Study On Rare Earth La-Iron And Coke Micro-Electrolysis Used For Pva Waste-Water

PVA is widely used in textile, printing and dyeing and chemical fiber industry as it has good adhesion,serous membrane tenacity and abrasive resistance, which leads that the waste water caused by these enterprises contains a large amount of PVA. PVAis a kind of typical refractory organic compounds and has poor biodegrability, therefore, it is an urgent need to solve the problem that ho-w to deal with PVA waste water effectively. Iron-coke micro-electrolysis is widely used in industr-ial water treatment because it is economical, easily acquired and stable, but this usually requires a-cid conditions. This paper makes a comprehensive review of the research about waste water whic-h contains PVAfrom domestic and abroad in recent years. In this paper, there has a study on the e-ffect of RE La-Fe0/C whose padding are 100 g Fe and 100 g coke is carried out for the first time o-n the degradation of the PVA, which improves the removal efficiency of PVAand expanded the scope of iron carbon micro electrolysis system. The main research contents are as follows:(1) Different amount of RE La were investigated and the best amount is 0.4g/L. It makes a study on the effect of different reaction systems which contain rare earth La system,La-coke syste-m, Fe- coke system and La-iron and coke system on PVA removal rate under the pH from 1 to 10 conditions and effect of different reaction system on PVAremoval rate over time under acidic con-ditions and alkaline conditions. The results show that the PVAremoval rate of the La-Fe0/C syste-m is more than 85% at pH =3 and t=6h and almost 60% at pH=9 and t=6h,which is far greater tha-n Fe0/C system.(2) It has a macro analysis of the role of RE La among the whole process by comparison with different reaction system and analysis of the SEM and EDS of iron and coke, the whole reaction process was analyzed in the final.(3) The actio-n kinetics models of Fe- coke system and La-iron and coke system under acidic condition and alkaline condition were established by using the power function type dynamic equation,which provides data supplies and theoretical basis for practical applications.(4) Reaction Mechanism: oxidation is the main among degradation of PVAby analysising the PVAdegradation product under acidic condition obtained by GC-MS.The internal structure of PV-A was broken and generates ketones, aldehydes, esters, alcohols and other organic matter under th-e electrochemical action, HNO3 oxidation and catalytic oxidation of rare earth La. Then,it genera-tes simple alkanes under the oxidation of ·OH. Finally,it was oxidized completely.(5) By comparing the content of La, Fe2+,Fe3+ and the pH of the effluent under acidic conditio-n and alkaline condition respectively, it gets the conclusion: RE La plays a role of catalytic oxidat-ion mainly while the flocculation effect is weak under acidic condition; RE La plays a role of floc-culation mainly and the coagulant effect acts as a supplement.