Studies On The Extracted Methods Of EPS In Activated Sludge And The Adsorption On Heavy Metals With It

With the increasing advance of sewage disposal craft,research scholars increase the studies on property and funtion of active sludge extrocellular polymeric substances (EPS).The studies include the research on method of its extraction,which is divided into physical method and chemical process,and finding out the method that is both able to guarantee EPS structure and able to extract entirely is an urgent problem.In addition ,with the incresing recognition on EPS as a sort of newfashioned biosorption agent absorbing heavy metal ion, it is noticed that EPS is important for the removal of heavy metal ions in activated sludge treating process and it used as metallic ion adsorbent become both domestic and overseas researchful hotspot.The paper starts with the above two researchful directions.On the one hand extract EPS from raw and processed materials that is membrane bio-reactor active sludge through the medium of three strain physical methods that include heating extration, supercentrifugal process and ultrasonic method. Proper changing per strain methodological abstraction condition proceeds and thereby hunts respective optimal abstraction condition. Contrast a given mass of EPS extracted in respective optimum conditions and thereby find out optimal method of extraction.On the other hand study EPS as adsorbent,which is given by best extracted way,adsorption removal effect versus heavy metal ion that includes Cu²⁺,Ni²⁺ and Cr³⁺.And seek optimal adsorption condition,review its feasibility as metallic ion biosorption agent. At the same time research the using value of EPS at reclaiming precious metal ion(Ag+).The experiment shows optimal method of extraction is heating extraction (80℃,15min)which extracts the most EPS measure and furthermore level of destruction on cell is the smallest in three strain physical method extraction outcome. The proper pH value on Extrocellular polymer (EPS) respectively absorbing three kinds of heavy metal ion including Cu²⁺,Ni²⁺ and Cr³⁺ is 3～5,4～6å’Œ4～6. The fitting throwing scale(EPS quality:Metallic ion quality)is 1.8:1, 1.6:1 and 2.0:1 respectively. EPS has different adsorption mechanism versus different metallic ion and can also absorb the rest metallic ion after a sort of metallic ion adsorptive saturation. EPS designed to reclaim heavy metal ion has definite potential as it has definite sorption versus precious metal ion Ag⁺.