수용액내 중금속 제거를 위한 미생물 흡착 공정(I)

Biosorption Process for Removing Heavy Metals in Aqueous Solution (I)

In recent years, waste heavy metals which have a reputation of detrimental effect on the en - vironment through the food chain are generated from mining, dyestuff, material, electric, and petroleum industries. In this study, the effect of heavy metals on human body and advantage or disadvantage of conventional technology for removal of heavy metals were reviewed, and biosorption process which have been deep studied recently was also investigated briefly. Conventional methods for removing heavy metals include chemical precipitation, electrolytic recovery, membrane technology, and ion exchange. These processes need to have pretreatment or aftertreatment, and may be ineffective or extremely expensive, especially when the concentration of heavy metals in solution are in the order of 1 to 100 mg/L. Biosorption process have lots of advantages in operating conditions and economical aspects and it is about to step into practical use in advanced states. The substances which have a capability to bind heavy metals are extracellular polymeric substances, cell wall, cell cytoplasm, and some excreta. The extracellular polymeric substances can be classified into proteins and polysaccharides excreted from microbial cells, and they may form complexation with heavy metals. The cell wall on the outside of the cytoplasmic membrane of the cell, determine the shape and the rigidity of the cell, have polysaccharides such as peptidoglycan and chitin, and bind with heavy metals well. It was reported that the organelles inside the cell membrane can sorb heavy metals too.