Microalgal removal of hazardous chemicals in the environment

Research Project

Project/Area Number	11672227
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Environmental pharmacy
Research Institution	Osaka University
Principal Investigator	MIYAMOTO Kazuhisa Osaka University, Graduate School of Pharmaceutical Sciences, Professor, 薬学研究科, 教授 (30028849)
Co-Investigator(Kenkyū-buntansha)	NAGASE Hiroyasu Osaka University, Graduate School of Pharmaceutical Sciences, Research Associate, 薬学研究科, 助手 (00252700)
Project Period (FY)	1999 – 2000
Project Status	Completed (Fiscal Year 2000)
Budget Amount *help	¥3,600,000 (Direct Cost: ¥3,600,000) Fiscal Year 2000: ¥1,200,000 (Direct Cost: ¥1,200,000) Fiscal Year 1999: ¥2,400,000 (Direct Cost: ¥2,400,000)
Keywords	Microalgae / Heavy metal / Hazardous organic compound / Bioremediation / 除去 / 緑藻 / ラン藻 / 有害化学物質 / カドミウム / 有機塩素化合物 / 環境浄化技術
Research Abstract	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.