Application Of Mg-Zn-Ca Metallic Glass In Treatmenting Organic Wastewater

The scale of agricultural production is huge in china. Water was polluted from the over production and use of herbicides and pesticides. How to effectively control the organic wastewater was a hot topic for researchers. Amorphous alloy has long range disorder and short range order structure, which gives it many unique properties, Such as good corrosion resistance and catalytic activity. As a new type of metal catalyst, amorphous alloy can be used in the degradation of organic pollutants in wastewater under the environment of the Fenton-like.Mg-based amorphous ribbons with different component(Mg75Zn20Ca5, Mg73Zn22Ca5 and Mg71Zn24Ca5) were prepared in this paper. Chemical oxygen demand(COD) as the main indicator of organic content in wastewater. XRD, SEM and EDS were used to characterize the surface morphology, structure and composition of the amorphous ribbons before and after the reaction. Mg-based amorphous ribbons were used in the degradation of herbicide wastewater and pesticide wastewater, and the influence of various reaction conditions on degradation effect was analyzed. The before and after reaction with Mg-based amorphous ribbons microstructure changes and degradation mechanism was investigated, in order to improve the catalytic activity of Mg-based amorphous ribbons.Simulation of herbicide glyphosate wastewater as the research object. The experimental results show that degradation efficiency of Mg-based amorphous ribbons is higher than magnesium, and the Mg element is the main source of catalytic activity in Mg-Zn-Ca amorphous ribbons. The amount of amorphous ribbon must be moderate in the process of degradation, and the degradation of the wastewater was affected by the solution pH and the surface area of the ribbons. The type of oxidant was ·OH during the reaction.Simulation of pesticide omethoate wastewater as the research object. By changing the initial concentration, reaction time and catalyst adding amount, pH and the dosage of H2O2 and the experimental parameters, to obtain the optimum reaction conditions of Mg-based amorphous ribbons in treamenting omethoate wastewater. The experimental results show that the optimum reaction conditions of 100 mL concentration of 1g/L simulated wastewater are: the dosage of ribbons: 0.3g, PH: 7 and H2O2: 2mL, the removal of COD isabout 65% after reaction for 10 min. The amorphous ribbons after 5 times of repeated use still has catalytic activity.The change of ribbons microstructure was investigated before and after reaction, found30 min after the reaction amorphous structure of Mg-based amorphous ribbons was no changed.The main composition of the particles on ribbons surface was MgO after reaction. Under the acidic condition, the surface of the particles increased sharply, and the catalytic activity of Mg75Zn20Ca5 amorphous ribbons was decreased. The degradation reaction mechanism of Mg-based amorphous ribbons for the degradation of omethoate wastewater was derived.Mg-based amorphous ribbons can be used as solid catalytic materials for the degradation of glyphosate and omethoate wastewater.