Study On Self-adaptive Conditions Of Heavy Metal-resistant Strains

With the rapid development of cities and industry, the pollution caused by the waste water containing heavy metals emitting into the environment becomes more and more serious. These hard-to-degradable, toxic heavy metal pollutants accumulate in the body of water, and it has a great harm to the environment and human health. Biological adsorption, as a newly-developed heavy metal removal technology, has a good effect in adsorption, no secondary pollution, lower operating cost and so much other advantages, and now it has drawn more and more attention.This topic based on Dalian Jinzhou District water purification plant a golden state of activated sludge vaccination of the training of the microorganism in biological membrane group as the research project. We choose beef anointed specially designed medium screened out four single strain, and identify them through the scanning electron microscope, physiological and biochemical properties,16s rDNA sequenced methods, then we named them ZH-1、ZH-2、ZH-3and ZH-4respectively. And we can domesticated the microflora in the mixed metal ions containing Pb2+, Zn2+, Ni2+, Cu2+、Cd2+, Cr6+in order to get the mixed strains of high tolerance and high adsorption.We discussed the influencing factors that the mixed bacteria adsorb six kinds of mixed metal ions. The experimental results show that under the same condition, the mixed bacteria to heavy metal ions in the adsorption effect which through the metal ion domestication is much more better than not through the metal ion domestication. Under the experiment conditions:pH=6.0, adsorbent dosage is2g/L, concentration of NaNO3is O.Olmol/L, initial concentration of miced metal ions is30mg/L, the adsorption can reach a balance after90min. Mixed metal ions adsorption rate can reach85%, the remove effect is good. We simulated the adsorption by thermodynamic models; results revealed that Langmuir equation can describe the adsorption process better. The mixed bacteria for metal ions adsorption process is based on surface adsorption. We also primarily discussed the infrared spectrum and atomic force microscope to adsorption mechanism at the same time. Infrared analysis showed that in the process of absorption, carbonyl, hydroxyl base was the main adsorption potential points. AFM demonstrate that the physical properties of strains changed. It mainly displays in elastic decrescent, viscous bigger, bacteria contraction, that bacteria lead ions to a certain biological accumulation.We also investigated the actual effect to heavy metal waste treatment by biomembrane trained by the mixed strains. The result showed that after treatment, metal ions adsorption rate of waste water reached81.2%. The COD removal rate reached78.7%. The efficient handling ability of biomembrane for the waste water, provided a reference to the biological membrane repairing method for heavy metal polluted water.