Process Properties Of Hemoglobin Modified Electrode Degradating Trichloroacetic Acid

Haloacetic acids (HAAs) are a high cancer risk, chlorinated disinfection by-products (DBPs) in water, generally. Since HAAs can retent in water for long time and have the properties of nov-volatile, hydrophilic, its influence is sustainability. As the strongest cancinogenic HAAs in chlorinated oganic compounds, trichloriacetic acid (TCAA) must be degradated by some efficient methods, such as electrochemistry.Firstly, the SA/Hb-MWCNTs/C modified electrode was made by embedding the hemoglobin (Hb) on the surface of MWCNTs/C with sodium alginate (SA). By Ultraviolet-visible (UV-vis), Fourier transform infrared (FT-IR) and scanning electron microscope (SEM), it was confirmed that Hb embedded on the surface of the modified electrode still maintained a structure similar to the native state. Cyclic vdtammetry of modified electrode showed a pair of well-defined and nearly reversible peaks for HbhemeFe(III)/Fe(II) redox couple in pH = 7.0 PBS buffers. Meanwhile, modified electrode has a obviously reduced peak, which was increased by the concerntration of substrate (TCAA) increasing. It is evident that Hb has good electro-catalytic activity on the surface of the modified electrode.Secondly, some main parameters of TCAA degradaton by SA-Hb/MWCNTs/C modified electrode were investigated in a low concentration aqueous solution. After the experiment, the optimal process parameters were got: electrolyte concerntration (0.2 mol/L), current density (1.69 mA/cm2), temperature (40°C), embedding capacity (3 g/L). Finally, the stability of SA-Hb/MWCNTs/C modified electrode was studied by removal rate and current efficiency. After using 5 times repeatly, the removal rate of TCAA still kept above 85%, approximately 1.2 times that of the Hb-PBS/MWCNTs/C modified electrode,which showed that Hb embeded maintained a high catalytic activity.