Sythesis Of Magnetic Surface Molecularly Imprinted Polymer Upon Yeast And Study On The Treatment Of Pesticide Wastewater

Pyrethroid pesticides are widely used throughout the world due to their high selectivity,relatively lower toxicity, short environmental residual and capacity of keep the advantages ofhigh-yield and high-guality in agriculture. However, more and more attention had been paidon the application of pyrethroid pesticides because of their negative effects which threaten thehumans’ daily lives and agricultural production. This paper reviews the progress ofdevelopment and the hazards of pyrethyroid pesticides in soil and water environment,especially humans’ health. At the same time, this paper showed the superiority of surfacemolecularly imprinting technology after comparison with other method in pyrethyroidpesticides wastewater treatment.Based on surface molecularly imprinting technology, the advantages of yeastbio-templates and magnetic materials, the magnetic surface molecularly imprinting adsorbentswere prepared and studied the adsorption and separation effect for pyrethyroid pesticideswastewater. This paper mainly consists of the following work:1. CoFe2O4magnetic microparticles were loaded on the surface of yeast byco-precipitation method, forming coblt ferrite magnetic microspheres, and the factors whichcan affect the size and dispersity of this material was analysised. The optimum reactionconditions were determined by the orthogonal experiment: Co2+ion concentration is0.1mol/L, the optimum reaction time is1h, the optimum pH is12, and the NaOH solution wasadded directly and quickly, the optimum annealing temperature is500℃and the dosage ofPEG is0.01g. The characterization results showed the CoFe2O4microparticles had uniformdiameter, strong magnetic dispersion, and pure crystalline phase.2. Using beta-cypermethrin as the template molecule, CoFe2O4magnetic microparticlesas the magnetic carriers, MAA as the function monomer, PVP as the dispersant, EGDMA as across-linking agent, DMSO as solvent and AIBN as the initiator, the magnetic surfacemolecularly imprinted and non-imprinted surface materials (MMIP and MNIP) weresuccessfully obtained by suspension polymerization. Characterization results showed thatMMIP and MNIP exhibited uniform ellipsoidal morphology, particle size uniformity andbetter dispersion, the particle size of MNIP slightly larger than MMIP. Saturation magnetization property of cobalt ferrite magnetic microspheres> MNIP> MMIP, and thehusteresis loops of MMIP close to S-type, almost have no coercive force and remanence.MMIP and MNIP exhibited good thermal stability.3. CoFe2O4magnetic microparticles, magnetic surface molecularly imprinted material(MMIP) and non-magnetic surface molecules imprinted material (MNIP) were all applied inthe adsorption process of beta-cypermethrin from solution, and through the initialconcentration, reaction time, temperature, pH, adsorbent dosage, the presence of interferingions and competitive target molecules such as single factor and orthogonal experiments onadsorption efficiency and adsorption capacity, the optimum reaction conditions of theadsorption process as follows: the optimum reaction temperature is35℃, the optimumreaction time is1h, the optimum pH is6. In addition, repetitive experiments also confirmedthat MMIP have stable adsorption capacity and reuse under the optimum reaction condiction.MMIP material herein was prepared with a relatively good selective recognition and highadsorptive capability which can realize the cypermethrin in the solution of specific adsorption,and have enough magnetic and stability, easy to recycle, has certain scientific research andpractical value.