Study On The Mechanism Of Fe₇₈Si₉B₁₃ Amorphous Ribbon In The Treatment Of Oil/Pesticide Wastewater

Wastewater is common in both industrial and domestic life,the most notable types of which are refractory oily wastewater and pesticide wastewater in agricultural production.These kinds of wastewater must be treated before being discharged into the environment to prevent pollution of water resources,coasts,soil and even air.Among the currently available treatment technologies,the electrocoagulation method has proven to be effective and reliable.The electrocoagulation method has attracted widespread attention in the treatment of wastewater due to its simple equipment,convenient operation,few chemical additives,small sedimentation or sludge volume,and fast sedimentation speed.Many transition metals and alloys have high catalytic activity because of their incomplete filling of d-orbital,which is easy to give or absorb electrons.However,due to its high chemical activity and poor corrosion resistance,its application as a catalyst in acid or alkaline electrolyte is limited.The results show that the homogeneous amorphous structure can improve the catalytic activity and electrochemical stability of the transition metal alloy at the same time.In addition,as a metastable material,amorphous alloy has higher energy levels than the corresponding crystal material,so it has more catalytic active centers,good degradation performance and structural stability.In this paper,Fe₇₈Si₉B₁₃amorphous ribbon was used as the research object to explore its degradation effect on oily wastewater and pesticide wastewater.The research results are as follows:Under the conditions of different p H value and current density,Fe₇₈Si₉B₁₃amorphous ribbon was used as anode and graphite plate as cathode to treat oily wastewater.Chemical oxygen demand（COD）was used to show the degradation effect of the wastewater.The changes of Fe₇₈Si₉B₁₃amorphous ribbon before and after the treatment of the wastewater were analyzed by X-ray diffraction（XRD）and scanning electron microscopy（SEM）.The results showed that the optimal degradation rate of COD was 73.22%at p H=3 and current density of3.125A/cm².Compared with other amorphous ribbons,the treatment effect of Fe₇₈Si₉B₁₃amorphous ribbons is also better.At the same time,Fe₇₈Si₉B₁₃amorphous ribbons show good structural stability after four cycles.The mechanism of Fe₇₈Si₉B₁₃amorphous ribbon in the treatment of oily wastewater is as follows:under the action of direct current,Fe₇₈Si₉B₁₃amorphous ribbon anode dissolves into Fe²⁺,Fe³⁺plasma,which makes the oil toxic substances dissolved in water turn into non-toxic macromolecular organic particles or inorganic small molecular particles.In the treatment of pesticide wastewater by electrocoagulation method with Fe₇₈Si₉B₁₃amorphous ribbon as anode,when the p H is 2,the initial concentration is 1200mol/L,and the current density is 10A/m²,the degradation efficiency of COD reaches 87.5%.At the same time,Fe₇₈Si₉B₁₃amorphous ribbons show good structural stability after five cycles.The mechanism of the treatment of pesticide wastewater by Fe₇₈Si₉B₁₃amorphous ribbon is as follows:after the contact between Fe₇₈Si₉B₁₃amorphous ribbon and pesticide toxic molecules,the oxidation-reduction reaction takes place on the surface,at the same time,the toxic molecules are adsorbed,and the highly active surface of Fe₇₈Si₉B₁₃amorphous starts to reduce and degrade the catalytic pesticide toxic molecules rapidly.