Study On Treatment Of Toilet-flushing Seawater By Advanced Electrocatalysis Oxidation Processes

The freshwater shortage is becoming a great threat to the development ofChinese economy. Making full use of seawater is an important way which canmitigate the contradiction between water supply and demand in China’s coastal areas.It can save about35%of domestic water in coastal area to use seawater fortoilet-flushing. The treatment technique of toilet-flushing seawater is critical. Recently,the advanced electrocatalysis oxidation process has attracted a great deal of attentionin the field of wastewater treatment, mainly because of its easily control, highefficiency and compatible with the environment.Titanium-base metal anode with Sn-Sb oxide was prepared by brush thermaldecomposition method. The surface morphology and crystal structure of the coatingswere characterized by scanning electron microscope (SEM) and X ray diffraction (XRD).The results show that the calcination temperature, brushing times and the Sn-Sbcontent ratio affect the properties of the electrode to a certain degree. The optimumtechnical parameters for the preparation of catalytic electrodes are determined asfollows:calcination temperature is500°C, brushing times is15, Sn-Sb content ratio is10:1.In this paper, titanium-base metal electrode with Sn-Sb oxide as anode andtitanium as cathode were used in the experiments. The treatment effect oftoilet-flushing seawater by three-dimensional electrode reactor filled with activatedcarbon was investigated. The current density, electrolysis time, the initial pH valueand the dosage of insulating particle on the removal efficiency were analyzed. Resultsshow that it is feasible to remove CODCrfrom toilet-flushing seawater bythree-dimensional electrode reactor filled with activated carbon. The removal ofCODCris above80%when the current density is8.5A/dm2, the electrolysis time is60min, pH value was controlled between6-8, the mass ratio of activated carbon toglass bead is2:1.Removal of CODCris high in efficiency by electrocatalysis process, whichincreases with the current density and electrolysis time. The process of removingCODCris generally consistent with the second-order reaction kinetics. The experimentexhibits the relation between electrolytic current, reaction time and the removal of CODCr. It provides a reference for the further study on high-efficiency treatment oftoilet-flushing sewage in theory.