The Studies Of Purification Properties On Lysozyme Amyloid Nanofibrilrs To Traces Of Heavy Metals And Organic Dyes In Water

Nowadays,all kinds of aspects of the production and life of mankind have made an impact on water environment.Fiding a wastewater treatment which is economic,environmentally and easy operation has become the hot topic that people focus on specially.In this paper,we prepared two adsorbents to purify traces of heavy metals and organic dyes in water separately,one of which is lysozyme amyloid nanofibrils and another one is a new composite adsorbent that is prepared by modifying lysozyme amyloid nanofibrils through polydopamine and polyethyleneimine.In the paper,the two kinds of adsorbents were well characterized by scanning electron microscopy?SEM?,transmission electron microscopy?TEM?and X-ray diffraction?XRD?.The results showed that the lysozyme amyloid nanofibrils have a nanofibrous structure with a width of 20³0 nm.And the new composite adsorbent has the same structure but the width is30⁴0nm.The adsorption behaviors about the lysozyme amyloid nanofibrils to the organic dyes have been studied firstly.The organic dyes removal onto lysozyme amyloid nanofibrils is a pH dependent process with the optimal pH ranges to Congo red and Xylenol orange are between 1 to 10 and 3 to 10.The prepared lysozyme amyloid nanofibrils can attach a prompt equilibrium within 20min for Congo red and 30min for Xylenol orange,and it could be found that the adsorption processes for organic dyes are more coincident with pseudo-first-order kinetic model by means of kinetics curve fitting and data analysis.It is temperature relating exothermal process with the maximum sorption capacities of1760mg/g for Congo red and 783mg/g for Xylenol orange and the fitting curves of Freundlich isotherm model exhibite good linearity.The resultant adsorbent can achieve efficient organic dyes removal in presence of the common competing ions SO₄^2-,Cl^-and NO₃^-at high contents,indicating its preferential selectivity.Organic dyes can be recovered by desorptive solutions.Another adsorbent was composited by modifying lysozyme amyloid nanofibrils with polyethylenimine and polydopamine,which can adsorb traces of heavy metals in wastewater.It is a pH dependent adsorbed process with the optimal pH at 6.The adsorption efficiency can be hardly influenced by common competing ions Ca²⁺?Mg²⁺and Na⁺at high contents.Additionally,the resultant adsorbent can attach a rapid equilibrium within 60 seconds and the sorption curve fitting could be well described by the pseudo-second-order kinetic model,which is an exothermal process with the maximum sorption capacity is approximately 511.56mg/g.The cmposite can be regenerated by desoptive solutions three times.The resultant column adsorption suggests that one kilogram Fiber-PDA-PEI has a treatment capacity of 12239Kg simulated Pb?II?wastewater.