Microalgal removal of hazardous chemicals in the environment

最近，各种化学品被产生，然后排放到环境中。其中一些化学物质对人类健康和生态系统具有有害影响，并造成严重的社会问题。提出利用微藻的功能作为环境生物修复的一种方法。利用光合作用的微藻修复被污染的环境似乎是非常有用的，因为微藻可以利用太阳能在营养不良的条件下生长。本研究为开发高效去除环境中重金属和有害有机物的系统进行了基础研究。微藻对环境水体中重金属的去除。考察了光照、搅拌、pH、温度和基质组成等因素对微藻去除镉的影响，得到了去除高浓度镉的最佳条件。考察了地下水、海水等环境水体中大量存在的Na~+、K~+、Ca~(2+)和Mg~(2+)对重金属去除的影响。结果表明，Ca^&lt；2+&gt；或Mg^&lt；2+&gt；会降低微藻的去除能力。为了提高对镉的选择性去除，对藻细胞的各种预处理进行了研究，结果表明，氢氧化钠对藻细胞中的镉有较好的去除效果。危险有机化合物分解的初步研究。对微藻进行了筛选，以去除氯酚和硝基酚等有害有机化合物。获得了几种具有较高去除能力的微藻，为进一步的研究奠定了基础。

Recently, a variety of chemicals are produced and afterwards discharged in the environment. Some of these chemicals have injurious effects in human health and ecosystem, and they cause a serious social problem. We proposed the utilization of the function of microalgae as a method for the environmental bioremediation. It seems to be very useful to use photosynthetic microalgae for the restoration of the polluted environment, because microalgae can grow under the poor nutrition conditions by utilizing the solar energy. In this study, the basic research for the development of efficient removal systems of heavy metals and hazardous organic compounds in the environment was carried out.1. The heavy metal removal from environmental water by microalgae. Effects of light, agitation, pH, tempenature and medium composition on the cadmium removal were examined using microalgae, and optimal conditions for high cadmium removal was obtained. Then, the effect of Na^+, K^+, Ca^<2+> and Mg^<2+>, which are abundantly found in environmental water such as ground water and seawater, on the heavy metal removal was examined. It was found that the removal ability of microalgae was lowered by Ca^<2+> or Mg^<2+>. In order to enhance selective cadmium removal, various pretreatments of algal cells were investigated, and treatment of the algal cells with sodium hydroxide was effective to remove the cadmium in the presence of Ca^<2+> or Mg^<2+>.2. The preliminary study on the decomposition of hazandous organic compounds. Microalgae were screened for the removal of the hazardous organic compounds such as chlorophenols and nitrophenols. Several microalgae that have high removal ability were obtained for the further studies.