分别达91.60%和92.10%。通过氮磷去除率-密度的非线性拟合模型,金鱼藻和穗花狐尾藻的最优种植密度分别为4.5-5.0 g/L和3.0 g/L。基于成本-效率均衡考虑,最终确定了两种沉水植物的单一种植最优密度为3.0 g/L。

水生生物与水质污染

不同种类的生物对环境有着不同的要求。有些种类生物只能生活在清洁水体中,称此类生物为敏感种类,有些种类生物耐污性强,能在污染严重的水体中大量繁殖,称此类生物为耐污种类,生物工作者就是利用生物这一特性进行水质分析、评价。下面选几种生物说明水污染与生物的关系。

浮游藻类在矿区水体评价中应用的探讨

近年来我国许多水域,受到工农业污水污染后,对水生生物构成了直接和间接的危害。浮游生物是水生生物链的基础,在水生生态系统中占有重要的地位,水体的污染不仅使污染物在浮游生物体内积累进而沿食物链逐级富集,而且改变了浮游生物的组成、数量和分布状况。

Heavy metal contamination, physico-chemical and microbial evaluation of water samples collected from chromite mine environment of Sukinda, India

Water samples from chromite mine quarry of Sukinda and its adjacent areas were analyzed for their heavy metal contamination along with physico-chemical and microbial contents. The chromite mine water samples possessed high concentrations of heavy metals in the order of Cr〉Fe〉Zn〉Ni〉Co〉Mn while ground water did not show any heavy metal contamination except Fe. Physico-chemical parameters of mine water samples showed deviation from those of normal water. Mine water harboured low microbial populations of bacteria, fungi and actinomycetes in comparison with mine adjacent water samples. The correlation of data between metals with physico-chemical parameters showed both positive and negative responses while that of metal and microbial population exhibited negative correlation. Bacterial strains isolated from chromite mine water exhibited high tolerance towards chromium and other heavy metals as well as antibiotics which could be used as an indicator of heavy metal pollution.